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author | William Joye <wjoye@cfa.harvard.edu> | 2016-10-17 15:22:52 (GMT) |
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committer | William Joye <wjoye@cfa.harvard.edu> | 2016-10-17 15:22:52 (GMT) |
commit | 7dd9b970cec6832b8f6118dc2dd91a08d2836648 (patch) | |
tree | 4b3c86596ab87f35a3c6213397da07afe1e24d3e /ast/box.c | |
parent | d7bf7c61e8507e3cf51f195392c0f41f27ae18d8 (diff) | |
parent | 7fde2daeed593684120d75de07598154f3ddaf2c (diff) | |
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Merge commit '7fde2daeed593684120d75de07598154f3ddaf2c' as 'ast'
Diffstat (limited to 'ast/box.c')
-rw-r--r-- | ast/box.c | 5062 |
1 files changed, 5062 insertions, 0 deletions
diff --git a/ast/box.c b/ast/box.c new file mode 100644 index 0000000..99aa780 --- /dev/null +++ b/ast/box.c @@ -0,0 +1,5062 @@ +/* +*class++ +* Name: +* Box + +* Purpose: +* A box region with sides parallel to the axes of a Frame. + +* Constructor Function: +c astBox +f AST_BOX + +* Description: +* The Box class implements a Region which represents a box with sides +* parallel to the axes of a Frame (i.e. an area which encloses a given +* range of values on each axis). A Box is similar to an Interval, the +* only real difference being that the Interval class allows some axis +* limits to be unspecified. Note, a Box will only look like a box if +* the Frame geometry is approximately flat. For instance, a Box centred +* close to a pole in a SkyFrame will look more like a fan than a box +* (the Polygon class can be used to create a box-like region close to a +* pole). + +* Inheritance: +* The Box class inherits from the Region class. + +* Attributes: +* The Box class does not define any new attributes beyond +* those which are applicable to all Regions. + +* Functions: +c The Box class does not define any new functions beyond those +f The Box class does not define any new routines beyond those +* which are applicable to all Regions. + +* Copyright: +* Copyright (C) 1997-2006 Council for the Central Laboratory of the +* Research Councils +* Copyright (C) 2008-2009 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: +* 22-MAR-2004 (DSB): +* Original version. +* 14-FEB-2006 (DSB): +* Override astGetObjSize. +* 5-JUN-2007 (DSB): +* Improve astSimplify algorithm. +* 6-JUN-2007 (DSB): +* Change the iterating algorithm in MakeGrid so that it uses +* pixel index rather than axis value. This is more robust against +* rounding errors. +* 9-OCT-2007 (DSB): +* - Fix bug in RegBaseMesh that could cause incorrect meshes for 2D +* Boxes. +* - In RegBaseMesh, use flat geometry if all axes come from simple +* frames or from 1-dimensional specialist frames. +* 26-MAY-2008 (DSB): +* Fix bug in RegBaseMesh that caused an error to be reported if +* the Box occupies a single point. +* 20-JAN-2009 (DSB): +* Over-ride astRegBasePick. +* 26-JAN-2009 (DSB): +* Over-ride astMapMerge. +* 12-JUL-2009 (DSB): +* Modify Simplify so that if a Box can be split into two +* simpler components and then joined together into a Prism, it +* does so. This is because being able to express a Region in +* its current Frame is more important than having the simplest +* possible structure. +* 28-FEB-2011 (DSB): +* Do not assume the first axis value is good in function BestBox. +* 22-MAR-2011 (DSB): +* Improve uniformity of points within grid produced by astRegBaseGrid. +* 16-JUL-2013 (DSB): +* Use a more robust algorithm for determining the order of the +* vertices whan a Box is simplified to a Polygon. The old method +* sometimes resulted in an unbounded "inside-out" polygon. +* 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. +* 10-APR-2014 (DSB): +* More work (in function Cache() ) on handling uncertainty regions that straddle +* a discontinuity. This time ensure that the extent of the box on each axis takes +* account of the possibly cyclic nature of the base Frame. +* 25-4-2016 (DSB): +* Remove the unused box shrinking facility (a hang over from the +* days when the RegBaseGrid function operated by creating multiple +* meshes on the surface of the box, shrinking the box each time). +*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 Box + +/* Include files. */ +/* ============== */ +/* Interface definitions. */ +/* ---------------------- */ + +#include "globals.h" /* Thread-safe global data access */ +#include "cmpmap.h" /* Compound Mappings */ +#include "cmpframe.h" /* Compound Frames */ +#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" /* Interface definition for this class */ +#include "polygon.h" /* Interface definition for this class */ +#include "mapping.h" /* Position mappings */ +#include "unitmap.h" /* Unit Mappings */ +#include "permmap.h" /* Axis permutation Mappings */ +#include "interval.h" /* Axis interval regions */ +#include "nullregion.h" /* Empty regions */ +#include "pointlist.h" /* List of points in a Frame */ +#include "prism.h" /* Extruded regions */ + +/* Error code definitions. */ +/* ----------------------- */ +#include "ast_err.h" /* AST error codes */ + +/* C header files. */ +/* --------------- */ +#include <float.h> +#include <math.h> +#include <stdarg.h> +#include <stddef.h> +#include <stdio.h> +#include <string.h> + +/* 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 int (* parent_getobjsize)( AstObject *, int * ); +static AstPointSet *(* parent_transform)( AstMapping *, AstPointSet *, int, AstPointSet *, int * ); +static AstMapping *(* parent_simplify)( AstMapping *, int * ); +static void (* parent_setnegated)( AstRegion *, int, int * ); +static void (* parent_setclosed)( AstRegion *, int, int * ); +static void (* parent_clearnegated)( AstRegion *, int * ); +static void (* parent_clearclosed)( AstRegion *, int * ); +static void (* parent_setunc)( AstRegion *, AstRegion *, int * ); +static void (* parent_setregfs)( AstRegion *, AstFrame *, int * ); +static void (* parent_resetcache)( AstRegion *, int * ); + + +#ifdef THREAD_SAFE +/* Define how to initialise thread-specific globals. */ +#define GLOBAL_inits \ + globals->Class_Init = 0; + +/* Create the function that initialises global data for this module. */ +astMAKE_INITGLOBALS(Box) + +/* Define macros for accessing each item of thread specific global data. */ +#define class_init astGLOBAL(Box,Class_Init) +#define class_vtab astGLOBAL(Box,Class_Vtab) + + +#include <pthread.h> + + +#else + + +/* Define the class virtual function table and its initialisation flag + as static variables. */ +static AstBoxVtab 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. */ +AstBox *astBoxId_( void *, int, const double[], const double[], void *, const char *, ... ); + +/* Prototypes for Private Member Functions. */ +/* ======================================== */ +static AstBox *BestBox( AstFrame *, AstPointSet *, AstRegion *, int * ); +static AstMapping *Simplify( AstMapping *, int * ); +static AstPointSet *RegBaseGrid( AstRegion *, int * ); +static AstPointSet *RegBaseMesh( AstRegion *, int * ); +static AstPointSet *Transform( AstMapping *, AstPointSet *, int, AstPointSet *, int * ); +static AstRegion *MergeBox( AstBox *, AstRegion *, int, int * ); +static AstRegion *RegBasePick( AstRegion *this, int, const int *, int * ); +static double *GeoCorner( AstFrame *, int, double *, double *, double *, int * ); +static double *GeoLengths( AstFrame *, int, double *, double *, double *, int * ); +static double *RegCentre( AstRegion *this, double *, double **, int, int, int * ); +static int GetObjSize( AstObject *, int * ); +static int MakeGrid( int, double **, int, double *, double *, int *, int, int, double, int * ); +static int MapMerge( AstMapping *, int, int, int *, AstMapping ***, int **, int * ); +static int RegPins( AstRegion *, AstPointSet *, AstRegion *, int **, int * ); +static int RegTrace( AstRegion *, int, double *, double **, int * ); +static void BoxPoints( AstBox *, double *, double *, int *); +static void Cache( AstBox *, int, int * ); +static void ClearClosed( AstRegion *, int * ); +static void ClearNegated( AstRegion *, int * ); +static void Copy( const AstObject *, AstObject *, int * ); +static void Delete( AstObject *, int * ); +static void Dump( AstObject *, AstChannel *, int * ); +static void RegBaseBox( AstRegion *this, double *, double *, int * ); +static void ResetCache( AstRegion *this, int * ); +static void SetClosed( AstRegion *, int, int * ); +static void SetNegated( AstRegion *, int, int * ); +static void SetRegFS( AstRegion *, AstFrame *, int * ); +static void SetUnc( AstRegion *, AstRegion *, int * ); + +/* Member functions. */ +/* ================= */ + +void BoxPoints( AstBox *this, double *centre, double *corner, int *status) { +/* +*+ +* Name: +* astBoxPoints + +* Purpose: +* Return the defining points of a Box. + +* Type: +* Protected function. + +* Synopsis: +* #include "box.h" +* astBoxPoints( AstBox *this, double *centre, double *corner ) + +* Class Membership: +* Region virtual function. + +* Description: +* This function returns the axis values at the points defining the +* supplied Box. + +* Parameters: +* this +* Pointer to the Box. +* centre +* A pointer to an array in which to return the centre position of +* the Box, in the base Frame of the encapsulated FrameSet. +* corner +* A pointer to an array in which to return the position of a corner +* of the Box, in the base Frame of the encapsulated FrameSet. + +* Notes: +* - It is assumed that the length of the supplied arrays is at least +* equal to the number of axes in the base frame of the encapsulated +* FrameSet. +*- +*/ + +/* Local Variables: */ + AstPointSet *pset; + double **ptr; + int nc; + int i; + +/* Check the inherited status. */ + if( !astOK ) return; + +/* Get a pointer to the PointSet holding the points defining the Box. */ + pset = ((AstRegion *) this)->points; + +/* Get a pointer to the PointSet's data arrays. */ + ptr = astGetPoints( pset ); + +/* See how many axes each point in the PointSet has. */ + nc = astGetNcoord( pset ); + +/* Copy the centre and corner positions form the PointSet into the + supplied arrays. */ + for( i = 0; i < nc; i++ ) { + centre[ i ] = ptr[ i ] [ 0 ]; + corner[ i ] = ptr[ i ] [ 1 ]; + } + +} + +static void ClearClosed( AstRegion *this, int *status ){ +/* +* Name: +* ClearClosed + +* Purpose: +* Clear the Closed attribute of a Region. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* void ClearClosed( AstRegion *this, int *status ) + +* Class Membership: +* Box member function (over-rides the protected astClearClosed +* method inherited from the Region class). + +* Description: +* This function clears the Closed attribute of the supplied Region. + +* Parameters: +* this +* Pointer to the Region. +* status +* Pointer to the inherited status variable. +*/ + +/* Local Variables: */ + int old; + +/* Check the global error status. */ + if ( !astOK ) return; + +/* Get the original attribute value */ + old = astGetClosed( this ); + +/* Invoke the clear method inherited from the parent Region class */ + (*parent_clearclosed)( this, status ); + +/* If the new value is not the same as the old value, inidcatethat we + need to re-calculate the cached information in the Box. */ + if( astGetClosed( this ) != old ) astResetCache( this ); +} + +static void ClearNegated( AstRegion *this, int *status ){ +/* +* Name: +* ClearNegated + +* Purpose: +* Clear the Negated attribute of a Region. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* void ClearNegated( AstRegion *this, int *status ) + +* Class Membership: +* Box member function (over-rides the protected astClearNegated +* method inherited from the Region class). + +* Description: +* This function clears the Negated attribute of the supplied Region. + +* Parameters: +* this +* Pointer to the Region. +* status +* Pointer to the inherited status variable. +*/ + +/* Local Variables: */ + int old; + +/* Check the global error status. */ + if ( !astOK ) return; + +/* Get the original attribute value */ + old = astGetNegated( this ); + +/* Invoke the clear method inherited from the parent Region class */ + (*parent_clearnegated)( this, status ); + +/* If the new value is not the same as the old value, inidcatethat we + need to re-calculate the cached information in the Box. */ + if( astGetNegated( this ) != old ) astResetCache( this ); +} + +static AstBox *BestBox( AstFrame *frm, AstPointSet *mesh, AstRegion *unc, int *status ){ +/* +* Name: +* BestBox + +* Purpose: +* Find the best fitting Box through a given mesh of points. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* AstBox *BestBox( AstFrame *frm, AstPointSet *mesh, AstRegion *unc, int *status ) + +* Class Membership: +* Box member function + +* Description: +* This function finds the best fitting Box through a given mesh of points. + +* Parameters: +* frm +* Defines the geometry of the axes. +* mesh +* Pointer to a PointSet holding the mesh of points. They are +* assumed to be in the Frame represented by "unc". +* unc +* A Region representing the uncertainty associated with each point +* on the mesh. +* status +* Pointer to the inherited status variable. + +* Returned Value: +* Pointer to the best fitting Region. It will inherit the positional +* uncertainty and Frame represented by "unc". NULL is returned if all +* the supplied positions are bad. + +* Notes: +* - A NULL pointer is returned if an error has already occurred, or if +* this function should fail for any reason. + +*/ + +/* Local Variables: */ + AstBox *result; + double **ptr; + double *axval; + double *blbnd; + double *bubnd; + double *lbnd; + double *p; + double *ubnd; + double eps; + double lb; + double lim2; + double lim; + double liml; + double limu; + double mxl; + double mxu; + double org; + double sxl2; + double sxl; + double sxu2; + double sxu; + double ub; + double p0; + double d; + double dinc; + int ic; + int ip; + int nc; + int np; + int nxl; + int nxu; + int ok; + +/* Initialise */ + result = NULL; + +/* Check the global error status. */ + if ( !astOK ) return result; + +/* Get no. of points in the mesh, and the number of axis values per point. */ + np = astGetNpoint( mesh ); + nc = astGetNcoord( mesh ); + +/* Get pointers to the axis values. */ + ptr = astGetPoints( mesh ); + +/* Allocate work space. */ + lbnd = astMalloc( sizeof( double )*(size_t) nc ); + ubnd = astMalloc( sizeof( double )*(size_t) nc ); + + blbnd = astMalloc( sizeof( double )*(size_t) nc ); + bubnd = astMalloc( sizeof( double )*(size_t) nc ); + + axval = astMalloc( sizeof( double )*(size_t) np ); + +/* Check pointers can be used safely */ + if( axval ) { + +/* Get the bounding box of the uncertainty region. */ + astGetRegionBounds( unc, lbnd, ubnd ); + +/* We fit the box one axis at a time. */ + ok = 1; + for( ic = 0; ic < nc; ic++ ) { + +/* Find the first good value on this axis. */ + for( ip = 0; ip < np; ip++ ) { + org = ptr[ ic ][ ip ]; + axval[ ip ] = org; + if( org != AST__BAD ) break; + } + +/* Abort if all the axis values werebad. */ + if( ip >= np ) { + ok = 0; + break; + } + +/* Find the upper and lower limits of the supplied mesh on this axis. */ + lb = 0.0; + ub = 0.0; + ip++; + p = ptr[ ic ] + ip; + p0 = org; + d = 0.0; + for( ; ip < np; ip++, p++ ) { + dinc = astAxDistance( frm, ic + 1, p0, *p ); + if( dinc != AST__BAD ) { + d += dinc; + if( d < lb ) lb = d; + if( d > ub ) ub = d; + } + axval[ ip ] = org + d; + p0 = *p; + } + +/* Now convert these relative offsets to actual axis values. */ + lb += org; + ub += org; + +/* Now scan the list of axis values again, looking for values which are + "close to" either lower or upper bound. These will be the points which + are on the faces of the box which are orthogonal to the current axis. Here + "close to" means within 20 times the uncertainty associated with this + axis, or one tenth of the box size (which ever is smaller). We find the + mean and standard deviation of such "close" values, and then do a + single sigma-clipping iteration (at 3-sigma) to get rid of any values + which are on one of the other faces of the box. */ + + lim = 20*( ubnd[ ic ] - lbnd[ ic ] ); + lim2 = 0.1*( ub - lb ); + if( lim2 < lim ) lim = lim2; + + sxl = 0.0; + sxl2 = 0.0; + nxl = 0; + sxu = 0.0; + sxu2 = 0.0; + nxu = 0; + + p = axval; + for( ip = 0; ip < np; ip++, p++ ) { + if( *p != AST__BAD ) { + if( fabs( *p - lb ) <= lim ) { + sxl += *p; + sxl2 += (*p)*(*p); + nxl++; + } else if( fabs( *p - ub ) <= lim ) { + sxu += *p; + sxu2 += (*p)*(*p); + nxu++; + } + } + } + + if( nxl > 0 ) { + mxl = sxl/nxl; + liml = sxl2/nxl - mxl*mxl; + eps = 100*mxl*DBL_EPSILON; + if( liml < eps*eps ) { + liml = eps; + } else { + liml = 3.0*sqrt( liml ); + } + } else { + mxl = lb; + liml = 0.0; + } + + if( nxu > 0 ) { + mxu = sxu/nxu; + limu = sxu2/nxu - mxu*mxu; + eps = 100*mxu*DBL_EPSILON; + if( limu < eps*eps ) { + limu = eps; + } else { + limu = 3.0*sqrt( limu ); + } + + } else { + mxu = ub; + limu = 0.0; + } + + sxl = 0.0; + nxl = 0; + sxu = 0.0; + nxu = 0; + + p = axval; + for( ip = 0; ip < np; ip++, p++ ) { + if( *p != AST__BAD ) { + if( fabs( *p - mxl ) <= liml ) { + sxl += *p; + nxl++; + } else if( fabs( *p - mxu ) <= limu ) { + sxu += *p; + nxu++; + } + } + } + + if( nxl > 0 ) { + mxl = sxl/nxl; + } else { + mxl = lb; + } + + if( nxu > 0 ) { + mxu = sxu/nxu; + } else { + mxu = ub; + } + +/* The resulting mean axis values are the bounds of the required box on + the current axis.