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Diffstat (limited to 'ast/polygon.c')
| -rw-r--r-- | ast/polygon.c | 7087 |
1 files changed, 0 insertions, 7087 deletions
diff --git a/ast/polygon.c b/ast/polygon.c deleted file mode 100644 index 1dfae39..0000000 --- a/ast/polygon.c +++ /dev/null @@ -1,7087 +0,0 @@ -/* -*class++ -* Name: -* Polygon - -* Purpose: -* A polygonal region within a 2-dimensional Frame. - -* Constructor Function: -c astPolygon -f AST_POLYGON - -* Description: -* The Polygon class implements a polygonal area, defined by a -* collection of vertices, within a 2-dimensional Frame. The vertices -* are connected together by geodesic curves within the encapsulated Frame. -* For instance, if the encapsulated Frame is a simple Frame then the -* geodesics will be straight lines, but if the Frame is a SkyFrame then -* the geodesics will be great circles. Note, the vertices must be -* supplied in an order such that the inside of the polygon is to the -* left of the boundary as the vertices are traversed. Supplying them -* in the reverse order will effectively negate the polygon. -* -* Within a SkyFrame, neighbouring vertices are always joined using the -* shortest path. Thus if an edge of 180 degrees or more in length is -* required, it should be split into section each of which is less -* than 180 degrees. The closed path joining all the vertices in order -* will divide the celestial sphere into two disjoint regions. The -* inside of the polygon is the region which is circled in an -* anti-clockwise manner (when viewed from the inside of the celestial -* sphere) when moving through the list of vertices in the order in -* which they were supplied when the Polygon was created (i.e. the -* inside is to the left of the boundary when moving through the -* vertices in the order supplied). - -* Inheritance: -* The Polygon class inherits from the Region class. - -* Attributes: -* In addition to those attributes common to all Regions, every -* Polygon also has the following attributes: -* - SimpVertices: Simplify by transforming the vertices? - -* Functions: -c In addition to those functions applicable to all Regions, the -c following functions may also be applied to all Polygons: -f In addition to those routines applicable to all Regions, the -f following routines may also be applied to all Polygons: -* -c - astDownsize: Reduce the number of vertices in a Polygon. -f - AST_DOWNSIZE: Reduce the number of vertices in a Polygon. -c - astConvex<X>: Create a Polygon giving the convex hull of a pixel array -f - AST_CONVEX<X>: Create a Polygon giving the convex hull of a pixel array -c - astOutline<X>: Create a Polygon outlining values in a pixel array -f - AST_OUTLINE<X>: Create a Polygon outlining values in a pixel array - -* Copyright: -* Copyright (C) 1997-2006 Council for the Central Laboratory of the -* Research Councils -* Copyright (C) 2009 Science & Technology Facilities Council. -* All Rights Reserved. - -* Licence: -* This program is free software: you can redistribute it and/or -* modify it under the terms of the GNU Lesser General Public -* License as published by the Free Software Foundation, either -* version 3 of the License, or (at your option) any later -* version. -* -* This program is distributed in the hope that it will be useful, -* but WITHOUT ANY WARRANTY; without even the implied warranty of -* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -* GNU Lesser General Public License for more details. -* -* You should have received a copy of the GNU Lesser General -* License along with this program. If not, see -* <http://www.gnu.org/licenses/>. - -* Authors: -* DSB: David S. Berry (Starlink) - -* History: -* 26-OCT-2004 (DSB): -* Original version. -* 28-MAY-2009 (DSB): -* Added astDownsize. -* 29-MAY-2009 (DSB): -* Added astOutline<X>. -* 30-JUN-2009 (DSB): -* Override astGetBounded. -* 4-NOV-2013 (DSB): -* Modify RegPins so that it can handle uncertainty regions that straddle -* a discontinuity. Previously, such uncertainty Regions could have a huge -* bounding box resulting in matching region being far too big. -* 6-DEC-2013 (DSB): -* Reverse the order of the vertices when the Polygon is created, -* if necessary, to ensure that the unnegated Polygon is bounded. -* The parent Region class assumes that unnegated regions are -* bounded. -* 6-JAN-2014 (DSB): -* Free edges when clearing the cache, not when establishing a new -* cache, as the number of edges may have changed. -* 10-JAN-2014 (DSB): -* - Remove unused parameter description in prologue of for astOutline<X> -* 24-FEB-2014 (DSB): -* Added astConvex<X>. -* 25-FEB-2014 (DSB): -* Added attribute SimpVertices. -* 7-SEP-2015 (DSB): -* Shrink outline polygons by a small fraction of a pixel, in order -* to avoid placing vertices exactly on pixel edges. This is because -* rounding errors in subsequent code may push the vertices into -* neighbouring pixels, which may have bad WCS coords (e.g. -* vertices on the boundary of a polar cusp in an HPX map). -*class-- -*/ - -/* Module Macros. */ -/* ============== */ -/* Set the name of the class we are implementing. This indicates to - the header files that define class interfaces that they should make - "protected" symbols available. */ -#define astCLASS Polygon - -/* Define a macro for testing if a pixel value <V> satisfies the requirements - specified by <Oper> and <Value>. Compiler optimisation should remove - all the "if" testing from this expression. */ -#define ISVALID(V,OperI,Value) ( \ - ( OperI == AST__LT ) ? ( (V) < Value ) : ( \ - ( OperI == AST__LE ) ? ( (V) <= Value ) : ( \ - ( OperI == AST__EQ ) ? ( (V) == Value ) : ( \ - ( OperI == AST__GE ) ? ( (V) >= Value ) : ( \ - ( OperI == AST__NE ) ? ( (V) != Value ) : ( \ - (V) > Value \ - ) \ - ) \ - ) \ - ) \ - ) \ -) - -/* Macros specifying whether a point is inside, outside or on the - boundary of the polygon. */ -#define UNKNOWN 0 -#define IN 1 -#define OUT 2 -#define ON 3 - -/* Size of pertubation (in pixels) used to avoid placing vertices exactly - on a pixel edge. */ -#define DELTA 0.01 - -/* Include files. */ -/* ============== */ -/* Interface definitions. */ -/* ---------------------- */ - -#include "globals.h" /* Thread-safe global data access */ -#include "error.h" /* Error reporting facilities */ -#include "memory.h" /* Memory allocation facilities */ -#include "object.h" /* Base Object class */ -#include "pointset.h" /* Sets of points/coordinates */ -#include "region.h" /* Coordinate regions (parent class) */ -#include "channel.h" /* I/O channels */ -#include "box.h" /* Box Regions */ -#include "wcsmap.h" /* Definitons of AST__DPI etc */ -#include "polygon.h" /* Interface definition for this class */ -#include "mapping.h" /* Position mappings */ -#include "unitmap.h" /* Unit Mapping */ -#include "pal.h" /* SLALIB library interface */ -#include "frame.h" /* Coordinate system description */ - -/* Error code definitions. */ -/* ----------------------- */ -#include "ast_err.h" /* AST error codes */ - -/* C header files. */ -/* --------------- */ -#include <float.h> -#include <math.h> -#include <stdarg.h> -#include <stdlib.h> -#include <stddef.h> -#include <stdio.h> -#include <string.h> -#include <limits.h> - -/* Type definitions. */ -/* ================= */ - -/* A structure that holds information about an edge of the new Polygon - being created by astDownsize. The edge is a line betweeen two of the - vertices of the original Polygon. */ -typedef struct Segment { - int i1; /* Index of starting vertex within old Polygon */ - int i2; /* Index of ending vertex within old Polygon */ - double error; /* Max geodesic distance from any old vertex to the line */ - int imax; /* Index of the old vertex at which max error is reached */ - struct Segment *next;/* Pointer to next Segment in a double link list */ - struct Segment *prev;/* Pointer to previous Segment in a double link list */ -} Segment; - - -/* Module Variables. */ -/* ================= */ - -/* Address of this static variable is used as a unique identifier for - member of this class. */ -static int class_check; - -/* Pointers to parent class methods which are extended by this class. */ -static AstPointSet *(* parent_transform)( AstMapping *, AstPointSet *, int, AstPointSet *, int * ); -static AstMapping *(* parent_simplify)( AstMapping *, int * ); -static void (* parent_setregfs)( AstRegion *, AstFrame *, int * ); -static void (* parent_resetcache)( AstRegion *, int * ); -static const char *(* parent_getattrib)( AstObject *, const char *, int * ); -static int (* parent_testattrib)( AstObject *, const char *, int * ); -static void (* parent_clearattrib)( AstObject *, const char *, int * ); -static void (* parent_setattrib)( AstObject *, const char *, int * ); - - -#ifdef THREAD_SAFE -/* Define how to initialise thread-specific globals. */ -#define GLOBAL_inits \ - globals->Class_Init = 0; \ - globals->GetAttrib_Buff[ 0 ] = 0; - -/* Create the function that initialises global data for this module. */ -astMAKE_INITGLOBALS(Polygon) - -/* Define macros for accessing each item of thread specific global data. */ -#define class_init astGLOBAL(Polygon,Class_Init) -#define class_vtab astGLOBAL(Polygon,Class_Vtab) -#define getattrib_buff astGLOBAL(Polygon,GetAttrib_Buff) - - -#include <pthread.h> - - -#else - -static char getattrib_buff[ 51 ]; - -/* Define the class virtual function table and its initialisation flag - as static variables. */ -static AstPolygonVtab class_vtab; /* Virtual function table */ -static int class_init = 0; /* Virtual function table initialised? */ - -#endif - -/* External Interface Function Prototypes. */ -/* ======================================= */ -/* The following functions have public prototypes only (i.e. no - protected prototypes), so we must provide local prototypes for use - within this module. */ -AstPolygon *astPolygonId_( void *, int, int, const double *, void *, const char *, ... ); - -/* Prototypes for Private Member Functions. */ -/* ======================================== */ - -/* Define a macro that expands to a single prototype for function - FindInsidePoint for a given data type and operation. */ -#define FINDINSIDEPOINT_PROTO0(X,Xtype,Oper) \ -static void FindInsidePoint##Oper##X( Xtype, const Xtype *, const int[2], const int[2], int *, int *, int *, int * ); - -/* Define a macro that expands to a set of prototypes for all operations - for function FindInsidePoint for a given data type. */ -#define FINDINSIDEPOINT_PROTO(X,Xtype) \ -FINDINSIDEPOINT_PROTO0(X,Xtype,LT) \ -FINDINSIDEPOINT_PROTO0(X,Xtype,LE) \ -FINDINSIDEPOINT_PROTO0(X,Xtype,EQ) \ -FINDINSIDEPOINT_PROTO0(X,Xtype,GE) \ -FINDINSIDEPOINT_PROTO0(X,Xtype,GT) \ -FINDINSIDEPOINT_PROTO0(X,Xtype,NE) - -/* Use the above macros to define all FindInsidePoint prototypes for all - data types and operations. */ -#if HAVE_LONG_DOUBLE /* Not normally implemented */ -FINDINSIDEPOINT_PROTO(LD,long double) -#endif -FINDINSIDEPOINT_PROTO(D,double) -FINDINSIDEPOINT_PROTO(L,long int) -FINDINSIDEPOINT_PROTO(UL,unsigned long int) -FINDINSIDEPOINT_PROTO(I,int) -FINDINSIDEPOINT_PROTO(UI,unsigned int) -FINDINSIDEPOINT_PROTO(S,short int) -FINDINSIDEPOINT_PROTO(US,unsigned short int) -FINDINSIDEPOINT_PROTO(B,signed char) -FINDINSIDEPOINT_PROTO(UB,unsigned char) -FINDINSIDEPOINT_PROTO(F,float) - -/* Define a macro that expands to a single prototype for function - TraceEdge for a given data type and operation. */ -#define TRACEEDGE_PROTO0(X,Xtype,Oper) \ -static AstPointSet *TraceEdge##Oper##X( Xtype, const Xtype *, const int[2], const int[2], int, int, int, int, int, int * ); - -/* Define a macro that expands to a set of prototypes for all operations - for function TraceEdge for a given data type. */ -#define TRACEEDGE_PROTO(X,Xtype) \ -TRACEEDGE_PROTO0(X,Xtype,LT) \ -TRACEEDGE_PROTO0(X,Xtype,LE) \ -TRACEEDGE_PROTO0(X,Xtype,EQ) \ -TRACEEDGE_PROTO0(X,Xtype,GE) \ -TRACEEDGE_PROTO0(X,Xtype,GT) \ -TRACEEDGE_PROTO0(X,Xtype,NE) - -/* Use the above macros to define all TraceEdge prototypes for all - data types and operations. */ -#if HAVE_LONG_DOUBLE /* Not normally implemented */ -TRACEEDGE_PROTO(LD,long double) -#endif -TRACEEDGE_PROTO(D,double) -TRACEEDGE_PROTO(L,long int) -TRACEEDGE_PROTO(UL,unsigned long int) -TRACEEDGE_PROTO(I,int) -TRACEEDGE_PROTO(UI,unsigned int) -TRACEEDGE_PROTO(S,short int) -TRACEEDGE_PROTO(US,unsigned short int) -TRACEEDGE_PROTO(B,signed char) -TRACEEDGE_PROTO(UB,unsigned char) -TRACEEDGE_PROTO(F,float) - -/* Define a macro that expands to a single prototype for function - PartHull for a given data type and operation. */ -#define PARTHULL_PROTO0(X,Xtype,Oper) \ -static void PartHull##Oper##X( Xtype, const Xtype[], int, int, int, int, int, int, int, const int[2], double **, double **, int *, int * ); - -/* Define a macro that expands to a set of prototypes for all operations - for function PartHull for a given data type. */ -#define PARTHULL_PROTO(X,Xtype) \ -PARTHULL_PROTO0(X,Xtype,LT) \ -PARTHULL_PROTO0(X,Xtype,LE) \ -PARTHULL_PROTO0(X,Xtype,EQ) \ -PARTHULL_PROTO0(X,Xtype,GE) \ -PARTHULL_PROTO0(X,Xtype,GT) \ -PARTHULL_PROTO0(X,Xtype,NE) - -/* Use the above macros to define all PartHull prototypes for all - data types and operations. */ -#if HAVE_LONG_DOUBLE /* Not normally implemented */ -PARTHULL_PROTO(LD,long double) -#endif -PARTHULL_PROTO(D,double) -PARTHULL_PROTO(L,long int) -PARTHULL_PROTO(UL,unsigned long int) -PARTHULL_PROTO(I,int) -PARTHULL_PROTO(UI,unsigned int) -PARTHULL_PROTO(S,short int) -PARTHULL_PROTO(US,unsigned short int) -PARTHULL_PROTO(B,signed char) -PARTHULL_PROTO(UB,unsigned char) -PARTHULL_PROTO(F,float) - -/* Define a macro that expands to a single prototype for function - ConvexHull for a given data type and operation. */ -#define CONVEXHULL_PROTO0(X,Xtype,Oper) \ -static AstPointSet *ConvexHull##Oper##X( Xtype, const Xtype[], const int[2], int, int, int, int * ); - -/* Define a macro that expands to a set of prototypes for all operations - for function ConvexHull for a given data type. */ -#define CONVEXHULL_PROTO(X,Xtype) \ -CONVEXHULL_PROTO0(X,Xtype,LT) \ -CONVEXHULL_PROTO0(X,Xtype,LE) \ -CONVEXHULL_PROTO0(X,Xtype,EQ) \ -CONVEXHULL_PROTO0(X,Xtype,GE) \ -CONVEXHULL_PROTO0(X,Xtype,GT) \ -CONVEXHULL_PROTO0(X,Xtype,NE) - -/* Use the above macros to define all ConvexHull prototypes for all - data types and operations. */ -#if HAVE_LONG_DOUBLE /* Not normally implemented */ -CONVEXHULL_PROTO(LD,long double) -#endif -CONVEXHULL_PROTO(D,double) -CONVEXHULL_PROTO(L,long int) -CONVEXHULL_PROTO(UL,unsigned long int) -CONVEXHULL_PROTO(I,int) -CONVEXHULL_PROTO(UI,unsigned int) -CONVEXHULL_PROTO(S,short int) -CONVEXHULL_PROTO(US,unsigned short int) -CONVEXHULL_PROTO(B,signed char) -CONVEXHULL_PROTO(UB,unsigned char) -CONVEXHULL_PROTO(F,float) - -/* Define a macro that expands to a single prototype for function - FindBoxEdge for a given data type and operation. */ -#define FINDBOXEDGE_PROTO0(X,Xtype,Oper) \ -static void FindBoxEdge##Oper##X( Xtype, const Xtype[], int, int, int, int, int *, int *, int *, int * ); - -/* Define a macro that expands to a set of prototypes for all operations - for function FindBoxEdge for a given data type. */ -#define FINDBOXEDGE_PROTO(X,Xtype) \ -FINDBOXEDGE_PROTO0(X,Xtype,LT) \ -FINDBOXEDGE_PROTO0(X,Xtype,LE) \ -FINDBOXEDGE_PROTO0(X,Xtype,EQ) \ -FINDBOXEDGE_PROTO0(X,Xtype,GE) \ -FINDBOXEDGE_PROTO0(X,Xtype,GT) \ -FINDBOXEDGE_PROTO0(X,Xtype,NE) - -/* Use the above macros to define all FindBoxEdge prototypes for all - data types and operations. */ -#if HAVE_LONG_DOUBLE /* Not normally implemented */ -FINDBOXEDGE_PROTO(LD,long double) -#endif -FINDBOXEDGE_PROTO(D,double) -FINDBOXEDGE_PROTO(L,long int) -FINDBOXEDGE_PROTO(UL,unsigned long int) -FINDBOXEDGE_PROTO(I,int) -FINDBOXEDGE_PROTO(UI,unsigned int) -FINDBOXEDGE_PROTO(S,short int) -FINDBOXEDGE_PROTO(US,unsigned short int) -FINDBOXEDGE_PROTO(B,signed char) -FINDBOXEDGE_PROTO(UB,unsigned char) -FINDBOXEDGE_PROTO(F,float) - - - - - - - - - -/* Non-generic function prototypes. */ -static AstMapping *Simplify( AstMapping *, int * ); -static AstPointSet *DownsizePoly( AstPointSet *, double, int, AstFrame *, int * ); -static AstPointSet *RegBaseMesh( AstRegion *, int * ); -static AstPointSet *Transform( AstMapping *, AstPointSet *, int, AstPointSet *, int * ); -static AstPolygon *Downsize( AstPolygon *, double, int, int * ); -static Segment *AddToChain( Segment *, Segment *, int * ); -static Segment *NewSegment( Segment *, int, int, int, int * ); -static Segment *RemoveFromChain( Segment *, Segment *, int * ); -static double Polywidth( AstFrame *, AstLineDef **, int, int, double[ 2 ], int * ); -static int GetBounded( AstRegion *, int * ); -static int IntCmp( const void *, const void * ); -static int RegPins( AstRegion *, AstPointSet *, AstRegion *, int **, int * ); -static int RegTrace( AstRegion *, int, double *, double **, int * ); -static void Cache( AstPolygon *, int * ); -static void Copy( const AstObject *, AstObject *, int * ); -static void Delete( AstObject *, int * ); -static void Dump( AstObject *, AstChannel *, int * ); -static void EnsureInside( AstPolygon *, int * ); -static void FindMax( Segment *, AstFrame *, double *, double *, int, int, int * ); -static void RegBaseBox( AstRegion *this, double *, double *, int * ); -static void ResetCache( AstRegion *this, int * ); -static void SetPointSet( AstPolygon *, AstPointSet *, int * ); -static void SetRegFS( AstRegion *, AstFrame *, int * ); -static void SmoothPoly( AstPointSet *, int, double, int * ); - -static const char *GetAttrib( AstObject *, const char *, int * ); -static void ClearAttrib( AstObject *, const char *, int * ); -static void SetAttrib( AstObject *, const char *, int * ); -static int TestAttrib( AstObject *, const char *, int * ); - -static int GetSimpVertices( AstPolygon *, int * ); -static int TestSimpVertices( AstPolygon *, int * ); -static void ClearSimpVertices( AstPolygon *, int * ); -static void SetSimpVertices( AstPolygon *, int, int * ); - - -/* Member functions. */ -/* ================= */ -static Segment *AddToChain( Segment *head, Segment *seg, int *status ){ -/* -* Name: -* AddToChain - -* Purpose: -* Add a Segment into the linked list of Segments, maintaining the -* required order in the list. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* Segment *AddToChain( Segment *head, Segment *seg, int *status ) - -* Class Membership: -* Polygon member function - -* Description: -* The linked list of Segments maintained by astDownsize is searched -* from the high error end (the head), until a Segment is foound which -* has a lower error than the supplied segment. The supplied Segment -* is then inserted into the list at that point. - -* Parameters: -* head -* The Segment structure at the head of the list (i.e. the segment -* with maximum error). -* seg -* The Segment to be added into the list. -* status -* Pointer to the inherited status variable. - -* Returned Value: -* Pointer to the link head (which will have changed if "seg" has a -* higher error than the original head). - -*/ - -/* Local Variables: */ - Segment *tseg; - -/* Check the global error status. */ - if ( !astOK ) return head; - -/* If the list is empty, return the supplied segment as the new list - head. */ - if( !head ) { - head = seg; - -/* If the supplied segment has a higher error than the original head, - insert the new segment in front of the original head. */ - } else if( seg->error > head->error ){ - seg->next = head; - head->prev = seg; - head = seg; - -/* Otherwise, move down the list from the head until a segment is found - which has a lower error than the supplied Segment. Then insert the - supplied segment into the list in front of it. */ - } else { - tseg = head; - seg->next = NULL; - - while( tseg->next ) { - if( seg->error > tseg->next->error ) { - seg->next = tseg->next; - seg->prev = tseg; - tseg->next->prev = seg; - tseg->next = seg; - break; - } - tseg = tseg->next; - } - - if( !seg->next ) { - tseg->next = seg; - seg->prev = tseg; - } - } - -/* Return the new head. */ - return head; -} - -static void Cache( AstPolygon *this, int *status ){ -/* -* Name: -* Cache - -* Purpose: -* Calculate intermediate values and cache them in the Polygon structure. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* void Cache( AstPolygon *this, int *status ) - -* Class Membership: -* Polygon member function - -* Description: -* This function uses the PointSet stored in the parent Region to calculate -* some intermediate values which are useful in other methods. These -* values are stored within the Polygon structure. - -* Parameters: -* this -* Pointer to the Polygon. -* status -* Pointer to the inherited status variable. - -*/ - -/* Local Variables: */ - AstFrame *frm; /* Pointer to base Frame in Polygon */ - double **ptr; /* Pointer to data in the encapsulated PointSet */ - double end[ 2 ]; /* Start position for edge */ - double maxwid; /* Maximum polygon width found so far */ - double polcen[ 2 ]; /* Polygon centre perpendicular to current edge */ - double polwid; /* Polygon width perpendicular to current edge */ - double start[ 2 ]; /* Start position for edge */ - int i; /* Axis index */ - int nv; /* Number of vertices in Polygon */ - -/* Check the global error status. */ - if ( !astOK ) return; - -/* Do nothing if the cached information is up to date. */ - if( this->stale ) { - -/* Get a pointer to the base Frame. */ - frm = astGetFrame( ((AstRegion *) this)->frameset, AST__BASE ); - -/* Get the number of vertices. */ - nv = astGetNpoint( ((AstRegion *) this)->points ); - -/* Get pointers to the coordinate data in the parent Region structure. */ - ptr = astGetPoints( ((AstRegion *) this)->points ); - -/* Free any existing edge information in the Polygon structure. */ - if( this->edges ) { - for( i = 0; i < nv; i++ ) { - this->edges[ i ] = astFree( this->edges[ i ] ); - } - -/* Allocate memory to store new edge information if necessary. */ - } else { - this->edges = astMalloc( sizeof( AstLineDef *)*(size_t) nv ); - this->startsat = astMalloc( sizeof( double )*(size_t) nv ); - } - -/* Check pointers can be used safely. */ - if( this->edges ) { - -/* Create and store a description of each edge. Also form the total - distance round the polygon, and the distance from the first vertex - at which each edge starts. */ - this->totlen = 0.0; - start[ 0 ] = ptr[ 0 ][ nv - 1 ]; - start[ 1 ] = ptr[ 1 ][ nv - 1 ]; - - for( i = 0; i < nv; i++ ) { - end[ 0 ] = ptr[ 0 ][ i ]; - end[ 1 ] = ptr[ 1 ][ i ]; - this->edges[ i ] = astLineDef( frm, start, end ); - start[ 0 ] = end[ 0 ]; - start[ 1 ] = end[ 1 ]; - - this->startsat[ i ] = this->totlen; - this->totlen += this->edges[ i ]->length; - } - -/* We now look for a point that is inside the polygon. We want a point - that is well within the polygon, since points that are only just inside - the polygon can give numerical problems. Loop round each edge with - non-zero length. */ - maxwid = -1.0; - for( i = 0; i < nv; i++ ) { - if( this->edges[ i ]->length > 0.0 ) { - -/* We define another line perpendicular to the current edge, passing - through the mid point of the edge, extending towards the inside of the - polygon. The following function returns the distance we can travel - along this line before we hit any of the other polygon edges. It also - puts the position corresponding to half that distance into "polcen". */ - polwid = Polywidth( frm, this->edges, i, nv, polcen, status ); - -/* If the width of the polygon perpendicular to the current edge is - greater than the width perpdeicular to any other edge, record the - width and also store the current polygon centre. */ - if( polwid > maxwid && polwid != AST__BAD ) { - maxwid = polwid; - (this->in)[ 0 ] = polcen[ 0 ]; - (this->in)[ 1 ] = polcen[ 1 ]; - } - } - } - -/* If no width was found it probably means that the polygon vertices were - given in clockwise order, resulting in the above process probing the - infinite extent outside the polygonal hole. In this case any point - outside the hole will do, so we use the current contents of the - "polcen" array. Set a flag indicating if the vertices are stored in - anti-clockwise order. */ - if( maxwid < 0.0 ) { - (this->in)[ 0 ] = polcen[ 0 ]; - (this->in)[ 1 ] = polcen[ 1 ]; - this->acw = 0; - } else { - this->acw = 1; - } - } - -/* Free resources */ - frm = astAnnul( frm ); - -/* Indicate cached information is up to date. */ - this->stale = 0; - } -} - -static void ClearAttrib( AstObject *this_object, const char *attrib, int *status ) { -/* -* Name: -* ClearAttrib - -* Purpose: -* Clear an attribute value for a Polygon. