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+/*
+*class++
+* Name:
+* NullRegion
+
+* Purpose:
+* A boundless region within a Frame.
+
+* Constructor Function:
+c astNullRegion
+f AST_NULLREGION
+
+* Description:
+* The NullRegion class implements a Region with no bounds within a Frame.
+* If the Negated attribute of a NullRegion is false, the NullRegion
+* represents a Region containing no points. If the Negated attribute of
+* a NullRegion is true, the NullRegion represents an infinite Region
+* (that is, all points in the coordinate system are inside the NullRegion).
+
+* Inheritance:
+* The NullRegion class inherits from the Region class.
+
+* Attributes:
+* The NullRegion class does not define any new attributes beyond
+* those which are applicable to all Regions.
+
+* Functions:
+c The NullRegion class does not define any new functions beyond those
+f The NullRegion 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) 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:
+* 11-OCT-2004 (DSB):
+* Original version.
+* 20-JAN-2009 (DSB):
+* Over-ride astRegBasePick.
+* 26-JAN-2009 (DSB):
+* Over-ride astMapMerge.
+*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 NullRegion
+
+/* Include files. */
+/* ============== */
+/* Interface definitions. */
+/* ---------------------- */
+
+#include "globals.h" /* Thread-safe global data access */
+#include "error.h" /* Error reporting facilities */
+#include "memory.h" /* Memory allocation facilities */
+#include "object.h" /* Base Object class */
+#include "pointset.h" /* Sets of points/coordinates */
+#include "region.h" /* Coordinate regions (parent class) */
+#include "channel.h" /* I/O channels */
+#include "nullregion.h" /* Interface definition for this class */
+#include "mapping.h" /* Position mappings */
+#include "circle.h" /* Circle regions */
+#include "prism.h" /* Extruded Regions */
+#include "unitmap.h" /* Unit Mapping */
+#include "cmpframe.h" /* Compound Frames */
+#include "cmpmap.h" /* Compound Mappings */
+
+/* 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 AstPointSet *(* parent_transform)( AstMapping *, AstPointSet *, int, AstPointSet *, int * );
+static AstMapping *(* parent_simplify)( AstMapping *, 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(NullRegion)
+
+/* Define macros for accessing each item of thread specific global data. */
+#define class_init astGLOBAL(NullRegion,Class_Init)
+#define class_vtab astGLOBAL(NullRegion,Class_Vtab)
+
+
+#include <pthread.h>
+
+
+#else
+
+
+/* Define the class virtual function table and its initialisation flag
+ as static variables. */
+static AstNullRegionVtab 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. */
+AstNullRegion *astNullRegionId_( void *, void *, const char *, ... );
+
+/* Prototypes for Private Member Functions. */
+/* ======================================== */
+static AstMapping *Simplify( AstMapping *, int * );
+static AstPointSet *RegBaseMesh( AstRegion *, int * );
+static AstPointSet *RegMesh( AstRegion *, int * );
+static AstPointSet *Transform( AstMapping *, AstPointSet *, int, AstPointSet *, int * );
+static AstRegion *RegBasePick( AstRegion *this, int, const int *, int * );
+static AstRegion *GetDefUnc( AstRegion *, int * );
+static AstRegion *MergeNullRegion( AstNullRegion *, AstRegion *, int, int * );
+static int MapMerge( AstMapping *, int, int, int *, AstMapping ***, int **, int * );
+static int Overlap( AstRegion *, AstRegion *, int * );
+static int OverlapX( AstRegion *, AstRegion *, int * );
+static void Dump( AstObject *, AstChannel *, int * );
+static void RegBaseBox( AstRegion *this, double *, double *, int * );
+static void GetRegionBounds( AstRegion *this, double *, double *, int * );
+
+/* Member functions. */
+/* ================= */
+static AstRegion *GetDefUnc( AstRegion *this, int *status ) {
+/*
+*+
+* Name:
+* astGetDefUnc
+
+* Purpose:
+* Obtain a pointer to the default uncertainty Region for a given Region.
+
+* Type:
+* Protected function.
+
+* Synopsis:
+* #include "nullregion.h"
+* AstRegion *astGetDefUnc( AstRegion *this )
+
+* Class Membership:
+* NullRegion member function (over-rides the astGetDefUnc protected
+* method inherited from the Region class).