*/ + blbnd[ ic ] = mxl; + bubnd[ ic ] = mxu; + } + +/* If possible, create the returned Box. */ + if( ok ) result = astBox( unc, 1, blbnd, bubnd, unc, " ", status ); + } + +/* Free resources */ + lbnd = astFree( lbnd ); + ubnd = astFree( ubnd ); + blbnd = astFree( blbnd ); + bubnd = astFree( bubnd ); + axval = astFree( axval ); + +/* Return NULL if anything went wrong. */ + if( !astOK ) result = astAnnul( result ); + +/* Return the result.*/ + return result; +} + +static void Cache( AstBox *this, int lohi, int *status ){ +/* +* Name: +* Cache + +* Purpose: +* Calculate intermediate values and cache them in the Box structure. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* void Cache( AstRegion *this, int lohi, int *status ) + +* Class Membership: +* Box 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 Box structure. + +* Parameters: +* this +* Pointer to the Box. +* lohi +* Are the lo and hi arrays to be used? +* status +* Pointer to the inherited status variable. + +*/ + +/* Local Variables: */ + AstFrame *frm; + AstPointSet *pset; + AstRegion *unc; + double **ptr; + double *centre; + double *extent; + double *hi; + double *lbnd_unc; + double *geolen; + double *lo; + double *ubnd_unc; + double wid; + int i; + int nc; + +/* Check the global error status. Also return if the currently cached + information is usable. */ + if ( !astOK || !this->stale ) return; + +/* Get the number of base Frame axes. */ + nc = astGetNin( ((AstRegion *)this)->frameset ); + +/* Allocate memory to store the half-width of the box on each axis. */ + extent = (double *) astMalloc( sizeof( double )*(size_t) nc ); + +/* Allocate memory to store the centre of the box on each axis. */ + centre = (double *) astMalloc( sizeof( double )*(size_t) nc ); + +/* Allocate memory to store the high and low bounds. */ + hi = (double *) astMalloc( sizeof( double )*(size_t) nc ); + lo = (double *) astMalloc( sizeof( double )*(size_t) nc ); + +/* Memory to store the uncertainty bounding box */ + lbnd_unc = astMalloc( sizeof( double)*(size_t) nc ); + ubnd_unc = astMalloc( sizeof( double)*(size_t) nc ); + +/* Memory to store the geodesic half-dimensions of the box. */ + geolen = astMalloc( sizeof( double)*(size_t) nc ); + +/* Get pointers to the coordinate data in the parent Region structure. */ + pset = ((AstRegion *) this)->points; + ptr = astGetPoints( pset ); + +/* Check pointers can be used safely. */ + if( ptr ) { + +/* Store the centre and corner axis values. */ + for( i = 0; i < nc; i++ ) { + centre[ i ] = ptr[ i ][ 0 ]; + hi[ i ] = ptr[ i ][ 1 ]; + } + +/* Calculate the geodesic half-dimensions of the box. */ + frm = astGetFrame( ((AstRegion *) this)->frameset, AST__BASE ); + GeoLengths( frm, nc, centre, hi, geolen, status ); + +/* Calculate the half-width and store in the above array. Also store the + lower and upper bounds. */ + for( i = 0; i < nc; i++ ) { + extent[ i ] = fabs( astAxDistance( frm, i + 1, ptr[ i ][ 1 ], + centre[ i ] ) ); + lo[ i ] = centre[ i ] - extent[ i ]; + hi[ i ] = centre[ i ] + extent[ i ]; + } + + frm = astAnnul( frm ); + +/* Store the pointers to these arrays in the Box structure, and indicate + the information is usable. */ + if( astOK ) { + astFree( this->extent ); + astFree( this->centre ); + astFree( this->lo ); + astFree( this->hi ); + astFree( this->geolen ); + this->extent = extent; + this->centre = centre; + this->lo = lo; + this->hi = hi; + this->geolen = geolen; + this->stale = 0; + extent = NULL; + centre = NULL; + lo = NULL; + hi = NULL; + geolen = NULL; + } + +/* If lo and hi values are to be used, ensure they are expanded to at + least the width of an uncertainty box. */ + if( lohi ) { + +/* If we are dealing with an unnegated closed Box or a negated open + Box, ensure that the box does not have zero width on any axis. We do + this by ensuring that the extent on all axes is at least half the + width of the bounding box of the uncertainty Region. */ + if( astGetNegated( this ) != astGetClosed( this ) ) { + +/* Get the bounding box of the uncertainty Region in the base Frame of + the supplied Box. */ + unc = astGetUncFrm( this, AST__BASE ); + astGetRegionBounds( unc, lbnd_unc, ubnd_unc ); + +/* Ensure the extents are at least half the width of the uncertainty + bounding box. */ + for ( i = 0; i < nc; i++ ) { + wid = 0.5*( ubnd_unc[ i ] - lbnd_unc[ i ] ); + if( this->extent[ i ] < wid ) { + this->extent[ i ] = wid; + this->lo[ i ] = this->centre[ i ] - wid; + this->hi[ i ] = this->centre[ i ] + wid; + } + } + +/* Free resources. */ + unc = astAnnul( unc ); + } + } + } + +/* Annul the memory allocated above if an error occurred. */ + if( !astOK ) { + extent = astFree( extent ); + centre = astFree( centre ); + lo = astFree( lo ); + hi = astFree( hi ); + } + +/* Free other resources */ + lbnd_unc = astFree( lbnd_unc ); + ubnd_unc = astFree( ubnd_unc ); + +} + +static double *GeoCorner( AstFrame *frm, int nc, double *centre, + double *geolen, double *corner, int *status ){ +/* +* Name: +* GeoCorner + +* Purpose: +* Find the corner position implied by the supplied centre position +* and geodesic box dimensions. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* double *GeoCorner( AstFrame *frm, int nc, double *centre, +* double *geolen, double *corner, int *status ) + +* Class Membership: +* Box member function + +* Description: +* This function returns the corner position that is implied by the +* supplied centre position and geodesic box dimensions. The returned +* corner position is found by offsetting away from the supplied +* centre position along each axis in turn, by the geodesic distance +* specified in "geolen". + +* Parameters: +* frm +* Defines the geometry of the axes. +* nc +* The number of Frame axes. +* centre +* Pointer to an array holding the box centre axis values. +* geolen +* Pointer to an array holding the geodesic distance corresponding +* to each half axis of the box. +* corner +* Pointer to an array in which to store the axis values at the +* returned corner position. If this is NULL a new array is +* allocated and a pointer to it returned as the function value. +* status +* Pointer to the inherited status variable. + +* Returned Value: +* Pointer to the array holding the corner axis values. If a non-NULL +* value is supplied for parameter "corner", then the same value will +* be returned as the function value. Otherwise, the returned value +* will be a pointer to a newly allocated array that should be freed +* using astFree when no longer needed. + +*/ + +/* Local Variables: */ + double *p1; + double *p2; + double *p3; + double *pt; + double *result; + double *work1; + double *work2; + double off; + double off0; + int i; + +/* Initialise */ + result = corner; + +/* Check the global error status. */ + if ( !astOK ) return result; + +/* Ensure we have a results array. */ + if( ! result ) result = astMalloc( sizeof( double )*nc ); + +/* Also allocate two work arrays to hold a single position. */ + work1 = astMalloc( sizeof( double )*nc ); + work2 = astMalloc( sizeof( double )*nc ); + +/* Check the pointers can be used safely. */ + if( astOK ) { + +/* Select which array to use as the initial results array so that the + final results end up in the returned array. */ + if( ( nc % 2 ) == 0 ) { + p1 = result; + p2 = work1; + p3 = work2; + } else { + p1 = work2; + p2 = work1; + p3 = result; + } + +/* Initialise the current corner position to be at the centre of the box. */ + for( i = 0; i < nc; i++ ) p1[ i ] = centre[ i ]; + +/* Loop round offsetting along each side of the box. */ + for( i = 0; i < nc; i++ ) { + +/* In the p2 array put the axis values at a point which is offset + slightly along the current axis away from the current "corner" + position (p1). */ + memcpy( p2, p1, sizeof( double )*nc ); + + if( geolen[ i ] != 0.0 ) { + off = 0.0001*fabs( geolen[ i ] ); + } else { + off = 1.0E-6; + } + + off0 = fabs( 1.0E-10*centre[ i ] ); + if( off < off0 ) off = off0; + p2[ i ] += off; + +/* Offset away from the current corner position (p1) towards the position + found above (p2), moving by the geodesic distance supplied for this axis. + Put the resulting axis values in p3. */ + astOffset( frm, p1, p2, geolen[ i ], p3 ); + +/* Swap the p3 and p1 arrays so that the offset position found above (p3) + becomes the starting position (p1) for the next offset. */ + pt = p1; + p1 = p3; + p3 = pt; + } + } + +/* Free resources */ + work1 = astFree( work1 ); + work2 = astFree( work2 ); + +/* Return the result */ + return result; +} + +static double *GeoLengths( AstFrame *frm, int nc, double *centre, + double *corner, double *geolen, int *status ){ +/* +* Name: +* GeoLengths + +* Purpose: +* Find the geodesic dimensions of a box. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* double *GeoLengths( AstFrame *frm, int nc, double *centre, +* double *corner, double *geolen, int *status ) + +* Class Membership: +* Box member function + +* Description: +* This function returns half the geodesic distance along each edge of +* the supplied box. + +* Parameters: +* frm +* Defines the geometry of the axes. +* nc +* The number of Frame axes. +* centre +* Pointer to an array holding rhe box centre axis values. +* corner +* Pointer to an array holding the axis values at the corner +* position. +* geolen +* Pointer to an array in which to return the geodesic distances +* corresponding to each half axis of the box. If this is NULL a +* new array is allocated and a pointer to it returned as the +* function value. +* status +* Pointer to the inherited status variable. + +* Returned Value: +* Pointer to the array holding the geodesic half-dimensions of the box. +* If a non-NULL value is supplied for parameter "corner", then the same +* value will be returned as the function value. Otherwise, the +* returned value will be a pointer to a newly allocated array that +* should be freed using astFree when no longer needed. + +*/ + +/* Local Variables: */ + double *result; + double *p1; + double *p2; + int i; + +/* Initialise */ + result = geolen; + +/* Check the global error status. */ + if ( !astOK ) return result; + +/* Ensure we have a results array. */ + if( ! result ) result = astMalloc( sizeof( double )*nc ); + +/* Also allocate two work arrays to hold a single position. */ + p1 = astMalloc( sizeof( double )*nc ); + p2 = astMalloc( sizeof( double )*nc ); + +/* Check the pointers can be used safely. */ + if( astOK ) { + +/* Initialise the coords as the start and end of the line. */ + memcpy( p1, centre, sizeof( double )*nc ); + memcpy( p2, centre, sizeof( double )*nc ); + +/* Loop round finding the geodesic half-length of each side of the box. */ + for( i = 0; i < nc; i++ ) { + +/* The end of the line is the same as the start of the line, except that + it has the corner value for the current axis. */ + p2[ i ] = corner[ i ]; + +/* Find and return the geodesic distance along the line (i.e. from p1 to + p2). */ + result[ i ] = astDistance( frm, p1, p2 ); + +/* The start of the next line wil lbe at the end of the current line. */ + p1[ i ] = corner[ i ]; + } + } + +/* Free resources */ + p1 = astFree( p1 ); + p2 = astFree( p2 ); + +/* Return the result */ + return result; +} + +static int GetObjSize( AstObject *this_object, int *status ) { +/* +* Name: +* GetObjSize + +* Purpose: +* Return the in-memory size of an Object. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* int GetObjSize( AstObject *this, int *status ) + +* Class Membership: +* Box member function (over-rides the astGetObjSize protected +* method inherited from the parent class). + +* Description: +* This function returns the in-memory size of the supplied Box, +* in bytes. + +* Parameters: +* this +* Pointer to the Box. +* status +* Pointer to the inherited status variable. + +* Returned Value: +* The Object size, in bytes. + +* 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: */ + AstBox *this; /* Pointer to Box structure */ + int result; /* Result value to return */ + +/* Initialise. */ + result = 0; + +/* Check the global error status. */ + if ( !astOK ) return result; + +/* Obtain a pointers to the Box structure. */ + this = (AstBox *) this_object; + +/* Invoke the GetObjSize method inherited from the parent class, and then + add on any components of the class structure defined by thsi class + which are stored in dynamically allocated memory. */ + result = (*parent_getobjsize)( this_object, status ); + + result += astTSizeOf( this->extent ); + result += astTSizeOf( this->centre ); + result += astTSizeOf( this->lo ); + result += astTSizeOf( this->hi ); + result += astTSizeOf( this->geolen ); + +/* If an error occurred, clear the result value. */ + if ( !astOK ) result = 0; + +/* Return the result, */ + return result; +} + +void astInitBoxVtab_( AstBoxVtab *vtab, const char *name, int *status ) { +/* +*+ +* Name: +* astInitBoxVtab + +* Purpose: +* Initialise a virtual function table for a Box. + +* Type: +* Protected function. + +* Synopsis: +* #include "box.h" +* void astInitBoxVtab( AstBoxVtab *vtab, const char *name ) + +* Class Membership: +* Box vtab initialiser. + +* Description: +* This function initialises the component of a virtual function +* table which is used by the Box 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 astIsABox) 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->BoxPoints = BoxPoints; + +/* 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_getobjsize = object->GetObjSize; + object->GetObjSize = GetObjSize; + + parent_transform = mapping->Transform; + mapping->Transform = Transform; + + parent_simplify = mapping->Simplify; + mapping->Simplify = Simplify; + + parent_setnegated = region->SetNegated; + region->SetNegated = SetNegated; + + parent_setunc = region->SetUnc; + region->SetUnc = SetUnc; + + parent_setclosed = region->SetClosed; + region->SetClosed = SetClosed; + + parent_clearnegated = region->ClearNegated; + region->ClearNegated = ClearNegated; + + parent_clearclosed = region->ClearClosed; + region->ClearClosed = ClearClosed; + + parent_setregfs = region->SetRegFS; + region->SetRegFS = SetRegFS; + + parent_resetcache = region->ResetCache; + region->ResetCache = ResetCache; + + mapping->MapMerge = MapMerge; + +/* Store replacement pointers for methods which will be over-ridden by + new member functions implemented here. */ + region->RegBaseGrid = RegBaseGrid; + region->RegBaseMesh = RegBaseMesh; + region->RegBasePick = RegBasePick; + region->RegBaseBox = RegBaseBox; + region->RegPins = RegPins; + region->RegTrace = RegTrace; + region->RegCentre = RegCentre; + +/* Declare the copy constructor, destructor and class dump + functions. */ + astSetDelete( vtab, Delete ); + astSetCopy( vtab, Copy ); + astSetDump( vtab, Dump, "Box", "Axis intervals" ); + +/* 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 MakeGrid( int naxes, double **ptr, int ip, double *lbnd, + double *ubnd, int *np_axes, int np_axis, int iaxis, + double axval, int *status ){ +/* +* Name: +* MakeGrid + +* Purpose: +* Create a grid covering the entire volume of a specified box. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* int MakeGrid( int naxes, double **ptr, int ip, double *lbnd, +* double *ubnd, int *np_axes, int np_axis, int iaxis, +* double axval, int *status ) + +* Class Membership: +* Box member function + +* Description: +* This function creates an evenly sampled grid covering a given +* volume of n-D space, putting the coordinates at the sample points +* into a supplied array and returning the number of samples added. +* Optionally, the volume can be assumed to have a constant value on +* a specified axis. + +* Parameters: +* naxes +* The number of axes. +* ptr +* Pointer to an array with "naxes" elements. Each element is a +* pointer to an array in which to store the values for the axis. +* ip +* The index of the first point to be added to the "ptr" arrays. +* lbnd +* Pointer to an array containing the lower axis bounds of the +* volume to be sampled. +* ubnd +* Pointer to an array containing the upper axis bounds of the +* volume to be sampled. +* np_axes +* Pointer to an array with one element for every axis, giving the +* number of samples along each axis (except, optionally, the axis +* specified by "iaxis"). The first sample (sample 0) for each axis +* will be at the lower bound given in "lbnd" and the last sample +* (sample "np_axes[iax]-1") will be at the upper bound given in +* "ubnd". If NULL, then the single scalar avalue given by +* "np_axis" is used for all axes. +* np_axis +* The constant number of samples along every axis (except, optionally, +* the axis specified by "iaxis"). The first sample (sample 0) for each +* axis will be at the lower bound given in "lbnd" and the last sample +* (sample "np_axis-1") will be at the upper bound given in "ubnd". +* The supplied value is only used if "np_axes" is NULL. +* iaxis +* The index of an axis which has constant value in the volume, or +* -1 if all axes are to span the full volume given by lbnd/ubnd. +* The values in "lbnd" and "ubnd" are ignored for this axis and all +* sample positions will have the axis value given by "axval". +* axval +* The constant value for the axis with index "iaxis". Ignored if +* "iaxis" is -1. +* status +* Pointer to the inherited status variable. + +* Returned Value: +* The number of points added to the "ptr" arrays. + +*/ + +/* Local Variables: */ + double *step; /* Pointer to array holding axis step sizes */ + int *maxi; /* Pointer to array of maximum index values */ + int *pi; /* Pointer to array holding current sample indices */ + int i; /* Axis index */ + int ipp; /* Index of next point */ + int nsamp; /* Number of samples along the axis */ + +/* Check the global error status. */ + if ( !astOK ) return 0; + +/* Allocate memory to hold the max indices on each axis. */ + maxi = astMalloc( sizeof( int )*(size_t) naxes ); + +/* Allocate memory to hold the indices of the current position.*/ + pi = astMalloc( sizeof( int )*(size_t) naxes ); + +/* Allocate memory to hold the step size for each axis. */ + step = astMalloc( sizeof( double )*(size_t) naxes ); + if( astOK ) { + +/* For every axis, set up the step size, initialise the current position to + the lower bound, and store a modified upper limit which includes some + safety marging to allow for rounding errors. */ + for( i = 0; i < naxes; i++ ) { + nsamp = np_axes ? np_axes[ i ] : np_axis; + step[ i ] = ( ubnd[ i ] - lbnd[ i ] )/( nsamp - 1 ); + pi[ i ] = 0; + maxi[ i ] = nsamp - 1; + } + + if( iaxis >= 0 ) { + maxi[ iaxis ] = 0; + step[ iaxis ] = 0.0; + pi[ iaxis ] = 0; + } + +/* Initialise the index of the next position to store. */ + ipp = ip; + +/* Loop round adding points to the array until the whole volume has been + done. */ + i = 0; + while( i < naxes ) { + +/* Add the current point to the supplied array,and increment the index of + the next point to add. */ + for( i = 0; i < naxes; i++ ) { + if( i == iaxis ) { + ptr[ i ][ ipp ] = axval; + } else { + ptr[ i ][ ipp ] = lbnd[ i ] + pi[ i ]*step[ i ]; + } + } + ipp++; + +/* We now move the current position on to the next sample */ + i = 0; + while( i < naxes ) { + pi[ i ]++; + if( pi[ i ] > maxi[ i ] ) { + pi[ i ] = 0; + i++; + } else { + break; + } + } + } + } else { + ipp = ip; + } + +/* Free resources. */ + maxi = astFree( maxi ); + pi = astFree( pi ); + step = astFree( step ); + +/* Return the result. */ + return astOK ? ( ipp - ip ): 0 ; +} + +static int MapMerge( AstMapping *this, int where, int series, int *nmap, + AstMapping ***map_list, int **invert_list, int *status ) { +/* +* Name: +* MapMerge + +* Purpose: +* Simplify a sequence of Mappings containing a Box. + +* Type: +* Private function. + +* Synopsis: +* #include "mapping.h" +* int MapMerge( AstMapping *this, int where, int series, int *nmap, +* AstMapping ***map_list, int **invert_list, int *status ) + +* Class Membership: +* Box method (over-rides the protected astMapMerge method +* inherited from the Region class). + +* Description: +* This function attempts to simplify a sequence of Mappings by +* merging a nominated Box in the sequence with its neighbours, +* so as to shorten the sequence if possible. +* +* In many cases, simplification will not be possible and the +* function will return -1 to indicate this, without further +* action. +* +* In most cases of interest, however, this function will either +* attempt to replace the nominated Box with a Mapping which it +* considers simpler, or to merge it with the Mappings which +* immediately precede it or follow it in the sequence (both will +* normally be considered). This is sufficient to ensure the +* eventual simplification of most Mapping sequences by repeated +* application of this function. +* +* In some cases, the function may attempt more elaborate +* simplification, involving any number of other Mappings in the +* sequence. It is not restricted in the type or scope of +* simplification it may perform, but will normally only attempt +* elaborate simplification in cases where a more straightforward +* approach is not adequate. + +* Parameters: +* this +* Pointer to the nominated Box which is to be merged with +* its neighbours. This should be a cloned copy of the Box +* pointer contained in the array element "(*map_list)[where]" +* (see below). This pointer will not be annulled, and the +* Box it identifies will not be modified by this function. +* where +* Index in the "*map_list" array (below) at which the pointer +* to the nominated Box resides. +* series +* A non-zero value indicates that the sequence of Mappings to +* be simplified will be applied in series (i.e. one after the +* other), whereas a zero value indicates that they will be +* applied in parallel (i.e. on successive sub-sets of the +* input/output coordinates). +* nmap +* Address of an int which counts the number of Mappings in the +* sequence. On entry this should be set to the initial number +* of Mappings. On exit it will be updated to record the number +* of Mappings remaining after simplification. +* map_list +* Address of a pointer to a dynamically allocated array of +* Mapping pointers (produced, for example, by the astMapList +* method) which identifies the sequence of Mappings. On entry, +* the initial sequence of Mappings to be simplified should be +* supplied. +* +* On exit, the contents of this array will be modified to +* reflect any simplification carried out. Any form of +* simplification may be performed. This may involve any of: (a) +* removing Mappings by annulling any of the pointers supplied, +* (b) replacing them with pointers to new Mappings, (c) +* inserting additional Mappings and (d) changing their order. +* +* The intention is to reduce the number of Mappings in the +* sequence, if possible, and any reduction will be reflected in +* the value of "*nmap" returned. However, simplifications which +* do not reduce the length of the sequence (but improve its +* execution time, for example) may also be performed, and the +* sequence might conceivably increase in length (but normally +* only in order to split up a Mapping into pieces that can be +* more easily merged with their neighbours on subsequent +* invocations of this function). +* +* If Mappings are removed from the sequence, any gaps that +* remain will be closed up, by moving subsequent Mapping +* pointers along in the array, so that vacated elements occur +* at the end. If the sequence increases in length, the array +* will be extended (and its pointer updated) if necessary to +* accommodate any new elements. +* +* Note that any (or all) of the Mapping pointers supplied in +* this array may be annulled by this function, but the Mappings +* to which they refer are not modified in any way (although +* they may, of course, be deleted if the annulled pointer is +* the final one). +* invert_list +* Address of a pointer to a dynamically allocated array which, +* on entry, should contain values to be assigned to the Invert +* attributes of the Mappings identified in the "*map_list" +* array before they are applied (this array might have been +* produced, for example, by the astMapList method). These +* values will be used by this function instead of the actual +* Invert attributes of the Mappings supplied, which are +* ignored. +* +* On exit, the contents of this array will be updated to +* correspond with the possibly modified contents of the +* "*map_list" array. If the Mapping sequence increases in +* length, the "*invert_list" array will be extended (and its +* pointer updated) if necessary to accommodate any new +* elements. +* status +* Pointer to the inherited status variable. + +* Returned Value: +* If simplification was possible, the function returns the index +* in the "map_list" array of the first element which was +* modified. Otherwise, it returns -1 (and makes no changes to the +* arrays supplied). + +* Notes: +* - A value of -1 will be returned if this function is invoked +* with the global error status set, or if it should fail for any +* reason. +*/ + +/* Local Variables: */ + AstBox *oldbox; /* Pointer to supplied Box */ + AstMapping *map; /* Pointer to adjacent Mapping */ + AstMapping *new; /* Simplified or merged Region */ + int i1; /* Index of first Mapping merged */ + int i; /* Loop counter */ + int result; /* Result value to return */ + +/* Initialise. */ + result = -1; + i1 = 0; + +/* Check the global error status. */ + if ( !astOK ) return result; + +/* Get a pointer to the Box. */ + oldbox = (AstBox *) this; + +/* First of all, see if the Box can be replaced by a simpler Region, + without reference to the neighbouring Regions in the list. */ +/* =====================================================================*/ + +/* Try to simplify the box. If the pointer value has changed, we assume + some simplification took place. */ + new = astSimplify( oldbox ); + if( new != (AstMapping *) oldbox ) { + +/* Annul the Box pointer in the list and replace it with the new Region + pointer, and indicate that the forward transformation of the returned + Region should be used (not really needed but keeps things clean). */ + (void) astAnnul( ( *map_list )[ where ] ); + ( *map_list )[ where ] = new; + ( *invert_list )[ where ] = 0; + +/* Return the index of the first modified element. */ + result = where; + +/* If the Box itself could not be simplified, see if it can be merged + with the Regions on either side of it in the list. We can only merge + in parallel. */ +/* =====================================================================*/ + } else if( ! series ){ + new = astAnnul( new ); + +/* Attempt to merge the Box with its lower neighbour (if any). */ + if( where > 0 ) { + i1 = where - 1; + map = ( *map_list )[ where - 1 ]; + if( astIsARegion( map ) ) { + new = (AstMapping *) MergeBox( oldbox, (AstRegion *) map, 0, + status ); + } + } + +/* If this did not produced a merged Region, attempt to merge the Box with its + upper neighbour (if any). */ + if( !new && where < *nmap - 1 ) { + i1 = where; + map = ( *map_list )[ where + 1 ]; + if( astIsARegion( map ) ) { + new = (AstMapping *) MergeBox( oldbox, (AstRegion *) map, 1, + status ); + } + } + +/* If succesfull... */ + if( new ){ + +/* Annul the first of the two Mappings, and replace it with the merged + Region. Also clear the invert flag. */ + (void) astAnnul( ( *map_list )[ i1 ] ); + ( *map_list )[ i1 ] = new; + ( *invert_list )[ i1 ] = 0; + +/* Annul the second of the two Mappings, and shuffle down the rest of the + list to fill the gap. */ + (void) astAnnul( ( *map_list )[ i1 + 1 ] ); + for ( i = i1 + 2; i < *nmap; i++ ) { + ( *map_list )[ i - 1 ] = ( *map_list )[ i ]; + ( *invert_list )[ i - 1 ] = ( *invert_list )[ i ]; + } + +/* Clear the vacated element at the end. */ + ( *map_list )[ *nmap - 1 ] = NULL; + ( *invert_list )[ *nmap - 1 ] = 0; + +/* Decrement the Mapping count and return the index of the first + modified element. */ + ( *nmap )--; + result = i1; + } + + } else { + new = astAnnul( new ); + } + +/* Return the result. */ + return result; +} + +static AstRegion *MergeBox( AstBox *this, AstRegion *reg, int boxfirst, + int *status ) { +/* +* Name: +* MergeBox + +* Purpose: +* Attempt to merge a Box with another Region to form a Region of higher +* dimensionality. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* AstRegion *MergeBox( AstBox *this, AstRegion *reg, int boxfirst, int *status ) + +* Class Membership: +* Box member function. + +* Description: +* This function attempts to combine the supplied Regions together +* into a Region of higher dimensionality. + +* Parameters: +* this +* Pointer to a Box. +* reg +* Pointer to another Region. +* boxfirst +* If non-zero, then the Box axes are put first in the new Region. +* Otherwise, the other Region's axes are put first. +* status +* Pointer to the inherited status value. + +* Returned Value: +* A pointer to a new region, or NULL if the supplied Regions could +* not be merged. +*/ + +/* Local Variables: */ + AstFrame *bfrm; /* Pointer to base Frame for "result" */ + AstFrame *cfrm; /* Pointer to current Frame for "result" */ + AstFrame *frm_reg; /* Pointer to Frame from "reg" */ + AstFrame *frm_this; /* Pointer to Frame from "this" */ + AstMapping *bcmap; /* Base->current Mapping for "result" */ + AstMapping *map_reg; /* Base->current Mapping from "reg" */ + AstMapping *map_this; /* Base->current Mapping from "this" */ + AstMapping *sbunc; /* Simplified uncertainty */ + AstPointSet *pset_new; /* PointSet holding PointList axis values for new */ + AstPointSet *pset_reg; /* PointSet holding PointList axis values for reg */ + AstRegion *bunc; /* Base Frame uncertainty Region */ + AstRegion *new; /* Pointer to new Interval in base Frame */ + AstRegion *result; /* Pointer to returned Interval in current Frame */ + AstRegion *unc_reg; /* Current Frame uncertainty Region from "reg" */ + AstRegion *unc_this; /* Current Frame uncertainty Region from "this" */ + double **ptr_new; /* Pointers to arrays holding new axis values */ + double **ptr_reg; /* Pointers to arrays holding reg axis values */ + double *centre; /* Array to hold box centre axis values */ + double *corner; /* Array to hold box corner axis values */ + double *lbnd; /* Array to hold lower axis bounds */ + double *p; /* Pointer to next input value */ + double *q; /* Pointer to next output value */ + double *ubnd; /* Array to hold upper axis bounds */ + double fac_reg; /* Ratio of used to default MeshSize for "reg" */ + double fac_this; /* Ratio of used to default MeshSize for "this" */ + double temp; /* Temporary storage */ + int i; /* Loop count */ + int j; /* Loop count */ + int msz_reg; /* Original MeshSize for "reg" */ + int msz_reg_set; /* Was MeshSize originally set for "reg"? */ + int msz_this; /* Original MeshSize for "this" */ + int msz_this_set; /* Was MeshSize originally set for "this"? */ + int nax; /* Number of axes in "result" */ + int nax_reg; /* Number of axes in "reg" */ + int nax_this; /* Number of axes in "this" */ + int neg_reg; /* Negated attribute value for other supplied Region */ + int neg_this; /* Negated attribute value for supplied Box */ + int npnt; /* Number of points in PointList */ + int ok; /* Can supplied Regions be merged? */ + +/* Initialise */ + result = NULL; + +/* Check the local error status. */ + if ( !astOK ) return result; + +/* Get the Closed attributes of the two Regions. They must be the same in + each Region if we are to merge the Regions. In addition, in order to + merge, either both Regions must have a defined uncertainty, or neither + Region must have a defined Uncertainty. */ + if( astGetClosed( this ) == astGetClosed( reg ) && + astTestUnc( this ) == astTestUnc( reg ) ) { + +/* Get the Nagated attributes of the two Regions. */ + neg_this = astGetNegated( this ); + neg_reg = astGetNegated( reg ); + +/* Get the number of axes in the two supplied Regions. */ + nax_reg = astGetNaxes( reg ); + nax_this = astGetNaxes( this ); + +/* If the Regions can be combined, get the number of axes the + combination will have. */ + nax = nax_reg + nax_this; + +/* Get the base Frames from the two Region FrameSets, and combine them + into a single CmpFrame that will be used to create any new Region. */ + frm_this = astGetFrame( ((AstRegion *) this)->frameset, AST__BASE ); + frm_reg = astGetFrame( reg->frameset, AST__BASE ); + + if( boxfirst ) { + bfrm = (AstFrame *) astCmpFrame( frm_this, frm_reg, "", status ); + } else { + bfrm = (AstFrame *) astCmpFrame( frm_reg, frm_this, "", status ); + } + + frm_this = astAnnul( frm_this ); + frm_reg = astAnnul( frm_reg ); + +/* Indicate we do not yet have a merged Region. */ + new = NULL; + +/* First attempt to merge with another Box. The result will be a Box. Both + Boxes must be un-negated. */ + if( astIsABox( reg ) && !neg_this && !neg_reg ) { + +/* Allocate memory to store the centre and corner of the returned Box. */ + centre = astMalloc( sizeof( double )*(size_t) nax ); + corner = astMalloc( sizeof( double )*(size_t) nax ); + +/* Copy the centres and corners from the supplied Boxes into the above + arrays, in the requested order. */ + if( boxfirst ) { + astBoxPoints( this, centre, corner ); + astBoxPoints( reg, centre + nax_this, corner + nax_this ); + } else { + astBoxPoints( reg, centre, corner ); + astBoxPoints( this, centre + nax_reg, corner + nax_reg ); + } + +/* Create the new Box, initially with no uncertainty. */ + new = (AstRegion *) astBox( bfrm, 0, centre, corner, NULL, "", + status ); + +/* Free resources .