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* void ClearAttrib( AstObject *this, const char *attrib, int *status ) - -* Class Membership: -* Polygon member function (over-rides the astClearAttrib protected -* method inherited from the Region class). - -* Description: -* This function clears the value of a specified attribute for a -* Polygon, so that the default value will subsequently be used. - -* Parameters: -* this -* Pointer to the Polygon. -* attrib -* Pointer to a null terminated string specifying the attribute -* name. This should be in lower case with no surrounding white -* space. -* status -* Pointer to the inherited status variable. -*/ - -/* Local Variables: */ - AstPolygon *this; /* Pointer to the Polygon structure */ - -/* Check the global error status. */ - if ( !astOK ) return; - -/* Obtain a pointer to the Polygon structure. */ - this = (AstPolygon *) this_object; - -/* Check the attribute name and clear the appropriate attribute. */ - -/* SimpVertices. */ -/* ------------- */ - if ( !strcmp( attrib, "simpvertices" ) ) { - astClearSimpVertices( this ); - -/* If the attribute is not recognised, pass it on to the parent method - for further interpretation. */ - } else { - (*parent_clearattrib)( this_object, attrib, status ); - } -} - -/* -*++ -* Name: -c astConvex<X> -f AST_CONVEX<X> - -* Purpose: -* Create a new Polygon representing the convex hull of a 2D data grid. - -* Type: -* Public function. - -* Synopsis: -c #include "polygon.h" -c AstPolygon *astConvex<X>( <Xtype> value, int oper, const <Xtype> array[], -c const int lbnd[2], const int ubnd[2], int starpix ) -f RESULT = AST_CONVEX<X>( VALUE, OPER, ARRAY, LBND, UBND, STARPIX, STATUS ) - -* Class Membership: -* Polygon method. - -* Description: -* This is a set of functions that create the shortest Polygon that -* encloses all pixels with a specified value within a gridded -* 2-dimensional data array (e.g. an image). -* -* A basic 2-dimensional Frame is used to represent the pixel coordinate -* system in the returned Polygon. The Domain attribute is set to -* "PIXEL", the Title attribute is set to "Pixel coordinates", and the -* Unit attribute for each axis is set to "pixel". All other -* attributes are left unset. The nature of the pixel coordinate system -* is determined by parameter -c "starpix". -f STARPIX. -* -* You should use a function which matches the numerical type of the -* data you are processing by replacing <X> in the generic function -* name -c astConvex<X> -f AST_CONVEX<X> -c by an appropriate 1- or 2-character type code. For example, if you -* are procesing data with type -c "float", you should use the function astConvexF -f REAL, you should use the function AST_CONVEXR -* (see the "Data Type Codes" section below for the codes appropriate to -* other numerical types). - -* Parameters: -c value -f VALUE = <Xtype> (Given) -* A data value that specifies the pixels to be included within the -* convex hull. -c oper -f OPER = INTEGER (Given) -* Indicates how the -c "value" -f VALUE -* parameter is used to select the required pixels. It can -* have any of the following values: -c - AST__LT: include pixels with value less than "value". -c - AST__LE: include pixels with value less than or equal to "value". -c - AST__EQ: include pixels with value equal to "value". -c - AST__NE: include pixels with value not equal to "value". -c - AST__GE: include pixels with value greater than or equal to "value". -c - AST__GT: include pixels with value greater than "value". -f - AST__LT: include pixels with value less than VALUE. -f - AST__LE: include pixels with value less than or equal to VALUE. -f - AST__EQ: include pixels with value equal to VALUE. -f - AST__NE: include pixels with value not equal to VALUE. -f - AST__GE: include pixels with value greater than or equal to VALUE. -f - AST__GT: include pixels with value greater than VALUE. -c array -f ARRAY( * ) = <Xtype> (Given) -c Pointer to a -f A -* 2-dimensional array containing the data to be processed. The -* numerical type of this array should match the 1- or -* 2-character type code appended to the function name (e.g. if -c you are using astConvexF, the type of each array element -c should be "float"). -f you are using AST_CONVEXR, the type of each array element -f should be REAL). -* -* The storage order of data within this array should be such -* that the index of the first grid dimension varies most -* rapidly and that of the second dimension least rapidly -c (i.e. Fortran array indexing is used). -f (i.e. normal Fortran array storage order). -c lbnd -f LBND( 2 ) = INTEGER (Given) -c Pointer to an array of two integers -f An array -* containing the coordinates of the centre of the first pixel -* in the input grid along each dimension. -c ubnd -f UBND( 2) = INTEGER (Given) -c Pointer to an array of two integers -f An array -* containing the coordinates of the centre of the last pixel in -* the input grid along each dimension. -* -c Note that "lbnd" and "ubnd" together define the shape -f Note that LBND and UBND together define the shape -* and size of the input grid, its extent along a particular -c (j'th) dimension being ubnd[j]-lbnd[j]+1 (assuming the -c index "j" to be zero-based). They also define -f (J'th) dimension being UBND(J)-LBND(J)+1. They also define -* the input grid's coordinate system, each pixel having unit -* extent along each dimension with integral coordinate values -* at its centre or upper corner, as selected by parameter -c "starpix". -f STARPIX. -c starpix -f STARPIX = LOGICAL (Given) -* A flag indicating the nature of the pixel coordinate system used -* to describe the vertex positions in the returned Polygon. If -c non-zero, -f .TRUE., -* the standard Starlink definition of pixel coordinate is used in -* which a pixel with integer index I spans a range of pixel coordinate -* from (I-1) to I (i.e. pixel corners have integral pixel coordinates). -c If zero, -f If .FALSE., -* the definition of pixel coordinate used by other AST functions -c such as astResample, astMask, -f such as AST_RESAMPLE, AST_MASK, -* etc., is used. In this definition, a pixel with integer index I -* spans a range of pixel coordinate from (I-0.5) to (I+0.5) (i.e. -* pixel centres have integral pixel coordinates). -f STATUS = INTEGER (Given and Returned) -f The global status. - -* Returned Value: -c astConvex<X>() -f AST_CONVEX<X> = INTEGER -* A pointer to the required Polygon. -c NULL -f AST__NULL -* is returned without error if the array contains no pixels that -* satisfy the criterion specified by -c "value" and "oper". -f VALUE and OPER. - -* Notes: -c - NULL -f - AST__NULL -* will be returned if this function is invoked with the global -* error status set, or if it should fail for any reason. - -* Data Type Codes: -* To select the appropriate masking function, you should -c replace <X> in the generic function name astConvex<X> with a -f replace <X> in the generic function name AST_CONVEX<X> with a -* 1- or 2-character data type code, so as to match the numerical -* type <Xtype> of the data you are processing, as follows: -c - D: double -c - F: float -c - L: long int -c - UL: unsigned long int -c - I: int -c - UI: unsigned int -c - S: short int -c - US: unsigned short int -c - B: byte (signed char) -c - UB: unsigned byte (unsigned char) -f - D: DOUBLE PRECISION -f - R: REAL -f - I: INTEGER -f - UI: INTEGER (treated as unsigned) -f - S: INTEGER*2 (short integer) -f - US: INTEGER*2 (short integer, treated as unsigned) -f - B: BYTE (treated as signed) -f - UB: BYTE (treated as unsigned) -* -c For example, astConvexD would be used to process "double" -c data, while astConvexS would be used to process "short int" -c data, etc. -f For example, AST_CONVEXD would be used to process DOUBLE -f PRECISION data, while AST_CONVEXS would be used to process -f short integer data (stored in an INTEGER*2 array), etc. -f -f For compatibility with other Starlink facilities, the codes W -f and UW are provided as synonyms for S and US respectively (but -f only in the Fortran interface to AST). - -*-- -*/ -/* Define a macro to implement the function for a specific data - type. Note, this function cannot be a virtual function since the - argument list does not include a Polygon, and so no virtual function - table is available. */ -#define MAKE_CONVEX(X,Xtype) \ -AstPolygon *astConvex##X##_( Xtype value, int oper, const Xtype array[], \ - const int lbnd[2], const int ubnd[2], \ - int starpix, int *status ) { \ -\ -/* Local Variables: */ \ - AstFrame *frm; /* Frame in which to define the Polygon */ \ - AstPointSet *candidate; /* Candidate polygon vertices */ \ - AstPolygon *result; /* Result value to return */ \ - int xdim; /* Number of pixels per row */ \ - int ydim; /* Number of rows */ \ - static double junk[ 6 ] = {0.0, 0.0, 1.0, 1.0, 0.0, 1.0 }; /* Junk poly */ \ -\ -/* Initialise. */ \ - result = NULL; \ - candidate = NULL; \ -\ -/* Check the global error status. */ \ - if ( !astOK ) return result; \ -\ -/* Get the array dimensions. */ \ - xdim = ubnd[ 0 ] - lbnd[ 0 ] + 1; \ - ydim = ubnd[ 1 ] - lbnd[ 1 ] + 1; \ -\ -/* Get the basic concvex hull. */ \ - if( oper == AST__LT ) { \ - candidate = ConvexHullLT##X( value, array, lbnd, starpix, xdim, ydim, status ); \ -\ - } else if( oper == AST__LE ) { \ - candidate = ConvexHullLE##X( value, array, lbnd, starpix, xdim, ydim, status ); \ -\ - } else if( oper == AST__EQ ) { \ - candidate = ConvexHullEQ##X( value, array, lbnd, starpix, xdim, ydim, status ); \ -\ - } else if( oper == AST__NE ) { \ - candidate = ConvexHullNE##X( value, array, lbnd, starpix, xdim, ydim, status ); \ -\ - } else if( oper == AST__GE ) { \ - candidate = ConvexHullGE##X( value, array, lbnd, starpix, xdim, ydim, status ); \ -\ - } else if( oper == AST__GT ) { \ - candidate = ConvexHullGT##X( value, array, lbnd, starpix, xdim, ydim, status ); \ -\ - } else if( astOK ){ \ - astError( AST__OPRIN, "astConvex"#X": Invalid operation code " \ - "(%d) supplied (programming error).", status, oper ); \ - } \ -\ -/* Check some good selected values were found. */ \ - if( candidate ) { \ -\ -/* Create a default Polygon with 3 junk vertices. */ \ - frm = astFrame( 2, "Domain=PIXEL,Unit(1)=pixel,Unit(2)=pixel," \ - "Title=Pixel coordinates", status ); \ - result = astPolygon( frm, 3, 3, junk, NULL, " ", status ); \ -\ -/* Change the PointSet within the Polygon to the one created above. */ \ - SetPointSet( result, candidate, status ); \ -\ -/* Free resources. */ \ - frm = astAnnul( frm ); \ - candidate = astAnnul( candidate ); \ - } \ -\ -/* If an error occurred, clear the returned result. */ \ - if ( !astOK ) result = astAnnul( result ); \ -\ -/* Return the result. */ \ - return result; \ -} - - -/* Expand the above macro to generate a function for each required - data type. */ -#if HAVE_LONG_DOUBLE /* Not normally implemented */ -MAKE_CONVEX(LD,long double) -#endif -MAKE_CONVEX(D,double) -MAKE_CONVEX(L,long int) -MAKE_CONVEX(UL,unsigned long int) -MAKE_CONVEX(I,int) -MAKE_CONVEX(UI,unsigned int) -MAKE_CONVEX(S,short int) -MAKE_CONVEX(US,unsigned short int) -MAKE_CONVEX(B,signed char) -MAKE_CONVEX(UB,unsigned char) -MAKE_CONVEX(F,float) - -/* Undefine the macros. */ -#undef MAKE_CONVEX - -/* -* Name: -* ConvexHull - -* Purpose: -* Find the convex hull enclosing selected pixels in a 2D array. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* AstPointSet *ConvexHull<Oper><X>( <Xtype> value, const <Xtype> array[], -* const int lbnd[2], int starpix, -* int xdim, int ydim, int *status ) - -* Class Membership: -* Polygon member function - -* Description: -* This function uses an algorithm similar to "Andrew's Monotone Chain -* Algorithm" to create a list of vertices describing the convex hull -* enclosing the selected pixels in the supplied array. The vertices -* are returned in a PointSet. - -* Parameters: -* value -* A data value that specifies the pixels to be selected. -* array -* Pointer to a 2-dimensional array containing the data to be -* processed. The numerical type of this array should match the 1- -* or 2-character type code appended to the function name. -* lbnd -* The lower pixel index bounds of the array. -* starpix -* If non-zero, the usual Starlink definition of pixel coordinate -* is used (integral values at pixel corners). Otherwise, the -* system used by other AST functions such as astResample is used -* (integral values at pixel centres). -* xdim -* The number of pixels along each row of the array. -* ydim -* The number of rows in the array. -* status -* Pointer to the inherited status variable. - -* Returned Value: -* A PointSet holding the vertices of the convex hull, or NULL if an -* error occurs. - -* Notes: -* - The following code has been designed with a view to it being -* multi-threaded at some point. - -*/ - -/* Define a macro to implement the function for a specific data - type and operation. */ -#define MAKE_CONVEXHULL(X,Xtype,Oper,OperI) \ -static AstPointSet *ConvexHull##Oper##X( Xtype value, const Xtype array[], \ - const int lbnd[2], int starpix, \ - int xdim, int ydim, int *status ) { \ -\ -/* Local Variables: */ \ - AstPointSet *result; \ - double **ptr; \ - double *xv1; \ - double *xv2; \ - double *xv3; \ - double *xv4; \ - double *xvert; \ - double *yv1; \ - double *yv2; \ - double *yv3; \ - double *yv4; \ - double *yvert; \ - int nv1; \ - int nv2; \ - int nv3; \ - int nv4; \ - int nv; \ - int xhi; \ - int xhiymax; \ - int xhiymin; \ - int xlo; \ - int xloymax; \ - int xloymin; \ - int yhi; \ - int yhixmax; \ - int yhixmin; \ - int ylo; \ - int yloxmax; \ - int yloxmin; \ -\ -/* Initialise */ \ - result = NULL; \ -\ -/* Check the global error status. */ \ - if ( !astOK ) return result; \ -\ -/* Find the lowest Y value at any selected pixel, and find the max and \ - min X value of the selected pixels at that lowest Y value. */ \ - FindBoxEdge##Oper##X( value, array, xdim, ydim, 1, 1, &ylo, &yloxmax, \ - &yloxmin, status ); \ -\ -/* Skip if there are no selected values in the array. */ \ - if( ylo > 0 ) { \ -\ -/* Find the highest Y value at any selected pixel, and find the max and \ - min X value of the selected pixels at that highest Y value. */ \ - FindBoxEdge##Oper##X( value, array, xdim, ydim, 1, 0, &yhi, &yhixmax, \ - &yhixmin, status ); \ -\ -/* Find the lowest X value at any selected pixel, and find the max and \ - min Y value of the selected pixels at that lowest X value. */ \ - FindBoxEdge##Oper##X( value, array, xdim, ydim, 0, 1, &xlo, &xloymax, \ - &xloymin, status ); \ -\ -/* Find the highest X value at any selected pixel, and find the max and \ - min Y value of the selected pixels at that highest X value. */ \ - FindBoxEdge##Oper##X( value, array, xdim, ydim, 0, 0, &xhi, &xhiymax, \ - &xhiymin, status ); \ -\ -/* Create a list of vertices for the bottom right corner of the bounding \ - box of the selected pixels. */ \ - PartHull##Oper##X( value, array, xdim, ydim, yloxmax, ylo, xhi, xhiymin, \ - starpix, lbnd, &xv1, &yv1, &nv1, status ); \ -\ -/* Create a list of vertices for the top right corner of the bounding \ - box of the selected pixels. */ \ - PartHull##Oper##X( value, array, xdim, ydim, xhi, xhiymax, yhixmax, yhi, \ - starpix, lbnd, &xv2, &yv2, &nv2, status ); \ -\ -/* Create a list of vertices for the top left corner of the bounding \ - box of the selected pixels. */ \ - PartHull##Oper##X( value, array, xdim, ydim, yhixmin, yhi, xlo, xloymax, \ - starpix, lbnd, &xv3, &yv3, &nv3, status ); \ -\ -/* Create a list of vertices for the bottom left corner of the bounding \ - box of the selected pixels. */ \ - PartHull##Oper##X( value, array, xdim, ydim, xlo, xloymin, yloxmin, ylo, \ - starpix, lbnd, &xv4, &yv4, &nv4, status ); \ -\ -/* Concatenate the four vertex lists and store them in the returned \ - PointSet. */ \ - nv = nv1 + nv2 + nv3 + nv4; \ - result = astPointSet( nv, 2, " ", status ); \ - ptr = astGetPoints( result ); \ - if( astOK ) { \ - xvert = ptr[ 0 ]; \ - yvert = ptr[ 1 ]; \ -\ - memcpy( xvert, xv1, nv1*sizeof( double ) ); \ - memcpy( yvert, yv1, nv1*sizeof( double ) ); \ - xvert += nv1; \ - yvert += nv1; \ -\ - memcpy( xvert, xv2, nv2*sizeof( double ) ); \ - memcpy( yvert, yv2, nv2*sizeof( double ) ); \ - xvert += nv2; \ - yvert += nv2; \ -\ - memcpy( xvert, xv3, nv3*sizeof( double ) ); \ - memcpy( yvert, yv3, nv3*sizeof( double ) ); \ - xvert += nv3; \ - yvert += nv3; \ -\ - memcpy( xvert, xv4, nv4*sizeof( double ) ); \ - memcpy( yvert, yv4, nv4*sizeof( double ) ); \ - } \ -\ -/* Free resources. */ \ - xv1 = astFree( xv1 ); \ - xv2 = astFree( xv2 ); \ - xv3 = astFree( xv3 ); \ - xv4 = astFree( xv4 ); \ - yv1 = astFree( yv1 ); \ - yv2 = astFree( yv2 ); \ - yv3 = astFree( yv3 ); \ - yv4 = astFree( yv4 ); \ - } \ -\ -/* Free the returned PointSet if an error occurred. */ \ - if( result && !astOK ) result = astAnnul( result ); \ -\ -/* Return the result. */ \ - return result; \ -} - -/* Define a macro that uses the above macro to to create implementations - of ConvexHull for all operations. */ -#define MAKEALL_CONVEXHULL(X,Xtype) \ -MAKE_CONVEXHULL(X,Xtype,LT,AST__LT) \ -MAKE_CONVEXHULL(X,Xtype,LE,AST__LE) \ -MAKE_CONVEXHULL(X,Xtype,EQ,AST__EQ) \ -MAKE_CONVEXHULL(X,Xtype,NE,AST__NE) \ -MAKE_CONVEXHULL(X,Xtype,GE,AST__GE) \ -MAKE_CONVEXHULL(X,Xtype,GT,AST__GT) - -/* Expand the above macro to generate a function for each required - data type and operation. */ -#if HAVE_LONG_DOUBLE /* Not normally implemented */ -MAKEALL_CONVEXHULL(LD,long double) -#endif -MAKEALL_CONVEXHULL(D,double) -MAKEALL_CONVEXHULL(L,long int) -MAKEALL_CONVEXHULL(UL,unsigned long int) -MAKEALL_CONVEXHULL(I,int) -MAKEALL_CONVEXHULL(UI,unsigned int) -MAKEALL_CONVEXHULL(S,short int) -MAKEALL_CONVEXHULL(US,unsigned short int) -MAKEALL_CONVEXHULL(B,signed char) -MAKEALL_CONVEXHULL(UB,unsigned char) -MAKEALL_CONVEXHULL(F,float) - -/* Undefine the macros. */ -#undef MAKE_CONVEXHULL -#undef MAKEALL_CONVEXHULL - -static AstPolygon *Downsize( AstPolygon *this, double maxerr, int maxvert, - int *status ) { -/* -*++ -* Name: -c astDownsize -f AST_DOWNSIZE - -* Purpose: -* Reduce the number of vertices in a Polygon. - -* Type: -* Public virtual function. - -* Synopsis: -c #include "polygon.h" -c AstPolygon *astDownsize( AstPolygon *this, double maxerr, int maxvert ) -f RESULT = AST_DOWNSIZE( THIS, MAXERR, MAXVERT, STATUS ) - -* Class Membership: -* Polygon method. - -* Description: -* This function returns a pointer to a new Polygon that contains a -* subset of the vertices in the supplied Polygon. The subset is -* chosen so that the returned Polygon is a good approximation to -* the supplied Polygon, within the limits specified by the supplied -* parameter values. That is, the density of points in the returned -* Polygon is greater at points where the curvature of the boundary of -* the supplied Polygon is greater. - -* Parameters: -c this -f THIS = INTEGER (Given) -* Pointer to the Polygon. -c maxerr -f MAXERR = DOUBLE PRECISION (Given) -* The maximum allowed discrepancy between the supplied and -* returned Polygons, expressed as a geodesic distance within the -* Polygon's coordinate frame. If this is zero or less, the -* returned Polygon will have the number of vertices specified by -c maxvert. -f MAXVERT. -c maxvert -f MAXVERT = INTEGER (Given) -* The maximum allowed number of vertices in the returned Polygon. -* If this is less than 3, the number of vertices in the returned -* Polygon will be the minimum needed to achieve the maximum -* discrepancy specified by -c maxerr. -f MAXERR. -f STATUS = INTEGER (Given and Returned) -f The global status. - -* Returned Value: -c astDownsize() -f AST_DOWNSIZE = INTEGER -* Pointer to the new Polygon. - -* Notes: -* - A null Object pointer (AST__NULL) will be returned if this -c function is invoked with the AST error status set, or if it -f function is invoked with STATUS set to an error value, or if it -* should fail for any reason. -*-- -*/ - -/* Local Variables: */ - AstFrame *frm; /* Base Frame from the Polygon */ - AstPointSet *pset; /* PointSet holding vertices of downsized polygon */ - AstPolygon *result; /* Returned pointer to new Polygon */ - -/* Initialise. */ - result = NULL; - -/* Check the global error status. */ - if ( !astOK ) return result; - -/* Get a pointer to the base Frame of the Polygon. */ - frm = astGetFrame( ((AstRegion *) this)->frameset, AST__BASE ); - -/* Create a PointSet holding the vertices of the downsized polygon. */ - pset = DownsizePoly( ((AstRegion *) this)->points, maxerr, maxvert, - frm, status ); - -/* Take a deep copy of the supplied Polygon. */ - result = astCopy( this ); - -/* Change the PointSet within the result Polygon to the one created above. */ \ - SetPointSet( result, pset, status ); \ - -/* Free resources. */ - frm = astAnnul( frm ); - pset = astAnnul( pset ); - -/* If an error occurred, annul the returned Polygon. */ - if ( !astOK ) result = astAnnul( result ); - -/* Return the result. */ - return result; -} - -static AstPointSet *DownsizePoly( AstPointSet *pset, double maxerr, - int maxvert, AstFrame *frm, int *status ) { -/* -* Name: -* DownsizePoly - -* Purpose: -* Reduce the number of vertices in a Polygon. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* AstPointSet *DownsizePoly( AstPointSet *pset, double maxerr, int maxvert, -* AstFrame *frm, int *status ) - -* Class Membership: -* Polygon member function. - -* Description: -* This function returns a pointer to a new PointSet that contains a -* subset of the vertices in the supplied PointSet. The subset is -* chosen so that the returned polygon is a good approximation to -* the supplied polygon, within the limits specified by the supplied -* parameter values. That is, the density of points in the returned -* polygon is greater at points where the curvature of the boundary of -* the supplied polygon is greater. - -* Parameters: -* pset -* Pointer to the PointSet holding the polygon vertices. -* maxerr -* The maximum allowed discrepancy between the supplied and -* returned Polygons, expressed as a geodesic distance within the -* Polygon's coordinate frame. If this is zero or less, the -* returned Polygon will have the number of vertices specified by -* maxvert. -* maxvert -* The maximum allowed number of vertices in the returned Polygon. -* If this is less than 3, the number of vertices in the returned -* Polygon will be the minimum needed to achieve the maximum -* discrepancy specified by -* maxerr. -* frm -* Pointer to the Frame in which the polygon is defined. -* status -* Pointer to the inherited status variable. - -* Returned Value: -* Pointer to the new PointSet. - -* Notes: -* - A null Object pointer (AST__NULL) will be returned if this -* function is invoked with the AST error status set, or if it -* should fail for any reason. -*/ - -/* Local Variables: */ - AstPointSet *result; /* Returned pointer to new PointSet */ - Segment *head; /* Pointer to new polygon edge with highest error */ - Segment *seg1; /* Pointer to new polygon edge */ - Segment *seg2; /* Pointer to new polygon edge */ - Segment *seg3; /* Pointer to new polygon edge */ - double **ptr; /* Pointer to arrays of axis values */ - double *x; /* Pointer to array of X values for old Polygon */ - double *xnew; /* Pointer to array of X values for new Polygon */ - double *y; /* Pointer to array of Y values for old Polygon */ - double *ynew; /* Pointer to array of Y values for new Polygon */ - double x1; /* Lowest X value at any vertex */ - double x2; /* Highest X value at any vertex */ - double y1; /* Lowest Y value at any vertex */ - double y2; /* Highest Y value at any vertex */ - int *newpoly; /* Holds indices of retained input vertices */ - int i1; /* Index of first vertex added to output polygon */ - int i1x; /* Index of vertex with lowest X */ - int i1y; /* Index of vertex with lowest Y */ - int i2; /* Index of second vertex added to output polygon */ - int i2x; /* Index of vertex with highest X */ - int i2y; /* Index of vertex with highest Y */ - int i3; /* Index of third vertex added to output polygon */ - int iadd; /* Normalised vertex index */ - int iat; /* Index at which to store new vertex index */ - int newlen; /* Number of vertices currently in new Polygon */ - int nv; /* Number of vertices in old Polygon */ - -/* Initialise. */ - result = NULL; - -/* Check the global error status. */ - if ( !astOK ) return result; - -/* Get the number of vertices in the supplied polygon. */ - nv = astGetNpoint( pset ); - -/* If the maximum error allowed is zero, and the maximum number of - vertices is equal to or greater than the number in the supplied - polygon, just return a deep copy of the supplied PointSet. */ - if( maxerr <= 0.0 && ( maxvert < 3 || maxvert >= nv ) ) { - result = astCopy( pset ); - -/* Otherwise... */ - } else { - -/* Get pointers to the X and Y arrays holding the vertex coordinates in - the supplied polygon. */ - ptr = astGetPoints( pset ); - x = ptr[ 0 ]; - y = ptr[ 1 ]; - -/* Allocate memory for an array to hold the original indices of the vertices - to be used to create the returned Polygon. This array is expanded as - needed. */ - newpoly = astMalloc( 10*sizeof( int ) ); - -/* Check the pointers can be used safely. */ - if( astOK ) { - -/* We first need to decide on three widely spaced vertices which form a - reasonable triangular approximation to the whole polygon. First find - the vertices with the highest and lowest Y values, and the highest and - lowest X values. */ - x1 = DBL_MAX; - x2 = -DBL_MAX; - y1 = DBL_MAX; - y2 = -DBL_MAX; - - i1y = i1x = 0; - i2y = i2x = nv/2; - - for( i3 = 0; i3 < nv; i3++ ) { - if( y[ i3 ] < y1 ) { - y1 = y[ i3 ]; - i1y = i3; - } else if( y[ i3 ] > y2 ) { - y2 = y[ i3 ]; - i2y = i3; - } - - if( x[ i3 ] < x1 ) { - x1 = x[ i3 ]; - i1x = i3; - } else if( x[ i3 ] > x2 ) { - x2 = x[ i3 ]; - i2x = i3; - } - } - -/* Use the axis which spans the greater range. */ - if( y2 - y1 > x2 - x1 ) { - i1 = i1y; - i2 = i2y; - } else { - i1 = i1x; - i2 = i2x; - } - -/* The index with vertex i1 is definitely going to be one of our three - vertices. We are going to use the line from i1 to i2 to choose the two - other vertices to use. Create a structure describing the segment of the - Polygon from the lowest value on the selected axis (X or Y) to the - highest value. As always, the polygons is traversed in an anti-clockwise - direction. */ - seg1 = NewSegment( NULL, i1, i2, nv, status ); - -/* Find the vertex within this segment which is furthest away from the - line on the right hand side (as moving from vertex i1 to vertex i2). */ - FindMax( seg1, frm, x, y, nv, 0, status ); - -/* Likewise, create a structure describing the remained of the Polygon - (i.e. the segment from the highest value on the selected axis to the - lowest value). Then find the vertex within this segment which is - furthest away from the line on the right hand side. */ - seg2 = NewSegment( NULL, i2, i1, nv, status ); - FindMax( seg2, frm, x, y, nv, 0, status ); - -/* Select the segment for which the found vertex is furthest from the - line. */ - if( seg2->error > seg1->error ) { - -/* If the second segment, we will use the vertex that is farthest from - the line as one of our threee vertices. To ensure that movement from - vertex i1 to i2 to i3 is anti-clockwise, we must use this new vertex - as vertex i3, not i2. */ - i3 = seg2->imax; - -/* Create a description of the polygon segment from vertex i1 to i3, and - find the vertex which is furthest to the right of the line joining the - two vertices. We use this as the middle vertex (i2). */ - seg1 = NewSegment( seg1, i1, i3, nv, status ); - FindMax( seg1, frm, x, y, nv, 0, status ); - i2 = seg1->imax; - -/* Do the same if we are choosing the other segment, ordering the - vertices to retain anti-clockwise movement from i1 to i2 to i3. */ - } else { - i2 = seg1->imax; - seg1 = NewSegment( seg1, i2, i1, nv, status ); - FindMax( seg1, frm, x, y, nv, 0, status ); - i3 = seg1->imax; - } - -/* Ensure the vertex indices are in the first cycle. */ - if( i2 >= nv ) i2 -= nv; - if( i3 >= nv ) i3 -= nv; - -/* Create Segment structures to describe each of these three edges. */ - seg1 = NewSegment( seg1, i1, i2, nv, status ); - seg2 = NewSegment( seg2, i2, i3, nv, status ); - seg3 = NewSegment( NULL, i3, i1, nv, status ); - -/* Record these 3 vertices in an array holding the original indices of - the vertices to be used to create the returned Polygon. */ - newpoly[ 0 ] = i1; - newpoly[ 1 ] = i2; - newpoly[ 2 ] = i3; - -/* Indicate the new polygon currently has 3 vertices. */ - newlen = 3; - -/* Search the old vertices between the start and end of segment 3, looking - for the vertex which lies furthest from the line of segment 3. The - residual between this point and the line is stored in the Segment - structure, as is the index of the vertex at which this maximum residual - occurred. */ - FindMax( seg3, frm, x, y, nv, 1, status ); - -/* The "head" variable points to the head of a double linked list of - Segment structures. This list is ordered by residual, so that the - Segment with the maximum residual is at the head, and the Segment - with the minimum residual is at the tail. Initially "seg3" is at the - head. */ - head = seg3; - -/* Search the old vertices between the start and end of segment 1, looking - for the vertex which lies furthest from the line of segment 1. The - residual between this point and the line is stored in the Segment - structure, as is the index of the vertex at which this maximum residual - occurred. */ - FindMax( seg1, frm, x, y, nv, 1, status ); - -/* Insert segment 1 into the linked list of Segments, at a position that - maintains the ordering of the segments by error. Thus the head of the - list will still have the max error. */ - head = AddToChain( head, seg1, status ); - -/* Do the same for segment 2. */ - FindMax( seg2, frm, x, y, nv, 1, status ); - head = AddToChain( head, seg2, status ); - -/* If the maximum allowed number of vertices in the output Polygon is - less than 3, allow any number of vertices up to the number in the - input Polygon (termination will then be determined just by "maxerr"). */ - if( maxvert < 3 ) maxvert = nv; - -/* Loop round adding an extra vertex to the returned Polygon until the - maximum residual between the new and old polygons is no more than - "maxerr". Abort early if the specified maximum number of vertices is - reached. */ - while( head->error > maxerr && newlen < maxvert ) { - -/* The segment at the head of the list has the max error (that is, it is - the segment that departs most from the supplied Polygon). To make the - new polygon a better fit to the old polygon, we add the vertex that is - furthest away from this segment to the new polygon. Remember that a - polygon is cyclic so if the vertex has an index that is greater than the - number of vertices in the old polygon, reduce the index by the number - of vertices in the old polygon. */ - iadd = head->imax; - if( iadd >= nv ) iadd -= nv; - iat = newlen++; - newpoly = astGrow( newpoly, newlen, sizeof( int ) ); - if( !astOK ) break; - newpoly[ iat ] = iadd; - -/* We now split the segment that had the highest error into two segments. - The split occurs at the vertex that had the highest error. */ - seg1 = NewSegment( NULL, head->imax, head->i2, nv, status ); - seg2 = head; - seg2->i2 = head->imax; - -/* We do not know where these two new segments should be in the ordered - linked list, so remove them from the list. */ - head = RemoveFromChain( head, seg1, status ); - head = RemoveFromChain( head, seg2, status ); - -/* Find the vertex that deviates most from the first of these two new - segments, and then add the segment into the list of vertices, using - the maximum deviation to determine the position of the segment within - the list. */ - FindMax( seg1, frm, x, y, nv, 1, status ); - head = AddToChain( head, seg1, status ); - -/* Do the same for the second new segment. */ - FindMax( seg2, frm, x, y, nv, 1, status ); - head = AddToChain( head, seg2, status ); - } - -/* Now we have reached the required accuracy, free resources. */ - while( head ) { - seg1 = head; - head = head->next; - seg1 = astFree( seg1 ); - } - -/* If no vertices have been left out, return a deep copy of the supplied - PointSet. */ - if( newlen == nv ) { - result = astCopy( pset ); - -/* Otherwise, sort the indices of the vertices to be retained so that they - are in the same order as they were in the supplied Polygon. */ - } else if( astOK ){ - qsort( newpoly, newlen, sizeof( int ), IntCmp ); - -/* Create a new PointSet and get pointers to its axis values. */ - result = astPointSet( newlen, 2, " ", status ); - ptr = astGetPoints( result ); - xnew = ptr[ 0 ]; - ynew = ptr[ 1 ]; - -/* Copy the axis values for the retained vertices from the old to the new - PointSet. */ - if( astOK ) { - for( iat = 0; iat < newlen; iat++ ) { - *(xnew++) = x[ newpoly[ iat ] ]; - *(ynew++) = y[ newpoly[ iat ] ]; - } - } - } - } - -/* Free resources. */ - newpoly = astFree( newpoly ); - } - -/* If an error occurred, annul the returned PointSet. */ - if ( !astOK ) result = astAnnul( result ); - -/* Return the result. */ - return result; -} - -static void EnsureInside( AstPolygon *this, int *status ){ -/* -* Name: -* EnsureInside - -* Purpose: -* Ensure the unnegated Polygon represents the inside of the polygon. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* void EnsureInside( AstPolygon *this, int *status ) - -* Class Membership: -* Polygon member function - -* Description: -* Reversing the order of the vertices of a Polygon is like negating -* the Polygon. But the parent Region class assumes that an unnegated -* region bounded by closed curves (e.g. boxes, circles, ellipses, etc) -* is bounded. So we need to have a way to ensure that a Polygon also -* follows this convention. So this function reverses the order of the -* vertices in the Polygon, if necessary, to ensure that the unnegated -* Polygon is bounded. - -* Parameters: -* this -* The Polygon. -* status -* Pointer to the inherited status variable. - -*/ - -/* Local Variables: */ - AstRegion *this_region; - double **ptr; - double *p; - double *q; - double tmp; - int bounded; - int i; - int j; - int jmid; - int negated; - int np; - -/* Check the global error status. */ - if ( !astOK ) return; - -/* Is the unnegated Polygon unbounded? If so, we need to reverse the - vertices. */ - bounded = astGetBounded( this ); - negated = astGetNegated( this ); - if( ( bounded && negated ) || ( !bounded && !negated ) ) { - this_region = (AstRegion *) this; - -/* Get a pointer to the arrays holding the coordinates at the Polygon - vertices. */ - ptr = astGetPoints( this_region->points ); - -/* Get the number of vertices. */ - np = astGetNpoint( this_region->points ); - -/* Store the index of the last vertex to swap. For odd "np" the central - vertex does not need to be swapped. */ - jmid = np/2; - -/* Loop round the two axes spanned by the Polygon. */ - for( i = 0; i < 2; i++ ) { - -/* Get pointers to the first pair of axis values to be swapped - i.e. the - first and last axis values. */ - p = ptr[ i ]; - q = p + np - 1; - -/* Loop round all pairs of axis values. */ - for( j = 0; j < jmid; j++ ) { - -/* Swap the pair. */ - tmp = *p; - *(p++) = *q; - *(q--) = tmp; - } - } - -/* Invert the value of the "Negated" attribute to cancel out the effect - of the above vertex reversal. */ - astNegate( this ); - -/* Indicate the cached information in the Polygon structure is stale. */ - this->stale = 1; - } -} - -/* -* Name: -* FindBoxEdge - -* Purpose: -* Find an edge of the bounding box containing the selected pixels. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* void FindBoxEdge<Oper><X>( <Xtype> value, const <Xtype> array[], -* int xdim, int ydim, int axis, int low, -* int *val, int *valmax, int *valmin, -* int *status ) - -* Class Membership: -* Polygon member function - -* Description: -* This function search for an edge of the bounding box containing the -* selected pixels in the supplied array. - -* Parameters: -* value -* A data value that specifies the pixels to be selected. -* array -* Pointer to a 2-dimensional array containing the data to be -* processed. The numerical type of this array should match the 1- -* or 2-character type code appended to the function name. -* xdim -* The number of pixels along each row of the array. -* ydim -* The number of rows in the array. -* axis -* The index (0 or 1) of the pixel axis perpendicular to the edge of the -* bounding box being found. -* low -* If non-zero, the lower edge of the bounding box on the axis -* specified by "axis" is found and returned. Otherwise, the higher -* edge of the bounding box on the axis specified by "axis" is -* found and returned. -* val -* Address of an int in which to return the value on axis "axis" of -* the higher or lower (as specified by "low") edge of the bounding -* box. -* valmax -* Address of an int in which to return the highest value on axis -* "1-axis" of the selected pixels on the returned edge. -* valmin -* Address of an int in which to return the lowest value on axis -* "1-axis" of the selected pixels on the returned edge. -* status -* Pointer to the inherited status variable. - -* Notes; -* - Zero is returned for "*val" if no good values are found, or if -* an error occurs. - -*/ - -/* Define a macro to implement the function for a specific data - type and operation. */ -#define MAKE_FINDBOXEDGE(X,Xtype,Oper,OperI) \ -static void FindBoxEdge##Oper##X( Xtype value, const Xtype array[], int xdim, \ - int ydim, int axis, int low, int *val, \ - int *valmax, int *valmin, int *status ) { \ -\ -/* Local Variables: */ \ - int astep; \ - int bstep; \ - int a0; \ - int a1; \ - int b0; \ - int b1; \ - int inc; \ - int a; \ - int b; \ - const Xtype *pc; \ -\ -/* Initialise. */ \ - *val = 0; \ - *valmin = 0; \ - *valmax = 0; \ -\ -/* Check the global error status. */ \ - if ( !astOK ) return; \ -\ -/* If we are finding an edge that is parallel to the X axis... */ \ - if( axis ) { \ -\ -/* Get the vector step between adjacent pixels on the selected axis, and \ - on the other axis. */ \ - astep = xdim; \ - bstep = 1; \ -\ -/* Get the first and last value to check on the selected axis, and the \ - increment between checks. */ \ - if( low ) { \ - a0 = 1; \ - a1 = ydim; \ - inc = 1; \ - } else { \ - a0 = ydim; \ - a1 = 1; \ - inc = -1; \ - } \ -\ -/* The first and last value to check on the other axis. */ \ - b0 = 1; \ - b1 = xdim; \ -\ -/* Do the same if we are finding an edge that is parallel to the Y axis. */ \ - } else { \ - astep = 1; \ - bstep = xdim; \ -\ - if( low ) { \ - a0 = 1; \ - a1 = xdim; \ - inc = 1; \ - } else { \ - a0 = xdim; \ - a1 = 1; \ - inc = -1; \ - } \ -\ - b0 = 1; \ - b1 = ydim; \ - } \ -\ -/* Loop round the axis values. */ \ - a = a0; \ - while( 1 ) { \ -\ -/* Get a pointer to the first value to be checked at this axis value. */ \ - pc = array + (a - 1)*astep + (b0 - 1)*bstep; \ -\ -/* Scan the other axis to find the first and last selected pixel. */ \ - for( b = b0; b <= b1; b++ ) { \ - if( ISVALID(*pc,OperI,value) ) { \ - if( *valmin == 0 ) *valmin = b; \ - *valmax = b; \ - } \ - pc += bstep; \ - } \ -\ -/* If any selected pixels were found, store the axis value and exit. */ \ - if( *valmax ) { \ - *val = a; \ - break; \ - } \ -\ -/* Move on to the next axis value. */ \ - if( a != a1 ) { \ - a += inc; \ - } else { \ - break; \ - } \ -\ - } \ -} - -/* Define a macro that uses the above macro to to create implementations - of FindBoxEdge for all operations. */ -#define MAKEALL_FINDBOXEDGE(X,Xtype) \ -MAKE_FINDBOXEDGE(X,Xtype,LT,AST__LT) \ -MAKE_FINDBOXEDGE(X,Xtype,LE,AST__LE) \ -MAKE_FINDBOXEDGE(X,Xtype,EQ,AST__EQ) \ -MAKE_FINDBOXEDGE(X,Xtype,NE,AST__NE) \ -MAKE_FINDBOXEDGE(X,Xtype,GE,AST__GE) \ -MAKE_FINDBOXEDGE(X,Xtype,GT,AST__GT) - -/* Expand the above macro to generate a function for each required - data type and operation. */ -#if HAVE_LONG_DOUBLE /* Not normally implemented */ -MAKEALL_FINDBOXEDGE(LD,long double) -#endif -MAKEALL_FINDBOXEDGE(D,double) -MAKEALL_FINDBOXEDGE(L,long int) -MAKEALL_FINDBOXEDGE(UL,unsigned long int) -MAKEALL_FINDBOXEDGE(I,int) -MAKEALL_FINDBOXEDGE(UI,unsigned int) -MAKEALL_FINDBOXEDGE(S,short int) -MAKEALL_FINDBOXEDGE(US,unsigned short int) -MAKEALL_FINDBOXEDGE(B,signed char) -MAKEALL_FINDBOXEDGE(UB,unsigned char) -MAKEALL_FINDBOXEDGE(F,float) - -/* Undefine the macros. */ -#undef MAKE_FINDBOXEDGE -#undef MAKEALL_FINDBOXEDGE - -/* -* Name: -* FindInsidePoint - -* Purpose: -* Find a point that is inside the required outline. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* void FindInsidePoint<Oper><X>( <Xtype> value, const <Xtype> array[], -* const int lbnd[ 2 ], const int ubnd[ 2 ], -* int *inx, int *iny, int *iv, -* int *status ); - -* Class Membership: -* Polygon member function - -* Description: -* The central pixel in the array is checked to see if its value meets -* the requirements implied by <Oper> and "value". If so, its pixel -* indices and vector index are returned> if not, a spiral search is -* made until such a pixel value is found. - -* Parameters: -* value -* The data value defining valid pixels. -* array -* The data array. -* lbnd -* The lower pixel index bounds of the array. -* ubnd -* The upper pixel index bounds of the array. -* inx -* Pointer to an int in which to return the X pixel index of the -* first point that meets the requirements implied by <oper> and -* "value". -* iny -* Pointer to an int in which to return the Y pixel index of the -* first point that meets the requirements implied by <oper> and -* "value". -* iv -* Pointer to an int in which to return the vector index of the -* first point that meets the requirements implied by <oper> and -* "value". -* status -* Pointer to the inherited status variable. - -* Notes: -* - <Oper> must be one of LT, LE, EQ, NE, GE, GT. - - -*/ - -/* Define a macro to implement the function for a specific data - type and operation. */ -#define MAKE_FINDINSIDEPOINT(X,Xtype,Oper,OperI) \ -static void FindInsidePoint##Oper##X( Xtype value, const Xtype array[], \ - const int lbnd[ 2 ], const int ubnd[ 2 ], \ - int *inx, int *iny, int *iv, \ - int *status ){ \ -\ -/* Local Variables: */ \ - const Xtype *pv; /* Pointer to next data value to test */ \ - const char *text; /* Pointer to text describing oper */ \ - int cy; /* Central row index */ \ - int iskin; /* Index of spiral layer being searched */ \ - int nskin; /* Number of spiral layers to search */ \ - int nx; /* Pixel per row */ \ - int tmp; /* Temporary storage */ \ - int xhi; /* High X pixel index bound of current skin */ \ - int xlo; /* Low X pixel index bound of current skin */ \ - int yhi; /* High X pixel index bound of current skin */ \ - int ylo; /* Low X pixel index bound of current skin */ \ -\ -/* Check the global error status. */ \ - if ( !astOK ) return; \ -\ -/* Find number of pixels in one row of the array. */ \ - nx = ( ubnd[ 0 ] - lbnd[ 0 ] + 1 ); \ -\ -/* Find the pixel indices of the central pixel */ \ - *inx = ( ubnd[ 0 ] + lbnd[ 0 ] )/2; \ - *iny = ( ubnd[ 1 ] + lbnd[ 1 ] )/2; \ -\ -/* Initialise the vector index and pointer to refer to the central pixel. */ \ - *iv = ( *inx - lbnd[ 0 ] ) + nx*( *iny - lbnd[ 1 ] ) ; \ - pv = array + (*iv); \ -\ -/* Test the pixel value, returning if it is valid. This \ - relies on the compiler optimisation to remove the "if" statements \ - for all but the operation appropriate to the function being defined. */ \ - if( OperI == AST__LT ) { \ - if( *pv < value ) return; \ -\ - } else if( OperI == AST__LE ) { \ - if( *pv <= value ) return; \ -\ - } else if( OperI == AST__EQ ) { \ - if( *pv == value ) return; \ -\ - } else if( OperI == AST__NE ) { \ - if( *pv != value ) return; \ -\ - } else if( OperI == AST__GE ) { \ - if( *pv >= value ) return; \ -\ - } else { \ - if( *pv > value ) return; \ - } \ -\ -/* The central pixel is invalid if we arrive here. So we need to do a \ - spiral search out from the centre looking for a valid pixel. Record \ - the central row index (this is the row at which we jump to the next \ - outer skin when doing the spiral search below). */ \ - cy = *iny; \ -\ -/* Find how many skins can be searched as part of the spiral search \ - before the edge of the array is encountered. */ \ - nskin = ubnd[ 0 ] - *inx; \ - tmp = *inx - lbnd[ 0 ]; \ - if( tmp < nskin ) nskin = tmp; \ - tmp = ubnd[ 1 ] - *iny; \ - if( tmp < nskin ) nskin = tmp; \ - tmp = *iny - lbnd[ 1 ]; \ - if( tmp < nskin ) nskin = tmp; \ -\ -/* Initialise the skin box bounds to be just the central pixel. */ \ - xlo = xhi = *inx; \ - ylo = yhi = *iny; \ -\ -/* Loop round each skin looking for a valid test pixel. */ \ - for( iskin = 0; iskin < nskin; iskin++ ) { \ -\ -/* Increment the upper and lower bounds of the box forming the next \ - skin. */ \ - xhi++; \ - xlo--; \ - yhi++; \ - ylo--; \ -\ -/* Initialise things for the first pixel in the new skin by moving one \ - pixel to the right. */ \ - pv++; \ - (*iv)++; \ - (*inx)++; \ -\ -/* Move up the right hand edge of the box corresponding to the current \ - skin. We start at the middle of the right hand edge. */ \ - for( *iny = cy; *iny <= yhi; (*iny)++ ) { \ -\ -/* Test the pixel value, returning if it is valid. This relies on the \ - compiler optimisation to remove the "if" statements for all but the \ - operation appropriate to the function being defined. */ \ - if( OperI == AST__LT ) { \ - if( *pv < value ) return; \ -\ - } else if( OperI == AST__LE ) { \ - if( *pv <= value ) return; \ -\ - } else if( OperI == AST__EQ ) { \ - if( *pv == value ) return; \ -\ - } else if( OperI == AST__NE ) { \ - if( *pv != value ) return; \ -\ - } else if( OperI == AST__GE ) { \ - if( *pv >= value ) return; \ -\ - } else { \ - if( *pv > value ) return; \ - } \ -\ -/* Move up a pixel. */ \ - pv += nx; \ - *iv += nx; \ - } \ -\ -/* Move down a pixel so that *iny == yhi. */ \ - pv -= nx; \ - *iv -= nx; \ - (*iny)--; \ -\ -/* Move left along the top edge of the box corresponding to the current \ - skin. */ \ - for( *inx = xhi; *inx >= xlo; (*inx)-- ) { \ -\ -/* Test the pixel value, returning if it is valid. */ \ - if( OperI == AST__LT ) { \ - if( *pv < value ) return; \ -\ - } else if( OperI == AST__LE ) { \ - if( *pv <= value ) return; \ -\ - } else if( OperI == AST__EQ ) { \ - if( *pv == value ) return; \ -\ - } else if( OperI == AST__NE ) { \ - if( *pv != value ) return; \ -\ - } else if( OperI == AST__GE ) { \ - if( *pv >= value ) return; \ -\ - } else { \ - if( *pv > value ) return; \ - } \ -\ -/* Move left a pixel. */ \ - pv--; \ - (*iv)--; \ - } \ -\ -/* Move right a pixel so that *inx == xlo. */ \ - pv++; \ - (*iv)++; \ - (*inx)++; \ -\ -/* Move down along the left hand edge of the box corresponding to the current \ - skin. */ \ - for( *iny = yhi; *iny >= ylo; (*iny)-- ) { \ -\ -/* Test the pixel value, returning if it is valid. */ \ - if( OperI == AST__LT ) { \ - if( *pv < value ) return; \ -\ - } else if( OperI == AST__LE ) { \ - if( *pv <= value ) return; \ -\ - } else if( OperI == AST__EQ ) { \ - if( *pv == value ) return; \ -\ - } else if( OperI == AST__NE ) { \ - if( *pv != value ) return; \ -\ - } else if( OperI == AST__GE ) { \ - if( *pv >= value ) return; \ -\ - } else { \ - if( *pv > value ) return; \ - } \ -\ -/* Move down a pixel. */ \ - pv -= nx; \ - *iv -= nx; \ - } \ -\ -/* Move up a pixel so that *iny == ylo. */ \ - pv += nx; \ - *iv += nx; \ - (*iny)++; \ -\ -/* Move right along the bottom edge of the box corresponding to the current \ - skin. */ \ - for( *inx = xlo; *inx <= xhi; (*inx)++ ) { \ -\ -/* Test the pixel value, returning if it is valid. */ \ - if( OperI == AST__LT ) { \ - if( *pv < value ) return; \ -\ - } else if( OperI == AST__LE ) { \ - if( *pv <= value ) return; \ -\ - } else if( OperI == AST__EQ ) { \ - if( *pv == value ) return; \ -\ - } else if( OperI == AST__NE ) { \ - if( *pv != value ) return; \ -\ - } else if( OperI == AST__GE ) { \ - if( *pv >= value ) return; \ -\ - } else { \ - if( *pv > value ) return; \ - } \ -\ -/* Move right a pixel. */ \ - pv++; \ - (*iv)++; \ - } \ -\ -/* Move left a pixel so that *inx == xhi. */ \ - pv--; \ - (*iv)--; \ - (*inx)--; \ -\ -/* Move up the right hand edge of the box correspionding to the current \ - skin. We stop just below the middle of the right hand edge. */ \ - for( *iny = ylo; *iny < cy; (*iny)++ ) { \ -\ -/* Test the pixel value, returning if it is valid. This relies on the \ - compiler optimisation to remove the "if" statements for all but the \ - operation appropriate to the function being defined. */ \ - if( OperI == AST__LT ) { \ - if( *pv < value ) return; \ -\ - } else if( OperI == AST__LE ) { \ - if( *pv <= value ) return; \ -\ - } else if( OperI == AST__EQ ) { \ - if( *pv == value ) return; \ -\ - } else if( OperI == AST__NE ) { \ - if( *pv != value ) return; \ -\ - } else if( OperI == AST__GE ) { \ - if( *pv >= value ) return; \ -\ - } else { \ - if( *pv > value ) return; \ - } \ -\ -/* Move up a pixel. */ \ - pv += nx; \ - *iv += nx; \ - } \ - } \ -\ -/* Report an error if no inside pooint could be found. */ \ - if( OperI == AST__LT ) { \ - text = "less than"; \ - } else if( OperI == AST__LE ) { \ - text = "less than or equal to"; \ - } else if( OperI == AST__EQ ) { \ - text = "equal to"; \ - } else if( OperI == AST__NE ) { \ - text = "not equal to"; \ - } else if( OperI == AST__GE ) { \ - text = "greater than or equal to"; \ - } else { \ - text = "greater than"; \ - } \ - astError( AST__NONIN, "astOutline"#X": Could not find a pixel value %s " \ - "%g in the supplied array.", status, text, (double) value ); \ -} - -/* Define a macro that uses the above macro to to create implementations - of FindInsidePoint for all operations. */ -#define MAKEALL_FINDINSIDEPOINT(X,Xtype) \ -MAKE_FINDINSIDEPOINT(X,Xtype,LT,AST__LT) \ -MAKE_FINDINSIDEPOINT(X,Xtype,LE,AST__LE) \ -MAKE_FINDINSIDEPOINT(X,Xtype,EQ,AST__EQ) \ -MAKE_FINDINSIDEPOINT(X,Xtype,GE,AST__GE) \ -MAKE_FINDINSIDEPOINT(X,Xtype,GT,AST__GT) \ -MAKE_FINDINSIDEPOINT(X,Xtype,NE,AST__NE) - -/* Expand the above macro to generate a function for each required - data type and operation. */ -#if HAVE_LONG_DOUBLE /* Not normally implemented */ -MAKEALL_FINDINSIDEPOINT(LD,long double) -#endif -MAKEALL_FINDINSIDEPOINT(D,double) -MAKEALL_FINDINSIDEPOINT(L,long int) -MAKEALL_FINDINSIDEPOINT(UL,unsigned long int) -MAKEALL_FINDINSIDEPOINT(I,int) -MAKEALL_FINDINSIDEPOINT(UI,unsigned int) -MAKEALL_FINDINSIDEPOINT(S,short int) -MAKEALL_FINDINSIDEPOINT(US,unsigned short int) -MAKEALL_FINDINSIDEPOINT(B,signed char) -MAKEALL_FINDINSIDEPOINT(UB,unsigned char) -MAKEALL_FINDINSIDEPOINT(F,float) - -/* Undefine the macros. */ -#undef MAKE_FINDINSIDEPOINT -#undef MAKEALL_FINDINSIDEPOINT - -static void FindMax( Segment *seg, AstFrame *frm, double *x, double *y, - int nv, int abs, int *status ){ -/* -* Name: -* FindMax - -* Purpose: -* Find the maximum discrepancy between a given line segment and the -* Polygon being downsized. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* void FindMax( Segment *seg, AstFrame *frm, double *x, double *y, -* int nv, int abs, int *status ) - -* Class Membership: -* Polygon member function - -* Description: -* The supplied Segment structure describes a range of vertices in -* the polygon being downsized. This function checks each of these -* vertices to find the one that lies furthest from the line joining the -* first and last vertices in the segment. The maximum error, and the -* vertex index at which this maximum error is found, is stored in the -* Segment structure. - -* Parameters: -* seg -* The structure describing the range of vertices to check. It -* corresponds to a candidate edge in the downsized polygon. -* frm -* The Frame in which the positions are defined. -* x -* Pointer to the X axis values in the original Polygon. -* y -* Pointer to the Y axis values in the original Polygon. -* nv -* Total number of vertics in the old Polygon.. -* abs -* If non-zero, then the stored maximum is the position with -* maximum absolute error. Otherwise, the stored maximum is the -* position with maximum positive error (positive errors are to the -* right when travelling from start to end of the segment). -* status -* Pointer to the inherited status variable. - -*/ - -/* Local Variables: */ - AstPointSet *pset1; /* PointSet holding vertex positions */ - AstPointSet *pset2; /* PointSet holding offset par/perp components */ - double **ptr1; /* Pointers to "pset1" data arrays */ - double **ptr2; /* Pointers to "pset2" data arrays */ - double *px; /* Pointer to next X value */ - double *py; /* Pointer to next Y value */ - double ax; /* X value at start */ - double ay; /* Y value at start */ - double ba; /* Distance between a and b */ - double bax; /* X increment from a to b */ - double bay; /* Y increment from a to b */ - double cax; /* X increment from a to c */ - double cay; /* Y increment from a to c */ - double end[ 2 ]; /* Position of starting vertex */ - double error; /* Error value for current vertex */ - double start[ 2 ]; /* Position of starting vertex */ - int i1; /* Starting index (always in first cycle) */ - int i2; /* Ending index converted to first cycle */ - int i2b; /* Upper vertex limit in first cycle */ - int i; /* Loop count */ - int n; /* Number of vertices to check */ - -/* Check the global error status. */ - if ( !astOK ) return; - -/* Stuff needed for handling cyclic redundancy of vertex indices. */ - i1 = seg->i1; - i2 = seg->i2; - n = i2 - i1 - 1; - i2b = i2; - if( i2 >= nv ) { - i2 -= nv; - i2b = nv; - } - -/* If the segment has no intermediate vertices, set the segment error to - zero and return. */ - if( n < 1 ) { - seg->error = 0.0; - seg->imax = i1; - -/* For speed, we use simple plane geometry if the Polygon is defined in a - simple Frame. */ - } else if( !strcmp( astGetClass( frm ), "Frame" ) ) { - -/* Point "a" is the vertex that marks the start of the segment. Point "b" - is the vertex that marks the end of the segment. */ - ax = x[ i1 ]; - ay = y[ i1 ]; - bax = x[ i2 ] - ax; - bay = y[ i2 ] - ay; - ba = sqrt( bax*bax + bay*bay ); - -/* Initialise the largest error found so far. */ - seg->error = -1.0; - -/* Check the vertices from the start (plus one) up to the end (minus one) - or the last vertex (which ever comes first). */ - for( i = i1 + 1; i < i2b; i++ ) { - -/* Position "c" is the vertex being tested. Find the squared distance from - "c" to the line joining "a" and "b". */ - cax = x[ i ] - ax; - cay = y[ i ] - ay; - error = ( bay*cax - cay*bax )/ba; - if( abs ) error = fabs( error ); - -/* If this is the largest value found so far, record it. Note the error - here is a squared distance. */ - if( error > seg->error ) { - seg->error = error; - seg->imax = i; - } - } - -/* If the end vertex is in the next cycle, check the remaining vertex - posI would have thought a telentitions in the same way. */ - if( i2b != i2 ) { - - for( i = 0; i < i2; i++ ) { - - cax = x[ i ] - ax; - cay = y[ i ] - ay; - error = ( bay*cax - cay*bax )/ba; - if( abs ) error = fabs( error ); - - if( error > seg->error ) { - seg->error = error; - seg->imax = i + i2b; - } - - } - } - -/* If the polygon is not defined in a simple Frame, we use the overloaded - Frame methods to do the geometry. */ - } else { - -/* Create a PointSet to hold the positions of the vertices to test. We do - not need to test the start or end vertex. */ - pset1 = astPointSet( n, 2, " ", status ); - ptr1 = astGetPoints( pset1 ); - if( astOK ) { - -/* Copy the vertex axis values form the start (plus one) up to the end - (minus one) vertex or the last vertex (which ever comes first). */ - px = ptr1[ 0 ]; - py = ptr1[ 1 ]; - - for( i = i1 + 1; i < i2b; i++ ){ - *(px++) = x[ i ]; - *(py++) = y[ i ]; - } - -/* If the end vertex is in the next cycle, copy the remaining vertex - positions into the PointSet. */ - if( i2b != i2 ) { - for( i = 0; i < i2; i++ ) { - *(px++) = x[ i ]; - *(py++) = y[ i ]; - } - } - -/* Record the start and end vertex positions. */ - start[ 0 ] = x[ i1 ]; - start[ 1 ] = y[ i1 ]; - end[ 0 ] = x[ i2 ]; - end[ 1 ] = y[ i2 ]; - -/* Resolve the vector from the start to each vertex into two components, - parallel and perpendicular to the start->end vector. */ - pset2 = astResolvePoints( frm, start, end, pset1, NULL ); - ptr2 = astGetPoints( pset2 ); - if( astOK ) { - -/* Find the vertex with largest perpendicular component. */ - seg->error = -1.0; - py = ptr2[ 1 ]; - for( i = 1; i <= n; i++ ) { - - error = *(py++); - if( abs ) error = fabs( error ); - - if( error > seg->error ) { - seg->error = error; - seg->imax = i + i1; - } - - } - } - -/* Free resources. */ - pset2 = astAnnul( pset2 ); - } - pset1 = astAnnul( pset1 ); - } -} - -static const char *GetAttrib( AstObject *this_object, const char *attrib, int *status ) { -/* -* Name: -* GetAttrib - -* Purpose: -* Get the value of a specified attribute for a Polygon. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* const char *GetAttrib( AstObject *this, const char *attrib, int *status ) - -* Class Membership: -* Polygon member function (over-rides the protected astGetAttrib -* method inherited from the Region class). - -* Description: -* This function returns a pointer to the value of a specified -* attribute for a Polygon, formatted as a character string. - -* Parameters: -* this -* Pointer to the Polygon. -* attrib -* Pointer to a null-terminated string containing the name of -* the attribute whose value is required. This name should be in -* lower case, with all white space removed. -* status -* Pointer to the inherited status variable. - -* Returned Value: -* - Pointer to a null-terminated string containing the attribute -* value. - -* Notes: -* - The returned string pointer may point at memory allocated -* within the Polygon, or at static memory. The contents of the -* string may be over-written or the pointer may become invalid -* following a further invocation of the same function or any -* modification of the Polygon. A copy of the string should -* therefore be made if necessary. -* - A NULL pointer will be returned if this function is invoked -* with the global error status set, or if it should fail for any -* reason. -*/ - -/* Local Variables: */ - astDECLARE_GLOBALS /* Pointer to thread-specific global data */ - AstPolygon *this; /* Pointer to the Polygon structure */ - const char *result; /* Pointer value to return */ - int ival; /* Integer attribute value */ - -/* Initialise. */ - result = NULL; - -/* Check the global error status. */ - if ( !astOK ) return result; - -/* Get a pointer to the thread specific global data structure. */ - astGET_GLOBALS(this_object); - -/* Obtain a pointer to the Polygon structure. */ - this = (AstPolygon *) this_object; - -/* Compare "attrib" with each recognised attribute name in turn, - obtaining the value of the required attribute. If necessary, write - the value into "getattrib_buff" as a null-terminated string in an appropriate - format. Set "result" to point at the result string. */ - -/* SimpVertices. */ -/* ------------- */ - if ( !strcmp( attrib, "simpvertices" ) ) { - ival = astGetSimpVertices( this ); - if ( astOK ) { - (void) sprintf( getattrib_buff, "%d", ival ); - result = getattrib_buff; - } - -/* If the attribute name was not recognised, pass it on to the parent - method for further interpretation. */ - } else { - result = (*parent_getattrib)( this_object, attrib, status ); - } - -/* Return the result. */ - return result; - -} - -static int GetBounded( AstRegion *this, int *status ) { -/* -* Name: -* GetBounded - -* Purpose: -* Is the Region bounded? - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* int GetBounded( AstRegion *this, int *status ) - -* Class Membership: -* Polygon method (over-rides the astGetBounded method inherited from -* the Region class). - -* Description: -* This function returns a flag indicating if the Region is bounded. -* The implementation provided by the base Region class is suitable -* for Region sub-classes representing the inside of a single closed -* curve (e.g. Circle, Interval, Box, etc). Other sub-classes (such as -* CmpRegion, PointList, etc ) may need to provide their own -* implementations. - -* Parameters: -* this -* Pointer to the Region. -* status -* Pointer to the inherited status variable. - -* Returned Value: -* Non-zero if the Region is bounded. Zero otherwise. - -*/ - -/* Local Variables: */ - int neg; /* Has the Polygon been negated? */ - int result; /* Returned result */ - -/* Initialise */ - result = 0; - -/* Check the global error status. */ - if ( !astOK ) return result; - -/* Ensure cached information is available. */ - Cache( (AstPolygon *) this, status ); - -/* See if the Polygon has been negated. */ - neg = astGetNegated( this ); - -/* If the polygon vertices are stored in anti-clockwise order, then the - polygon is bounded if it has not been negated. */ - if( ( (AstPolygon *) this)->acw ) { - result = (! neg ); - -/* If the polygon vertices are stored in clockwise order, then the - polygon is bounded if it has been negated. */ - } else { - result = neg; - } - -/* Return the result. */ - return result; -} - -void astInitPolygonVtab_( AstPolygonVtab *vtab, const char *name, int *status ) { -/* -*+ -* Name: -* astInitPolygonVtab - -* Purpose: -* Initialise a virtual function table for a Polygon. - -* Type: -* Protected function. - -* Synopsis: -* #include "polygon.h" -* void astInitPolygonVtab( AstPolygonVtab *vtab, const char *name ) - -* Class Membership: -* Polygon vtab initialiser. - -* Description: -* This function initialises the component of a virtual function -* table which is used by the Polygon class. - -* Parameters: -* vtab -* Pointer to the virtual function table. The components used by -* all ancestral classes will be initialised if they have not already -* been initialised. -* name -* Pointer to a constant null-terminated character string which contains -* the name of the class to which the virtual function table belongs (it -* is this pointer value that will subsequently be returned by the Object -* astClass function). -*- -*/ - -/* Local Variables: */ - astDECLARE_GLOBALS /* Pointer to thread-specific global data */ - AstMappingVtab *mapping; /* Pointer to Mapping component of Vtab */ - AstRegionVtab *region; /* Pointer to Region component of Vtab */ - AstObjectVtab *object; /* Pointer to Object component of Vtab */ - -/* Check the local error status. */ - if ( !astOK ) return; - -/* Get a pointer to the thread specific global data structure. */ - astGET_GLOBALS(NULL); - -/* Initialize the component of the virtual function table used by the - parent class. */ - astInitRegionVtab( (AstRegionVtab *) vtab, name ); - -/* Store a unique "magic" value in the virtual function table. This - will be used (by astIsAPolygon) to determine if an object belongs - to this class. We can conveniently use the address of the (static) - class_check variable to generate this unique value. */ - vtab->id.check = &class_check; - vtab->id.parent = &(((AstRegionVtab *) vtab)->id); - -/* Initialise member function pointers. */ -/* ------------------------------------ */ -/* Store pointers to the member functions (implemented here) that provide - virtual methods for this class. */ - vtab->Downsize = Downsize; - -/* Save the inherited pointers to methods that will be extended, and - replace them with pointers to the new member functions. */ - object = (AstObjectVtab *) vtab; - mapping = (AstMappingVtab *) vtab; - region = (AstRegionVtab *) vtab; - - parent_transform = mapping->Transform; - mapping->Transform = Transform; - - parent_simplify = mapping->Simplify; - mapping->Simplify = Simplify; - - parent_setregfs = region->SetRegFS; - region->SetRegFS = SetRegFS; - - parent_resetcache = region->ResetCache; - region->ResetCache = ResetCache; - - parent_clearattrib = object->ClearAttrib; - object->ClearAttrib = ClearAttrib; - parent_getattrib = object->GetAttrib; - object->GetAttrib = GetAttrib; - parent_setattrib = object->SetAttrib; - object->SetAttrib = SetAttrib; - parent_testattrib = object->TestAttrib; - object->TestAttrib = TestAttrib; - - region->RegPins = RegPins; - region->RegBaseMesh = RegBaseMesh; - region->RegBaseBox = RegBaseBox; - region->RegTrace = RegTrace; - region->GetBounded = GetBounded; - - vtab->ClearSimpVertices = ClearSimpVertices; - vtab->GetSimpVertices = GetSimpVertices; - vtab->SetSimpVertices = SetSimpVertices; - vtab->TestSimpVertices = TestSimpVertices; - -/* Store replacement pointers for methods which will be over-ridden by - new member functions implemented here. */ - -/* Declare the copy constructor, destructor and class dump - functions. */ - astSetDump( vtab, Dump, "Polygon", "Polygonal region" ); - astSetDelete( vtab, Delete ); - astSetCopy( vtab, Copy ); - -/* If we have just initialised the vtab for the current class, indicate - that the vtab is now initialised, and store a pointer to the class - identifier in the base "object" level of the vtab. */ - if( vtab == &class_vtab ) { - class_init = 1; - astSetVtabClassIdentifier( vtab, &(vtab->id) ); - } -} - -static int IntCmp( const void *a, const void *b ){ -/* -* Name: -* IntCmp - -* Purpose: -* An integer comparison function for the "qsort" function. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* int IntCmp( const void *a, const void *b ) - -* Class Membership: -* Polygon member function - -* Description: -* See the docs for "qsort". - -* Parameters: -* a -* Pointer to the first int -* b -* Pointer to the second int - -* Returnd Value: -* Positive, negative or zero, depending on whether a is larger than, -* equal to, or less than b. - -*/ - - return *((int*)a) - *((int*)b); -} - -static Segment *NewSegment( Segment *seg, int i1, int i2, int nvert, - int *status ){ -/* -* Name: -* NewSegment - -* Purpose: -* Initialise a structure describing a segment of the new Polygon -* created by astDownsize. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* Segment *NewSegment( Segment *seg, int i1, int i2, int nvert, -* int *status ) - -* Class Membership: -* Polygon member function - -* Description: -* This function initialises the contents of a structure describing -* the specified range of vertices within a Polygon. The cyclic nature -* of vertex indices is taken into account. -* -* If no structure is supplied, memory is allocated to hold a new -* structure. - -* Parameters: -* seg -* Pointer to a structure to initialise, or NULL if a new structure -* is to be allocated. -* i1 -* The index of a vertex within the old Polygon (supplied to -* astDownsize) that marks the start of the new line segment in -* the downsized polygon. -* i2 -* The index of a vertex within the old Polygon (supplied to -* astDownsize) that marks the end of the new line segment in -* the downsized polygon. -* nvert -* Total number of vertics in the old Polygon.. -* status -* Pointer to the inherited status variable. - -* Returnd Value: -* Pointer to the initialised Segment structure. It should be freed using -* astFree when no longer needed. - -*/ - -/* Local Variables: */ - Segment *result; - -/* Check the global error status. */ - if ( !astOK ) return NULL; - -/* Get a pointer to the structure to be initialised, allocating memory - for a new structure if none was supplied. */ - result = seg ? seg : astMalloc( sizeof( Segment ) ); - -/* Check the pointer can be used safely. */ - if( result ) { - -/* If the supplied ending index is less than the starting index, the - ending index must have gone all the way round the polygon and started - round again. Increase the ending index by the number of vertices to - put it in the same cycle as the starting index. */ - if( i2 < i1 ) i2 += nvert; - -/* If the supplied starting index is within the first cycle (i.e. zero -> - nvert-1 ), use the indices as they are (which may mean that the ending - index is greater than nvert, but this is handled correctly by other - functions). */ - if( i1 < nvert ) { - result->i1 = i1; - result->i2 = i2; - -/* If the supplied starting index is within the second cycle (i.e. nvert - or greater) the ending index will be even greater, so we can reduce - both by "nvert" to put them both in the first cycle. The goal is that - the starting index should always be in the first cycle, but the ending - index may possibly be in the second cycle. */ - } else { - result->i1 = i1 - nvert; - result->i2 = i2 - nvert; - } - -/* Nullify the links to other Segments */ - result->next = NULL; - result->prev = NULL; - } - -/* Return the pointer to the new Segment structure. */ - return result; -} - -/* -*++ -* Name: -c astOutline<X> -f AST_OUTLINE<X> - -* Purpose: -* Create a new Polygon outling values in a 2D data grid. - -* Type: -* Public function. - -* Synopsis: -c #include "polygon.h" -c AstPolygon *astOutline<X>( <Xtype> value, int oper, const <Xtype> array[], -c const int lbnd[2], const int ubnd[2], double maxerr, -c int maxvert, const int inside[2], int starpix ) -f RESULT = AST_OUTLINE<X>( VALUE, OPER, ARRAY, LBND, UBND, MAXERR, -f MAXVERT, INSIDE, STARPIX, STATUS ) - -* Class Membership: -* Polygon method. - -* Description: -* This is a set of functions that create a Polygon enclosing a single -* contiguous set of pixels that have a specified value within a gridded -* 2-dimensional data array (e.g. an image). -* -* A basic 2-dimensional Frame is used to represent the pixel coordinate -* system in the returned Polygon. The Domain attribute is set to -* "PIXEL", the Title attribute is set to "Pixel coordinates", and the -* Unit attribute for each axis is set to "pixel". All other -* attributes are left unset. The nature of the pixel coordinate system -* is determined by parameter -c "starpix". -f STARPIX. -* -* The -c "maxerr" and "maxvert" -f MAXERR and MAXVERT -* parameters can be used to control how accurately the returned -* Polygon represents the required region in the data array. The -* number of vertices in the returned Polygon will be the minimum -* needed to achieve the required accuracy. -* -* You should use a function which matches the numerical type of the -* data you are processing by replacing <X> in the generic function -* name -c astOutline<X> -f AST_OUTLINE<X> -c by an appropriate 1- or 2-character type code. For example, if you -* are procesing data with type -c "float", you should use the function astOutlineF -f REAL, you should use the function AST_OUTLINER -* (see the "Data Type Codes" section below for the codes appropriate to -* other numerical types). - -* Parameters: -c value -f VALUE = <Xtype> (Given) -* A data value that specifies the pixels to be outlined. -c oper -f OPER = INTEGER (Given) -* Indicates how the -c "value" -f VALUE -* parameter is used to select the outlined pixels. It can -* have any of the following values: -c - AST__LT: outline pixels with value less than "value". -c - AST__LE: outline pixels with value less than or equal to "value". -c - AST__EQ: outline pixels with value equal to "value". -c - AST__NE: outline pixels with value not equal to "value". -c - AST__GE: outline pixels with value greater than or equal to "value". -c - AST__GT: outline pixels with value greater than "value". -f - AST__LT: outline pixels with value less than VALUE. -f - AST__LE: outline pixels with value less than or equal to VALUE. -f - AST__EQ: outline pixels with value equal to VALUE. -f - AST__NE: outline pixels with value not equal to VALUE. -f - AST__GE: outline pixels with value greater than or equal to VALUE. -f - AST__GT: outline pixels with value greater than VALUE. -c array -f ARRAY( * ) = <Xtype> (Given) -c Pointer to a -f A -* 2-dimensional array containing the data to be processed. The -* numerical type of this array should match the 1- or -* 2-character type code appended to the function name (e.g. if -c you are using astOutlineF, the type of each array element -c should be "float"). -f you are using AST_OUTLINER, the type of each array element -f should be REAL). -* -* The storage order of data within this array should be such -* that the index of the first grid dimension varies most -* rapidly and that of the second dimension least rapidly -c (i.e. Fortran array indexing is used). -f (i.e. normal Fortran array storage order). -c lbnd -f LBND( 2 ) = INTEGER (Given) -c Pointer to an array of two integers -f An array -* containing the pixel index of the first pixel in the input grid -* along each dimension. -c ubnd -f UBND( 2) = INTEGER (Given) -c Pointer to an array of two integers -f An array -* containing the pixel index of the last pixel in the input grid -* along each dimension. -* -c Note that "lbnd" and "ubnd" together define the shape -f Note that LBND and UBND together define the shape -* and size of the input pixel grid, its extent along a particular -c (j'th) dimension being ubnd[j]-lbnd[j]+1 pixels. -f (J'th) dimension being UBND(J)-LBND(J)+1 pixels. -* For FITS images, -c the lbnd values will be 1 and the ubnd -f the LBND values will be 1 and the UBND -* values will be equal to the NAXISi header values. Other -* data systems, such as the Starlink NDF system, allow an -c arbitrary pixel origin to be used (i.e. lbnd -f arbitrary pixel origin to be used (i.e. LBND -* is not necessarily 1). -* -* These bounds also define the input grid's floating point coordinate -* system, each pixel having unit extent along each dimension with -* integral coordinate values at its centre or upper corner, as selected -* by parameter -c "starpix". -f STARPIX. -c maxerr -f MAXERR = DOUBLE PRECISION (Given) -* Together with -c "maxvert", -f MAXVERT, -* this determines how accurately the returned Polygon represents -* the required region of the data array. It gives the target -* discrepancy between the returned Polygon and the accurate outline -* in the data array, expressed as a number of pixels. Insignificant -* vertices are removed from the accurate outline, one by one, until -* the number of vertices remaining in the returned Polygon equals -c "maxvert", -f MAXVERT, -* or the largest discrepancy between the accurate outline and the -* returned Polygon is greater than -c "maxerr". If "maxerr" -f MAXERR. If MAXERR -* is zero or less, its value is ignored and the returned Polygon will -* have the number of vertices specified by -c "maxvert". -f MAXVERT. -c maxvert -f MAXVERT = INTEGER (Given) -* Together with -c "maxerr", -f MAXERR, -* this determines how accurately the returned Polygon represents -* the required region of the data array. It gives the maximum -* allowed number of vertices in the returned Polygon. Insignificant -* vertices are removed from the accurate outline, one by one, until -* the number of vertices remaining in the returned Polygon equals -c "maxvert", -f MAXVERT, -* or the largest discrepancy between the accurate outline and the -* returned Polygon is greater than -c "maxerr". If "maxvert" -f MAXERR. If MAXVERT -* is less than 3, its value is ignored and the number of vertices in -* the returned Polygon will be the minimum needed to ensure that the -* discrepancy between the accurate outline and the returned -* Polygon is less than -c "maxerr". -f MAXERR. -c inside -f INSIDE( 2 ) = INTEGER (Given) -c Pointer to an array of two integers -f An array -* containing the pixel indices of a pixel known to be inside the -* required region. This is needed because the supplied data -* array may contain several disjoint areas of pixels that satisfy -* the criterion specified by -c "value" and "oper". -f VALUE and OPER. -* In such cases, the area described by the returned Polygon will -* be the one that contains the pixel specified by -c "inside". -f INSIDE. -* If the specified pixel is outside the bounds given by -c "lbnd" and "ubnd", -f LBND and UBND, -* or has a value that does not meet the criterion specified by -c "value" and "oper", -f VALUE and OPER, -* then this function will search for a suitable pixel. The search -* starts at the central pixel and proceeds in a spiral manner until -* a pixel is found that meets the specified crierion. -c starpix -f STARPIX = LOGICAL (Given) -* A flag indicating the nature of the pixel coordinate system used -* to describe the vertex positions in the returned Polygon. If -c non-zero, -f .TRUE., -* the standard Starlink definition of pixel coordinate is used in -* which a pixel with integer index I spans a range of pixel coordinate -* from (I-1) to I (i.e. pixel corners have integral pixel coordinates). -c If zero, -f If .FALSE., -* the definition of pixel coordinate used by other AST functions -c such as astResample, astMask, -f such as AST_RESAMPLE, AST_MASK, -* etc., is used. In this definition, a pixel with integer index I -* spans a range of pixel coordinate from (I-0.5) to (I+0.5) (i.e. -* pixel centres have integral pixel coordinates). -f STATUS = INTEGER (Given and Returned) -f The global status. - -* Returned Value: -c astOutline<X>() -f AST_OUTLINE<X> = INTEGER -* A pointer to the required Polygon. - -* Notes: -* - This function proceeds by first finding a very accurate polygon, -* and then removing insignificant vertices from this fine polygon -* using -c astDownsize. -f AST_DOWNSIZE. -* - The returned Polygon is the outer boundary of the contiguous set -* of pixels that includes ths specified "inside" point, and satisfy -* the specified value requirement. This set of pixels may potentially -* include "holes" where the pixel values fail to meet the specified -* value requirement. Such holes will be ignored by this function. -c - NULL -f - AST__NULL -* will be returned if this function is invoked with the global -* error status set, or if it should fail for any reason. - -* Data Type Codes: -* To select the appropriate masking function, you should -c replace <X> in the generic function name astOutline<X> with a -f replace <X> in the generic function name AST_OUTLINE<X> with a -* 1- or 2-character data type code, so as to match the numerical -* type <Xtype> of the data you are processing, as follows: -c - D: double -c - F: float -c - L: long int -c - UL: unsigned long int -c - I: int -c - UI: unsigned int -c - S: short int -c - US: unsigned short int -c - B: byte (signed char) -c - UB: unsigned byte (unsigned char) -f - D: DOUBLE PRECISION -f - R: REAL -f - I: INTEGER -f - UI: INTEGER (treated as unsigned) -f - S: INTEGER*2 (short integer) -f - US: INTEGER*2 (short integer, treated as unsigned) -f - B: BYTE (treated as signed) -f - UB: BYTE (treated as unsigned) -* -c For example, astOutlineD would be used to process "double" -c data, while astOutlineS would be used to process "short int" -c data, etc. -f For example, AST_OUTLINED would be used to process DOUBLE -f PRECISION data, while AST_OUTLINES would be used to process -f short integer data (stored in an INTEGER*2 array), etc. -f -f For compatibility with other Starlink facilities, the codes W -f and UW are provided as synonyms for S and US respectively (but -f only in the Fortran interface to AST). - -*-- -*/ -/* Define a macro to implement the function for a specific data - type. Note, this function cannot be a virtual function since the - argument list does not include a Polygon, and so no virtual function - table is available. */ -#define MAKE_OUTLINE(X,Xtype) \ -AstPolygon *astOutline##X##_( Xtype value, int oper, const Xtype array[], \ - const int lbnd[2], const int ubnd[2], double maxerr, \ - int maxvert, const int inside[2], int starpix, \ - int *status ) { \ -\ -/* Local Variables: */ \ - AstFrame *frm; /* Frame in which to define the Polygon */ \ - AstPointSet *candidate; /* Candidate polygon vertices */ \ - AstPointSet *pset; /* PointSet holding downsized polygon vertices */ \ - AstPolygon *result; /* Result value to return */ \ - const Xtype *pv; /* Pointer to next test point */ \ - Xtype v; /* Value of current pixel */ \ - double **ptr; /* Pointers to PointSet arrays */ \ - int boxsize; /* Half width of smoothign box in vertices */ \ - int inx; /* X index of inside point */ \ - int iny; /* Y index of inside point */ \ - int iv; /* Vector index of next test pixel */ \ - int ixv; /* X pixel index of next test point */ \ - int nv0; /* Number of vertices in accurate outline */ \ - int nx; /* Length of array x axis */ \ - int smooth; /* Do we need to smooth the polygon? */ \ - int stop_at_invalid; /* Indicates when to stop rightwards search */ \ - int tmp; /* Alternative boxsize */ \ - int valid; /* Does current pixel meet requirements? */ \ - static double junk[ 6 ] = {0.0, 0.0, 1.0, 1.0, 0.0, 1.0 }; /* Junk poly */ \ -\ -/* Initialise. */ \ - result = NULL; \ -\ -/* Check the global error status. */ \ - if ( !astOK ) return result; \ -\ -/* Avoid compiler warnings. */ \ - iv = 0; \ -\ -/* If we are going to be smoothing the polygon before downsizing it, we \ - need to ensure that the full polygon is retained within TraceEdge. if \ - this is not the case, TraceEdge can remove all vertices from straight \ - lines, except for the vertices that mark the beinning and end of the \ - straight line. */ \ - smooth = ( maxerr > 0.0 || maxvert > 2 ); \ -\ -/* Store the X dimension of the array. */ \ - nx = ubnd[ 0 ] - lbnd[ 0 ] + 1; \ -\ -/* See if a valid inside point was supplied. It must be inside the bounds \ - of the array, and must have a pixel value that meets the specified \ - requirement. */ \ - inx = inside[ 0 ]; \ - iny = inside[ 1 ]; \ - valid = ( inx >= lbnd[ 0 ] && inx <= ubnd[ 0 ] && \ - iny >= lbnd[ 1 ] && iny <= ubnd[ 1 ] ); \ -\ - if( valid ) { \ - iv = ( inx - lbnd[ 0 ] ) + (iny - lbnd[ 1 ] )*nx; \ - v = array[ iv ]; \ -\ - if( oper == AST__LT ) { \ - valid = ( v < value ); \ -\ - } else if( oper == AST__LE ) { \ - valid = ( v <= value ); \ -\ - } else if( oper == AST__EQ ) { \ - valid = ( v == value ); \ -\ - } else if( oper == AST__NE ) { \ - valid = ( v != value ); \ -\ - } else if( oper == AST__GE ) { \ - valid = ( v >= value ); \ -\ - } else if( oper == AST__GT ) { \ - valid = ( v > value ); \ -\ - } else if( astOK ){ \ - astError( AST__OPRIN, "astOutline"#X": Invalid operation code " \ - "(%d) supplied (programming error).", status, oper ); \ - } \ - } \ -\ -/* If no valid inside point was supplied, find one now. */ \ - if( !valid ) { \ -\ - if( oper == AST__LT ) { \ - FindInsidePointLT##X( value, array, lbnd, ubnd, &inx, &iny, &iv, status ); \ -\ - } else if( oper == AST__LE ) { \ - FindInsidePointLE##X( value, array, lbnd, ubnd, &inx, &iny, &iv, status ); \ -\ - } else if( oper == AST__EQ ) { \ - FindInsidePointEQ##X( value, array, lbnd, ubnd, &inx, &iny, &iv, status ); \ -\ - } else if( oper == AST__NE ) { \ - FindInsidePointNE##X( value, array, lbnd, ubnd, &inx, &iny, &iv, status ); \ -\ - } else if( oper == AST__GE ) { \ - FindInsidePointGE##X( value, array, lbnd, ubnd, &inx, &iny, &iv, status ); \ -\ - } else if( oper == AST__GT ) { \ - FindInsidePointGT##X( value, array, lbnd, ubnd, &inx, &iny, &iv, status ); \ -\ - } else if( astOK ){ \ - astError( AST__OPRIN, "astOutline"#X": Invalid operation code " \ - "(%d) supplied (programming error).", status, oper ); \ - } \ - } \ -\ -/* We now need to find a point on the boundary of the region containing \ - the inside point. Starting at the inside point, move to the right \ - through the array until a pixel is found which fails to meet the value \ - requirement or the edge of the array is reached. */ \ -\ - candidate = NULL; \ - pv = array + iv; \ - ixv = inx; \ - stop_at_invalid = 1; \ -\ - while( ++ixv <= ubnd[ 0 ] ) { \ -\ -/* Get the next pixel value. */ \ - v = *(++pv); \ -\ -/* See if it meets the value requirement. */ \ - if( oper == AST__LT ) { \ - valid = ( v < value ); \ -\ - } else if( oper == AST__LE ) { \ - valid = ( v <= value ); \ -\ - } else if( oper == AST__EQ ) { \ - valid = ( v == value ); \ -\ - } else if( oper == AST__NE ) { \ - valid = ( v != value ); \ -\ - } else if( oper == AST__GE ) { \ - valid = ( v >= value ); \ -\ - } else if( oper == AST__GT ) { \ - valid = ( v > value ); \ -\ - } else if( astOK ){ \ - astError( AST__OPRIN, "astOutline"#X": Invalid operation code " \ - "(%d) supplied (programming error).", status, oper ); \ - break; \ - } \ -\ -/* If we are currently looking for the next invalid pixel, and this pixel \ - is invalid... */ \ - if( stop_at_invalid ) { \ - if( ! valid ) { \ -\ -/* The current pixel may be on the required polygon, or it may be on the \ - edge of a hole contained within the region being outlined. We would \ - like to jump over such holes so that we can continue to look for the \ - real edge of the region being outlined. In order to determine if we \ - have reached a hole, we trace the edge that passes through the current \ - pixel, forming a candidate polygon in the process. In the process, We \ - see if the inside point falls within this candidate polygon. If it does \ - then the polygon is accepted as the required polygon. Otherwise, it is \ - rejected as a mere hole, and we continue moving away from the inside \ - point, looking for a new edge. */ \ - if( oper == AST__LT ) { \ - candidate = TraceEdgeLT##X( value, array, lbnd, ubnd, iv - 1, \ - ixv - 1, iny, starpix, smooth, status ); \ -\ - } else if( oper == AST__LE ) { \ - candidate = TraceEdgeLE##X( value, array, lbnd, ubnd, iv - 1, \ - ixv - 1, iny, starpix, smooth, status ); \ -\ - } else if( oper == AST__EQ ) { \ - candidate = TraceEdgeEQ##X( value, array, lbnd, ubnd, iv - 1, \ - ixv - 1, iny, starpix, smooth, status ); \ -\ - } else if( oper == AST__NE ) { \ - candidate = TraceEdgeNE##X( value, array, lbnd, ubnd, iv - 1, \ - ixv - 1, iny, starpix, smooth, status ); \ -\ - } else if( oper == AST__GE ) { \ - candidate = TraceEdgeGE##X( value, array, lbnd, ubnd, iv - 1, \ - ixv - 1, iny, starpix, smooth, status ); \ -\ - } else if( oper == AST__GT ) { \ - candidate = TraceEdgeGT##X( value, array, lbnd, ubnd, iv - 1, \ - ixv - 1, iny, starpix, smooth, status ); \ -\ - } else if( astOK ){ \ - astError( AST__OPRIN, "astOutline"#X": Invalid operation code " \ - "(%d) supplied (programming error).", status, oper ); \ - } \ -\ -/* If the candidate polygon is the required polygon, break out of the \ - loop. Otherwise, indicate that we want to continue moving right, \ - across the hole, until we reach the far side of the hole (i.e. find \ - the next valid pixel). */ \ - if( candidate ) { \ - break; \ - } else { \ - stop_at_invalid = 0; \ - } \ - } \ -\ -/* If we are currently looking for the next valid pixel, and the current \ - pixel is valid... */ \ - } else if( valid ) { \ -\ -/* We have reached the far side of a hole. Continue moving right, looking \ - now for the next invalid pixel (which may be on the required polygon). */ \ - stop_at_invalid = 1; \ - } \ - } \ -\ -/* If we have not yet found the required polygon, we must have reached \ - the right hand edge of the array. So we now follow the edge of the \ - array round until we meet the boundary of the required region. */ \ - if( !candidate ) { \ - if( oper == AST__LT ) { \ - candidate = TraceEdgeLT##X( value, array, lbnd, ubnd, iv - 1, \ - ixv - 1, iny, starpix, smooth, status ); \ -\ - } else if( oper == AST__LE ) { \ - candidate = TraceEdgeLE##X( value, array, lbnd, ubnd, iv - 1, \ - ixv - 1, iny, starpix, smooth, status ); \ -\ - } else if( oper == AST__EQ ) { \ - candidate = TraceEdgeEQ##X( value, array, lbnd, ubnd, iv - 1, \ - ixv - 1, iny, starpix, smooth, status ); \ -\ - } else if( oper == AST__NE ) { \ - candidate = TraceEdgeNE##X( value, array, lbnd, ubnd, iv - 1, \ - ixv - 1, iny, starpix, smooth, status ); \ -\ - } else if( oper == AST__GE ) { \ - candidate = TraceEdgeGE##X( value, array, lbnd, ubnd, iv - 1, \ - ixv - 1, iny, starpix, smooth, status ); \ -\ - } else if( oper == AST__GT ) { \ - candidate = TraceEdgeGT##X( value, array, lbnd, ubnd, iv - 1, \ - ixv - 1, iny, starpix, smooth, status ); \ -\ - } else if( astOK ){ \ - astError( AST__OPRIN, "astOutline"#X": Invalid operation code " \ - "(%d) supplied (programming error).", status, oper ); \ - } \ - } \ -\ -/* If required smooth the full resolution polygon before downsizing it. */ \ - if( smooth ) { \ -\ -/* Initially, set the boxsize to be equal to the required accouracy. */ \ - if( maxerr > 0 ) { \ - boxsize = (int) maxerr; \ - } else { \ - boxsize = INT_MAX; \ - } \ -\ -/* Determine a second box size equal to the average number of vertices in \ - the accurate outline, per vertex in the returned Polygon. */ \ - nv0 = astGetNpoint( candidate ); \ - if( maxvert > 2 ) { \ - tmp = nv0/(2*maxvert); \ - } else { \ - tmp = INT_MAX; \ - } \ -\ -/* Use the minimum of the two box sizes. */ \ - if( tmp < boxsize ) boxsize = tmp; \ -\ -/* Ensure the box is sufficiently small to allow at least 10 full boxes \ - (=20 half boxes) around the polygon. */ \ - tmp = nv0/20; \ - if( tmp < boxsize ) boxsize = tmp; \ - if( boxsize == 0 ) boxsize = 1; \ -\ -/* Smooth the polygon. */ \ - SmoothPoly( candidate, boxsize, 1.0, status ); \ - } \ -\ -/* Reduce the number of vertices in the outline. */ \ - frm = astFrame( 2, "Domain=PIXEL,Unit(1)=pixel,Unit(2)=pixel," \ - "Title=Pixel coordinates", status ); \ - pset = DownsizePoly( candidate, maxerr, maxvert, frm, status ); \ -\ -/* Create a default Polygon with 3 junk vertices. */ \ - result = astPolygon( frm, 3, 3, junk, NULL, " ", status ); \ -\ -/* Change the PointSet within the Polygon to the one created above. */ \ - SetPointSet( result, pset, status ); \ -\ -/* Free resources. Note, we need to free the arrays within the candidate \ - PointSet explicitly, since they were not created as part of the \ - construction of the PointSet (see TraceEdge). */ \ - pset = astAnnul( pset ); \ - frm = astAnnul( frm ); \ - ptr = astGetPoints( candidate ); \ - if( astOK ) { \ - astFree( ptr[ 0 ] ); \ - astFree( ptr[ 1 ] ); \ - } \ - candidate = astAnnul( candidate ); \ -\ -/* If an error occurred, clear the returned result. */ \ - if ( !astOK ) result = astAnnul( result ); \ -\ -/* Return the result. */ \ - return result; \ -} - - -/* Expand the above macro to generate a function for each required - data type. */ -#if HAVE_LONG_DOUBLE /* Not normally implemented */ -MAKE_OUTLINE(LD,long double) -#endif -MAKE_OUTLINE(D,double) -MAKE_OUTLINE(L,long int) -MAKE_OUTLINE(UL,unsigned long int) -MAKE_OUTLINE(I,int) -MAKE_OUTLINE(UI,unsigned int) -MAKE_OUTLINE(S,short int) -MAKE_OUTLINE(US,unsigned short int) -MAKE_OUTLINE(B,signed char) -MAKE_OUTLINE(UB,unsigned char) -MAKE_OUTLINE(F,float) - -/* Undefine the macros. */ -#undef MAKE_OUTLINE - -/* -* Name: -* PartHull - -* Purpose: -* Find the convex hull enclosing selected pixels in one corner of a 2D array. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* void PartHull<Oper><X>( <Xtype> value, const <Xtype> array[], int xdim, -* int ydim, int xs, int ys, int xe, int ye, -* int starpix, const int lbnd[2], double **xvert, -* double **yvert, int *nvert, int *status ) - -* Class Membership: -* Polygon member function - -* Description: -* This function uses an algorithm similar to "Andrew's Monotone Chain -* Algorithm" to create a list of vertices describing one corner of the -* convex hull enclosing the selected pixels in the supplied array. -* The corner is defined to be the area of the array to the right of -* the line from (xs,ys) to (xe,ye). - -* Parameters: -* value -* A data value that specifies the pixels to be selected. -* array -* Pointer to a 2-dimensional array containing the data to be -* processed. The numerical type of this array should match the 1- -* or 2-character type code appended to the function name. -* xdim -* The number of pixels along each row of the array. -* ydim -* The number of rows in the array. -* xs -* The X GRID index of the first pixel on the line to be checked. -* ys -* The Y GRID index of the first pixel on the line to be checked. -* xe -* The X GRID index of the last pixel on the line to be checked. -* ye -* The Y GRID index of the last pixel on the line to be checked. -* starpix -* If non-zero, the usual Starlink definition of pixel coordinate -* is used (integral values at pixel corners). Otherwise, the -* system used by other AST functions such as astResample is used -* (integral values at pixel centres). -* lbnd -* The lower pixel index bounds of the array. -* xvert -* Address of a pointer in which to return a pointer to the list -* of GRID x values on the hull. -* yvert -* Address of a pointer in which to return a pointer to the list -* of GRID y values on the hull. -* nvert -* Address of a pointer in which to return the number of points in -* the returned xvert and yvert arrays. -* status -* Pointer to the inherited status variable. - -*/ - -/* Define a macro to implement the function for a specific data - type and operation. */ -#define MAKE_PARTHULL(X,Xtype,Oper,OperI) \ -static void PartHull##Oper##X( Xtype value, const Xtype array[], int xdim, \ - int ydim, int xs, int ys, int xe, int ye, \ - int starpix, const int lbnd[2], \ - double **xvert, double **yvert, int *nvert, \ - int *status ) { \ -\ -/* Local Variables: */ \ - const Xtype *pc; \ - double *pxy; \ - double dx2; \ - double dx1; \ - double dy1; \ - double dy2; \ - double off; \ - double xdelta; \ - int ivert; \ - int ix; \ - int iy; \ - int x0; \ - int x1; \ - int xl; \ - int xlim; \ - int xr; \ - int yinc; \ -\ -/* Initialise */ \ - *yvert = NULL; \ - *xvert = NULL; \ - *nvert = 0; \ -\ -/* Check the global error status. */ \ - if ( !astOK ) return; \ -\ -/* If the line has zero length. just return a single vertex. */ \ - if( xs == xe && ys == ye ) { \ - *xvert = astMalloc( sizeof( double ) ); \ - *yvert = astMalloc( sizeof( double ) ); \ - if( astOK ) { \ - if( starpix ) { \ - (*xvert)[ 0 ] = xs + lbnd[ 0 ] - 1.5; \ - (*yvert)[ 0 ] = ys + lbnd[ 1 ] - 1.5; \ - } else { \ - (*xvert)[ 0 ] = xs + lbnd[ 0 ] - 1.0; \ - (*yvert)[ 0 ] = ys + lbnd[ 1 ] - 1.0; \ - } \ - *nvert = 1; \ - } \ - return; \ - } \ -\ -/* Otherwise check the line is sloping. */ \ - if( xs == xe ) { \ - astError( AST__INTER, "astOutline(Polygon): Bounding box " \ - "has zero width (internal AST programming error).", \ - status ); \ - return; \ - } else if( ys == ye ) { \ - astError( AST__INTER, "astOutline(Polygon): Bounding box " \ - "has zero height (internal AST programming error).", \ - status ); \ - return; \ - } \ -\ -/* Calculate the difference in length between adjacent rows of the area \ - to be tested. */ \ - xdelta = ((double)( xe - xs ))/((double)( ye - ys )); \ -\ -/* The left and right X limits */ \ - if( xe > xs ) { \ - xl = xs; \ - xr = xe; \ - } else { \ - xl = xe; \ - xr = xs; \ - } \ -\ -/* Get the increment in row number as we move from the start to the end \ - of the line. */ \ - yinc = ( ye > ys ) ? 1 : -1; \ -\ -/* Loop round all rows that cross the region to be tested, from start to \ - end of the supplied line. */ \ - iy = ys; \ - while( astOK ) { \ -\ -/* Get the GRID X coord where the line crosses this row. */ \ - xlim = (int)( 0.5 + xs + xdelta*( iy - ys ) ); \ -\ -/* Get the index of the first and last columns to be tested on this row. */ \ - if( yinc < 0 ) { \ - x0 = xl; \ - x1 = xlim; \ - } else { \ - x0 = xlim; \ - x1 = xr; \ - } \ -\ -/* Get a pointer to the first pixel to be tested at this row. */ \ - pc = array + ( iy - 1 )*xdim + x0 - 1; \ -\ -/* Loop round all columns to be tested in this row. */ \ - for( ix = x0; ix <= x1 && astOK; ix++,pc++ ) { \ -\ -/* Ignore pixels that are not selected. */ \ - if( ISVALID(*pc,OperI,value) ) { \ -\ -/* If this is the very first pixel, initialise the hull to contain just \ - the first pixel. */ \ - if( *nvert == 0 ){ \ - *xvert = astMalloc( 200*sizeof( double ) ); \ - *yvert = astMalloc( 200*sizeof( double ) ); \ - if( astOK ) { \ - (*xvert)[ 0 ] = ix; \ - (*yvert)[ 0 ] = iy; \ - *nvert = 1; \ - } else { \ - break; \ - } \ -\ -/* Otherwise.... */ \ - } else { \ -\ -/* Loop until the hull has been corrected to include the current pixel. */ \ - while( 1 ) { \ -\ -/* If the hull currently contains only one pixel, add the current pixel to \ - the end of the hull. */ \ - if( *nvert == 1 ){ \ - (*xvert)[ 1 ] = ix; \ - (*yvert)[ 1 ] = iy; \ - *nvert = 2; \ - break; \ -\ -/* Otherwise... */ \ - } else { \ -\ -/* Extend the line from the last-but-one pixel on the hull to the last \ - pixel on the hull, and see if the current pixel is to the left of \ - this line. If it is, it too is on the hull and so push it onto the end \ - of the list of vertices. */ \ - dx1 = (*xvert)[ *nvert - 1 ] - (*xvert)[ *nvert - 2 ]; \ - dy1 = (*yvert)[ *nvert - 1 ] - (*yvert)[ *nvert - 2 ]; \ - dx2 = ix - (*xvert)[ *nvert - 2 ]; \ - dy2 = iy - (*yvert)[ *nvert - 2 ]; \ -\ - if( dx1*dy2 > dx2*dy1 ) { \ - ivert = (*nvert)++; \ - *xvert = astGrow( *xvert, *nvert, sizeof( double ) ); \ - *yvert = astGrow( *yvert, *nvert, sizeof( double ) ); \ - if( astOK ) { \ - (*xvert)[ ivert ] = ix; \ - (*yvert)[ ivert ] = iy; \ - } \ -\ -/* Leave the loop now that the new point is on the hull. */ \ - break; \ -\ -/* If the new point is to the left of the line, then the last point \ - previously thought to be on hull is in fact not on the hull, so remove \ - it. We then loop again to compare the new pixel with modified hull. */ \ - } else { \ - (*nvert)--; \ - } \ - } \ - } \ - } \ - } \ - } \ -\ - if( iy == ye ) { \ - break; \ - } else { \ - iy += yinc; \ - } \ -\ - } \ -\ -/* Convert GRID coords to PIXEL coords. */ \ - if( astOK ) { \ - pxy = *xvert; \ - off = starpix ? lbnd[ 0 ] - 1.5 : lbnd[ 0 ] - 1.0; \ - for( ivert = 0; ivert < *nvert; ivert++ ) *(pxy++) += off; \ -\ - pxy = *yvert; \ - off = starpix ? lbnd[ 1 ] - 1.5 : lbnd[ 1 ] - 1.0; \ - for( ivert = 0; ivert < *nvert; ivert++ ) *(pxy++) += off; \ -\ -/* Free lists if an error has occurred. */ \ - } else { \ - *xvert = astFree( *xvert ); \ - *yvert = astFree( *yvert ); \ - *nvert = 0; \ - } \ -} - -/* Define a macro that uses the above macro to to create implementations - of PartHull for all operations. */ -#define MAKEALL_PARTHULL(X,Xtype) \ -MAKE_PARTHULL(X,Xtype,LT,AST__LT) \ -MAKE_PARTHULL(X,Xtype,LE,AST__LE) \ -MAKE_PARTHULL(X,Xtype,EQ,AST__EQ) \ -MAKE_PARTHULL(X,Xtype,NE,AST__NE) \ -MAKE_PARTHULL(X,Xtype,GE,AST__GE) \ -MAKE_PARTHULL(X,Xtype,GT,AST__GT) - -/* Expand the above macro to generate a function for each required - data type and operation. */ -#if HAVE_LONG_DOUBLE /* Not normally implemented */ -MAKEALL_PARTHULL(LD,long double) -#endif -MAKEALL_PARTHULL(D,double) -MAKEALL_PARTHULL(L,long int) -MAKEALL_PARTHULL(UL,unsigned long int) -MAKEALL_PARTHULL(I,int) -MAKEALL_PARTHULL(UI,unsigned int) -MAKEALL_PARTHULL(S,short int) -MAKEALL_PARTHULL(US,unsigned short int) -MAKEALL_PARTHULL(B,signed char) -MAKEALL_PARTHULL(UB,unsigned char) -MAKEALL_PARTHULL(F,float) - -/* Undefine the macros. */ -#undef MAKE_PARTHULL -#undef MAKEALL_PARTHULL - -static double Polywidth( AstFrame *frm, AstLineDef **edges, int i, int nv, - double cen[ 2 ], int *status ){ -/* -* Name: -* Polywidth - -* Purpose: -* Find the width of a polygon perpendicular to a given edge. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* double Polywidth( AstFrame *frm, AstLineDef **edges, int i, int nv, -* double cen[ 2 ], int *status ) - -* Class Membership: -* Polygon member function - -* Description: -* This function defines a line perpendicular to a given polygon edge, -* passing through the mid point of the edge, extending towards the -* inside of the polygon. It returns the distance that can be travelled -* along this line before any of the other polygon edges are hit (the -* "width" of the polygon perpendicular to the given edge). It also -* puts the position corresponding to half that distance into "cen". - -* Parameters: -* frm -* The Frame in which the lines are defined. -* edges -* Array of "nv" pointers to AstLineDef structures, each defining an -* edge of the polygon. -* i -* The index of the edge that is to define the polygon width. -* nv -* Total number of edges. -* cen -* An array into which are put the coords of the point half way -* along the polygon width line. -* status -* Pointer to the inherited status variable. - -* Returnd Value: -* The width of the polygon perpendicular to the given edge, or -* AST__BAD if the width cannot be determined (usually because the -* vertices been supplied in a clockwise direction, effectively -* negating the Polygon). - -*/ - -/* Local Variables: */ - AstLineDef *line; - double *cross; - double d; - double end[ 2 ]; - double l1; - double l2; - double result; - double start[ 2 ]; - int j; - -/* Check the global error status. */ - result = AST__BAD; - if ( !astOK ) return result; - -/* Create a Line description for a line perpendicular to the specified - edge, passing through the mid point of the edge, and extending towards - the inside of the polygon. First move away from the start along the - line to the mid point. This gives the start of the new line. */ - l1 = 0.5*( edges[ i ]->length ); - astLineOffset( frm, edges[ i ], l1, 0.0, start ); - -/* We now move away from this position at right angles to the line. We - start off by moving 5 times the length of the specified edge. For - some Frames (e.g. SkyFrames) this may result in a position that is - much too close (i.e. if it goes all the way round the great circle - and comes back to the beginning). Therefore, we check that the end - point is the requested distance from the start point, and if not, we - halve the length of the line and try again. */ - l2 = 10.0*l1; - while( 1 ) { - astLineOffset( frm, edges[ i ], l1, l2, end ); - d = astDistance( frm, start, end ); - if( d != AST__BAD && fabs( d - l2 ) < 1.0E-6*l2 ) break; - l2 *= 0.5; - } - -/* Create a description of the required line. */ - line = astLineDef( frm, start, end ); - -/* Loop round every edge, except for the supplied edge. */ - for( j = 0; j < nv; j++ ) { - if( j != i ) { - -/* Find the position at which the line created above crosses the current - edge. Skip to the next edge if the line does not intersect the edge - within the length of the edge. */ - if( astLineCrossing( frm, line, edges[ j ], &cross ) ) { - -/* Find the distance between the crossing point and the line start. */ - d = astDistance( frm, start, cross ); - -/* If this is less than the smallest found so far, record it. */ - if( d != AST__BAD && ( d < result || result == AST__BAD ) ) { - result = d; - } - } - -/* Free resources */ - cross = astFree( cross ); - } - } - line = astFree( line ); - -/* If a width was found, return the point half way across the polygon. */ - if( result != AST__BAD ) { - astOffset( frm, start, end, 0.5*result, cen ); - -/* The usual reason for not finding a width is if the polygon vertices - are supplied in clockwise order, effectively negating the polygon, and - resulting in the "inside" of the polygon being the infinite region - outside a polygonal hole. In this case, the end point of the line - perpendicular to the initial edge can be returned as a representative - "inside" point. */ - } else { - cen[ 0 ] = end[ 0 ]; - cen[ 1 ] = end[ 1 ]; - } - -/* Return the width. */ - return result; - -} - -static void RegBaseBox( AstRegion *this_region, double *lbnd, double *ubnd, int *status ){ -/* -* Name: -* RegBaseBox - -* Purpose: -* Returns the bounding box of an un-negated Region in the base Frame of -* the encapsulated FrameSet. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* void RegBaseBox( AstRegion *this, double *lbnd, double *ubnd, int *status ) - -* Class Membership: -* Polygon member function (over-rides the astRegBaseBox protected -* method inherited from the Region class). - -* Description: -* This function returns the upper and lower axis bounds of a Region in -* the base Frame of the encapsulated FrameSet, assuming the Region -* has not been negated. That is, the value of the Negated attribute -* is ignored. - -* Parameters: -* this -* Pointer to the Region. -* lbnd -* Pointer to an array in which to return the lower axis bounds -* covered by the Region in the base Frame of the encapsulated -* FrameSet. It should have at least as many elements as there are -* axes in the base Frame. -* ubnd -* Pointer to an array in which to return the upper axis bounds -* covered by the Region in the base Frame of the encapsulated -* FrameSet. It should have at least as many elements as there are -* axes in the base Frame. -* status -* Pointer to the inherited status variable. - -*/ - -/* Local Variables: */ - AstFrame *frm; /* Pointer to encapsulated Frame */ - AstPointSet *pset; /* Pointer to PointSet defining the Region */ - AstPolygon *this; /* Pointer to Polygon structure */ - AstRegion *reg; /* Base Frame equivalent of supplied Polygon */ - double **ptr; /* Pointer to PointSet data */ - double *x; /* Pointer to next X axis value */ - double *y; /* Pointer to next Y axis value */ - double dist; /* Offset along an axis */ - double x0; /* The first X axis value */ - double y0; /* The first Y axis value */ - int ip; /* Point index */ - int np; /* No. of points in PointSet */ - -/* Check the global error status. */ - if ( !astOK ) return; - -/* Get a pointer to the Polygon structure. */ - this = (AstPolygon *) this_region; - -/* If the base Frame bounding box has already been found, return the - values stored in the Polygon structure. */ - if( this->lbnd[ 0 ] != AST__BAD ) { - lbnd[ 0 ] = this->lbnd[ 0 ]; - lbnd[ 1 ] = this->lbnd[ 1 ]; - ubnd[ 0 ] = this->ubnd[ 0 ]; - ubnd[ 1 ] = this->ubnd[ 1 ]; - -/* If the base Frame bounding box has not yet been found, find it now and - store it in the Polygon structure. */ - } else { - -/* Get the axis values for the PointSet which defines the location and - extent of the region in the base Frame of the encapsulated FrameSet. */ - pset = this_region->points; - ptr = astGetPoints( pset ); - np = astGetNpoint( pset ); - -/* Get a pointer to the base Frame in the frameset encapsulated by the - parent Region structure. */ - frm = astGetFrame( this_region->frameset, AST__BASE ); - -/* Find the upper and lower bounds of the box enclosing all the vertices. - The box is expressed in terms of axis offsets from the first vertex, in - order to avoid problems with boxes that cross RA=0 or RA=12h */ - lbnd[ 0 ] = 0.0; - lbnd[ 1 ] = 0.0; - ubnd[ 0 ] = 0.0; - ubnd[ 1 ] = 0.0; - - x = ptr[ 0 ]; - y = ptr[ 1 ]; - - x0 = *x; - y0 = *y; - - for( ip = 0; ip < np; ip++, x++, y++ ) { - - dist = astAxDistance( frm, 1, x0, *x ); - if( dist < lbnd[ 0 ] ) { - lbnd[ 0 ] = dist; - } else if( dist > ubnd[ 0 ] ) { - ubnd[ 0 ] = dist; - } - - dist = astAxDistance( frm, 2, y0, *y ); - if( dist < lbnd[ 1 ] ) { - lbnd[ 1 ] = dist; - } else if( dist > ubnd[ 1 ] ) { - ubnd[ 1 ] = dist; - } - - } - -/* Convert the box bounds to absolute values, rather than values relative - to the first vertex. */ - lbnd[ 0 ] += x0; - lbnd[ 1 ] += y0; - ubnd[ 0 ] += x0; - ubnd[ 1 ] += y0; - -/* The astNormBox requires a Mapping which can be used to test points in - this base Frame. Create a copy of the Polygon and then set its - FrameSet so that the current Frame in the copy is the same as the base - Frame in the original. */ - reg = astCopy( this ); - astSetRegFS( reg, frm ); - astSetNegated( reg, 0 ); - -/* Normalise this box. */ - astNormBox( frm, lbnd, ubnd, reg ); - -/* Free resources */ - reg = astAnnul( reg ); - frm = astAnnul( frm ); - -/* Store it in the olygon structure for future use. */ - this->lbnd[ 0 ] = lbnd[ 0 ]; - this->lbnd[ 1 ] = lbnd[ 1 ]; - this->ubnd[ 0 ] = ubnd[ 0 ]; - this->ubnd[ 1 ] = ubnd[ 1 ]; - - } -} - -static AstPointSet *RegBaseMesh( AstRegion *this_region, int *status ){ -/* -* Name: -* RegBaseMesh - -* Purpose: -* Return a PointSet containing a mesh of points on the boundary of a -* Region in its base Frame. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* AstPointSet *astRegBaseMesh( AstRegion *this, int *status ) - -* Class Membership: -* Polygon member function (over-rides the astRegBaseMesh protected -* method inherited from the Region class). - -* Description: -* This function returns a PointSet containing a mesh of points on the -* boundary of the Region. The points refer to the base Frame of -* the encapsulated FrameSet. - -* Parameters: -* this -* Pointer to the Region. -* status -* Pointer to the inherited status variable. - -* Returned Value: -* Pointer to the PointSet. Annul the pointer using astAnnul when it -* is no longer needed. - -* Notes: -* - A NULL pointer is returned if an error has already occurred, or if -* this function should fail for any reason. - -*/ - -/* Local Variables: */ - AstFrame *frm; /* Base Frame in encapsulated FrameSet */ - AstPointSet *result; /* Returned pointer */ - AstPolygon *this; /* The Polygon structure */ - double **rptr; /* Pointers to returned mesh data */ - double **vptr; /* Pointers to vertex data */ - double *lens; /* Pointer to work space holding edge lengths */ - double d; /* Length of this edge */ - double delta; /* Angular separation of points */ - double end[ 2 ]; /* End position */ - double mp; /* No. of mesh points per unit distance */ - double p[ 2 ]; /* Position in 2D Frame */ - double start[ 2 ]; /* Start position */ - double total; /* Total length of polygon */ - int ip; /* Point index */ - int iv; /* Vertex index */ - int n; /* No. of points on this edge */ - int next; /* Index of next point in returned PointSet */ - int np; /* No. of points in returned PointSet */ - int nv; /* No. of polygon vertices */ - -/* Initialise */ - result= NULL; - -/* Check the global error status. */ - if ( !astOK ) return result; - -/* If the Region structure contains a pointer to a PointSet holding - a previously created mesh, return it. */ - if( this_region->basemesh ) { - result = astClone( this_region->basemesh ); - -/* Otherwise, create a new mesh. */ - } else { - -/* Get a pointer to the Polygon structure. */ - this = (AstPolygon *) this_region; - -/* Get a pointer to the base Frame in the encapsulated FrameSet. */ - frm = astGetFrame( this_region->frameset, AST__BASE ); - -/* Get the number of vertices and pointers to the vertex axis values. */ - nv = astGetNpoint( this_region->points ); - vptr = astGetPoints( this_region->points ); - -/* Allocate memory to hold the geodesic length of each edge. */ - lens = astMalloc( sizeof( double )*(size_t) nv ); - - if( astOK ) { - -/* Find the total geodesic distance around the boundary. */ - total = 0.0; - - start[ 0 ] = vptr[ 0 ][ 0 ]; - start[ 1 ] = vptr[ 1 ][ 0 ]; - - for( iv = 1; iv < nv; iv++ ) { - end[ 0 ] = vptr[ 0 ][ iv ]; - end[ 1 ] = vptr[ 1 ][ iv ]; - - d = astDistance( frm, start, end ); - if( d != AST__BAD ) total += fabs( d ); - lens[ iv ] = d; - start[ 0 ] = end[ 0 ]; - start[ 1 ] = end[ 1 ]; - } - - end[ 0 ] = vptr[ 0 ][ 0 ]; - end[ 1 ] = vptr[ 1 ][ 0 ]; - - d = astDistance( frm, start, end ); - if( d != AST__BAD ) total += fabs( d ); - lens[ 0 ] = d; - -/* Find the number of mesh points per unit geodesic distance. */ - if( total > 0.0 ){ - mp = astGetMeshSize( this )/total; - -/* Find the total number of mesh points required. */ - np = 0; - for( iv = 0; iv < nv; iv++ ) { - if( lens[ iv ] != AST__BAD ) np += 1 + (int)( lens[ iv ]*mp ); - } - -/* Create a suitable PointSet to hold the returned positions. */ - result = astPointSet( np, 2, "", status ); - rptr = astGetPoints( result ); - if( astOK ) { - -/* Initialise the index of the next point to be added to the returned - PointSet. */ - next = 0; - -/* Loop round each good edge of the polygon. The edge ends at vertex "iv". */ - start[ 0 ] = vptr[ 0 ][ 0 ]; - start[ 1 ] = vptr[ 1 ][ 0 ]; - - for( iv = 1; iv < nv; iv++ ) { - end[ 0 ] = vptr[ 0 ][ iv ]; - end[ 1 ] = vptr[ 1 ][ iv ]; - if( lens[ iv ] != AST__BAD ) { - -/* Add the position of the starting vertex to the returned mesh. */ - rptr[ 0 ][ next ] = start[ 0 ]; - rptr[ 1 ][ next ] = start[ 1 ]; - next++; - -/* Find the number of points on this edge, and the geodesic distance - between them. */ - n = 1 + (int) ( lens[ iv ]*mp ); - -/* If more than one point, find the distance between points. */ - if( n > 1 ) { - delta = lens[ iv ]/n; - -/* Loop round the extra points. */ - for( ip = 1; ip < n; ip++ ) { - -/* Find the position of the next mesh point. */ - astOffset( frm, start, end, delta*ip, p ); - -/* Add it to the mesh. */ - rptr[ 0 ][ next ] = p[ 0 ]; - rptr[ 1 ][ next ] = p[ 1 ]; - next++; - - } - } - } - -/* The end of this edge becomes the start of the next. */ - start[ 0 ] = end[ 0 ]; - start[ 1 ] = end[ 1 ]; - } - -/* Now do the edge which ends at the first vertex. */ - end[ 0 ] = vptr[ 0 ][ 0 ]; - end[ 1 ] = vptr[ 1 ][ 0 ]; - if( lens[ 0 ] != AST__BAD ) { - rptr[ 0 ][ next ] = start[ 0 ]; - rptr[ 1 ][ next ] = start[ 1 ]; - next++; - - n = 1 + (int)( lens[ 0 ]*mp ); - if( n > 1 ) { - delta = lens[ 0 ]/n; - for( ip = 1; ip < n; ip++ ) { - astOffset( frm, start, end, delta*ip, p ); - rptr[ 0 ][ next ] = p[ 0 ]; - rptr[ 1 ][ next ] = p[ 1 ]; - next++; - } - } - } - -/* Check the PointSet size was correct. */ - if( next != np && astOK ) { - astError( AST__INTER, "astRegBaseMesh(%s): Error in the " - "allocated PointSet size (%d) - should have " - "been %d (internal AST programming error).", status, - astGetClass( this ), np, next ); - } - -/* Save the returned pointer in the Region structure so that it does not - need to be created again next time this function is called. */ - if( astOK ) this_region->basemesh = astClone( result ); - - } - - } else if( astOK ) { - astError( AST__BADIN, "astRegBaseMesh(%s): The boundary of " - "the supplied %s has an undefined length.", status, - astGetClass( this ), astGetClass( this ) ); - } - - } - -/* Free resources. */ - frm = astAnnul( frm ); - lens = astFree( lens ); - } - -/* Annul the result if an error has occurred. */ - if( !astOK ) result = astAnnul( result ); - -/* Return a pointer to the output PointSet. */ - return result; -} - -static int RegPins( AstRegion *this_region, AstPointSet *pset, AstRegion *unc, - int **mask, int *status ){ -/* -* Name: -* RegPins - -* Purpose: -* Check if a set of points fall on the boundary of a given Polygon. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* int RegPins( AstRegion *this, AstPointSet *pset, AstRegion *unc, -* int **mask, int *status ) - -* Class Membership: -* Polygon member function (over-rides the astRegPins protected -* method inherited from the Region class). - -* Description: -* This function returns a flag indicating if the supplied set of -* points all fall on the boundary of the given Polygon. -* -* Some tolerance is allowed, as specified by the uncertainty Region -* stored in the supplied Polygon "this", and the supplied uncertainty -* Region "unc" which describes the uncertainty of the supplied points. - -* Parameters: -* this -* Pointer to the Polygon. -* pset -* Pointer to the PointSet. The points are assumed to refer to the -* base Frame of the FrameSet encapsulated by "this". -* unc -* Pointer to a Region representing the uncertainties in the points -* given by "pset". The Region is assumed to represent the base Frame -* of the FrameSet encapsulated by "this". Zero uncertainity is assumed -* if NULL is supplied. -* mask -* Pointer to location at which to return a pointer to a newly -* allocated dynamic array of ints. The number of elements in this -* array is equal to the value of the Npoint attribute of "pset". -* Each element in the returned array is set to 1 if the -* corresponding position in "pset" is on the boundary of the Region -* and is set to zero otherwise. A NULL value may be supplied -* in which case no array is created. If created, the array should -* be freed using astFree when no longer needed. -* status -* Pointer to the inherited status variable. - -* Returned Value: -* Non-zero if the points all fall on the boundary of the given -* Region, to within the tolerance specified. Zero otherwise. - -*/ - -/* Local variables: */ - AstFrame *frm; /* Base Frame in supplied Polygon */ - AstPointSet *pset1; /* Pointer to copy of supplied PointSet */ - AstPointSet *pset2; /* Pointer to PointSet holding resolved components */ - AstPolygon *this; /* Pointer to the Polygon structure. */ - AstRegion *tunc; /* Uncertainity Region from "this" */ - double **ptr1; /* Pointer to axis values in "pset1" */ - double **ptr2; /* Pointer to axis values in "pset2" */ - double **vptr; /* Pointer to axis values at vertices */ - double *safe; /* An interior point in "this" */ - double edge_len; /* Length of current edge */ - double end[2]; /* Position of end of current edge */ - double l1; /* Length of bounding box diagonal */ - double l2; /* Length of bounding box diagonal */ - double lbnd_tunc[2]; /* Lower bounds of "this" uncertainty Region */ - double lbnd_unc[2]; /* Lower bounds of supplied uncertainty Region */ - double par; /* Parallel component */ - double parmax; /* Max acceptable parallel component */ - double prp; /* Perpendicular component */ - double start[2]; /* Position of start of current edge */ - double ubnd_tunc[2]; /* Upper bounds of "this" uncertainty Region */ - double ubnd_unc[2]; /* Upper bounds of supplied uncertainty Region */ - double wid; /* Width of acceptable margin around polygon */ - int *m; /* Pointer to next mask value */ - int i; /* Edge index */ - int ip; /* Point index */ - int np; /* No. of supplied points */ - int nv; /* No. of vertices */ - int result; /* Returned flag */ - -/* Initialise */ - result = 0; - if( mask ) *mask = NULL; - -/* Check the inherited status. */ - if( !astOK ) return result; - -/* Get a pointer to the Polygon structure. */ - this = (AstPolygon *) this_region; - -/* Check the supplied PointSet has 2 axis values per point. */ - if( astGetNcoord( pset ) != 2 && astOK ) { - astError( AST__INTER, "astRegPins(%s): Illegal number of axis " - "values per point (%d) in the supplied PointSet - should be " - "2 (internal AST programming error).", status, astGetClass( this ), - astGetNcoord( pset ) ); - } - -/* Get the number of axes in the uncertainty Region and check it is also 2. */ - if( unc && astGetNaxes( unc ) != 2 && astOK ) { - astError( AST__INTER, "astRegPins(%s): Illegal number of axes (%d) " - "in the supplied uncertainty Region - should be 2 " - "(internal AST programming error).", status, astGetClass( this ), - astGetNaxes( unc ) ); - } - -/* Get pointers to the axis values at the polygon vertices. */ - vptr = astGetPoints( this_region->points ); - -/* Get the number of vertices. */ - nv = astGetNpoint( this_region->points ); - -/* Take a copy of the supplied PointSet and get pointers to its axis - values,and its size */ - pset1 = astCopy( pset ); - ptr1 = astGetPoints( pset1 ); - np = astGetNpoint( pset1 ); - -/* Create a PointSet to hold the resolved components and get pointers to its - axis data. */ - pset2 = astPointSet( np, 2, "", status ); - ptr2 = astGetPoints( pset2 ); - -/* Create a mask array if required. */ - if( mask ) *mask = astMalloc( sizeof(int)*(size_t) np ); - -/* Get the centre of the region in the base Frame. We use this as a "safe" - interior point within the region. */ - safe = astRegCentre( this, NULL, NULL, 0, AST__BASE ); - -/* We now find the maximum distance on each axis that a point can be from the - boundary of the Polygon for it still to be considered to be on the boundary. - First get the Region which defines the uncertainty within the Polygon - being checked (in its base Frame), re-centre it on the interior point - found above (to avoid problems if the uncertainty region straddles a - discontinuity), and get its bounding box. The current Frame of the - uncertainty Region is the same as the base Frame of the Polygon. */ - tunc = astGetUncFrm( this, AST__BASE ); - if( safe ) astRegCentre( tunc, safe, NULL, 0, AST__CURRENT ); - astGetRegionBounds( tunc, lbnd_tunc, ubnd_tunc ); - -/* Find the geodesic length within the base Frame of "this" of the diagonal of - the bounding box. */ - frm = astGetFrame( this_region->frameset, AST__BASE ); - l1 = astDistance( frm, lbnd_tunc, ubnd_tunc ); - -/* Also get the Region which defines the uncertainty of the supplied - points and get its bounding box. First re-centre the uncertainty at the - interior position to avoid problems from uncertainties that straddle a - discontinuity. */ - if( unc ) { - if( safe ) astRegCentre( unc, safe, NULL, 0, AST__CURRENT ); - astGetRegionBounds( unc, lbnd_unc, ubnd_unc ); - -/* Find the geodesic length of the diagonal of this bounding box. */ - l2 = astDistance( frm, lbnd_unc, ubnd_unc ); - -/* Assume zero uncertainty if no "unc" Region was supplied. */ - } else { - l2 = 0.0; - } - -/* The required border width is half of the total diagonal of the two bounding - boxes. */ - if( astOK ) { - wid = 0.5*( l1 + l2 ); - -/* Loop round each edge of the polygon. Edge "i" starts at vertex "i-1" - and ends at vertex "i". Edge zero starts at vertex "nv-1" and ends at - vertex zero. */ - start[ 0 ] = vptr[ 0 ][ nv - 1 ]; - start[ 1 ] = vptr[ 1 ][ nv - 1 ]; - for( i = 0; i < nv; i++ ) { - end[ 0 ] = vptr[ 0 ][ i ]; - end[ 1 ] = vptr[ 1 ][ i ]; - -/* Find the length of this edge. */ - edge_len = astDistance( frm, start, end ); - -/* Resolve all the supplied mesh points into components parallel and - perpendicular to this edge. */ - (void) astResolvePoints( frm, start, end, pset1, pset2 ); - -/* A point is effectively on this edge if the parallel component is - greater than (-wid) and less than (edge_len+wid) AND the perpendicular - component has an absolute value less than wid. Identify such positions - and set them bad in pset1. */ - parmax = edge_len + wid; - for( ip = 0; ip < np; ip++ ) { - par = ptr2[ 0 ][ ip ]; - prp = ptr2[ 1 ][ ip ]; - - if( par != AST__BAD && prp != AST__BAD ) { - if( par > -wid && par < parmax && prp > -wid && prp < wid ) { - ptr1[ 0 ][ ip ] = AST__BAD; - ptr1[ 1 ][ ip ] = AST__BAD; - } - } - } - -/* The end of the current edge becomes the start of the next. */ - start[ 0 ] = end[ 0 ]; - start[ 1 ] = end[ 1 ]; - } - -/* See if any good points are left in pset1. If so, it means that those - points were not on any edge of hte Polygon. We use two alogorithms - here depending on whether we are creating a mask array, since we can - abort the check upon finding the first good point if we are not - producing a mask. */ - result = 1; - if( mask ) { - m = *mask; - for( ip = 0; ip < np; ip++, m++ ) { - if( ptr1[ 0 ][ ip ] != AST__BAD && - ptr1[ 1 ][ ip ] != AST__BAD ) { - *m = 0; - result = 0; - } else { - *m = 1; - } - } - } else { - for( ip = 0; ip < np; ip++ ) { - if( ptr1[ 0 ][ ip ] != AST__BAD && - ptr1[ 1 ][ ip ] != AST__BAD ) { - result = 0; - break; - } - } - } - } - -/* Free resources. */ - tunc = astAnnul( tunc ); - frm = astAnnul( frm ); - safe = astFree( safe ); - pset1 = astAnnul( pset1 ); - pset2 = astAnnul( pset2 ); - -/* If an error has occurred, return zero. */ - if( !astOK ) { - result = 0; - if( mask ) *mask = astAnnul( *mask ); - } - -/* Return the result. */ - return result; -} - -static int RegTrace( AstRegion *this_region, int n, double *dist, double **ptr, - int *status ){ -/* -*+ -* Name: -* RegTrace - -* Purpose: -* Return requested positions on the boundary of a 2D Region. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* int astTraceRegion( AstRegion *this, int n, double *dist, double **ptr ); - -* Class Membership: -* Polygon member function (overrides the astTraceRegion method -* inherited from the parent Region class). - -* Description: -* This function returns positions on the boundary of the supplied -* Region, if possible. The required positions are indicated by a -* supplied list of scalar parameter values in the range zero to one. -* Zero corresponds to some arbitrary starting point on the boundary, -* and one corresponds to the end (which for a closed region will be -* the same place as the start). - -* Parameters: -* this -* Pointer to the Region. -* n -* The number of positions to return. If this is zero, the function -* returns without action (but the returned function value still -* indicates if the method is supported or not). -* dist -* Pointer to an array of "n" scalar parameter values in the range -* 0 to 1.0. -* ptr -* A pointer to an array of pointers. The number of elements in -* this array should equal tthe number of axes in the Frame spanned -* by the Region. Each element of the array should be a pointer to -* an array of "n" doubles, in which to return the "n" values for -* the corresponding axis. The contents of the arrays are unchanged -* if the supplied Region belongs to a class that does not -* implement this method. - -* Returned Value: -* Non-zero if the astTraceRegion method is implemented by the class -* of Region supplied, and zero if not. - -*- -*/ - -/* Local Variables; */ - AstFrame *frm; - AstMapping *map; - AstPointSet *bpset; - AstPointSet *cpset; - AstPolygon *this; - double **bptr; - double d; - double p[ 2 ]; - int i; - int j0; - int j; - int ncur; - int nv; - int monotonic; - -/* Check inherited status, and the number of points to return, returning - a non-zero value to indicate that this class supports the astRegTrace - method. */ - if( ! astOK || n == 0 ) return 1; - -/* Get a pointer to the Polygon structure. */ - this = (AstPolygon *) this_region; - -/* Ensure cached information is available. */ - Cache( this, status ); - -/* Get a pointer to the base Frame in the encapsulated FrameSet. */ - frm = astGetFrame( this_region->frameset, AST__BASE ); - -/* We first determine the required positions in the base Frame of the - Region, and then transform them into the current Frame. Get the - base->current Mapping, and the number of current Frame axes. */ - map = astGetMapping( this_region->frameset, AST__BASE, AST__CURRENT ); - -/* If it's a UnitMap we do not need to do the transformation, so put the - base Frame positions directly into the supplied arrays. */ - if( astIsAUnitMap( map ) ) { - bpset = NULL; - bptr = ptr; - ncur = 2; - -/* Otherwise, create a PointSet to hold the base Frame positions (known - to be 2D since this is an polygon). */ - } else { - bpset = astPointSet( n, 2, " ", status ); - bptr = astGetPoints( bpset ); - ncur = astGetNout( map ); - } - -/* Check the pointers can be used safely. */ - if( astOK ) { - -/* Get the number of vertices. */ - nv = astGetNpoint( this_region->points ); - -/* If we have a reasonable number of pointsand there are a reasonable - number of vertices, we can be quicker if we know if the parameteric - distances are monotonic increasing. Find out now. */ - if( n > 5 && nv > 5 ) { - - monotonic = 1; - for( i = 1; i < n; i++ ) { - if( dist[ i ] < dist[ i - 1 ] ) { - monotonic = 0; - break; - } - } - - } else { - monotonic = 0; - } - -/* Loop round each point. */ - j0 = 1; - for( i = 0; i < n; i++ ) { - -/* Get the required round the polygon, starting from vertex zero. */ - d = dist[ i ]*this->totlen; - -/* Loop round each vertex until we find one which is beyond the required - point. If the supplied distances are monotonic increasing, we can - start the checks at the same vertex that was used for the previous - since we know there will never be a backward step. */ - for( j = j0; j < nv; j++ ) { - if( this->startsat[ j ] > d ) break; - } - -/* If the distances are monotonic increasing, record the vertex that we - have reached so far. */ - if( monotonic ) j0 = j; - -/* Find the distance to travel beyond the previous vertex. */ - d -= this->startsat[ j - 1 ]; - -/* Find the position, that is the required distance from the previous - vertex towards the next vertex. */ - astLineOffset( frm, this->edges[ j - 1 ], d, 0.0, p ); - -/* Store the resulting axis values. */ - bptr[ 0 ][ i ] = p[ 0 ]; - bptr[ 1 ][ i ] = p[ 1 ]; - } - } - -/* If required, transform the base frame positions into the current - Frame, storing them in the supplied array. Then free resources. */ - if( bpset ) { - cpset = astPointSet( n, ncur, " ", status ); - astSetPoints( cpset, ptr ); - - (void) astTransform( map, bpset, 1, cpset ); - - cpset = astAnnul( cpset ); - bpset = astAnnul( bpset ); - } - -/* Free remaining resources. */ - map = astAnnul( map ); - frm = astAnnul( frm ); - -/* Return a non-zero value to indicate that this class supports the - astRegTrace method. */ - return 1; -} - -static Segment *RemoveFromChain( Segment *head, Segment *seg, int *status ){ -/* -* Name: -* RemoveFromChain - -* Purpose: -* Remove a Segment from the link list maintained by astDownsize. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* Segment *RemoveFromChain( Segment *head, Segment *seg, int *status ) - -* Class Membership: -* Polygon member function - -* Description: -* The supplied Segment is removed form the list, and the gap is -* closed up. - -* Parameters: -* head -* The Segment structure at the head of the list. -* seg -* The Segment to be removed from the list. -* status -* Pointer to the inherited status variable. - -* Returned Value: -* Pointer to the link head (which will have changed if "seg" was the -* original head). - -*/ - -/* Check the global error status. */ - if ( !astOK ) return head; - -/* If the Segment was the original head, make the next segment the new - head. */ - if( head == seg ) head = seg->next; - -/* Close up the links between the Segments on either side of the segment - being removed. */ - if( seg->prev ) seg->prev->next = seg->next; - if( seg->next ) seg->next->prev = seg->prev; - -/* Nullify the links in the segment being removed. */ - seg->next = NULL; - seg->prev = NULL; - -/* Return the new head. */ - return head; -} - -static void ResetCache( AstRegion *this_region, int *status ){ -/* -* Name: -* ResetCache - -* Purpose: -* Clear cached information within the supplied Region. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* void ResetCache( AstRegion *this, int *status ) - -* Class Membership: -* Region member function (overrides the astResetCache method -* inherited from the parent Region class). - -* Description: -* This function clears cached information from the supplied Region -* structure. - -* Parameters: -* this -* Pointer to the Region. -* status -* Pointer to the inherited status variable. -*/ - -/* Local Variables: */ - AstPolygon *this; - int i; - int nv; - -/* Get a pointer to the Polygon structure. */ - this = (AstPolygon *) this_region; - -/* If a Polygon was supplied, indicate cached information needs to be - recalculated. */ - if( this ) { - this->stale = 1; - this->lbnd[ 0 ] = AST__BAD; - -/* Free any edge structures (number of vertices may be about to change so - this cannot be left until the next call to "Cache()". */ - if( this->edges ) { - nv = astGetNpoint( this_region->points ); - for( i = 0; i < nv; i++ ) { - this->edges[ i ] = astFree( this->edges[ i ] ); - } - this->edges = astFree( this->edges ); - } - -/* Clear the cache of the parent class. */ - (*parent_resetcache)( this_region, status ); - } -} - -static void SetAttrib( AstObject *this_object, const char *setting, int *status ) { -/* -* Name: -* SetAttrib - -* Purpose: -* Set an attribute value for a Polygon. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* void SetAttrib( AstObject *this, const char *setting, int *status ) - -* Class Membership: -* Polygon member function (extends the astSetAttrib method inherited from -* the Region class). - -* Description: -* This function assigns an attribute value for a Polygon, the attribute -* and its value being specified by means of a string of the form: -* -* "attribute= value " -* -* Here, "attribute" specifies the attribute name and should be in lower -* case with no white space present. The value to the right of the "=" -* should be a suitable textual representation of the value to be assigned -* and this will be interpreted according to the attribute's data type. -* White space surrounding the value is only significant for string -* attributes. - -* Parameters: -* this -* Pointer to the Polygon. -* setting -* Pointer to a null terminated string specifying the new attribute -* value. -* status -* Pointer to the inherited status variable. - -* Returned Value: -* void -*/ - -/* Local Vaiables: */ - AstPolygon *this; /* Pointer to the Polygon structure */ - int ival; /* Integer attribute value */ - int len; /* Length of setting string */ - int nc; /* Number of characters read by astSscanf */ - -/* Check the global error status. */ - if ( !astOK ) return; - -/* Obtain a pointer to the Polygon structure. */ - this = (AstPolygon *) this_object; - -/* Obtain the length of the setting string. */ - len = strlen( setting ); - -/* Test for each recognised attribute in turn, using "astSscanf" to parse the - setting string and extract the attribute value (or an offset to it in the - case of string values). In each case, use the value set in "nc" to check - that the entire string was matched. Once a value has been obtained, use the - appropriate method to set it. */ - -/* SimpVertices. */ -/* ------------- */ - if ( nc = 0, - ( 1 == astSscanf( setting, "simpvertices= %d %n", &ival, &nc ) ) - && ( nc >= len ) ) { - astSetSimpVertices( this, ival ); - -/* Pass any unrecognised setting to the parent method for further - interpretation. */ - } else { - (*parent_setattrib)( this_object, setting, status ); - } -} - -static void SetPointSet( AstPolygon *this, AstPointSet *pset, int *status ){ -/* -* Name: -* SetPointSet - -* Purpose: -* Store a new set of vertices in an existing Polygon. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* void SetPointSet( AstPolygon *this, AstPointSet *pset, int *status ) - -* Class Membership: -* Polygon member function - -* Description: -* The PointSet in the supplied Polygon is annulled, and replaced by a -* clone of the supplied PointSet pointer. - -* Parameters: -* this -* Pointer to the Polygon to be changed. -* pset -* The PointSet containing the new vertex information. -* status -* Pointer to the inherited status variable. - -*/ - - -/* Check the global error status. */ - if ( !astOK ) return; - -/* Indicate the cached information in the polygon will need to be - re-calculated when needed. */ - astResetCache( this ); - -/* Annul the pointer to the PointSet already in the supplied Polygon. */ - (void) astAnnul( ((AstRegion *) this)->points ); - -/* Store a clone of the supplied new PointSet pointer. */ - ((AstRegion *) this)->points = astClone( pset ); - -} - -static void SetRegFS( AstRegion *this_region, AstFrame *frm, int *status ) { -/* -* Name: -* SetRegFS - -* Purpose: -* Stores a new FrameSet in a Region - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* void SetRegFS( AstRegion *this_region, AstFrame *frm, int *status ) - -* Class Membership: -* Polygon method (over-rides the astSetRegFS method inherited from -* the Region class). - -* Description: -* This function creates a new FrameSet and stores it in the supplied -* Region. The new FrameSet contains two copies of the supplied -* Frame, connected by a UnitMap. - -* Parameters: -* this -* Pointer to the Region. -* frm -* The Frame to use. -* status -* Pointer to the inherited status variable. - -*/ - - -/* Check the global error status. */ - if ( !astOK ) return; - -/* Indicate cached information eeds re-calculating. */ - astResetCache( this_region ); - -/* Invoke the parent method to store the FrameSet in the parent Region - structure. */ - (* parent_setregfs)( this_region, frm, status ); - -} - -static AstMapping *Simplify( AstMapping *this_mapping, int *status ) { -/* -* Name: -* Simplify - -* Purpose: -* Simplify the Mapping represented by a Region. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* AstMapping *Simplify( AstMapping *this, int *status ) - -* Class Membership: -* Polygon method (over-rides the astSimplify method inherited -* from the Region class). - -* Description: -* This function invokes the parent Region Simplify method, and then -* performs any further region-specific simplification. -* -* If the Mapping from base to current Frame is not a UnitMap, this -* will include attempting to fit a new Region to the boundary defined -* in the current Frame. - -* Parameters: -* this -* Pointer to the original Region. -* status -* Pointer to the inherited status variable. - -* Returned Value: -* A pointer to the simplified Region. A cloned pointer to the -* supplied Region will be returned if no simplication could be -* performed. - -* Notes: -* - A NULL pointer value will be returned if this function is -* invoked with the AST error status set, or if it should fail for -* any reason. -*/ - -/* Local Variables: */ - AstFrame *frm; /* Current Frame */ - AstMapping *map; /* Base -> current Mapping */ - AstMapping *result; /* Result pointer to return */ - AstPointSet *mesh; /* Mesh of current Frame positions */ - AstPointSet *ps2; /* Polygon PointSet in current Frame */ - AstPolygon *newpol; /* New Polygon */ - AstRegion *new; /* Pointer to simplified Region */ - AstRegion *this; /* Pointer to supplied Region structure */ - AstRegion *unc; /* Pointer to uncertainty Region */ - double **ptr2; /* Pointer axis values in "ps2" */ - double *mem; /* Pointer to array holding new vertex coords */ - double *p; /* Pointer to next vertex coords */ - double *q; /* Pointer to next vertex coords */ - int iv; /* Vertex index */ - int nv; /* Number of vertices in polygon */ - int ok; /* Are the new polygon vertices good? */ - int simpler; /* Has some simplication taken place? */ - -/* Initialise. */ - result = NULL; - -/* Check the global error status. */ - if ( !astOK ) return result; - -/* Get a pointer to the supplied Region structure. */ - this = (AstRegion *) this_mapping; - -/* Invoke the parent Simplify method inherited from the Region class. This - will simplify the encapsulated FrameSet and uncertainty Region. */ - new = (AstRegion *) (*parent_simplify)( this_mapping, status ); - -/* Note if any simplification took place. This is assumed to be the case - if the pointer returned by the above call is different to the supplied - pointer. */ - simpler = ( new != this ); - -/* We attempt to simplify the Polygon by re-defining it within its current - Frame. Transforming the Polygon from its base to its current Frame may - result in the region no having the same edges. If required, we test this - by transforming a set of bounds on the Polygon boundary. This can only - be done if the current Frame is 2-dimensional. Also, there is only any - point in doing it if the Mapping from base to current Frame in the - Polygon is not a UnitMap. */ - map = astGetMapping( new->frameset, AST__BASE, AST__CURRENT ); - if( !astIsAUnitMap( map ) && astGetNout( map ) == 2 ) { - -/* Get a pointer to the Frame represented by the Polgon. */ - frm = astGetFrame( new->frameset, AST__CURRENT ); - -/* Get the Region describing the positional uncertainty in this Frame. */ - unc = astGetUncFrm( new, AST__CURRENT ); - -/* Get the positions of the vertices within this Frame. */ - ps2 = astRegTransform( this, this->points, 1, NULL, NULL ); - ptr2 = astGetPoints( ps2 ); - -/* Get the number of vertices. */ - nv = astGetNpoint( ps2 ); - -/* Re-organise the vertex axis values into the form required by the - Polygon constructor function. */ - mem = astMalloc( sizeof( double)*(size_t)( 2*nv ) ); - if( astOK ) { - ok = 1; - p = mem; - q = ptr2[ 0 ]; - for( iv = 0; iv < nv; iv++ ) { - if( ( *(p++) = *(q++) ) == AST__BAD ) ok = 0; - } - q = ptr2[ 1 ]; - for( iv = 0; iv < nv; iv++ ) *(p++) = *(q++); - -/* Create a new Polygon using these transformed vertices. */ - if( ok ) { - newpol = astPolygon( frm, nv, nv, mem, unc, "", status ); - -/* If the SimpVertices attribute is zero, we now check that the - transformation has not bent the edges of the polygon significantly. - If it has, we annul the new Polygon. */ - if( !astGetSimpVertices( this ) ) { - -/* Get a mesh of points covering the Polygon in this Frame. */ - mesh = astRegMesh( new ); - -/* See if all points within the mesh created from the original Polygon fall - on the boundary of the new Polygon, to within the uncertainty of the - Region. If not, annul the new Polgon. */ - if( !astRegPins( newpol, mesh, NULL, NULL ) ) { - newpol = astAnnul( newpol ); - } - -/* Free the mesh. */ - mesh = astAnnul( mesh ); - } - -/* If we still have a new polygon, use the new Polygon in place of the - original Region. */ - if( newpol ) { - (void) astAnnul( new ); - new = (AstRegion *) newpol; - simpler = 1; - } - } - } - -/* Free other resources. */ - frm = astAnnul( frm ); - unc = astAnnul( unc ); - ps2 = astAnnul( ps2 ); - mem = astFree( mem ); - } - map = astAnnul( map ); - -/* If any simplification could be performed, copy Region attributes from - the supplied Region to the returned Region, and return a pointer to it. - If the supplied Region had no uncertainty, ensure the returned Region - has no uncertainty. Otherwise, return a clone of the supplied pointer. */ - if( simpler ){ - astRegOverlay( new, this, 1 ); - result = (AstMapping *) new; - - } else { - new = astAnnul( new ); - result = astClone( this ); - } - -/* If an error occurred, annul the returned pointer. */ - if ( !astOK ) result = astAnnul( result ); - -/* Return the result. */ - return result; -} - -static void SmoothPoly( AstPointSet *pset, int boxsize, double strength, - int *status ) { -/* -* Name: -* SmoothPoly - -* Purpose: -* Smoooth a polygon assuming plane geometry. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* void SmoothPoly( AstPointSet *pset, int boxsize, double strength, -* int *status ) - -* Class Membership: -* Polygon member function - -* Description: -* This function smooths a polygon, without changing the number of -* vertices. It assumes plane geometry, so should not be used to -* smooth polygons defined within a SkyFrame or CmpFrame. -* -* Each vertex is replaced by a new vertex determined as follows: the -* mean X and Y axis value of the vertices in a section of the polygon -* centred on the vertex being replaced are found (the length of the -* section is given by parameter "boxsize"). The new vertex position -* is then the weighted mean of this mean (X,Y) position and the old -* vertex position. The weight for the mean (X,Y) position is given -* by parameter "strength", and the weight for the old vertex -* position is (1.0 - strength) - -* Parameters: -* pset -* A PointSet holding the polygon vertices. -* boxsize -* Half width of the box filter, given as a number of vertices. -* strength -* The weight to use for the mean (X,Y) position when finding each -* new vertex position. Should be in the range 0.0 to 1.0. A value -* of zero results in no change being made to the polygon. A value -* of 1.0 results in the returned polygon being fully smoothed. -* status -* Pointer to the inherited status variable. - -*/ - -/* Local Variables: */ - double **ptr; - double *newx; - double *newy; - double *nx; - double *ny; - double *oldx; - double *oldy; - double *ox; - double *oy; - double *px; - double *py; - double *qx; - double *qy; - double a; - double b; - double sx; - double sy; - int half_width; - int i; - int nv; - int top; - -/* Check the global error status. */ - if ( !astOK ) return; - -/* Get the number of vertices. */ - nv = astGetNpoint( pset ); - -/* Get pointers to arrays holding the supplied vertex positions. */ - ptr = astGetPoints( pset ); - oldx = ptr[ 0 ]; - oldy = ptr[ 1 ]; - -/* Allocate arrays to hold the returned vertex positions. */ - newx = astMalloc( nv*sizeof( double ) ); - newy = astMalloc( nv*sizeof( double ) ); - -/* Check these pointers can be used safely. */ - if( astOK ) { - -/* Get weighting factors for the fully smoothed and unsmoothed positions. */ - a = strength; - b = 1.0 - a; - -/* Ensure the box size is sufficiently small for there to be room for - two boxes along the polygon. */ - half_width = nv/4 - 1; - if( boxsize < half_width ) half_width = boxsize; - if( half_width < 1 ) half_width = 1; - -/* Modify the weight for the fully smoothed position to include the - normalisation factor needed to account for the box width. */ - a /= 2*half_width + 1; - -/* Find the sum of the x and y coordinates within a box centred on the - first vertex. This includes vertices from the end of the polygon. */ - px = oldx + 1; - qx = oldx + nv; - sx = (oldx)[ 0 ]; - - py = oldy + 1; - qy = oldy + nv; - sy = (oldy)[ 0 ]; - - for( i = 0; i < half_width; i++ ) { - sx += *(px++) + *(--qx); - sy += *(py++) + *(--qy); - } - -/* Replacing vertices within the first half box will include vertices at - both ends of the polygon. Set up the pointers accordingly, and then - find replacements for each vertex in the first half box.