+
+* Description:
+* This function returns a pointer to a Region which represents the
+* default uncertainty associated with a position on the boundary of the
+* given Region. The returned Region refers to the base Frame within the
+* FrameSet encapsulated by the supplied Region.
+
+* Parameters:
+* this
+* Pointer to the Region.
+
+* Returned Value:
+* A pointer to the Region. This should be annulled (using astAnnul)
+* when no longer needed.
+
+* 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: */
+ AstRegion *result;
+ double *cen;
+ double rad;
+ int i;
+ int n;
+
+/* Initialise */
+ result = NULL;
+
+/* Check inherited status */
+ if( !astOK ) return result;
+
+/* Create a Circle centred on the origin with zero radius. */
+ n = astGetNaxes( this );
+ cen = astMalloc( sizeof(double)*(size_t) n );
+ if( cen ) {
+ for( i = 0; i < n; i++ ) cen[ i ] = 0.0;
+ rad = 0.0;
+ result = (AstRegion *) astCircle( this, 1, cen, &rad, NULL, "", status );
+ cen = astFree( cen );
+ }
+
+/* Return the default uncertainty Region. */
+ return result;
+}
+
+void astInitNullRegionVtab_( AstNullRegionVtab *vtab, const char *name, int *status ) {
+/*
+*+
+* Name:
+* astInitNullRegionVtab
+
+* Purpose:
+* Initialise a virtual function table for a NullRegion.
+
+* Type:
+* Protected function.
+
+* Synopsis:
+* #include "nullregion.h"
+* void astInitNullRegionVtab( AstNullRegionVtab *vtab, const char *name )
+
+* Class Membership:
+* NullRegion vtab initialiser.
+
+* Description:
+* This function initialises the component of a virtual function
+* table which is used by the NullRegion 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 */
+
+/* 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 astIsANullRegion) 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. */
+
+/* Save the inherited pointers to methods that will be extended, and
+ replace them with pointers to the new member functions. */
+ mapping = (AstMappingVtab *) vtab;
+ region = (AstRegionVtab *) vtab;
+
+ parent_transform = mapping->Transform;
+ mapping->Transform = Transform;
+
+ parent_simplify = mapping->Simplify;
+ mapping->Simplify = Simplify;
+
+/* Store replacement pointers for methods which will be over-ridden by
+ new member functions implemented here. */
+ mapping->MapMerge = MapMerge;
+
+ region->GetDefUnc = GetDefUnc;
+ region->Overlap = Overlap;
+ region->OverlapX = OverlapX;
+ region->RegBaseBox = RegBaseBox;
+ region->RegBaseMesh = RegBaseMesh;
+ region->GetRegionBounds = GetRegionBounds;
+ region->RegMesh = RegMesh;
+ region->RegBasePick = RegBasePick;
+
+/* Declare the copy constructor, destructor and class dump
+ functions. */
+ astSetDump( vtab, Dump, "NullRegion", "Boundless region" );
+
+/* 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 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 NullRegion.
+
+* 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:
+* NullRegion 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 NullRegion 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 NullRegion 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 NullRegion which is to be merged with
+* its neighbours. This should be a cloned copy of the NullRegion
+* pointer contained in the array element "(*map_list)[where]"
+* (see below). This pointer will not be annulled, and the
+* NullRegion it identifies will not be modified by this function.
+* where
+* Index in the "*map_list" array (below) at which the pointer
+* to the nominated NullRegion 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: */
+ AstNullRegion *oldint; /* Pointer to supplied NullRegion */
+ 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 = -1;
+
+/* Check the global error status. */
+ if ( !astOK ) return result;
+
+/* Get a pointer to the NullRegion. */
+ oldint = (AstNullRegion *) this;
+
+/* First of all, see if the NullRegion can be replaced by a simpler Region,
+ without reference to the neighbouring Regions in the list. */
+/* =====================================================================*/
+
+/* Try to simplify the NullRegion. If the pointer value has changed, we assume
+ some simplification took place. */
+ new = astSimplify( oldint );
+ if( new != (AstMapping *) oldint ) {
+
+/* Annul the NullRegion 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 NullRegion 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 NullRegion with its lower neighbour (if any). */
+ if( where > 0 ) {
+ i1 = where - 1;
+ map = ( *map_list )[ where - 1 ];
+ if( astIsARegion( map ) ) {
+ new = (AstMapping *) MergeNullRegion( oldint, (AstRegion *) map,
+ 0, status );
+ }
+ }
+
+/* If this did not produced a merged Region, attempt to merge the NullRegion
+ with its upper neighbour (if any). */
+ if( !new && where < *nmap - 1 ) {
+ i1 = where;
+ map = ( *map_list )[ where + 1 ];
+ if( astIsARegion( map ) ) {
+ new = (AstMapping *) MergeNullRegion( oldint, (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 *MergeNullRegion( AstNullRegion *this, AstRegion *reg,
+ int intfirst, int *status ) {
+/*
+* Name:
+* MergeNullRegion
+
+* Purpose:
+* Attempt to merge a NullRegion with another Region to form a Region of
+* higher dimensionality.