*/ + centre = astFree( centre ); + corner = astFree( corner ); + +/* Now attempt to merge with an Interval. The result will be an Interval. + Both Intervals must be un-negated. */ + } else if( astIsAInterval( reg ) && !neg_this && !neg_reg ) { + +/* Allocate memory to store the bounds of the returned Interval. */ + lbnd = astMalloc( sizeof( double )*(size_t) nax ); + ubnd = astMalloc( sizeof( double )*(size_t) nax ); + +/* Copy the centre and corner from the supplied Box into the required part + of the above arrays. */ + if( boxfirst ) { + centre = lbnd; + corner = ubnd; + } else { + centre = lbnd + nax_reg; + corner = ubnd + nax_reg; + } + astBoxPoints( this, centre, corner ); + +/* Convert these centre and corner positions into upper and lower bounds. */ + if( astOK ) { + for( i = 0; i < nax_this; i++ ) { + centre[ i ] = 2*centre[ i ] - corner[ i ]; + if( centre[ i ] > corner[ i ] ) { + temp = centre[ i ]; + centre[ i ] = corner[ i ]; + corner[ i ] = temp; + } + } + } + +/* Get the bounds from the interval and add them into the above arrays. */ + if( boxfirst ) { + astIntervalPoints( reg, lbnd + nax_this, ubnd + nax_this ); + } else { + astIntervalPoints( reg, lbnd, ubnd ); + } + +/* Create the new Interval, initially with no uncertainty. */ + new = (AstRegion *) astInterval( bfrm, lbnd, ubnd, NULL, "", + status ); + +/* Free resources .*/ + lbnd = astFree( lbnd ); + ubnd = astFree( ubnd ); + +/* Now attempt to merge with a NullRegion. The result will be an + Interval. The NullRegion must be negated and the Box must not. */ + } else if( astIsANullRegion( reg ) && !neg_this && neg_reg ) { + +/* Allocate memory to store the bounds of the returned Interval. */ + lbnd = astMalloc( sizeof( double )*(size_t) nax ); + ubnd = astMalloc( sizeof( double )*(size_t) nax ); + +/* Copy the centre and corner from the supplied Box into the required part + of the above arrays. */ + if( boxfirst ) { + centre = lbnd; + corner = ubnd; + } else { + centre = lbnd + nax_reg; + corner = ubnd + nax_reg; + } + astBoxPoints( this, centre, corner ); + +/* Convert these centre and corner positions into upper and lower bounds. */ + if( astOK ) { + for( i = 0; i < nax_this; i++ ) { + centre[ i ] = 2*centre[ i ] - corner[ i ]; + if( centre[ i ] > corner[ i ] ) { + temp = centre[ i ]; + centre[ i ] = corner[ i ]; + corner[ i ] = temp; + } + } + +/* Fill the other axes with bad values to indicate they are unbounded. */ + if( boxfirst ) { + for( i = nax_this; i < nax; i++ ) { + lbnd[ i ] = AST__BAD; + ubnd[ i ] = AST__BAD; + } + } else { + for( i = 0; i < nax_reg; i++ ) { + lbnd[ i ] = AST__BAD; + ubnd[ i ] = AST__BAD; + } + } + +/* Create the new Interval, initially with no uncertainty. */ + new = (AstRegion *) astInterval( bfrm, lbnd, ubnd, NULL, "", + status ); + } + +/* Free resources .*/ + lbnd = astFree( lbnd ); + ubnd = astFree( ubnd ); + +/* Now attempt to merge with a PointList. The result will be a PointList. + Both Regions must be un-negated. */ + } else if( astIsAPointList( reg ) && !neg_this && !neg_reg ) { + +/* We can only do this if the Box has zero width on each axis (i.e. + represents a point). Get the Box centre and corner. */ + centre = astMalloc( sizeof( double )*(size_t) nax_this ); + corner = astMalloc( sizeof( double )*(size_t) nax_this ); + astBoxPoints( this, centre, corner ); + +/* Get the size of the Box's uncertainty region. */ + lbnd = astMalloc( sizeof( double )*(size_t) nax_this ); + ubnd = astMalloc( sizeof( double )*(size_t) nax_this ); + bunc = astGetUncFrm( this, AST__BASE ); + astGetRegionBounds( bunc, lbnd, ubnd ); + +/* Set "ok" to zero if the Box does not have zero width on any axis. Here + "zero width" means a width less than half the uncertainty on the axis. */ + if( astOK ) { + + ok = 1; + for( i = 0; i < nax_this; i++ ) { + if( fabs( centre[ i ] - corner[ i ] ) > + 0.25*fabs( ubnd[ i ] - lbnd[ i ] ) ) { + ok = 0; + break; + } + } + +/* If the Box is a point, we go on to create a new PointList. */ + if( ok ) { + +/* Get a PointSet holding the axis values in the supplied PointList data. + Also get the number of points in the PointSet and pointers to the arrays + holding the axis values. */ + astPointListPoints( reg, &pset_reg ); + npnt = astGetNpoint( pset_reg ); + ptr_reg = astGetPoints( pset_reg ); + +/* Create a new PointSet with room for the same number of points, but + with the extra required axes. Get pointers to its axis arrays. */ + pset_new = astPointSet( npnt, nax, "", status ); + ptr_new = astGetPoints( pset_new ); + +/* Copy the PointList axis values into the new PointSet, and then include + the extra axis values defined by the Box to each point. */ + if( astOK ) { + + for( j = 0; j < nax_reg; j++ ) { + p = ptr_reg[ j ]; + q = ptr_new[ boxfirst ? nax_this + j : j ]; + for( i = 0; i < npnt; i++ ) *(q++) = *(p++); + } + + for( j = 0; j < nax_this; j++ ) { + p = centre + j; + q = ptr_new[ boxfirst ? j : nax_reg + j ]; + for( i = 0; i < npnt; i++ ) *(q++) = *p; + } + +/* Create the new PointList, initially with no uncertainty. */ + new = (AstRegion *) astPointList( bfrm, pset_new, NULL, + "", status ); + } + +/* Free resources .*/ + pset_new = astAnnul( pset_new ); + pset_reg = astAnnul( pset_reg ); + } + } + centre = astFree( centre ); + corner = astFree( corner ); + lbnd = astFree( lbnd ); + ubnd = astFree( ubnd ); + bunc = astAnnul( bunc ); + + } + +/* If a new Region was created above, propagate remaining attributes of + the supplied Region to it. */ + if( new ) { + astRegOverlay( new, this, 1 ); + +/* The above Prism constructors create the Prism with the correct value + for the Nagated attribute (i.e. zero). Ensure the above call to + astRegOverlay has not changed this. */ + astClearNegated( new ); + +/* If both the supplied Regions have uncertainty, assign the new Region an + uncertainty. */ + if( astTestUnc( this ) && astTestUnc( reg ) ) { + +/* Get the uncertainties from the two supplied Regions. */ + unc_this = astGetUncFrm( this, AST__BASE ); + unc_reg = astGetUncFrm( reg, AST__BASE ); + +/* Combine them into a single Region (a Prism), in the correct order. */ + if( boxfirst ) { + bunc = (AstRegion *) astPrism( unc_this, unc_reg, "", status ); + } else { + bunc = (AstRegion *) astPrism( unc_reg, unc_this, "", status ); + } + +/* Attempt to simplify the Prism. */ + sbunc = astSimplify( bunc ); + +/* Use the simplified Prism as the uncertainty for the returned Region. */ + astSetUnc( new, sbunc ); + +/* Free resources. */ + sbunc = astAnnul( sbunc ); + bunc = astAnnul( bunc ); + unc_reg = astAnnul( unc_reg ); + unc_this = astAnnul( unc_this ); + } + +/* Get the current Frames from the two Region FrameSets, and combine them + into a single CmpFrame. */ + frm_this = astGetFrame( ((AstRegion *) this)->frameset, AST__CURRENT ); + frm_reg = astGetFrame( reg->frameset, AST__CURRENT ); + + if( boxfirst ) { + cfrm = (AstFrame *) astCmpFrame( frm_this, frm_reg, "", status ); + } else { + cfrm = (AstFrame *) astCmpFrame( frm_reg, frm_this, "", status ); + } + +/* Get the base -> current Mappings from the two Region FrameSets, and + combine them into a single parallel CmpMap that connects bfrm and cfrm. */ + map_this = astGetMapping( ((AstRegion *) this)->frameset, AST__BASE, + AST__CURRENT ); + map_reg = astGetMapping( reg->frameset, AST__BASE, AST__CURRENT ); + + if( boxfirst ) { + bcmap = (AstMapping *) astCmpMap( map_this, map_reg, 0, "", + status ); + } else { + bcmap = (AstMapping *) astCmpMap( map_reg, map_this, 0, "", + status ); + } + +/* Map the new Region into the new current Frame. */ + result = astMapRegion( new, bcmap, cfrm ); + +/* The filling factor in the returned is the product of the filling + factors for the two supplied Regions. */ + if( astTestFillFactor( reg ) || astTestFillFactor( this ) ) { + astSetFillFactor( result, astGetFillFactor( reg )* + astGetFillFactor( this ) ); + } + +/* If the MeshSize value is set in either supplied Region, set a value + for the returned Region which scales the default value by the + product of the scaling factors for the two supplied Regions. First see + if either MeshSize value is set. */ + msz_this_set = astTestMeshSize( this ); + msz_reg_set = astTestMeshSize( reg ); + if( msz_this_set || msz_reg_set ) { + +/* If so, get the two MeshSize values (one of which may be a default + value), and then clear them so that the default value will be returned + in future. */ + msz_this = astGetMeshSize( this ); + msz_reg = astGetMeshSize( reg ); + astClearMeshSize( this ); + astClearMeshSize( reg ); + +/* Get the ratio of the used MeshSize to the default MeshSize for both + Regions. */ + fac_this = (double)msz_this/(double)astGetMeshSize( this ); + fac_reg = (double)msz_reg/(double)astGetMeshSize( reg ); + +/* The MeshSize of the returned Returned is the default value scaled by + the product of the two ratios found above. */ + astSetMeshSize( result, fac_this*fac_reg*astGetMeshSize( result ) ); + +/* Re-instate the original MeshSize values for the supplied Regions (if + set) */ + if( msz_this_set ) astSetMeshSize( this, msz_this ); + if( msz_reg_set ) astSetMeshSize( reg, msz_reg ); + } + +/* Free remaining resources */ + frm_this = astAnnul( frm_this ); + frm_reg = astAnnul( frm_reg ); + map_this = astAnnul( map_this ); + map_reg = astAnnul( map_reg ); + bcmap = astAnnul( bcmap ); + new = astAnnul( new ); + cfrm = astAnnul( cfrm ); + } + bfrm = astAnnul( bfrm ); + } + +/* If an error has occurred, annul the returned pointer. */ + if( !astOK ) result = astAnnul( result ); + +/* Return the result. */ + 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 "box.h" +* void RegBaseBox( AstRegion *this, double *lbnd, double *ubnd, int *status ) + +* Class Membership: +* Box 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: */ + AstBox *this; /* Pointer to Box structure */ + double axcen; /* Central axis value */ + double axlen; /* Half width of box on axis */ + int i; /* Axis index */ + int nc; /* No. of axes in base Frame */ + +/* Check the global error status. */ + if ( !astOK ) return; + +/* Get a pointer to the Box structure */ + this = (AstBox *) this_region; + +/* Ensure cached information is up to date. */ + Cache( this, 0, status ); + +/* Get the number of base Frame axes in the Region. */ + nc = astGetNin( this_region->frameset ); + +/* The first point is the centre of the box, the second point is the half + size of the box on each axis.*/ + for( i = 0; i < nc; i++ ) { + axcen = this->centre[ i ]; + axlen = this->extent[ i ]; + lbnd[ i ] = axcen - axlen; + ubnd[ i ] = axcen + axlen; + } +} + +static AstPointSet *RegBaseGrid( AstRegion *this, int *status ){ +/* +* Name: +* RegBaseGrid + +* Purpose: +* Return a PointSet containing points spread through the volume of a +* Region. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* AstPointSet *RegBaseGrid( AstRegion *this, int *status ) + +* Class Membership: +* Box member function (over-rides the astRegBaseGrid protected +* method inherited from the Region class). + +* Description: +* This function returns a PointSet containing a set of points spread +* through the volume of the supplied Box. 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. If the Region is unbounded, a NULL pointer +* will be returned. + +* 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 */ + double *lbnd; /* Pointer to array of lower bounds of box */ + double *ubnd; /* Pointer to array of upper bounds of box */ + int meshsize; /* Requested size of grid */ + int naxes; /* No. of axes in base Frame */ + +/* Initialise */ + result = NULL; + +/* Check the local error status. */ + if ( !astOK ) return NULL; + +/* If the Region structure contains a pointer to a PointSet holding + a previously created grid, return it. */ + if( this->basegrid ) { + result = astClone( this->basegrid ); + +/* Otherwise, create a new one, but only if the Box is bounded. */ + } else if( astGetBounded( this ) ) { + +/* Get the base Frame in the Region's FrameSet. */ + frm = astGetFrame( this->frameset, AST__BASE ); + +/* Get the number of axes in the base Frame */ + naxes = astGetNaxes( frm ); + +/* Get the bounds of the Region in the base Frame. */ + lbnd = astMalloc( sizeof( double )*(size_t) naxes ); + ubnd = astMalloc( sizeof( double )*(size_t) naxes ); + astRegBaseBox( this, lbnd, ubnd ); + +/* Get the number of points which would be used to create a boundary + mesh. We use the same number to determine the number of points in the + grid. */ + meshsize = astGetMeshSize( this ); + +/* Create the PointSet holding the grid. */ + result = astFrameGrid( frm, meshsize, lbnd, ubnd ); + +/* 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 && result ) this->basegrid = astClone( result ); + +/* Free remaining resources. */ + frm = astAnnul( frm ); + lbnd = astFree( lbnd ); + ubnd = astFree( ubnd ); + } + +/* Annul the result if an error occurred. */ + if( !astOK ) result = astAnnul( result ); + +/* Return the result */ + return result; +} + +static AstPointSet *RegBaseMesh( AstRegion *this, 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 "box.h" +* AstPointSet *RegBaseMesh( AstRegion *this, int *status ) + +* Class Membership: +* Box 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. The axis values in this PointSet will have +* associated accuracies derived from the accuracies which were +* supplied when the Region was created. + +* Notes: +* - A NULL pointer is returned if an error has already occurred, or if +* this function should fail for any reason. + +*/ + +/* Local Constants: */ +#define NP_EDGE 50 /* No. of points for determining geodesic + length of each axis. */ + +/* Local Variables: */ + AstFrame *frm; /* Base Frame in encapsulated FrameSet */ + AstFrame *pfrm0; /* Primary Frame defining axis 0 */ + AstFrame *pfrm1; /* Primary Frame defining axis 1 */ + AstPointSet *result; /* Returned pointer */ + const char *class0; /* Pointer to class string from pfrm0 */ + const char *class1; /* Pointer to class string from pfrm1 */ + double **ptr; /* Pointers to data */ + double *ax; /* Pointer to next first axis value */ + double *ay; /* Pointer to next second axis value */ + double *lbnd; /* Pointer to array of lower bounds of box */ + double *ubnd; /* Pointer to array of lower bounds of box */ + double c[ 5 ][ 2 ]; /* Positions of corners for 2D boxes */ + double dx; /* Increment along first axis of 2D box */ + double dy; /* Increment along second axis of 2D box */ + double edge_len[ 4 ]; /* Length of each edge of 2D boundary */ + double lax; /* Previous value on first axis */ + double lay; /* Previous value on second axis */ + double len; /* Length of edge of 2D boundary */ + double p0[ 2 ]; /* Position in 2D Frame */ + double p1[ 2 ]; /* Position in 2D Frame */ + double ppd; /* Points per unit distance */ + double total_len; /* Total length of 2D boundary */ + int flat; /* Assume Frame geometry is flat? */ + int i; /* Point index */ + int iaxis; /* Axis index */ + int iedge; /* Edge index */ + int ip; /* Index of next point */ + int metric; /* Does Frame have a usable metric? */ + int nax0; /* No. of axes in first primary Frame */ + int nax1; /* No. of axes in