*/ - ox = oldx; - oy = oldy; - nx = newx; - ny = newy; - for( i = 0; i < half_width; i++ ) { - -/* Form the new vertex (x,y) values as the weighted mean of the mean - (x,y) values in the box, and the old (x,y) values. */ - *(nx++) = a*sx + b*( *(ox++) ); - *(ny++) = a*sy + b*( *(oy++) ); - -/* Add in the next vertex X and Y axis values to the running sums, and - remove the position that has now passed out of the box. */ - sx += *(px++) - *(qx++); - sy += *(py++) - *(qy++); - } - -/* Adjust the pointer for the rest of the polygon, up to one half box away - from the end. In this section, the smoothing box does not touch either - end of the polygon. */ - top = nv - half_width - 1; - qx = oldx; - qy = oldy; - for( ; i < top; i++ ){ - -/* Form the new vertex (x,y) values as the weighted mean of the mean - (x,y) values in the box, and the old (x,y) values. */ - *(nx++) = a*sx + b*( *(ox++) ); - *(ny++) = a*sy + b*( *(oy++) ); - -/* Add in the next vertex X and Y axis values to the running sums, and - remove the position that has now passed out of the box. */ - sx += *(px++) - *(qx++); - sy += *(py++) - *(qy++); - } - -/* Now do the last half box (which includes vertices from the start of - the polygon). */ - top = nv; - px = oldx; - py = oldy; - for( ; i < top; i++ ){ - *(nx++) = a*sx + b*( *(ox++) ); - *(ny++) = a*sy + b*( *(oy++) ); - sx += *(px++) - *(qx++); - sy += *(py++) - *(qy++); - } - -/* Replace the data points in the PointSet. */ - ptr[ 0 ] = newx; - ptr[ 1 ] = newy; - oldx = astFree( oldx ); - oldy = astFree( oldy ); - } -} - -static int TestAttrib( AstObject *this_object, const char *attrib, int *status ) { -/* -* Name: -* TestAttrib - -* Purpose: -* Test if a specified attribute value is set for a Polygon. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* int TestAttrib( AstObject *this, const char *attrib, int *status ) - -* Class Membership: -* Polygon member function (over-rides the astTestAttrib protected -* method inherited from the Region class). - -* Description: -* This function returns a boolean result (0 or 1) to indicate whether -* a value has been set for one of a Polygon's attributes. - -* Parameters: -* this -* Pointer to the Polygon. -* attrib -* Pointer to a null terminated string specifying the attribute -* name. This should be in lower case with no surrounding white -* space. -* status -* Pointer to the inherited status variable. - -* Returned Value: -* One if a value has been set, otherwise zero. - -* Notes: -* - A value of zero will be returned if this function is invoked -* with the global status set, or if it should fail for any reason. -*/ - -/* Local Variables: */ - AstPolygon *this; /* Pointer to the Polygon structure */ - int result; /* Result value to return */ - -/* Initialise. */ - result = 0; - -/* Check the global error status. */ - if ( !astOK ) return result; - -/* Obtain a pointer to the Polygon structure. */ - this = (AstPolygon *) this_object; - -/* Check the attribute name and test the appropriate attribute. */ - -/* SimpVertices. */ -/* ------------- */ - if ( !strcmp( attrib, "simpvertices" ) ) { - result = astTestSimpVertices( this ); - -/* If the attribute is not recognised, pass it on to the parent method - for further interpretation. */ - } else { - result = (*parent_testattrib)( this_object, attrib, status ); - } - -/* Return the result, */ - return result; -} - -/* -* Name: -* TraceEdge - -* Purpose: -* Find a point that is inside the required outline. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* void TraceEdge<Oper><X>( <Xtype> value, const <Xtype> array[], -* const int lbnd[ 2 ], const int ubnd[ 2 ], -* int iv0, int ix0, int iy0, int starpix, -* int full, int *status ); - -* Class Membership: -* Polygon member function - -* Description: -* This function forms a polygon enclosing the region of the data -* array specified by <Oper> and "value". If this polygon contains -* the point "(inx,iny)", then a PointSet is returned holding the -* pixel coordinates of the Polygon vertices. If the polygon -* does not contain "(inx,iny)", a NULL pointer is returned. -* -* Each vertex in the polygon corresponds to a corner of a pixel in -* the data array. - -* Parameters: -* value -* The data value defining valid pixels. -* array -* The data array. -* lbnd -* The lower pixel index bounds of the array. -* ubnd -* The upper pixel index bounds of the array. -* iv0 -* The vector index of a pixel inside the region such that the -* pixel to the right is NOT inside the region. This defines the -* start of the polygon. -* ix0 -* The X pixel index of the pixel specified by "iv0". -* inx -* The X pixel index of a point which must be inside the polygon -* for the polygon to be acceptable. -* iny -* The Y pixel index of a point which must be inside the polygon -* for the polygon to be acceptable. -* starpix -* If non-zero, the usual Starlink definition of pixel coordinate -* is used (integral values at pixel corners). Otherwise, the -* system used by other AST functions such as astResample is used -* (integral values at pixel centres). -* full -* If non-zero, the full polygon is stored. If zero, vertices in the -* middle of straight sections of the Polygon are omitted. -* status -* Pointer to the inherited status variable. - -* Returned Value: -* A pointer to a PointSet holding the vertices of the polygon, or -* NULL if the polygon did not contain "(inx,iny)". - -* Notes: -* - <Oper> must be one of LT, LE, EQ, GE, GT, NE. - - -*/ - -/* Define a macro to implement the function for a specific data - type and operation. */ -#define MAKE_TRACEEDGE(X,Xtype,Oper,OperI) \ -static AstPointSet *TraceEdge##Oper##X( Xtype value, const Xtype array[], \ - const int lbnd[ 2 ], const int ubnd[ 2 ], \ - int iv0, int ix0, int iy0, \ - int starpix, int full, \ - int *status ){ \ -\ -/* Local Variables: */ \ - AstPointSet *result; /* Pointer to text describing oper */ \ - const Xtype *pa; /* Pointer to current valid pixel value */ \ - const Xtype *pb; /* Pointer to neigbouring valid pixel value */ \ - const Xtype *pc; /* Pointer to neigbouring valid pixel value */ \ - double *ptr[ 2 ]; /* PointSet data pointers */ \ - double *xvert; /* Pointer to array holding vertex X axis values */ \ - double *yvert; /* Pointer to array holding vertex Y axis values */ \ - double dx; /* Pertubation in X (pixels) to avoid the pixel edge */ \ - double dy; /* Pertubation in Y (pixels) to avoid the pixel edge */ \ - double xx; /* Pixel X coord at corner */ \ - double yy; /* Pixel Y coord at corner */ \ - int at; /* The pixel corner to draw to */ \ - int done; /* Have we arrived back at the start of the polygon? */ \ - int ii; /* Index of new vertex */ \ - int ix; /* X pixel index of current valid pixel */ \ - int iy; /* Y pixel index of current valid pixel */ \ - int nright; /* Overall number of right hand turns along polygon */ \ - int nvert; /* Number of vertices */ \ - int nx; /* Pixels per row */ \ -\ -/* Initialise */ \ - result = NULL; \ -\ -/* Check the global error status. */ \ - if ( !astOK ) return result; \ -\ -\ -/* Initialise pointers to arrays holding the X and Y pixel coordinates at \ - the vertices of the polygon. */ \ - xvert = NULL; \ - yvert = NULL; \ - nvert = 0; \ -\ -/* Find number of pixels in one row of the array. */ \ - nx = ( ubnd[ 0 ] - lbnd[ 0 ] + 1 ); \ -\ -/* The four corners of a pixel are numbered as follows: 0=bottom left, \ - 1=top left, 2=top right, 3=bottom right. The following algorithm moves \ - along pixel edges, from corner to corner, using the above numbering \ - scheme to identify the corners. We start the polygon by moving from the \ - bottom right to the top right corner of pixel "(ix0,iy0)". */ \ - ix = ix0; \ - iy = iy0; \ - at = 2; \ -\ -/* Store a pointer to the first good pixel value. */ \ - pa = array + ( ix - lbnd[ 0 ] ) + nx*( iy - lbnd[ 1 ] ) ; \ -\ -/* We count the number of times the polygon turns to the right compared \ - to the left. Initialise it to zero. */ \ - nright = 0; \ -\ -/* Loop round tracing out the polygon until we arrive back at the \ - beginning. The Polygon class requires that the inside of the polygon \ - is to the left as we move round the polygon in an anti-clockwise \ - direction. So at each corner, we attempt to move to the next \ - anti-clockwise good pixel corner. */ \ - done = 0; \ - while( !done ) { \ -\ -/* If we have arrived at the bottom left corner of the good pixel, we must \ - have come from the top left corner since all movements around a pixel \ - must be anti-clockwise. */ \ - if( at == 0 ) { \ -\ -/* Note the pixel coordinates at the bottom left corner of the current \ - pixel. */ \ - if( starpix ) { \ - xx = ix - 1.0; \ - yy = iy - 1.0; \ - } else { \ - xx = ix - 0.5; \ - yy = iy - 0.5; \ - } \ -\ -/* Get a pointer to lower left pixel value */ \ - pb = pa - nx - 1; \ -\ -/* Get a pointer to lower mid pixel value. */ \ - pc = pb + 1; \ -\ -/* If the lower left pixel is within the array and meets the validity \ - requirements, move to the left along its top edge. */ \ - if( iy > lbnd[ 1 ] && ix > lbnd[ 0 ] && ISVALID(*pb,OperI,value) ) { \ - nright++; \ - pa = pb; \ - at = 1; \ - ix--; \ - iy--; \ - dx = DELTA; \ - dy = -DELTA; \ -\ -/* Otherwise, if lower mid pixel is good, move down its left edge. */ \ - } else if( iy > lbnd[ 1 ] && ISVALID(*pc,OperI,value) ) { \ - pa = pc; \ - at = 0; \ - iy--; \ - dx = DELTA; \ - dy = 0.0; \ -\ -/* Otherwise, move to the right along the bottom edge of the current pixel. */ \ - } else { \ - nright--; \ - at = 3; \ - dx = DELTA; \ - dy = DELTA; \ - } \ -\ -/* If the polygon bends at this point, or if we will be smoothing the \ - polygon, append the pixel coordinates at this pixel corner to the \ - polygon. */ \ - if( full || pa != pc ) ADD( xx, yy ); \ -\ -/* If we have arrived at the top left corner of the good pixel, we must \ - have come from the top right corner. */ \ - } else if( at == 1 ) { \ -\ -/* Note the pixel coordinates at the top left corner of the current \ - pixel. */ \ - if( starpix ) { \ - xx = ix - 1.0; \ - yy = iy; \ - } else { \ - xx = ix - 0.5; \ - yy = iy + 0.5; \ - } \ -\ -/* Get a pointer to upper left pixel value */ \ - pb = pa + nx - 1; \ -\ -/* Get a pointer to mid left pixel value. */ \ - pc = pa - 1; \ -\ -/* If upper left pixel is good, move up its left edge. */ \ - if( iy < ubnd[ 1 ] && ix > lbnd[ 0 ] && ISVALID(*pb,OperI,value) ) { \ - nright++; \ - pa = pb; \ - at = 2; \ - ix--; \ - iy++; \ - dx = -DELTA; \ - dy = -DELTA; \ -\ -/* Otherwise, if left mid pixel is good, move left along its top edge. */ \ - } else if( ix > lbnd[ 0 ] && ISVALID(*pc,OperI,value) ) { \ - pa = pc; \ - at = 1; \ - ix--; \ - dx = 0.0; \ - dy = -DELTA; \ -\ -/* Otherwise, move down the left edge of the current pixel. */ \ - } else { \ - nright--; \ - at = 0; \ - dx = DELTA; \ - dy = -DELTA; \ - } \ -\ -/* If the polygon bends at this point, or if we will be smoothing the \ - polygon, append the pixel coordinates at this pixel corner to the \ - polygon. */ \ - if( full || pa != pc ) ADD( xx, yy ); \ -\ -/* If we have arrived at the top right corner of the good pixel, we must \ - have come from the bottom right corner. */ \ - } else if( at == 2 ) { \ -\ -/* Note the pixel coordinates at the top right corner of the current \ - pixel. */ \ - if( starpix ) { \ - xx = ix; \ - yy = iy; \ - } else { \ - xx = ix + 0.5; \ - yy = iy + 0.5; \ - } \ -\ -/* Pointer to upper right pixel value */ \ - pb = pa + nx + 1; \ -\ -/* Pointer to top mid pixel value. */ \ - pc = pa + nx; \ -\ -/* If upper right pixel is good, move right along its bottom edge. */ \ - if( iy < ubnd[ 1 ] && ix < ubnd[ 0 ] && ISVALID(*pb,OperI,value) ){ \ - nright++; \ - pa = pb; \ - at = 3; \ - ix++; \ - iy++; \ - dx = -DELTA; \ - dy = DELTA; \ -\ -/* Otherwise, if upper mid pixel is good, move up its right edge. */ \ - } else if( iy < ubnd[ 1 ] && ISVALID(*pc,OperI,value) ) { \ - pa = pc; \ - at = 2; \ - iy++; \ - dx = -DELTA; \ - dy = 0.0; \ -\ -/* Otherwise, move left along the top edge of the current pixel. */ \ - } else { \ - nright--; \ - at = 1; \ - dx = -DELTA; \ - dy = -DELTA; \ - } \ -\ -/* If the polygon bends at this point, or if we will be smoothing the \ - polygon, append the pixel coordinates at this pixel corner to the \ - polygon. */ \ - if( full || pa != pc ) ADD( xx, yy ); \ -\ -/* Arrived at bottom right corner of good pixel from lower left. */ \ - } else { \ -\ -/* Note the pixel coordinates at the bottom right corner of the current \ - pixel. */ \ - if( starpix ) { \ - xx = ix; \ - yy = iy - 1.0; \ - } else { \ - xx = ix + 0.5; \ - yy = iy - 0.5; \ - } \ -\ -/* Pointer to lower right pixel value */ \ - pb = pa - ( nx - 1 ); \ -\ -/* Pointer to mid right pixel value. */ \ - pc = pa + 1; \ -\ -/* If lower right pixel is good, move down its left edge. */ \ - if( iy > lbnd[ 1 ] && ix < ubnd[ 0 ] && ISVALID(*pb,OperI,value) ) { \ - nright++; \ - pa = pb; \ - at = 0; \ - ix++; \ - iy--; \ - dx = DELTA; \ - dy = DELTA; \ -\ -/* Otherwise, if right mid pixel is good, move right along its lower edge. */ \ - } else if( ix < ubnd[ 0 ] && ISVALID(*pc,OperI,value) ) { \ - pa = pc; \ - at = 3; \ - ix++; \ - dx = 0.0; \ - dy = DELTA; \ -\ -/* Otherwise, move up the right edge of the current pixel. */ \ - } else { \ - nright--; \ - at = 2; \ - dx = -DELTA; \ - dy = DELTA; \ - } \ -\ -/* If the polygon bends at this point, or if we will be smoothing the \ - polygon, append the pixel coordinates at this pixel corner to the \ - polygon. */ \ - if( full || pa != pc ) ADD( xx, yy ); \ - } \ -\ -/* If we have arrived back at the start, break out of the loop. */ \ - if( ix == ix0 && iy == iy0 && at == 2 ) done = 1; \ - } \ -\ -/* If we have circled round to the right, the polygon will not enclosed \ - the specified position, so free resources and return a NULL pointer. */ \ - if( nright > 0 ) { \ - xvert = astFree( xvert ); \ - yvert = astFree( yvert ); \ -\ -/* If we have circled round to the left, the polygon will enclose \ - the specified position, so create and return a PointSet. */ \ - } else { \ - result = astPointSet( nvert, 2, " ", status ); \ - ptr[ 0 ] = xvert; \ - ptr[ 1 ] = yvert; \ - astSetPoints( result, ptr ); \ - } \ -\ -/* Annul the returned PointSet if anythign went wrong. */ \ - if( !astOK && result ) result = astAnnul( result ); \ -\ -/* Return the PointSet pointer. */ \ - return result; \ -} - -/* Define a macro to add a vertex position to dynamically allocated - arrays of X and Y positions. We offset the supplied position by - a small fraction of a pixel towards the centre of hte polygon to - avoid placing vertices exactly on the edge, which may cause problems - later for pixels that are on the edge of an area of bad pixel. */ -#define ADD(X,Y) {\ - ii = nvert++; \ - xvert = (double *) astGrow( xvert, nvert, sizeof( double ) ); \ - yvert = (double *) astGrow( yvert, nvert, sizeof( double ) ); \ - if( astOK ) { \ - xvert[ ii ] = (X+dx); \ - yvert[ ii ] = (Y+dy); \ - } \ -} - -/* Define a macro that uses the above macro to to create implementations - of TraceEdge for all operations. */ -#define MAKEALL_TRACEEDGE(X,Xtype) \ -MAKE_TRACEEDGE(X,Xtype,LT,AST__LT) \ -MAKE_TRACEEDGE(X,Xtype,LE,AST__LE) \ -MAKE_TRACEEDGE(X,Xtype,EQ,AST__EQ) \ -MAKE_TRACEEDGE(X,Xtype,NE,AST__NE) \ -MAKE_TRACEEDGE(X,Xtype,GE,AST__GE) \ -MAKE_TRACEEDGE(X,Xtype,GT,AST__GT) - -/* Expand the above macro to generate a function for each required - data type and operation. */ -#if HAVE_LONG_DOUBLE /* Not normally implemented */ -MAKEALL_TRACEEDGE(LD,long double) -#endif -MAKEALL_TRACEEDGE(D,double) -MAKEALL_TRACEEDGE(L,long int) -MAKEALL_TRACEEDGE(UL,unsigned long int) -MAKEALL_TRACEEDGE(I,int) -MAKEALL_TRACEEDGE(UI,unsigned int) -MAKEALL_TRACEEDGE(S,short int) -MAKEALL_TRACEEDGE(US,unsigned short int) -MAKEALL_TRACEEDGE(B,signed char) -MAKEALL_TRACEEDGE(UB,unsigned char) -MAKEALL_TRACEEDGE(F,float) - -/* Undefine the macros. */ -#undef MAKE_TRACEEDGE -#undef MAKEALL_TRACEEDGE - -static AstPointSet *Transform( AstMapping *this_mapping, AstPointSet *in, - int forward, AstPointSet *out, int *status ) { -/* -* Name: -* Transform - -* Purpose: -* Apply a Polygon to transform a set of points. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* AstPointSet *Transform( AstMapping *this, AstPointSet *in, -* int forward, AstPointSet *out, int *status ) - -* Class Membership: -* Polygon member function (over-rides the astTransform protected -* method inherited from the Region class). - -* Description: -* This function takes a Polygon and a set of points encapsulated in a -* PointSet and transforms the points by setting axis values to -* AST__BAD for all points which are outside the region. Points inside -* the region are copied unchanged from input to output. - -* Parameters: -* this -* Pointer to the Polygon. -* in -* Pointer to the PointSet holding the input coordinate data. -* forward -* A non-zero value indicates that the forward coordinate transformation -* should be applied, while a zero value requests the inverse -* transformation. -* out -* Pointer to a PointSet which will hold the transformed (output) -* coordinate values. A NULL value may also be given, in which case a -* new PointSet will be created by this function. -* status -* Pointer to the inherited status variable. - -* Returned Value: -* Pointer to the output (possibly new) PointSet. - -* Notes: -* - The forward and inverse transformations are identical for a -* Region. -* - A null pointer will be returned if this function is invoked with the -* global error status set, or if it should fail for any reason. -* - The number of coordinate values per point in the input PointSet must -* match the number of axes in the Frame represented by the Polygon. -* - If an output PointSet is supplied, it must have space for sufficient -* number of points and coordinate values per point to accommodate the -* result. Any excess space will be ignored. -*/ - -/* Local Variables: */ - AstFrame *frm; /* Pointer to base Frame in FrameSet */ - AstLineDef *a; /* Line from inside point to test point */ - AstLineDef *b; /* Polygon edge */ - AstPointSet *in_base; /* PointSet holding base Frame input positions*/ - AstPointSet *result; /* Pointer to output PointSet */ - AstPolygon *this; /* Pointer to Polygon */ - double **ptr_in; /* Pointer to input base Frame coordinate data */ - double **ptr_out; /* Pointer to output current Frame coordinate data */ - double *px; /* Pointer to array of first axis values */ - double *py; /* Pointer to array of second axis values */ - double p[ 2 ]; /* Current test position */ - int closed; /* Is the boundary part of the Region? */ - int i; /* Edge index */ - int icoord; /* Coordinate index */ - int in_region; /* Is the point inside the Region? */ - int ncoord_out; /* No. of current Frame axes */ - int ncross; /* Number of crossings */ - int neg; /* Has the Region been negated? */ - int npoint; /* No. of input points */ - int nv; /* No. of vertices */ - int point; /* Loop counter for input points */ - int pos; /* Is test position in, on, or outside boundary? */ - -/* Check the global error status. */ - if ( !astOK ) return NULL; - -/* Obtain a pointer to the Polygon structure. */ - this = (AstPolygon *) this_mapping; - -/* Apply the parent mapping using the stored pointer to the Transform member - function inherited from the parent Region class. This function validates - all arguments and generates an output PointSet if necessary, - containing a copy of the input PointSet. */ - result = (*parent_transform)( this_mapping, in, forward, out, status ); - -/* Get the number of points to be transformed. */ - npoint = astGetNpoint( result ); - -/* Get a pointer to the output axis values. */ - ptr_out = astGetPoints( result ); - -/* Find the number of axes in the current Frame. This need not be 2 (the - number of axes in the *base* Frame must be 2 however). */ - ncoord_out = astGetNcoord( result ); - -/* We will now extend the parent astTransform method by performing the - calculations needed to generate the output coordinate values. */ - -/* First use the encapsulated FrameSet to transform the supplied positions - from the current Frame in the encapsulated FrameSet (the Frame - represented by the Region), to the base Frame (the Frame in which the - Region is defined). This call also returns a pointer to the base Frame - of the encapsulated FrameSet. Note, the returned pointer may be a - clone of the "in" pointer, and so we must be carefull not to modify the - contents of the returned PointSet. */ - in_base = astRegTransform( this, in, 0, NULL, &frm ); - ptr_in = astGetPoints( in_base ); - -/* Get the number of vertices in the polygon. */ - nv = astGetNpoint( ((AstRegion *) this)->points ); - -/* See if the boundary is part of the Region. */ - closed = astGetClosed( this ); - -/* See if the Region has been negated. */ - neg = astGetNegated( this ); - -/* Perform coordinate arithmetic. */ -/* ------------------------------ */ - if ( astOK ) { - px = ptr_in[ 0 ]; - py = ptr_in[ 1 ]; - -/* Loop round each supplied point in the base Frame of the polygon. */ - for ( point = 0; point < npoint; point++, px++, py++ ) { - -/* If the input point is bad, indicate that bad output values should be - returned. */ - if( *px == AST__BAD || *py == AST__BAD ) { - in_region = 0; - -/* Otherwise, we first determine if the point is inside, outside, or on, - the Polygon boundary. Initialially it is unknown. */ - } else { - -/* Ensure cached information is available.*/ - Cache( this, status ); - -/* Create a definition of the line from a point which is inside the - polygon to the supplied point. This is a structure which includes - cached intermediate information which can be used to speed up - subsequent calculations. */ - p[ 0 ] = *px; - p[ 1 ] = *py; - a = astLineDef( frm, this->in, p ); - -/* We now determine the number of times this line crosses the polygon - boundary. Initialise the number of crossings to zero. */ - ncross = 0; - pos = UNKNOWN; - -/* Loop rouind all edges of the polygon. */ - for( i = 0; i < nv; i++ ) { - b = this->edges[ i ]; - -/* If this point is on the current edge, then we need do no more checks - since we know it is either inside or outside the polygon (depending on - whether the polygon is closed or not). */ - if( astLineContains( frm, b, 0, p ) ) { - pos = ON; - break; - -/* Otherwise, see if the two lines cross within their extent. If so, - increment the number of crossings. */ - } else if( astLineCrossing( frm, b, a, NULL ) ) { - ncross++; - } - } - -/* Free resources */ - a = astFree( a ); - -/* If the position is not on the boundary, it is inside the boundary if - the number of crossings is even, and outside otherwise. */ - if( pos == UNKNOWN ) pos = ( ncross % 2 == 0 )? IN : OUT; - -/* Whether the point is in the Region depends on whether the point is - inside the polygon boundary, whether the Polygon has been negated, and - whether the polygon is closed. */ - if( neg ) { - if( pos == IN ) { - in_region = 0; - } else if( pos == OUT ) { - in_region = 1; - } else if( closed ) { - in_region = 1; - } else { - in_region = 0; - } - - } else { - if( pos == IN ) { - in_region = 1; - } else if( pos == OUT ) { - in_region = 0; - } else if( closed ) { - in_region = 1; - } else { - in_region = 0; - } - } - } - -/* If the point is not inside the Region, store bad output values. */ - if( !in_region ) { - for ( icoord = 0; icoord < ncoord_out; icoord++ ) { - ptr_out[ icoord ][ point ] = AST__BAD; - } - } - } - } - -/* Free resources */ - in_base = astAnnul( in_base ); - frm = astAnnul( frm ); - -/* Annul the result if an error has occurred. */ - if( !astOK ) result = astAnnul( result ); - -/* Return a pointer to the output PointSet. */ - return result; -} - -/* Functions which access class attributes. */ -/* ---------------------------------------- */ -/* Implement member functions to access the attributes associated with - this class using the macros defined for this purpose in the - "object.h" file. For a description of each attribute, see the class - interface (in the associated .h file). */ - -/* -*att++ -* Name: -* SimpVertices - -* Purpose: -* Simplify a Polygon by transforming its vertices? - -* Type: -* Public attribute. - -* Synopsis: -* Integer (boolean). - -* Description: -* This attribute controls the behaviour of the -c astSimplify -f AST_SIMPLIFY -* method when applied to a Polygon. The simplified Polygon is created -* by transforming the vertices from the Frame in which the Polygon -* was originally defined into the Frame currently represented by the -* Polygon. If SimpVertices is non-zero (the default) then this -* simplified Polygon is returned without further checks. If SimpVertices -* is zero, a check is made that the edges of the new Polygon do not -* depart significantly from the edges of the original Polygon (as -* determined by the uncertainty associated with the Polygon). This -* could occur, for instance, if the Mapping frrm the original to the -* current Frame is highly non-linear. If this check fails, the -* original unsimplified Polygon is returned without change. - -* Applicability: -* Polygon -* All Polygons have this attribute. - -*att-- -*/ -astMAKE_CLEAR(Polygon,SimpVertices,simp_vertices,-INT_MAX) -astMAKE_GET(Polygon,SimpVertices,int,0,( ( this->simp_vertices != -INT_MAX ) ? - this->simp_vertices : 1 )) -astMAKE_SET(Polygon,SimpVertices,int,simp_vertices,( value != 0 )) -astMAKE_TEST(Polygon,SimpVertices,( this->simp_vertices != -INT_MAX )) - -/* Copy constructor. */ -/* ----------------- */ -static void Copy( const AstObject *objin, AstObject *objout, int *status ) { -/* -* Name: -* Copy - -* Purpose: -* Copy constructor for Polygon objects. - -* Type: -* Private function. - -* Synopsis: -* void Copy( const AstObject *objin, AstObject *objout, int *status ) - -* Description: -* This function implements the copy constructor for Polygon objects. - -* Parameters: -* objin -* Pointer to the object to be copied. -* objout -* Pointer to the object being constructed. -* status -* Pointer to the inherited status variable. - -* Notes: -* - This constructor makes a deep copy. -*/ - -/* Local Variables: */ - AstPolygon *out; /* Pointer to output Polygon */ - -/* Check the global error status. */ - if ( !astOK ) return; - -/* Obtain pointers to the output Polygon. */ - out = (AstPolygon *) objout; - -/* For safety, first clear any references to the input memory from - the output Polygon. */ - out->edges = NULL; - out->startsat = NULL; - -/* Indicate cached information needs nre-calculating. */ - astResetCache( (AstPolygon *) out ); -} - - -/* Destructor. */ -/* ----------- */ -static void Delete( AstObject *obj, int *status ) { -/* -* Name: -* Delete - -* Purpose: -* Destructor for Polygon objects. - -* Type: -* Private function. - -* Synopsis: -* void Delete( AstObject *obj, int *status ) - -* Description: -* This function implements the destructor for Polygon objects. - -* Parameters: -* obj -* Pointer to the object to be deleted. -* status -* Pointer to the inherited status variable. - -* Notes: -* This function attempts to execute even if the global error status is -* set. -*/ - -/* Local Variables: */ - AstPointSet *ps; /* Pointer to PointSet inside Region */ - AstPolygon *this; /* Pointer to Polygon */ - int i; /* Index of vertex */ - int istat; /* Original AST error status */ - int nv; /* Number of vertices */ - int rep; /* Original error reporting state */ - -/* Obtain a pointer to the Polygon structure. */ - this = (AstPolygon *) obj; - -/* Annul all resources. */ - ps = ((AstRegion *) this)->points; - if( this->edges && ps ) { - -/* Ensure we get a value for "nv" even if an error has occurred. */ - istat = astStatus; - astClearStatus; - rep = astReporting( 0 ); - - nv = astGetNpoint( ps ); - - astSetStatus( istat ); - astReporting( rep ); - -/* Free the structures holding the edge information. */ - for( i = 0; i < nv; i++ ) { - this->edges[ i ] = astFree( this->edges[ i ] ); - } - this->edges = astFree( this->edges ); - this->startsat = astFree( this->startsat ); - - } -} - -/* Dump function. */ -/* -------------- */ -static void Dump( AstObject *this_object, AstChannel *channel, int *status ) { -/* -* Name: -* Dump - -* Purpose: -* Dump function for Polygon objects. - -* Type: -* Private function. - -* Synopsis: -* void Dump( AstObject *this, AstChannel *channel, int *status ) - -* Description: -* This function implements the Dump function which writes out data -* for the Polygon class to an output Channel. - -* Parameters: -* this -* Pointer to the Polygon whose data are being written. -* channel -* Pointer to the Channel to which the data are being written. -* status -* Pointer to the inherited status variable. -*/ - -/* Local Variables: */ - AstPolygon *this; /* Pointer to the Polygon structure */ - int ival; /* Integer attribute value */ - int set; /* Attribute value set? */ - -/* Check the global error status. */ - if ( !astOK ) return; - -/* Obtain a pointer to the Polygon structure. */ - this = (AstPolygon *) this_object; - -/* Write out values representing the instance variables for the - Polygon class. Accompany these with appropriate comment strings, - possibly depending on the values being written.*/ - -/* In the case of attributes, we first use the appropriate (private) - Test... member function to see if they are set. If so, we then use - the (private) Get... function to obtain the value to be written - out. - - For attributes which are not set, we use the astGet... method to - obtain the value instead. This will supply a default value - (possibly provided by a derived class which over-rides this method) - which is more useful to a human reader as it corresponds to the - actual default attribute value. Since "set" will be zero, these - values are for information only and will not be read back. */ - -/* SimpVertices. */ -/* ------------ */ -/* Write out the forward-inverse simplification flag. */ - set = TestSimpVertices( this, status ); - ival = set ? GetSimpVertices( this, status ) : astGetSimpVertices( this ); - astWriteInt( channel, "SimpVT", set, 0, ival, "Simplify by transforming vertices?" ); - -/* A flag indicating the convention used for determining the interior of - the polygon. A zero value indicates that the old AST system is in - use (inside to the left when moving anti-clockwise round the vertices - as viewed from the outside of the celestial sphere). A non-zero value - indicates the STC system is in use (inside to the left when moving - anti-clockwise round the vertices as viewed from the inside of the - celestial sphere). AST currently uses the STC system. */ - astWriteInt( channel, "Order", 1, 0, 1, "Polygon uses STC vertex order convention" ); -} - -/* Standard class functions. */ -/* ========================= */ -/* Implement the astIsAPolygon and astCheckPolygon functions using the macros - defined for this purpose in the "object.h" header file. */ -astMAKE_ISA(Polygon,Region) -astMAKE_CHECK(Polygon) - -AstPolygon *astPolygon_( void *frame_void, int npnt, int dim, - const double *points, AstRegion *unc, - const char *options, int *status, ...) { -/* -*++ -* Name: -c astPolygon -f AST_POLYGON - -* Purpose: -* Create a Polygon. - -* Type: -* Public function. - -* Synopsis: -c #include "polygon.h" -c AstPolygon *astPolygon( AstFrame *frame, int npnt, int dim, -c const double *points, AstRegion *unc, -c const char *options, ... ) -f RESULT = AST_POLYGON( FRAME, NPNT, DIM, POINTS, UNC, OPTIONS, STATUS ) - -* Class Membership: -* Polygon constructor. - -* Description: -* This function creates a new Polygon object and optionally initialises -* its attributes. -* -* The Polygon class implements a polygonal area, defined by a -* collection of vertices, within a 2-dimensional Frame. The vertices -* are connected together by geodesic curves within the encapsulated Frame. -* For instance, if the encapsulated Frame is a simple Frame then the -* geodesics will be straight lines, but if the Frame is a SkyFrame then -* the geodesics will be great circles. Note, the vertices must be -* supplied in an order such that the inside of the polygon is to the -* left of the boundary as the vertices are traversed. Supplying them -* in the reverse order will effectively negate the polygon. -* -* Within a SkyFrame, neighbouring vertices are always joined using the -* shortest path. Thus if an edge of 180 degrees or more in length is -* required, it should be split into section each of which is less -* than 180 degrees. The closed path joining all the vertices in order -* will divide the celestial sphere into two disjoint regions. The -* inside of the polygon is the region which is circled in an -* anti-clockwise manner (when viewed from the inside of the celestial -* sphere) when moving through the list of vertices in the order in -* which they were supplied when the Polygon was created (i.e. the -* inside is to the left of the boundary when moving through the -* vertices in the order supplied). - -* Parameters: -c frame -f FRAME = INTEGER (Given) -* A pointer to the Frame in which the region is defined. It must -* have exactly 2 axes. A deep copy is taken of the supplied Frame. -* This means that any subsequent changes made to the Frame using the -* supplied pointer will have no effect the Region. -c npnt -f NPNT = INTEGER (Given) -* The number of points in the Region. -c dim -f DIM = INTEGER (Given) -c The number of elements along the second dimension of the "points" -f The number of elements along the first dimension of the POINTS -* array (which contains the point coordinates). This value is -* required so that the coordinate values can be correctly -* located if they do not entirely fill this array. The value -c given should not be less than "npnt". -f given should not be less than NPNT. -c points -f POINTS( DIM, 2 ) = DOUBLE PRECISION (Given) -c The address of the first element of a 2-dimensional array of -c shape "[2][dim]" giving the physical coordinates of the vertices. -c These should be stored such that the value of coordinate -c number "coord" for point number "pnt" is found in element -c "in[coord][pnt]". -f A 2-dimensional array giving the physical coordinates of the -f vertices. These should be stored such that the value of coordinate -f number COORD for point number PNT is found in element IN(PNT,COORD). -c unc -f UNC = INTEGER (Given) -* An optional pointer to an existing Region which specifies the -* uncertainties associated with the boundary of the Polygon being created. -* The uncertainty in any point on the boundary of the Polygon is found by -* shifting the supplied "uncertainty" Region so that it is centred at -* the boundary point being considered. The area covered by the -* shifted uncertainty Region then represents the uncertainty in the -* boundary position. The uncertainty is assumed to be the same for -* all points. -* -* If supplied, the uncertainty Region must be of a class for which -* all instances are centro-symetric (e.g. Box, Circle, Ellipse, etc.) -* or be a Prism containing centro-symetric component Regions. A deep -* copy of the supplied Region will be taken, so subsequent changes to -* the uncertainty Region using the supplied pointer will have no -* effect on the created Polygon. Alternatively, -f a null Object pointer (AST__NULL) -c a NULL Object pointer -* may be supplied, in which case a default uncertainty is used -* equivalent to a box 1.0E-6 of the size of the Polygon being created. -* -* The uncertainty Region has two uses: 1) when the -c astOverlap -f AST_OVERLAP -* function compares two Regions for equality the uncertainty -* Region is used to determine the tolerance on the comparison, and 2) -* when a Region is mapped into a different coordinate system and -* subsequently simplified (using -c astSimplify), -f AST_SIMPLIFY), -* the uncertainties are used to determine if the transformed boundary -* can be accurately represented by a specific shape of Region. -c options -f OPTIONS = CHARACTER * ( * ) (Given) -c Pointer to a null-terminated string containing an optional -c comma-separated list of attribute assignments to be used for -c initialising the new Polygon. The syntax used is identical to -c that for the astSet function and may include "printf" format -c specifiers identified by "%" symbols in the normal way. -f A character string containing an optional comma-separated -f list of attribute assignments to be used for initialising the -f new Polygon. The syntax used is identical to that for the -f AST_SET routine. -c ... -c If the "options" string contains "%" format specifiers, then -c an optional list of additional arguments may follow it in -c order to supply values to be substituted for these -c specifiers. The rules for supplying these are identical to -c those for the astSet function (and for the C "printf" -c function). -f STATUS = INTEGER (Given and Returned) -f The global status. - -* Returned Value: -c astPolygon() -f AST_POLYGON = INTEGER -* A pointer to the new Polygon. - -* Notes: -* - A null Object pointer (AST__NULL) will be returned if this -c function is invoked with the AST error status set, or if it -f function is invoked with STATUS set to an error value, or if it -* should fail for any reason. - -* Status Handling: -* The protected interface to this function includes an extra -* parameter at the end of the parameter list descirbed above. This -* parameter is a pointer to the integer inherited status -* variable: "int *status". - -*-- -*/ - -/* Local Variables: */ - astDECLARE_GLOBALS /* Pointer to thread-specific global data */ - AstFrame *frame; /* Pointer to Frame structure */ - AstPolygon *new; /* Pointer to new Polygon */ - va_list args; /* Variable argument list */ - -/* Get a pointer to the thread specific global data structure. */ - astGET_GLOBALS(NULL); - -/* Check the global status. */ - if ( !astOK ) return NULL; - -/* Obtain and validate a pointer to the supplied Frame structure. */ - frame = astCheckFrame( frame_void ); - -/* Initialise the Polygon, allocating memory and initialising the - virtual function table as well if necessary. */ - new = astInitPolygon( NULL, sizeof( AstPolygon ), !class_init, - &class_vtab, "Polygon", frame, npnt, - dim, points, unc ); - -/* If successful, note that the virtual function table has been - initialised. */ - if ( astOK ) { - class_init = 1; - -/* Obtain the variable argument list and pass it along with the options string - to the astVSet method to initialise the new Polygon's attributes. */ - va_start( args, status ); - astVSet( new, options, NULL, args ); - va_end( args ); - -/* If an error occurred, clean up by deleting the new object. */ - if ( !astOK ) new = astDelete( new ); - } - -/* Return a pointer to the new Polygon. */ - return new; -} - -AstPolygon *astPolygonId_( void *frame_void, int npnt, int dim, - const double *points, void *unc_void, - const char *options, ... ) { -/* -* Name: -* astPolygonId_ - -* Purpose: -* Create a Polygon. - -* Type: -* Private function. - -* Synopsis: -* #include "polygon.h" -* AstPolygon *astPolygonId_( void *frame_void, int npnt, -* int dim, const double *points, void *unc_void, -* const char *options, ... ) - -* Class Membership: -* Polygon constructor. - -* Description: -* This function implements the external (public) interface to the -* astPolygon constructor function. It returns an ID value (instead -* of a true C pointer) to external users, and must be provided -* because astPolygon_ has a variable argument list which cannot be -* encapsulated in a macro (where this conversion would otherwise -* occur). -* -* The variable argument list also prevents this function from -* invoking astPolygon_ directly, so it must be a re-implementation -* of it in all respects, except for the final conversion of the -* result to an ID value. - -* Parameters: -* As for astPolygon_. - -* Returned Value: -* The ID value associated with the new Polygon. -*/ - -/* Local Variables: */ - astDECLARE_GLOBALS /* Pointer to thread-specific global data */ - AstFrame *frame; /* Pointer to Frame structure */ - AstPolygon *new; /* Pointer to new Polygon */ - AstRegion *unc; /* Pointer to Region structure */ - va_list args; /* Variable argument list */ - - int *status; /* Get a pointer to the thread specific global data structure. */ - astGET_GLOBALS(NULL); - -/* Get a pointer to the inherited status value. */ - status = astGetStatusPtr; - -/* Check the global status. */ - if ( !astOK ) return NULL; - -/* Obtain a Frame pointer from the supplied ID and validate the - pointer to ensure it identifies a valid Frame. */ - frame = astVerifyFrame( astMakePointer( frame_void ) ); - -/* Obtain a Region pointer from the supplied "unc" ID and validate the - pointer to ensure it identifies a valid Region . */ - unc = unc_void ? astCheckRegion( astMakePointer( unc_void ) ) : NULL; - -/* Initialise the Polygon, allocating memory and initialising the - virtual function table as well if necessary. */ - new = astInitPolygon( NULL, sizeof( AstPolygon ), !class_init, - &class_vtab, "Polygon", frame, npnt, dim, - points, unc ); - -/* If successful, note that the virtual function table has been - initialised. */ - if ( astOK ) { - class_init = 1; - -/* Obtain the variable argument list and pass it along with the options string - to the astVSet method to initialise the new Polygon's attributes. */ - va_start( args, options ); - astVSet( new, options, NULL, args ); - va_end( args ); - -/* If an error occurred, clean up by deleting the new object. */ - if ( !astOK ) new = astDelete( new ); - } - -/* Return an ID value for the new Polygon. */ - return astMakeId( new ); -} - - -AstPolygon *astInitPolygon_( void *mem, size_t size, int init, AstPolygonVtab *vtab, - const char *name, AstFrame *frame, int npnt, - int dim, const double *points, AstRegion *unc, int *status ) { -/* -*+ -* Name: -* astInitPolygon - -* Purpose: -* Initialise a Polygon. - -* Type: -* Protected function. - -* Synopsis: -* #include "polygon.h" -* AstPolygon *astInitPolygon( void *mem, size_t size, int init, AstPolygonVtab *vtab, -* const char *name, AstFrame *frame, int npnt, -* int dim, const double *points, AstRegion *unc ) - -* Class Membership: -* Polygon initialiser. - -* Description: -* This function is provided for use by class implementations to initialise -* a new Polygon object. It allocates memory (if necessary) to accommodate -* the Polygon plus any additional data associated with the derived class. -* It then initialises a Polygon structure at the start of this memory. If -* the "init" flag is set, it also initialises the contents of a virtual -* function table for a Polygon at the start of the memory passed via the -* "vtab" parameter. - -* Parameters: -* mem -* A pointer to the memory in which the Polygon is to be initialised. -* This must be of sufficient size to accommodate the Polygon data -* (sizeof(Polygon)) plus any data used by the derived class. If a value -* of NULL is given, this function will allocate the memory itself using -* the "size" parameter to determine its size. -* size -* The amount of memory used by the Polygon (plus derived class data). -* This will be used to allocate memory if a value of NULL is given for -* the "mem" parameter. This value is also stored in the Polygon -* structure, so a valid value must be supplied even if not required for -* allocating memory. -* init -* A logical flag indicating if the Polygon's virtual function table is -* to be initialised. If this value is non-zero, the virtual function -* table will be initialised by this function. -* vtab -* Pointer to the start of the virtual function table to be associated -* with the new Polygon. -* name -* Pointer to a constant null-terminated character string which contains -* the name of the class to which the new object belongs (it is this -* pointer value that will subsequently be returned by the astGetClass -* method). -* frame -* A pointer to the Frame in which the region is defined. -* npnt -* The number of points in the Region. -* dim -* The number of elements along the second dimension of the "points" -* array (which contains the point coordinates). This value is -* required so that the coordinate values can be correctly -* located if they do not entirely fill this array. The value -* given should not be less than "npnt". -* points -* The address of the first element of a 2-dimensional array of -* shape "[2][dim]" giving the physical coordinates of the -* points. These should be stored such that the value of coordinate -* number "coord" for point number "pnt" is found in element -* "in[coord][pnt]". -* unc -* A pointer to a Region which specifies the uncertainty in the -* supplied positions (all points in the new Polygon being -* initialised are assumed to have the same uncertainty). A NULL -* pointer can be supplied, in which case default uncertainties equal -* to 1.0E-6 of the dimensions of the new Polygon's bounding box are -* used. If an uncertainty Region is supplied, it must be either a Box, -* a Circle or an Ellipse, and its encapsulated Frame must be related -* to the Frame supplied for parameter "frame" (i.e. astConvert -* should be able to find a Mapping between them). Two positions -* the "frame" Frame are considered to be co-incident if their -* uncertainty Regions overlap. The centre of the supplied -* uncertainty Region is immaterial since it will be re-centred on the -* point being tested before use. A deep copy is taken of the supplied -* Region. - -* Returned Value: -* A pointer to the new Polygon. - -* Notes: -* - A null pointer will be returned if this function is invoked with the -* global error status set, or if it should fail for any reason. -*- -*/ - -/* Local Variables: */ - AstPolygon *new; /* Pointer to new Polygon */ - AstPointSet *pset; /* Pointer to PointSet holding points */ - const double *q; /* Pointer to next supplied axis value */ - double **ptr; /* Pointer to data in pset */ - double *p; /* Pointer to next PointSet axis value */ - int i; /* Axis index */ - int j; /* Point index */ - int nin; /* No. of axes */ - -/* Check the global status. */ - if ( !astOK ) return NULL; - -/* If necessary, initialise the virtual function table. */ - if ( init ) astInitPolygonVtab( vtab, name ); - -/* Initialise. */ - new = NULL; - -/* Check the number of axis values per position is correct. */ - nin = astGetNaxes( frame ); - if( nin != 2 ) { - astError( AST__BADIN, "astInitPolygon(%s): The supplied %s has %d " - "axes - polygons must have exactly 2 axes.", status, name, - astGetClass( frame ), nin ); - -/* If so create a PointSet and store the supplied points in it. Check - none are bad. */ - } else { - pset = astPointSet( npnt, 2, "", status ); - ptr = astGetPoints( pset ); - for( i = 0; i < 2 && astOK; i++ ) { - p = ptr[ i ]; - q = points + i*dim; - for( j = 0; j < npnt; j++ ) { - if( (*(p++) = *(q++)) == AST__BAD ) { - astError( AST__BADIN, "astInitPolygon(%s): One or more " - "bad axis values supplied for the vertex " - "number %d.", status, name, j + 1 ); - break; - } - } - } - -/* Initialise a Region structure (the parent class) as the first component - within the Polygon structure, allocating memory if necessary. */ - new = (AstPolygon *) astInitRegion( mem, size, 0, (AstRegionVtab *) vtab, - name, frame, pset, unc ); - if ( astOK ) { - -/* Initialise the Polygon data. */ -/* ------------------------------ */ - new->lbnd[ 0 ] = AST__BAD; - new->ubnd[ 0 ] = AST__BAD; - new->lbnd[ 1 ] = AST__BAD; - new->ubnd[ 1 ] = AST__BAD; - new->simp_vertices = -INT_MAX; - new->edges = NULL; - new->startsat = NULL; - new->totlen = 0.0; - new->acw = 1; - new->stale = 1; - -/* Ensure the vertices are stored such that the unnegated Polygon - represents the inside of the polygon. */ - EnsureInside( new, status ); - -/* If an error occurred, clean up by deleting the new Polygon. */ - if ( !astOK ) new = astDelete( new ); - } - -/* Free resources. */ - pset = astAnnul( pset ); - - } - -/* Return a pointer to the new Polygon. */ - return new; -} - -AstPolygon *astLoadPolygon_( void *mem, size_t size, AstPolygonVtab *vtab, - const char *name, AstChannel *channel, int *status ) { -/* -*+ -* Name: -* astLoadPolygon - -* Purpose: -* Load a Polygon. - -* Type: -* Protected function. - -* Synopsis: -* #include "polygon.h" -* AstPolygon *astLoadPolygon( void *mem, size_t size, AstPolygonVtab *vtab, -* const char *name, AstChannel *channel ) - -* Class Membership: -* Polygon loader. - -* Description: -* This function is provided to load a new Polygon using data read -* from a Channel. It first loads the data used by the parent class -* (which allocates memory if necessary) and then initialises a -* Polygon structure in this memory, using data read from the input -* Channel. -* -* If the "init" flag is set, it also initialises the contents of a -* virtual function table for a Polygon at the start of the memory -* passed via the "vtab" parameter. - -* Parameters: -* mem -* A pointer to the memory into which the Polygon is to be -* loaded. This must be of sufficient size to accommodate the -* Polygon data (sizeof(Polygon)) plus any data used by derived -* classes. If a value of NULL is given, this function will -* allocate the memory itself using the "size" parameter to -* determine its size. -* size -* The amount of memory used by the Polygon (plus derived class -* data). This will be used to allocate memory if a value of -* NULL is given for the "mem" parameter. This value is also -* stored in the Polygon structure, so a valid value must be -* supplied even if not required for allocating memory. -* -* If the "vtab" parameter is NULL, the "size" value is ignored -* and sizeof(AstPolygon) is used instead. -* vtab -* Pointer to the start of the virtual function table to be -* associated with the new Polygon. If this is NULL, a pointer -* to the (static) virtual function table for the Polygon class -* is used instead. -* name -* Pointer to a constant null-terminated character string which -* contains the name of the class to which the new object -* belongs (it is this pointer value that will subsequently be -* returned by the astGetClass method). -* -* If the "vtab" parameter is NULL, the "name" value is ignored -* and a pointer to the string "Polygon" is used instead. - -* Returned Value: -* A pointer to the new Polygon. - -* Notes: -* - A null pointer will be returned if this function is invoked -* with the global error status set, or if it should fail for any -* reason. -*- -*/ - -/* Local Variables: */ - astDECLARE_GLOBALS /* Pointer to thread-specific global data */ - AstPolygon *new; /* Pointer to the new Polygon */ - int order; /* Is the new (STC) order convention used? */ - -/* Initialise. */ - new = NULL; - -/* Check the global error status. */ - if ( !astOK ) return new; - -/* Get a pointer to the thread specific global data structure. */ - astGET_GLOBALS(channel); - -/* If a NULL virtual function table has been supplied, then this is - the first loader to be invoked for this Polygon. In this case the - Polygon belongs to this class, so supply appropriate values to be - passed to the parent class loader (and its parent, etc.). */ - if ( !vtab ) { - size = sizeof( AstPolygon ); - vtab = &class_vtab; - name = "Polygon"; - -/* If required, initialise the virtual function table for this class. */ - if ( !class_init ) { - astInitPolygonVtab( vtab, name ); - class_init = 1; - } - } - -/* Invoke the parent class loader to load data for all the ancestral - classes of the current one, returning a pointer to the resulting - partly-built Polygon. */ - new = astLoadRegion( mem, size, (AstRegionVtab *) vtab, name, - channel ); - - if ( astOK ) { - -/* Read input data. */ -/* ================ */ -/* Request the input Channel to read all the input data appropriate to - this class into the internal "values list". */ - astReadClassData( channel, "Polygon" ); - -/* Now read each individual data item from this list and use it to - initialise the appropriate instance variable(s) for this class. */ - -/* In the case of attributes, we first read the "raw" input value, - supplying the "unset" value as the default. If a "set" value is - obtained, we then use the appropriate (private) Set... member - function to validate and set the value properly. */ - - new->simp_vertices = astReadInt( channel, "simpvt", -INT_MAX ); - if ( TestSimpVertices( new, status ) ) SetSimpVertices( new, new->simp_vertices, status ); - -/* A flag indicating what order the vertices are stored in. See the Dump - function. */ - order = astReadInt( channel, "order", 0 ); - -/* Initialise other class properties. */ - new->lbnd[ 0 ] = AST__BAD; - new->ubnd[ 0 ] = AST__BAD; - new->lbnd[ 1 ] = AST__BAD; - new->ubnd[ 1 ] = AST__BAD; - new->edges = NULL; - new->startsat = NULL; - new->totlen = 0.0; - new->acw = 1; - new->stale = 1; - -/* If the order in which the vertices were written used the old AST - convention, negate the Polygon so that it is consistent with the - current conevtion (based on STC). */ - if( ! order ) astNegate( new ); - -/* Ensure the vertices are stored such that the unnegated Polygon - represents the inside of the polygon. */ - EnsureInside( new, status ); - -/* If an error occurred, clean up by deleting the new Polygon. */ - if ( !astOK ) new = astDelete( new ); - } - -/* Return the new Polygon pointer. */ - return new; -} - -/* Virtual function interfaces. */ -/* ============================ */ -/* These provide the external interface to the virtual functions defined by - this class. Each simply checks the global error status and then locates and - executes the appropriate member function, using the function pointer stored - in the object's virtual function table (this pointer is located using the - astMEMBER macro defined in "object.h"). - - Note that the member function may not be the one defined here, as it may - have been over-ridden by a derived class. However, it should still have the - same interface. */ - - -AstPolygon *astDownsize_( AstPolygon *this, double maxerr, int maxvert, - int *status ) { - if ( !astOK ) return NULL; - return (**astMEMBER(this,Polygon,Downsize))( this, maxerr, maxvert, status ); -} - - |