second primary Frame */ + int naxes; /* No. of axes in base Frame */ + int np; /* No. of points in returned PointSet */ + int np0; /* No. of points per edge */ + int np_axis; /* No. of points per axis in ND box */ + int np_edge[ 4 ]; /* No. of points per edge in 2D box */ + int paxis; /* Axis index in primary Frame */ + int single; /* Does the Box occupy a single point? */ + +/* 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->basemesh ) { + result = astClone( this->basemesh ); + +/* Otherwise, create a new mesh. */ + } else { + +/* Get the base Frame in the Region's FrameSet. */ + frm = astGetFrame( this->frameset, AST__BASE ); + +/* Get the number of axes in the base Frame */ + naxes = astGetNaxes( frm ); + +/* Get the bounds of the Region in the base Frame. */ + lbnd = astMalloc( sizeof( double )*(size_t) naxes ); + ubnd = astMalloc( sizeof( double )*(size_t) naxes ); + astRegBaseBox( this, lbnd, ubnd ); + +/* Get the requested number of points to put on the mesh. */ + np = astGetMeshSize( this ); + +/* See if the box occupies a single point. */ + single = 1; + for( i = 0; i < naxes; i++ ) { + if( ubnd[ i ] > lbnd[ i ] ) { + single = 0; + break; + } + } + +/* If so, we return a PointSet holding a single point. */ + if( single ) { + result = astPointSet( 1, naxes, "", status ); + ptr = astGetPoints( result ); + if( astOK ) { + for( i = 0; i < naxes; i++ ) { + ptr[ i ][ 0 ] = 0.5*( lbnd[ 0 ] + ubnd[ 0 ] ); + } + } + +/* Otherwise, first deal with 1-D boxes. */ + } else if( naxes == 1 ) { + +/* The boundary of a 1-D box consists of 2 points - the two extreme values. + Create a PointSet to hold 2 1-D values, and store the extreme values. */ + result = astPointSet( 2, 1, "", status ); + ptr = astGetPoints( result ); + if( astOK ) { + ptr[ 0 ][ 0 ] = lbnd[ 0 ]; + ptr[ 0 ][ 1 ] = ubnd[ 0 ]; + } + +/* Now deal with 2-D boxes. */ + } else if( naxes == 2 ){ + +/* Store the coords of each corner for easy access. */ + c[ 0 ][ 0 ] = lbnd[ 0 ]; + c[ 0 ][ 1 ] = lbnd[ 1 ]; + c[ 1 ][ 0 ] = lbnd[ 0 ]; + c[ 1 ][ 1 ] = ubnd[ 1 ]; + c[ 2 ][ 0 ] = ubnd[ 0 ]; + c[ 2 ][ 1 ] = ubnd[ 1 ]; + c[ 3 ][ 0 ] = ubnd[ 0 ]; + c[ 3 ][ 1 ] = lbnd[ 1 ]; + c[ 4 ][ 0 ] = lbnd[ 0 ]; + c[ 4 ][ 1 ] = lbnd[ 1 ]; + +/* See if we can assume that the frame has flat geometry. This is the case + if both axes belong to simple Frames, or are 1D, but may not be the case + if either axis does not belong to a simple Frame that has more than 1 + axis. */ + astPrimaryFrame( frm, 0, &pfrm0, &paxis ); + astPrimaryFrame( frm, 1, &pfrm1, &paxis ); + class0 = astGetClass( pfrm0 ); + class1 = astGetClass( pfrm1 ); + nax0 = astGetNaxes( pfrm0 ); + nax1 = astGetNaxes( pfrm1 ); + if( astOK ) { + flat = ( !strcmp( class0, "Frame" ) || nax0 == 1 ) && + ( !strcmp( class1, "Frame" ) || nax1 == 1 ); + } else { + flat = 0; + } + +/* Our choice of distribution of points depends on whether the axes have the + same units or not. If the axes have the same units, or if they share the + same primary Frame, then we assume that the axes span some space in which + a single "distance" is defined. If not, (e.g. for a Frame representing + frequency in Hz on one axis - typical value 1.0E10, and slit position in + metres on the other axis - typical value 1.0E-2) we assume that "distance" + is defined differently for each axis. The primary frame requirement is + because some classes of Frame (e.g. SkyFrame) have a defined distance, + even though the Units attributes for its axes may differ (since Units + refers to the external representation - e.g. hours and degrees for a + SkyFrame - rather than the internal representation). */ + if( astOK && !strcmp( astGetUnit( frm, 0 ), astGetUnit( frm, 1 ) ) ) { + metric = 1; + } else { + metric = ( pfrm0 == pfrm1 ); + } + +/* If we have a usable metric, distribute the points according to the aspect + ratio of the box (i.e. the shorter box sides gets fewer points). */ + if( metric ){ + +/* Find the approximate geodesic length of each edge of the box. Since + the edges of the box may not correspond to single geodesic (e.g. a + line of constant latitude is not a geodesic), we do this by testing + a set of points along each edge of the box and finding the total of the + geodesic distances between each pair of adjacent points. Initialise the + total length round all edges. */ + total_len = 0.0; + +/* Do each edge in turn.*/ + for( iedge = 0; iedge < 4; iedge++ ) { + +/* Find the increment in x and y between adjacent points along this edge. + We put a point at each end of the edge. Note, one of dx or dy will be + zero since the edges are parallel to the axes. */ + dx = ( c[ iedge + 1 ][ 0 ] - c[ iedge ][ 0 ] )/( NP_EDGE - 1 ); + dy = ( c[ iedge + 1 ][ 1 ] - c[ iedge ][ 1 ] )/( NP_EDGE - 1 ); + +/* Store the coords of the first point. */ + p0[ 0 ] = c[ iedge ][ 0 ]; + p0[ 1 ] = c[ iedge ][ 1 ]; + +/* Initialise the length of this edge and loop round the remaining points. */ + len = 0.0; + for( i = 1; i < NP_EDGE; i++ ) { + +/* Save the position of the previous point. */ + p1[ 0 ] = p0[ 0 ]; + p1[ 1 ] = p0[ 1 ]; + +/* Find the position of the new point. */ + p0[ 0 ] = p1[ 0 ] + dx; + p0[ 1 ] = p1[ 1 ] + dy; + +/* Increment the length of the edge by the geodesic distance from this point + to the previous point. If the Frame is flat, this is simple (given that we + know that one of dx and dy must be zero). */ + if( flat ) { + len += fabs( dx + dy ); + } else { + len += astDistance( frm, p0, p1 ); + } + } + +/* Save the length of this edge, and also form the total length round all + edges. */ + edge_len[ iedge ] = len; + total_len += len; + } + +/* Find the average number of points per unit geodesic distance around the + boundary. */ + if( total_len > 0.0 ) { + ppd = np / total_len; + +/* Use this, with the geodesic length of each edge found above, to find the + number of points to put along each edge of the boundary, and update the + total number of points to use. In the returned boundary we put a point at + the start of each edge but not at the end (since the end of one edge will + be the start of the next edge). */ + np = 0; + for( iedge = 0; iedge < 4; iedge++ ) { + np_edge[ iedge ] = (int) ( edge_len[ iedge ]*ppd ); + if( np_edge[ iedge ] == 0 ) np_edge[ iedge ] = 1; + np += np_edge[ iedge ]; + } + +/* Report error if total length round box is zero. */ + } else if( astOK ) { + astError( AST__INTER, "astRegBaseMesh(%s): Distance around " + "box perimeter is zero (internal AST programming " + "error).", status, astGetClass( this ) ); + } + +/* If the Frame has no usable metric, give an equal number of points + (equal to a quarter of the total) to all 4 sides of the box. */ + } else { + np0 = (int) ( 0.25*np ); + np = 0; + for( iedge = 0; iedge < 4; iedge++ ) { + np_edge[ iedge ] = np0; + np += np_edge[ iedge ]; + } + } + +/* Create a PointSet with enough room and get a pointer to its data arrays. */ + result = astPointSet( np, 2, "", status ); + ptr = astGetPoints( result ); + if( astOK ) { + +/* Initialise pointers to the first element for each axis in the returned + PointSet. */ + ax = ptr[ 0 ]; + ay = ptr[ 1 ]; + +/* Loop round each edge. */ + for( iedge = 0; iedge < 4; iedge++ ) { + +/* Find the increment in x and y between adjacent points along this edge. */ + dx = ( c[ iedge + 1 ][ 0 ] - c[ iedge ][ 0 ] )/ np_edge[ iedge ]; + dy = ( c[ iedge + 1 ][ 1 ] - c[ iedge ][ 1 ] )/ np_edge[ iedge ]; + +/* Store the first point. */ + lax = c[ iedge ][ 0 ]; + lay = c[ iedge ][ 1 ]; + *(ax++) = lax; + *(ay++) = lay; + +/* Loop round the remaining points, incrementing the pointers at the same + time. */ + for( i = 1; i < np_edge[ iedge ]; i++, ax++, ay++ ) { + +/* Find the position of the new point and store it. */ + lax += dx; + lay += dy; + *ax = lax; + *ay = lay; + } + } + } + +/* Free resources. */ + pfrm0 = astAnnul( pfrm0 ); + pfrm1 = astAnnul( pfrm1 ); + +/* Now deal with boxes with more than 2 dimensions. */ + } else { + +/* Number of samples along each edge of the hyper-cube. */ + np_axis = 1 + (int) pow( np/(2*naxes), 1.0/(naxes-1) ); + if( np_axis < 2 ) np_axis = 2; + +/* Each face of the hyper-cube will have np_axis**(naxes-1) points, and there + are 2*naxes faces. Create a PointSet with the correct number of + points. */ + np = 2*naxes; + for( iaxis = 1; iaxis < naxes; iaxis++ ) np *= np_axis; + result = astPointSet( np, naxes, "", status ); + ptr = astGetPoints( result ); + if( astOK ) { + +/* Initialise the index of the next point to add into the PointSet. */ + ip = 0; + +/* Create the upper and lower faces for each axis in turn. */ + for( iaxis = 0; iaxis < naxes; iaxis++ ) { + +/* First do the upper face for this axis. */ + ip += MakeGrid( naxes, ptr, ip, lbnd, ubnd, NULL, np_axis, + iaxis, ubnd[ iaxis ], status ); + +/* Now do the lower face for this axis. */ + ip += MakeGrid( naxes, ptr, ip, lbnd, ubnd, NULL, np_axis, + iaxis, lbnd[ iaxis ], status ); + } + +/* Remove any unused space at the end of the PointSet. */ + if( ip < np ) astSetNpoint( result, ip ); + } + } + +/* Same 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 && result ) this->basemesh = astClone( result ); + +/* Free resources. */ + frm = astAnnul( frm ); + lbnd = astFree( lbnd ); + ubnd = astFree( ubnd ); + } + +/* Annul the result if an error has occurred. */ + if( !astOK ) result = astAnnul( result ); + +/* Return a pointer to the output PointSet. */ + return result; + +/* Undefine macros local to this function. */ +#undef NP_EDGE + +} + +static AstRegion *RegBasePick( AstRegion *this_region, int naxes, const int *axes, + int *status ){ +/* +* Name: +* RegBasePick + +* Purpose: +* Return a Region formed by picking selected base Frame axes from the +* supplied Region. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* AstRegion *RegBasePick( AstRegion *this, int naxes, const int *axes, +* int *status ) + +* Class Membership: +* Box member function (over-rides the astRegBasePick protected +* method inherited from the Region class). + +* Description: +* This function attempts to return a Region that is spanned by selected +* axes from the base Frame of the encapsulated FrameSet of the supplied +* Region. This may or may not be possible, depending on the class of +* Region. If it is not possible a NULL pointer is returned. + +* Parameters: +* this +* Pointer to the Region. +* naxes +* The number of base Frame axes to select. +* axes +* An array holding the zero-based indices of the base Frame axes +* that are to be selected. +* status +* Pointer to the inherited status variable. + +* Returned Value: +* Pointer to the Region, or NULL if no region can be formed. + +* Notes: +* - A NULL pointer is returned if an error has already occurred, or if +* this function should fail for any reason. +*/ + +/* Local Variables: */ + AstFrame *bfrm; /* The base Frame in the supplied Region */ + AstFrame *frm; /* The base Frame in the returned Region */ + AstPointSet *pset; /* Holds axis values defining the supplied Region */ + AstRegion *bunc; /* The uncertainty in the supplied Region */ + AstRegion *result; /* Returned Region */ + AstRegion *unc; /* The uncertainty in the returned Region */ + double **ptr; /* Holds axis values defining the supplied Region */ + double *cen; /* Base Frm axis values at centre of returned Box */ + double *cor; /* Base Frm axis values at a corner of returned Box */ + int i; /* Index of axis within returned Region */ + +/* Initialise */ + result = NULL; + +/* Check the global error status. */ + if ( !astOK ) return result; + +/* Get a pointer to the base Frame of the encapsulated FrameSet. */ + bfrm = astGetFrame( this_region->frameset, AST__BASE ); + +/* Create a Frame by picking the selected axes from the base Frame of the + encapsulated FrameSet. */ + frm = astPickAxes( bfrm, naxes, axes, NULL ); + +/* Get the uncertainty Region (if any) within the base Frame of the supplied + Region, and select the required axes from it. If the resulting Object + is not a Region, annul it so that the returned Region will have no + uncertainty. */ + if( astTestUnc( this_region ) ) { + bunc = astGetUncFrm( this_region, AST__BASE ); + unc = astPickAxes( bunc, naxes, axes, NULL ); + bunc = astAnnul( bunc ); + + if( ! astIsARegion( unc ) ) unc = astAnnul( unc ); + + } else { + unc = NULL; + } + +/* Get pointers to the coordinate data in the parent Region structure. */ + pset = this_region->points; + ptr = astGetPoints( pset ); + +/* Get space to hold the centre and corner of the Box in the new Frame. */ + cen = astMalloc( sizeof( *cen )*naxes ); + cor = astMalloc( sizeof( *cor )*naxes ); + +/* Check pointers can be used safely. */ + if( astOK ) { + +/* Copy the centre and corner axis values for the selected axes into the + arrays allocated above. */ + for( i = 0; i < naxes; i++ ) { + cen[ i ] = ptr[ axes[ i ] ][ 0 ]; + cor[ i ] = ptr[ axes[ i ] ][ 1 ]; + } + +/* Create the new Box. */ + result = (AstRegion *) astBox( frm, 0, cen, cor, unc, "", status ); + } + +/* Free resources */ + frm = astAnnul( frm ); + bfrm = astAnnul( bfrm ); + if( unc ) unc = astAnnul( unc ); + cen = astFree( cen ); + cor = astFree( cor ); + +/* Return a NULL pointer if an error has occurred. */ + if( !astOK ) result = astAnnul( result ); + +/* Return the result. */ + return result; +} + +static double *RegCentre( AstRegion *this_region, double *cen, double **ptr, + int index, int ifrm, int *status ){ +/* +* Name: +* RegCentre + +* Purpose: +* Re-centre a Region. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* double *RegCentre( AstRegion *this, double *cen, double **ptr, +* int index, int ifrm, int *status ) + +* Class Membership: +* Box member function (over-rides the astRegCentre protected +* method inherited from the Region class). + +* Description: +* This function shifts the centre of the supplied Region to a +* specified position, or returns the current centre of the Region. + +* Parameters: +* this +* Pointer to the Region. +* cen +* Pointer to an array of axis values, giving the new centre. +* Supply a NULL value for this in order to use "ptr" and "index" to +* specify the new centre. +* ptr +* Pointer to an array of points, one for each axis in the Region. +* Each pointer locates an array of axis values. This is the format +* returned by the PointSet method astGetPoints. Only used if "cen" +* is NULL. +* index +* The index of the point within the arrays identified by "ptr" at +* which is stored the coords for the new centre position. Only used +* if "cen" is NULL. +* ifrm +* Should be AST__BASE or AST__CURRENT. Indicates whether the centre +* position is supplied and returned in the base or current Frame of +* the FrameSet encapsulated within "this". +* status +* Pointer to the inherited status variable. + +* Returned Value: +* If both "cen" and "ptr" are NULL then a pointer to a newly +* allocated dynamic array is returned which contains the centre +* coords of the Region. This array should be freed using astFree when +* no longer needed. If either of "ptr" or "cen" is not NULL, then a +* NULL pointer is returned. + +* Notes: +* - Some Region sub-classes do not have a centre. Such classes will report +* an AST__INTER error code if this method is called with either "ptr" or +* "cen" not NULL. If "ptr" and "cen" are both NULL, then no error is +* reported if this method is invoked on a Region of an unsuitable class, +* but NULL is always returned. + +*/ + +/* Local Variables: */ + AstBox *this; /* Pointer to Box structure */ + AstFrame *frm; /* Pointer to Box's base Frame */ + double **rptr; /* Data pointers for Region PointSet */ + double *bc; /* Base Frame centre position */ + double *corner; /* Array holding corner axis values */ + double *result; /* Returned pointer */ + double *tmp; /* Temporary array pointer */ + double axval; /* Axis value */ + int ic; /* Coordinate index */ + int ncb; /* Number of base frame coordinate values per point */ + int ncc; /* Number of current frame coordinate values per point */ + +/* Initialise */ + result = NULL; + +/* Check the local error status. */ + if ( !astOK ) return result; + +/* Get a pointer to the Box structure. */ + this = (AstBox *) this_region; + +/* First ensure cached information (which includes the centre coords) + is up to date. */ + Cache( this, 0, status ); + +/* Get the number of axis values per point in the base and current Frames. */ + ncb = astGetNin( this_region->frameset ); + ncc = astGetNout( this_region->frameset ); + +/* If the centre coords are to be returned, return either a copy of the + base Frame centre coords, or transform the base Frame centre coords + into the current Frame. First ensure cached information (which + includes the centre coords) is up to date. */ + if( !ptr && !cen ) { + if( ifrm == AST__CURRENT ) { + result = astRegTranPoint( this_region, this->centre, 1, 1 ); + } else { + result = astStore( NULL, this->centre, sizeof( double )*ncb ); + } + +/* Otherwise, we store the supplied new centre coords and return a NULL + pointer. */ + } else { + +/* Get a pointer to the axis values stored in the Region structure. */ + rptr = astGetPoints( this_region->points ); + +/* Check pointers can be used safely */ + if( astOK ) { + +/* If the centre position was supplied in the current Frame, find the + corresponding base Frame position... */ + if( ifrm == AST__CURRENT ) { + if( cen ) { + bc = astRegTranPoint( this_region, cen, 1, 0 ); + } else { + tmp = astMalloc( sizeof( double)*(size_t)ncc ); + if( astOK ) { + for( ic = 0; ic < ncc; ic++ ) tmp[ ic ] = ptr[ ic ][ index ]; + } + bc = astRegTranPoint( this_region, tmp, 1, 0 ); + tmp = astFree( tmp ); + } + +/* Replace any bad centre values with their current values. */ + for( ic = 0; ic < ncb; ic++ ) { + if( bc[ ic ] == AST__BAD ) bc[ ic ] = this->centre[ ic ]; + } + +/* If the centre position was supplied in the base Frame, store the + centre coords in this->centre, skipping bad values. */ + } else { + bc = this->centre; + for( ic = 0; ic < ncb; ic++ ) { + axval = cen ? cen[ ic ] : ptr[ ic ][ index ]; + if( axval != AST__BAD ) bc[ ic ] = axval; + } + } + +/* Find the coordinates at the new box corner. */ + frm = astGetFrame( this_region->frameset, AST__BASE ); + corner = GeoCorner( frm, ncb, bc, this->geolen, NULL, status ); + frm = astAnnul( frm ); + +/* ... and change the coords in the parent Region structure. */ + for( ic = 0; ic < ncb; ic++ ) { + rptr[ ic ][ 0 ] = bc[ ic ]; + rptr[ ic ][ 1 ] = corner[ ic ]; + } + +/* Free resources */ + if( ifrm == AST__CURRENT ) bc = astFree( bc ); + corner = astFree( corner ); + +/* Indicate the cached info in the Box structure is out of date. */ + astResetCache( this ); + +/* Any base Frame mesh or grid is now no good, so annul it. */ + if( this_region->basemesh ) this_region->basemesh = astAnnul( this_region->basemesh ); + if( this_region->basegrid ) this_region->basegrid = astAnnul( this_region->basegrid ); + + } + } + + +/* Return the result. */ + 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 Box. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* int RegPins( AstRegion *this, AstPointSet *pset, AstRegion *unc, +* int **mask, int *status ) + +* Class Membership: +* Box 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 Box. +* +* Some tolerance is allowed, as specified by the uncertainty Region +* stored in the supplied Box "this", and the supplied uncertainty +* Region "unc" which describes the uncertainty of the supplied points. + +* Parameters: +* this +* Pointer to the Box. +* 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: */ + AstBox *large_box; /* Box slightly larger than "this" */ + AstBox *small_box; /* Box slightly smaller than "this" */ + AstBox *this; /* Pointer to the Box structure. */ + AstFrame *frm; /* Base Frame in supplied Box */ + AstPointSet *ps1; /* Points masked by larger Box */ + AstPointSet *ps2; /* Points masked by larger and smaller Boxes */ + AstRegion *tunc; /* Uncertainity Region from "this" */ + double **ptr; /* Pointer to axis values in "ps2" */ + double *large; /* A corner position in the larger Box */ + double *safe; /* An interior point in "this" */ + double *lbnd_tunc; /* Lower bounds of "this" uncertainty Region */ + double *lbnd_unc; /* Lower bounds of supplied uncertainty Region */ + double *p; /* Pointer to next axis value */ + double *small; /* A corner position in the smaller Box */ + double *ubnd_tunc; /* Upper bounds of "this" uncertainty Region */ + double *ubnd_unc; /* Upper bounds of supplied uncertainty Region */ + double *wid; /* Widths of "this" border */ + int i; /* Axis index */ + int j; /* Point index */ + int nc; /* No. of axes in Box base frame */ + int np; /* No. of supplied points */ + int result; /* Returned flag */ + +/* Initialise */ + result = 0; + if( mask ) *mask = NULL; + +/* Check the inherited status. */ + if( !astOK ) return result; + +/* Get a pointer to the Box structure. */ + this = (AstBox *) this_region; + +/* Ensure cached information is up to date. */ + Cache( this, 0, status ); + +/* Get the number of base Frame axes in the Box, and check the supplied + PointSet has the same number of axis values per point. */ + frm = astGetFrame( this_region->frameset, AST__BASE ); + nc = astGetNaxes( frm ); + if( astGetNcoord( pset ) != nc && astOK ) { + astError( AST__INTER, "astRegPins(%s): Illegal number of axis " + "values per point (%d) in the supplied PointSet - should be " + "%d (internal AST programming error).", status, astGetClass( this ), + astGetNcoord( pset ), nc ); + } + +/* Get the number of axes in the uncertainty Region and check it is the + same as above. */ + if( unc && astGetNaxes( unc ) != nc && astOK ) { + astError( AST__INTER, "astRegPins(%s): Illegal number of axes (%d) " + "in the supplied uncertainty Region - should be " + "%d (internal AST programming error).", status, astGetClass( this ), + astGetNaxes( unc ), nc ); + } + +/* 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 Box for it still to be considered to be on the boundary. + First get the Region which defines the uncertainty within the Box 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. */ + tunc = astGetUncFrm( this, AST__BASE ); + if( safe ) astRegCentre( tunc, safe, NULL, 0, AST__CURRENT ); + lbnd_tunc = astMalloc( sizeof( double )*(size_t) nc ); + ubnd_tunc = astMalloc( sizeof( double )*(size_t) nc ); + astGetRegionBounds( tunc, 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 ); + lbnd_unc = astMalloc( sizeof( double )*(size_t) nc ); + ubnd_unc = astMalloc( sizeof( double )*(size_t) nc ); + astGetRegionBounds( unc, lbnd_unc, ubnd_unc ); + } else { + lbnd_unc = NULL; + ubnd_unc = NULL; + } + +/* The required border width for each axis is half of the total width + of the two bounding boxes. Use a zero sized box "unc" if no box was + supplied. */ + wid = astMalloc( sizeof( double )*(size_t) nc ); + large = astMalloc( sizeof( double )*(size_t) nc ); + small = astMalloc( sizeof( double )*(size_t) nc ); + if( astOK ) { + if( unc ) { + for( i = 0; i < nc; i++ ) { + wid[ i ] = 0.5*( fabs( astAxDistance( frm, i + 1, lbnd_tunc[ i ], ubnd_tunc[ i ] ) ) + + fabs( astAxDistance( frm, i + 1, lbnd_unc[ i ], ubnd_unc[ i ] ) ) ); + } + } else { + for( i = 0; i < nc; i++ ) { + wid[ i ] = fabs( 0.5*astAxDistance( frm, i + 1, lbnd_tunc[ i ], ubnd_tunc[ i ] ) ); + } + } + +/* Create two new Boxes, one of which is larger than "this" by the widths + found above, and the other of which is smaller than "this" by the widths + found above. */ + for( i = 0; i < nc; i++ ) { + large[ i ] = this->centre[ i ] + this->extent[ i ] + wid[ i ]; + small[ i ] = this->extent[ i ] - wid[ i ]; + if( small[ i ] < 0.0 ) small[ i ] = 0.0; + small[ i ] += this->centre[ i ]; + } + + large_box = astBox( frm, 0, this->centre, large, NULL, "", status ); + small_box = astBox( frm, 0, this->centre, small, NULL, "", status ); + +/* Negate the smaller region.*/ + astNegate( small_box ); + +/* Points are on the boundary of "this" if they are inside both the large + box and the negated smallbox. First transform the supplied PointSet + using the large box, then transform them using the negated smaller Box. */ + ps1 = astTransform( large_box, pset, 1, NULL ); + ps2 = astTransform( small_box, ps1, 1, NULL ); + +/* Get a point to the resulting axis values, and the number of axis + values per axis. */ + ptr = astGetPoints( ps2 ); + np = astGetNpoint( ps2 ); + +/* If a mask array is to be returned, create one. */ + if( mask ) { + *mask = astMalloc( sizeof(int)*(size_t) np ); + +/* Check all the resulting points, setting mask values for all of them. */ + if( astOK ) { + +/* Initialise the mask elements on the basis of the first axis values */ + result = 1; + p = ptr[ 0 ]; + for( j = 0; j < np; j++ ) { + if( *(p++) == AST__BAD ) { + result = 0; + (*mask)[ j ] = 0; + } else { + (*mask)[ j ] = 1; + } + } + +/* Now check for bad values on other axes. */ + for( i = 1; i < nc; i++ ) { + p = ptr[ i ]; + for( j = 0; j < np; j++ ) { + if( *(p++) == AST__BAD ) { + result = 0; + (*mask)[ j ] = 0; + } + } + } + } + +/* If no output mask is to be made, we can break out of the check as soon + as the first bad value is found. */ + } else if( astOK ) { + result = 1; + for( i = 0; i < nc && result; i++ ) { + p = ptr[ i ]; + for( j = 0; j < np; j++ ) { + if( *(p++) == AST__BAD ) { + result = 0; + break; + } + } + } + } + +/* Free resources. */ + large_box = astAnnul( large_box ); + small_box = astAnnul( small_box ); + ps1 = astAnnul( ps1 ); + ps2 = astAnnul( ps2 ); + } + + tunc = astAnnul( tunc ); + frm = astAnnul( frm ); + lbnd_tunc = astFree( lbnd_tunc ); + ubnd_tunc = astFree( ubnd_tunc ); + if( unc ) lbnd_unc = astFree( lbnd_unc ); + if( unc ) ubnd_unc = astFree( ubnd_unc ); + wid = astFree( wid ); + large = astFree( large ); + small = astFree( small ); + safe = astFree( safe ); + +/* 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 "box.h" +* int astTraceRegion( AstRegion *this, int n, double *dist, double **ptr ); + +* Class Membership: +* Box 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; */ + AstMapping *map; + AstPointSet *bpset; + AstPointSet *cpset; + double **bptr; + double d; + double lbnd[ 2 ]; + double ubnd[ 2 ]; + int i; + int ncur; + int result; + +/* Initialise */ + result = 0; + +/* Check inherited status. */ + if( ! astOK ) return result; + +/* Check it is 2-dimensional. */ + if( astGetNin( this_region->frameset ) == 2 ) result = 1; + +/* Check we have some points to find. */ + if( result && n > 0 ) { + +/* 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. */ + } else { + bpset = astPointSet( n, 2, " ", status ); + bptr = astGetPoints( bpset ); + ncur = astGetNout( map ); + } + +/* Check the pointers can be used safely. */ + if( astOK ) { + +/* Get the bounds of the Region in the base Frame. */ + astRegBaseBox( this_region, lbnd, ubnd ); + +/* Loop round each point. Each edge of the box covers a parameteric + distance of 0.25, regardless of the aspect ratio of the box. */ + for( i = 0; i < n; i++ ) { + +/* The right hand edge starts at 0.75 (parameter increases top to bottom). */ + d = 4*dist[ i ] - 3; + if( d > 0 ) { + bptr[ 0 ][ i ] = ubnd[ 0 ]; + bptr[ 1 ][ i ] = ( 1.0 - d )*ubnd[ 1 ] + d*lbnd[ 1 ]; + +/* The top edge starts at 0.5 (parameter increases left to right). */ + } else { + d += 1.0; + if( d > 0 ) { + bptr[ 0 ][ i ] = ( 1.0 - d )*lbnd[ 0 ] + d*ubnd[ 0 ]; + bptr[ 1 ][ i ] = ubnd[ 1 ]; + +/* The left hand edge starts at 0.25 (parameter increases bottom to top). */ + } else { + d += 1.0; + if( d > 0 ) { + bptr[ 0 ][ i ] = lbnd[ 0 ]; + bptr[ 1 ][ i ] = ( 1.0 - d )*lbnd[ 1 ] + d*ubnd[ 1 ]; + +/* The bottom edge starts at 0.0 (parameter increases right to left). */ + } else { + d += 1.0; + bptr[ 0 ][ i ] = ( 1.0 - d )*ubnd[ 0 ] + d*lbnd[ 0 ]; + bptr[ 1 ][ i ] = lbnd[ 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 ); + } + +/* Return the result. */ + return result; +} + +static void ResetCache( AstRegion *this, int *status ){ +/* +* Name: +* ResetCache + +* Purpose: +* Clear cached information within the supplied Region. + +* Type: +* Private function. + +* Synopsis: +* #include "box.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. +*/ + if( this ) { + ((AstBox *) this )->stale = 1; + (*parent_resetcache)( this, status ); + } +} + +static void SetClosed( AstRegion *this, int value, int *status ){ +/* +* Name: +* SetClosed + +* Purpose: +* Set a value for the Closed attribute of a Region. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* void SetClosed( AstRegion *this, int value, int *status ) + +* Class Membership: +* Box member function (over-rides the protected astSetClosed +* method inherited from the Region class). + +* Description: +* This function sets a new value for the Closed attribute of a Region. + +* Parameters: +* this +* Pointer to the Region. +* value +* The new attribute value. +* status +* Pointer to the inherited status variable. +*/ + +/* Local Variables: */ + int old; + +/* Check the global error status. */ + if ( !astOK ) return; + +/* Get the original attribute value */ + old = astGetClosed( this ); + +/* Invoke the set method inherited from the parent Region class */ + (*parent_setclosed)( this, value, status ); + +/* If the new value is not the same as the old value, indicate that we + need to re-calculate the cached information in the Box. */ + if( value != old ) astResetCache( this ); +} + +static void SetNegated( AstRegion *this, int value, int *status ){ +/* +* Name: +* SetNegated + +* Purpose: +* Set a value for the Negated attribute of a Region. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* void SetNegated( AstRegion *this, int value, int *status ) + +* Class Membership: +* Box member function (over-rides the protected astSetNegated +* method inherited from the Region class). + +* Description: +* This function sets a new value for the Negated attribute of a Region. + +* Parameters: +* this +* Pointer to the Region. +* value +* The new attribute value. +* status +* Pointer to the inherited status variable. +*/ + +/* Local Variables: */ + int old; + +/* Check the global error status. */ + if ( !astOK ) return; + +/* Get the original attribute value */ + old = astGetNegated( this ); + +/* Invoke the set method inherited from the parent Region class */ + (*parent_setnegated)( this, value, status ); + +/* If the new value is not the same as the old value, indicate that we + need to re-calculate the cached information in the Box. */ + if( value != old ) astResetCache( this ); +} + +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 "box.h" +* void SetRegFS( AstRegion *this_region, AstFrame *frm, int *status ) + +* Class Membership: +* Box 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; + +/* Invoke the parent method to store the FrameSet in the parent Region + structure. */ + (* parent_setregfs)( this_region, frm, status ); + +/* Indicate that we need to re-calculate the cached information in the Box. */ + astResetCache( this_region ); +} + +static void SetUnc( AstRegion *this, AstRegion *unc, int *status ){ +/* +* Name: +* SetUnc + +* Purpose: +* Store uncertainty information in a Region. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* void SetUnc( AstRegion *this, AstRegion *unc, int *status ) + +* Class Membership: +* Box method (over-rides the astSetUnc method inherited from the +* Region class). + +* Description: +* Each Region (of any class) can have an "uncertainty" which specifies +* the uncertainties associated with the boundary of the Region. This +* information is supplied in the form of a second Region. The uncertainty +* in any point on the boundary of a Region is found by shifting the +* associated "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. +* +* The uncertainty is usually specified when the Region is created, but +* this function allows it to be changed at any time. + +* Parameters: +* this +* Pointer to the Region which is to be assigned a new uncertainty. +* unc +* Pointer to the new uncertainty Region. This must be either a Box, +* a Circle or an Ellipse. 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 Region "this". +* status +* Pointer to the inherited status variable. +*/ + +/* Check the inherited status. */ + if( !astOK ) return; + +/* Invoke the astSetUnc method inherited from the parent Region class. */ + (*parent_setunc)( this, unc, status ); + +/* Indicate that we need to re-calculate the cached information in the Box. */ + astResetCache( this ); +} + +static AstMapping *Simplify( AstMapping *this_mapping, int *status ) { +/* +* Name: +* Simplify + +* Purpose: +* Simplify the Mapping represented by a Region. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* AstMapping *Simplify( AstMapping *this, int *status ) + +* Class Membership: +* Box 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: */ + AstBox *box; /* Pointer to Box structure */ + AstBox *newbox; /* Pointer to simpler Box */ + AstFrame *frm; /* Pointer to current Frame */ + AstMapping *map; /* Base -> current Mapping */ + AstMapping *result; /* Result pointer to return */ + AstPointSet *basemesh; /* Mesh of base Frame positions */ + AstPointSet *mesh; /* Mesh of current Frame positions */ + AstPointSet *ps1; /* Box corners in base Frame */ + AstPointSet *ps2; /* Box corners in current Frame */ + AstPolygon *newpoly; /* New Polygon to replace Box */ + AstRegion *prism; /* Prism combining all axes */ + AstRegion *new; /* Pointer to simplified Region */ + AstRegion *this; /* Pointer to supplied Region structure */ + AstRegion *unc; /* Pointer to uncertainty Region */ + double **ptr1; /* Pointers to axis values in ps1 */ + double **ptr2; /* Pointers to axis values in ps2 */ + double *constants; /* Axis constants array */ + double *lbnd; /* Lower bounds for new Box */ + double *ubnd; /* Upper bounds for new Box */ + double corners[8]; /* Box corners in current Frame */ + double k; /* Axis constant value */ + double lb; /* Lower axis bound */ + double ub; /* Upper axis bound */ + int *inperm; /* Input axis permutation array */ + int *outperm; /* Output axis permutation array */ + int closed; /* Was original Region closed? */ + int feed; /* Source of value for current axis */ + int right_handed; /* Is the new Frame right handed? */ + int ic; /* Axis index */ + int isInterval; /* Is the simplified Box an Interval */ + int isNull; /* Is the simplified Box a NullRegion? */ + int neg; /* Was original Region negated? */ + int nin; /* No. of base Frame axes (Mapping inputs) */ + int nout; /* No. of current Frame axes (Mapping outputs) */ + int simpler; /* Has some simplication taken place? */ + +/* Initialise. */ + result = NULL; + +/* Check the global error status. */ + if ( !astOK ) return result; + +/* Obtain a pointer to the 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 ); + +/* Get the Mapping from base to current Frame. */ + map = astGetMapping( new->frameset, AST__BASE, AST__CURRENT ); + +/* Get the number of inputs and outputs for the PermMap */ + nin = astGetNin( map ); + nout = astGetNout( map ); + +/* If the Mapping from base to current Frame is a PermMap, we now explicitly + how to swap the axes of the Box to produce either a new Box or an + Interval. */ + if( astIsAPermMap( map ) ){ + +/* See if the new Box is Negated and/or Closed.*/ + neg = astGetNegated( new ); + closed = astGetClosed( new ); + +/* Get a pointer to the Box structure. */ + newbox = (AstBox *) new; + +/* Ensure cached information is up to date. */ + Cache( newbox, 0, status ); + +/* Get the input and output permutation arrays and the array of constants + from the PermMap. */ + inperm = astGetInPerm( map ); + outperm = astGetOutPerm( map ); + constants = astGetConstants( map ); + +/* Allocate memory to hold the axis bounds for the box in the current + Frame. */ + lbnd = astMalloc( sizeof( double )*(size_t) nout ); + ubnd = astMalloc( sizeof( double )*(size_t) nout ); + +/* Check pointers can be used safely. */ + if( astOK ) { + +/* Set flags indicating that the Box can be simplified, and does not result + in a NullRegion or an Interval. */ + simpler = 1; + isNull = 0; + isInterval = 0; + +/* Check each output (which corresponds to an axis in the current Frame + of the Box). */ + for( ic = 0; ic < nout; ic++ ) { + +/* Find the input (a base Frame axis) which feeds this output when the + forward transformation of the PermMap is used. */ + feed = outperm[ ic ]; + +/* If this output is fed a constant (i.e. does not depend on any of the + inputs), then the output axis limits are equal to this constant. */ + if( feed < 0 ) { + lbnd[ ic ] = constants[ (-feed) - 1 ]; + ubnd[ ic ] = constants[ (-feed) - 1 ]; + +/* If this output is fed the constant AST__BAD (i.e. does not depend on any of + the inputs), then the output axis is unbounded and we will consequently + create an Interval rather than a Box. */ + } else if( feed >= nin ) { + lbnd[ ic ] = AST__BAD; + ubnd[ ic ] = AST__BAD; + +/* If this output is fed the value of an input, then the output limits + are equal to the corresponding input limits. */ + } else { + lbnd[ ic ] = newbox->centre[ feed ] - newbox->extent[ feed ]; + ubnd[ ic ] = newbox->centre[ feed ] + newbox->extent[ feed ]; + } + +/* If either bound is missing we will produce an Interval rather than a + Box. */ + if( lbnd[ ic ] == AST__BAD || ubnd[ ic ] == AST__BAD ) { + isInterval = 1; + } + } + +/* If any base Frame axes are not present in the current Frame, we need + to check that the PermMap selects a slice which intersects the base + Frame box. If the slice does not intersect the base Frame box, then + the resulting Region willbe NullRegion. To do this, we check each + element in the input axis permutation array, "inperm". */ + for( ic = 0; ic < nin; ic++ ) { + +/* Find the output (a current Frame axis) which feeds this input when the + inverse transformation of the PermMap is used. */ + feed = inperm[ ic ]; + +/* If this input is fed a constant (i.e. does not depend on any of the + outputs), then we must check that this constant is within the range of + axis values covered by the Box. If not then the simplified Box represents + a slice through the coordinate system which does not pass through the + original Box. In this case the simplified Region is a NullRegion + instead of a Box. */ + if( feed < 0 ) { + k = constants[ (-feed) - 1 ]; + lb = newbox->centre[ ic ] - newbox->extent[ ic ]; + ub = newbox->centre[ ic ] + newbox->extent[ ic ]; + + if( closed == neg ) { + isNull = ( k <= lb || k >= ub ); + } else { + isNull = ( k < lb || k > ub ); + } + +/* If this input is fed the constant AST__BAD (i.e. does not depend on any of + the outputs), then the input axis is unbounded and will consequently + extend beyond the Box. In this case the simplified Region will be a + NullRegion. */ + } else if( feed >= nout ) { + isNull = 1; + +/* If this input is fed the value of an output, then check that the + relationship is bi-directional. If it is not, we cannot simplify the + Box. */ + } else if( outperm[ feed ] != ic ) { + simpler = 0; + break; + } + } + +/* If the Box can be simplified, create a new Region of an appropriate + class. */ + if( simpler ) { + +/* Get any uncertainty from the supplied Box (it will already have been + simplified by the parent Simplify method). */ + unc = astTestUnc( new ) ? astGetUncFrm( new, AST__CURRENT ) : NULL; + +/* Get the Frame represented by the Region. */ + frm = astGetFrame( new->frameset, AST__CURRENT ); + +/* We can now replace the original Region with the simplified Region so annul + the original pointer. */ + new = astAnnul( new ); + +/* Create a new Region of the required class. */ + if( isNull ) { + new = (AstRegion *) astNullRegion( frm, unc, "", status ); + + } else if( isInterval ){ + new = (AstRegion *) astInterval( frm, lbnd, ubnd, unc, "", status ); + + } else { + new = (AstRegion *) astBox( frm, 1, lbnd, ubnd, unc, "", status ); + } + +/* If the original box was Negated. Negate the new one. */ + if( neg ) astNegate( new ); + +/* Free resources */ + if( unc ) unc = astAnnul( unc ); + frm = astAnnul( frm ); + + } + } + +/* Free resources */ + inperm = astFree( inperm ); + outperm = astFree( outperm ); + constants = astFree( constants ); + lbnd = astFree( lbnd ); + ubnd = astFree( ubnd ); + +/* If the Mapping from base to current Frame is not a PermMap or a UnitMap, we + attempt to simplify the Box by re-defining it within its current Frame. + Transforming the box from its base to its current FRame may result in + the region no longer being a box. We test this by transforming a set of + bounds on the box boundary. */ + } else if( !astIsAUnitMap( map ) ){ + +/* Get pointer to current Frame. */ + frm = astGetFrame( new->frameset, AST__CURRENT ); + +/* Get a mesh of points covering the Box in its current Frame. */ + mesh = astRegMesh( new ); + +/* Get the Region describing the positional uncertainty within the Box in + its current Frame. */ + unc = astGetUncFrm( new, AST__CURRENT ); + +/* Find the best fitting box (defined in the current Frame) through these + points */ + newbox = BestBox( frm, mesh, unc, status ); + +/* See if all points within this mesh fall on the boundary of the best + fitting Box, to within the uncertainty of the Region. */ + if( newbox && astRegPins( newbox, mesh, NULL, NULL ) ) { + +/* If so, check that the inverse is true (we need to transform the + simplified boxes mesh into the base Frame of he original box for use by + astRegPins). */ + (void) astAnnul( mesh ); + mesh = astRegMesh( newbox ); + basemesh = astTransform( map, mesh, 0, NULL ); + if( astRegPins( new, basemesh, NULL, NULL ) ) { + +/* If so, use the new Box in place of the original Box. */ + (void) astAnnul( new ); + new = astClone( newbox ); + simpler = 1; + } + +/* Free resources. */ + basemesh = astAnnul( basemesh ); + +/* If the transformed Box is not itself a Box, see if it can be + represented accurately by a Polygon. This is only possible for + 2-dimensional Boxes. */ + } else if( nin == 2 && nout == 2 ) { + +/* Create a PointSet holding the base Frame axis values at the four + corners of the Box. */ + ps1 = astPointSet( 4, 2, "", status ); + ptr1 = astGetPoints( ps1 ); + if( astOK ) { + box = (AstBox *) new; + Cache( box, 0, status ); + +/* The order in which the polygon vertices are stored determines whether + the interior or exterior of the polygon forms the inside of the + Region. We want the inside to be the interior. First create a Polygon + in which the vertices are stored in clockwise order within the + new coordinate Frame. If the new Polygon is not bounded, use + anti-clockwise order. */ + for( right_handed = 0; right_handed < 2; right_handed++ ) { + + if( right_handed ) { + ptr1[ 0 ][ 0 ] = box->centre[ 0 ] - box->extent[ 0 ]; + ptr1[ 1 ][ 0 ] = box->centre[ 1 ] + box->extent[ 1 ]; + + ptr1[ 0 ][ 1 ] = box->centre[ 0 ] - box->extent[ 0 ]; + ptr1[ 1 ][ 1 ] = box->centre[ 1 ] - box->extent[ 1 ]; + + ptr1[ 0 ][ 2 ] = box->centre[ 0 ] + box->extent[ 0 ]; + ptr1[ 1 ][ 2 ] = box->centre[ 1 ] - box->extent[ 1 ]; + + ptr1[ 0 ][ 3 ] = box->centre[ 0 ] + box->extent[ 0 ]; + ptr1[ 1 ][ 3 ] = box->centre[ 1 ] + box->extent[ 1 ]; + + } else { + ptr1[ 0 ][ 3 ] = box->centre[ 0 ] - box->extent[ 0 ]; + ptr1[ 1 ][ 3 ] = box->centre[ 1 ] + box->extent[ 1 ]; + + ptr1[ 0 ][ 2 ] = box->centre[ 0 ] - box->extent[ 0 ]; + ptr1[ 1 ][ 2 ] = box->centre[ 1 ] - box->extent[ 1 ]; + + ptr1[ 0 ][ 1 ] = box->centre[ 0 ] + box->extent[ 0 ]; + ptr1[ 1 ][ 1 ] = box->centre[ 1 ] - box->extent[ 1 ]; + + ptr1[ 0 ][ 0 ] = box->centre[ 0 ] + box->extent[ 0 ]; + ptr1[ 1 ][ 0 ] = box->centre[ 1 ] + box->extent[ 1 ]; + } + +/* Transform the Box corners into the current Frame. */ + ps2 = astTransform( map, ps1, 1, NULL ); + ptr2 = astGetPoints( ps2 ); + if( astOK ) { + +/* Create a Polygon from these points. */ + for( ic = 0; ic < 4; ic++ ) { + corners[ ic ] = ptr2[ 0 ][ ic ]; + corners[ 4 + ic ] = ptr2[ 1 ][ ic ]; + } + newpoly = astPolygon( frm, 4, 4, corners, unc, "", status ); + +/* If the Polygon is bounded, break out of the loop. */ + if( astGetBounded( newpoly ) ) break; + } + +/* Free resources. */ + newpoly = astAnnul( newpoly ); + ps2 = astAnnul( ps2 ); + } + +/* See if all points within the Box mesh fall on the boundary of this + Polygon, to within the uncertainty of the Region. */ + if( astRegPins( newpoly, mesh, NULL, NULL ) ) { + +/* If so, use the new Polygon in place of the original Box. */ + (void) astAnnul( new ); + new = astClone( newpoly ); + simpler = 1; + } + +/* Free resources. */ + newpoly = astAnnul( newpoly ); + } + + ps1 = astAnnul( ps1 ); + } + +/* If we have yet been able to produce a simpler region, we now try + splitting the Box into two separate Boxes defined in separate + coordinate Frames. If either of these two Boxes can be simplified, + create a Prism containing the two simplified Boxes, and attempt to + simplify the Prism. Otherwise a clone of "new" is returned by + astConvertToPrism. */ + if( !simpler ) { + prism = astConvertToPrism( new ); + + if( prism != new ) { + simpler = 1; + (void) astAnnul( new ); + new = prism; + + } else { + prism = astAnnul( prism ); + } + } + + frm = astAnnul( frm ); + mesh = astAnnul( mesh ); + unc = astAnnul( unc ); + if( newbox ) newbox = astAnnul( newbox ); + } + + 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 AstPointSet *Transform( AstMapping *this, AstPointSet *in, + int forward, AstPointSet *out, int *status ) { +/* +* Name: +* Transform + +* Purpose: +* Apply a Box to transform a set of points. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* AstPointSet *Transform( AstMapping *this, AstPointSet *in, +* int forward, AstPointSet *out, int *status ) + +* Class Membership: +* Box member function (over-rides the astTransform protected +* method inherited from the Mapping class). + +* Description: +* This function takes a Box 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 Box. +* 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 Box. +* - 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: */ + AstBox *box; /* Pointer to Box */ + AstFrame *frm; /* Pointer to base Frame in FrameSet */ + AstPointSet *pset_tmp; /* Pointer to PointSet holding base Frame positions*/ + AstPointSet *result; /* Pointer to output PointSet */ + AstRegion *reg; /* Pointer to Region */ + double **ptr_out; /* Pointer to output coordinate data */ + double **ptr_tmp; /* Pointer to base Frame coordinate data */ + double axval; /* Input axis value */ + int closed; /* Is the boundary part of the Region? */ + int coord; /* Zero-based index for coordinates */ + int ncoord_out; /* No. of coordinates per output point */ + int ncoord_tmp; /* No. of coordinates per base Frame point */ + int neg; /* Is the Box negated?*/ + int npoint; /* No. of points */ + int ok; /* Is the point inside the Region? */ + int point; /* Loop counter for points */ + + +/* Check the global error status. */ + if ( !astOK ) return NULL; + +/* Obtain pointers to the Regionand to the Box. */ + reg = (AstRegion *) this; + box = (AstBox *) this; + +/* 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, in, forward, out, status ); + +/* 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. */ + pset_tmp = astRegTransform( reg, in, 0, NULL, &frm ); + +/* Determine the numbers of points and coordinates per point from the base + Frame PointSet and obtain pointers for accessing the base Frame and output + coordinate values. */ + npoint = astGetNpoint( pset_tmp ); + ncoord_tmp = astGetNcoord( pset_tmp ); + ptr_tmp = astGetPoints( pset_tmp ); + ncoord_out = astGetNcoord( result ); + ptr_out = astGetPoints( result ); + +/* See if the boundary is part of the Region. */ + closed = astGetClosed( reg ); + +/* See if the Box is negated */ + neg = astGetNegated( reg ); + +/* Ensire the cached information is up to date. */ + Cache( box, 1, status ); + +/* Perform coordinate arithmetic. */ +/* ------------------------------ */ + if ( astOK ) { + +/* The logic used to combine axis values for negated and un-negated boxes + is different. For negated boxes, a position is in the region if *any + one* axis is not "close" to the box centre. */ + if( neg ) { + +/* Loop round each point */ + for ( point = 0; point < npoint; point++ ) { + +/* Assume the point is outside the Region (since the Region is + negated, this means assuming it is within the box). */ + ok = 0; + +/* Loop round each axis value at this point. We break as soon as we find + a bad axis value or an axis value which is outside the box. */ + for ( coord = 0; coord < ncoord_tmp; coord++ ) { + +/* The point is definiately not in the Region if any input axis value is bad. */ + axval = ptr_tmp[ coord ][ point ]; + if( axval == AST__BAD ) { + break; + +/* Otherwise check the current axis value, depending on whether the + boundary is included in the Region or not. Break as soon as an axis + value is found which is outside the box limits (i.e. in the Region). */ + } else if( !astAxIn( frm, coord, box->lo[ coord ], box->hi[ coord ], + axval, !closed ) ) { + ok = 1; + break; + } + } + +/* If this point is not inside the Region store bad output axis values. */ + if( !ok ) { + for ( coord = 0; coord < ncoord_out; coord++ ) { + ptr_out[ coord ][ point ] = AST__BAD; + } + } + } + +/* For un-negated boxes, a position is in the region if *all* axes are "close" + to the box centre. */ + } else { + +/* Loop round each point */ + for ( point = 0; point < npoint; point++ ) { + +/* Assume the point is within the Region (i.e.inside the box). */ + ok = 1; + +/* Loop round each axis value at this point. We break when we find a bad + input point or if any axis value is outside the box. */ + for ( coord = 0; coord < ncoord_tmp; coord++ ) { + +/* The point is not in the Region if any input axis value is bad. */ + axval = ptr_tmp[ coord ][ point ]; + if( axval == AST__BAD ) { + ok = 0; + break; + +/* Otherwise check the current axis value, depending on whether the + boundary is included in the Region or not. Break as soon as an axis + value is found which is outside the box limits (i.e. outside the Region). */ + } else if( !astAxIn( frm, coord, box->lo[ coord ], box->hi[ coord ], + axval, closed ) ) { + ok = 0; + break; + } + } + +/* If this point is outside the Region store bad output axis values. */ + if( !ok ) { + for ( coord = 0; coord < ncoord_out; coord++ ) { + ptr_out[ coord ][ point ] = AST__BAD; + } + } + } + } + } + +/* Free resources */ + pset_tmp = astAnnul( pset_tmp ); + 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). */ + +/* Copy constructor. */ +/* ----------------- */ +static void Copy( const AstObject *objin, AstObject *objout, int *status ) { +/* +* Name: +* Copy + +* Purpose: +* Copy constructor for Region objects. + +* Type: +* Private function. + +* Synopsis: +* void Copy( const AstObject *objin, AstObject *objout, int *status ) + +* Description: +* This function implements the copy constructor for Region 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: */ + AstBox *in; /* Pointer to input Box */ + AstBox *out; /* Pointer to output Box */ + int nax; /* Number of base Frame axes */ + +/* Check the global error status. */ + if ( !astOK ) return; + +/* Obtain pointers to the input and output Boxs. */ + in = (AstBox *) objin; + out = (AstBox *) objout; + +/* For safety, first clear any references to the input memory from + the output Box. */ + out->extent = NULL; + out->centre = NULL; + out->lo = NULL; + out->hi = NULL; + out->geolen = NULL; + +/* Copy dynamic memory contents */ + nax = astGetNin( ((AstRegion *) in)->frameset ); + out->extent = astStore( NULL, in->extent, + sizeof( double )*(size_t)nax ); + out->centre = astStore( NULL, in->centre, + sizeof( double )*(size_t)nax ); + out->lo = astStore( NULL, in->lo, + sizeof( double )*(size_t)nax ); + out->hi = astStore( NULL, in->hi, + sizeof( double )*(size_t)nax ); + out->geolen = astStore( NULL, in->geolen, + sizeof( double )*(size_t)nax ); +} + + +/* Destructor. */ +/* ----------- */ +static void Delete( AstObject *obj, int *status ) { +/* +* Name: +* Delete + +* Purpose: +* Destructor for Box objects. + +* Type: +* Private function. + +* Synopsis: +* void Delete( AstObject *obj, int *status ) + +* Description: +* This function implements the destructor for Box 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: */ + AstBox *this; /* Pointer to Box */ + +/* Obtain a pointer to the Box structure. */ + this = (AstBox *) obj; + +/* Annul all resources. */ + this->extent = astFree( this->extent ); + this->centre = astFree( this->centre ); + this->lo = astFree( this->lo ); + this->hi = astFree( this->hi ); + this->geolen = astFree( this->geolen ); +} + +/* Dump function. */ +/* -------------- */ +static void Dump( AstObject *this_object, AstChannel *channel, int *status ) { +/* +* Name: +* Dump + +* Purpose: +* Dump function for Box 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 Box class to an output Channel. + +* Parameters: +* this +* Pointer to the Box whose data are being written. +* channel +* Pointer to the Channel to which the data are being written. +* status +* Pointer to the inherited status variable. +*/ + +/* Check the global error status. */ + if ( !astOK ) return; + +/* Write out values representing the instance variables for the + Box 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. */ + +/* There are no values to write, so return without further action. */ +} + +/* Standard class functions. */ +/* ========================= */ +/* Implement the astIsABox and astCheckBox functions using the macros + defined for this purpose in the "object.h" header file. */ +astMAKE_ISA(Box,Region) +astMAKE_CHECK(Box) + +AstBox *astBox_( void *frame_void, int form, const double point1[], + const double point2[], AstRegion *unc, const char *options, int *status, ...) { +/* +*++ +* Name: +c astBox +f AST_BOX + +* Purpose: +* Create a Box. + +* Type: +* Public function. + +* Synopsis: +c #include "box.h" +c AstBox *astBox( AstFrame *frame, int form, const double point1[], +c const double point2[], AstRegion *unc, +c const char *options, ... ) +f RESULT = AST_BOX( FRAME, FORM, POINT1, POINT2, UNC, OPTIONS, STATUS ) + +* Class Membership: +* Box constructor. + +* Description: +* This function creates a new Box and optionally initialises its +* attributes. +* +* The Box class implements a Region which represents a box with sides +* parallel to the axes of a Frame (i.e. an area which encloses a given +* range of values on each axis). A Box is similar to an Interval, the +* only real difference being that the Interval class allows some axis +* limits to be unspecified. Note, a Box will only look like a box if +* the Frame geometry is approximately flat. For instance, a Box centred +* close to a pole in a SkyFrame will look more like a fan than a box +* (the Polygon class can be used to create a box-like region close to a +* pole). + +* Parameters: +c frame +f FRAME = INTEGER (Given) +* A pointer to the Frame in which the region is defined. 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 form +f FORM = INTEGER (Given) +* Indicates how the box is described by the remaining parameters. +* A value of zero indicates that the box is specified by a centre +* position and a corner position. A value of one indicates that the +* box is specified by a two opposite corner positions. +c point1 +f POINT1( * ) = DOUBLE PRECISION (Given) +c An array of double, with one element for each Frame axis +f An array with one element for each Frame axis +* (Naxes attribute). If +c "form" +f FORM +* is zero, this array should contain the coordinates at the centre of +* the box. +c If "form" +f If FORM +* is one, it should contain the coordinates at the corner of the box +* which is diagonally opposite the corner specified by +c "point2". +f POINT2. +c point2 +f POINT2( * ) = DOUBLE PRECISION (Given) +c An array of double, with one element for each Frame axis +f An array with one element for each Frame axis +* (Naxes attribute) containing the coordinates at any corner of the +* box. +c unc +f UNC = INTEGER (Given) +* An optional pointer to an existing Region which specifies the +* uncertainties associated with the boundary of the Box being created. +* The uncertainty in any point on the boundary of the Box 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 Box. 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 Box 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 Box. 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 Box. 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 astBox() +f AST_BOX = INTEGER +* A pointer to the new Box. + +* 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 */ + AstBox *new; /* Pointer to new Box */ + 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 Box, allocating memory and initialising the + virtual function table as well if necessary. */ + new = astInitBox( NULL, sizeof( AstBox ), !class_init, &class_vtab, + "Box", frame, form, point1, point2, 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 Box'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 Box. */ + return new; +} + +AstBox *astBoxId_( void *frame_void, int form, const double point1[], + const double point2[], void *unc_void, const char *options, + ... ) { +/* +* Name: +* astBoxId_ + +* Purpose: +* Create a Box. + +* Type: +* Private function. + +* Synopsis: +* #include "box.h" +* AstBox *astBoxId_( AstFrame *frame, int form, const double point1[], +* const double point2[], AstRegion *unc, +* const char *options, ... ) + +* Class Membership: +* Box constructor. + +* Description: +* This function implements the external (public) interface to the +* astBox constructor function. It returns an ID value (instead +* of a true C pointer) to external users, and must be provided +* because astBox_ 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 astBox_ 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 astBox_. + +* Returned Value: +* The ID value associated with the new Box. +*/ + +/* Local Variables: */ + astDECLARE_GLOBALS /* Pointer to thread-specific global data */ + AstFrame *frame; /* Pointer to Frame structure */ + AstBox *new; /* Pointer to new Box */ + 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); + +/* Pointer to inherited status value */ + +/* 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 Box, allocating memory and initialising the + virtual function table as well if necessary. */ + new = astInitBox( NULL, sizeof( AstBox ), !class_init, &class_vtab, + "Box", frame, form, point1, point2, 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 Box'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 Box. */ + return astMakeId( new ); +} + +AstBox *astInitBox_( void *mem, size_t size, int init, AstBoxVtab *vtab, + const char *name, AstFrame *frame, int form, + const double point1[], const double point2[], + AstRegion *unc, int *status ) { +/* +*+ +* Name: +* astInitBox + +* Purpose: +* Initialise a Box. + +* Type: +* Protected function. + +* Synopsis: +* #include "box.h" +* AstBox *astInitBox_( void *mem, size_t size, int init, AstBoxVtab *vtab, +* const char *name, AstFrame *frame, int form, +* const double point1[], const double point2[], +* AstRegion *unc ) + +* Class Membership: +* Box initialiser. + +* Description: +* This function is provided for use by class implementations to initialise +* a new Box object. It allocates memory (if necessary) to accommodate +* the Box plus any additional data associated with the derived class. +* It then initialises a Box 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 Box at the start of the memory passed via the +* "vtab" parameter. + +* Parameters: +* mem +* A pointer to the memory in which the Box is to be initialised. +* This must be of sufficient size to accommodate the Box data +* (sizeof(Box)) 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 Box (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 Box +* structure, so a valid value must be supplied even if not required for +* allocating memory. +* init +* A logical flag indicating if the Box'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 Box. +* 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. +* form +* Indicates how the box is described by the remaining parameters. +* A value of zero indicates that the box is specified by a centre +* position and a corner position. A value of one indicates that the +* box is specified by a two opposite corner positions. +* point1 +* An array of double, with one element for each Frame axis (Naxes +* attribute). If "form" is zero, this array should contain the +* coordinates at the centre of the box. If "form" is one, it should +* contain the coordinates at the corner of the box which is diagonally +* opposite the corner specified by "point2". +* point2 +* An array of double, with one element for each Frame axis (Naxes +* attribute) containing the coordinates at any of the corners of +* the box. +* unc +* A pointer to a Region which specifies the uncertainty in the +* supplied positions (all points on the boundary of the new Box +* 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 Box'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 Box. + +* 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: */ + AstBox *new; /* Pointer to new Box */ + AstPointSet *pset; /* PointSet to pass to Region initialiser */ + double **ptr; /* Pointer to coords data in pset */ + int i; /* axis index */ + int nc; /* No. of axes */ + +/* Check the global status. */ + if ( !astOK ) return NULL; + +/* If necessary, initialise the virtual function table. */ + if ( init ) astInitBoxVtab( vtab, name ); + +/* Initialise. */ + new = NULL; + +/* Get the number of axis values required for each position. */ + nc = astGetNaxes( frame ); + +/* Create a PointSet to hold the supplied values, and get points to the + data arrays. */ + pset = astPointSet( 2, nc, "", status ); + ptr = astGetPoints( pset ); + +/* Copy the supplied coordinates into the PointSet, checking that no bad + values have been supplied. */ + for( i = 0; astOK && i < nc; i++ ) { + if( point1[ i ] == AST__BAD ) { + astError( AST__BADIN, "astInitBox(%s): The value of axis %d is " + "undefined at point 1 of the box.", status, name, i + 1 ); + break; + } + if( point2[ i ] == AST__BAD ) { + astError( AST__BADIN, "astInitBox(%s): The value of axis %d is " + "undefined at point 2 of the box.", status, name, i + 1 ); + break; + } + ptr[ i ][ 0 ] = point1[ i ]; + ptr[ i ][ 1 ] = point2[ i ]; + } + +/* If two corners were supplied, find and store the centre. */ + if( form == 1 ) { + for( i = 0; i < nc; i++ ) { + ptr[ i ][ 0 ] = 0.5*( point1[ i ] + point2[ i ] ); + } + } + +/* Check pointers can be used safely. */ + if( astOK ) { + +/* Initialise a Region structure (the parent class) as the first component + within the Box structure, allocating memory if necessary. */ + new = (AstBox *) astInitRegion( mem, size, 0, (AstRegionVtab *) vtab, + name, frame, pset, unc ); + + if ( astOK ) { + +/* Initialise the Box data. */ +/* ------------------------ */ + new->extent = NULL; + new->centre = NULL; + new->lo = NULL; + new->hi = NULL; + new->geolen = NULL; + new->stale = 1; + +/* If an error occurred, clean up by deleting the new Box. */ + if ( !astOK ) new = astDelete( new ); + } + } + +/* Free resources. */ + pset = astAnnul( pset ); + +/* Return a pointer to the new Box. */ + return new; +} + +AstBox *astLoadBox_( void *mem, size_t size, AstBoxVtab *vtab, + const char *name, AstChannel *channel, int *status ) { +/* +*+ +* Name: +* astLoadBox + +* Purpose: +* Load a Box. + +* Type: +* Protected function. + +* Synopsis: +* #include "box.h" +* AstBox *astLoadBox( void *mem, size_t size, AstBoxVtab *vtab, +* const char *name, AstChannel *channel ) + +* Class Membership: +* Box loader. + +* Description: +* This function is provided to load a new Box 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 +* Box 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 Box at the start of the memory +* passed via the "vtab" parameter. + +* Parameters: +* mem +* A pointer to the memory into which the Box is to be +* loaded. This must be of sufficient size to accommodate the +* Box data (sizeof(Box)) 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 Box (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 Box 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(AstBox) is used instead. +* vtab +* Pointer to the start of the virtual function table to be +* associated with the new Box. If this is NULL, a pointer +* to the (static) virtual function table for the Box 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 "Box" is used instead. + +* Returned Value: +* A pointer to the new Box. + +* 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 */ + AstBox *new; /* Pointer to the new Box */ + +/* 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 Box. In this case the + Box belongs to this class, so supply appropriate values to be + passed to the parent class loader (and its parent, etc.). */ + if ( !vtab ) { + size = sizeof( AstBox ); + vtab = &class_vtab; + name = "Box"; + +/* If required, initialise the virtual function table for this class. */ + if ( !class_init ) { + astInitBoxVtab( 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 Box. */ + 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, "Box" ); + +/* 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. */ + +/* There are no values to read. */ +/* ---------------------------- */ + +/* Initialise Box data */ + new->extent = NULL; + new->centre = NULL; + new->lo = NULL; + new->hi = NULL; + new->geolen = NULL; + new->stale = 1; + +/* If an error occurred, clean up by deleting the new Box. */ + if ( !astOK ) new = astDelete( new ); + } + +/* Return the new Box 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. */ + + +void astBoxPoints_( AstBox *this, double *centre, double *corner, + int *status) { + if ( !astOK ) return; + (**astMEMBER(this,Box,BoxPoints))( this, centre, corner, status ); + return; +} + + + + + + + + + + + + + + + |