+
+* Type:
+* Private function.
+
+* Synopsis:
+* #include "nullregion.h"
+* AstRegion *MergeNullRegion( AstNullRegion *this, AstRegion *reg,
+* int intfirst, int *status )
+
+* Class Membership:
+* NullRegion member function.
+
+* Description:
+* This function attempts to combine the supplied Regions together
+* into a Region of higher dimensionality.
+
+* Parameters:
+* this
+* Pointer to a NullRegion.
+* reg
+* Pointer to another Region.
+* intfirst
+* If non-zero, then the NullRegion 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 */
+ AstRegion *bunc; /* Base Frame uncertainty Region */
+ AstRegion *new; /* Pointer to new NullRegion in base Frame */
+ AstRegion *result; /* Pointer to returned NullRegion in current Frame */
+ AstRegion *unc_reg; /* Current Frame uncertainty Region from "reg" */
+ AstRegion *unc_this; /* Current Frame uncertainty Region from "this" */
+ double fac_reg; /* Ratio of used to default MeshSize for "reg" */
+ double fac_this; /* Ratio of used to default MeshSize for "this" */
+ 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 NullRegion */
+
+/* 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( intfirst ) {
+ 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;
+
+/* We only check for merging with another NullRegion (other classes such
+ as Box and Interval check for merging of NullRegions with other classes).
+ The result will be an NullRegion. Both Regions must have the same value
+ for the Negated flag. */
+ if( astIsANullRegion( reg ) && neg_this == neg_reg ) {
+ new = (AstRegion *) astNullRegion( bfrm, NULL, "", status );
+
+/* Propagate remaining attributes of the supplied Region to it. */
+ astRegOverlay( new, this, 1 );
+
+/* Ensure the Negated flag is set correctly in the returned NullRegion. */
+ if( neg_this ) {
+ astSetNegated( new, neg_this );
+ } else {
+ 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( intfirst ) {
+ 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( intfirst ) {
+ 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( intfirst ) {
+ 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 );
+ }
+ }
+
+/* If an error has occurred, annul the returned pointer. */
+ if( !astOK ) result = astAnnul( result );
+
+/* Return the result. */
+ return result;
+}
+
+static int Overlap( AstRegion *this, AstRegion *that, int *status ){
+/*
+* Name:
+* Overlap
+
+* Purpose:
+* Test if two regions overlap each other.
+
+* Type:
+* Private function.
+
+* Synopsis:
+* #include "nullregion.h"
+* int Overlap( AstRegion *this, AstRegion *that )
+
+* Class Membership:
+* NullRegion member function (over-rides the astOverlap method inherited
+* from the Region class).
+
+* Description:
+* This function returns an integer value indicating if the two
+* supplied Regions overlap. The two Regions are converted to a commnon
+* coordinate system before performing the check. If this conversion is
+* not possible (for instance because the two Regions represent areas in
+* different domains), then the check cannot be performed and a zero value
+* is returned to indicate this.
+
+* Parameters:
+* this
+* Pointer to the first Region.
+* that
+* Pointer to the second Region.
+
+* Returned Value:
+* astOverlap()
+* A value indicating if there is any overlap between the two Regions.
+* Possible values are:
+*
+* 0 - The check could not be performed because the second Region
+* could not be mapped into the coordinate system of the first
+* Region.
+*
+* 1 - There is no overlap between the two Regions.
+*
+* 2 - The first Region is completely inside the second Region.
+*
+* 3 - The second Region is completely inside the first Region.
+*
+* 4 - There is partial overlap between the two Regions.
+*
+* 5 - The Regions are identical.
+*
+* 6 - The second Region is the negation of the first Region.
+
+* Notes:
+* - The returned values 5 and 6 do not check the value of the Closed
+* attribute in the two Regions.
+* - A value of zero will be returned if this function is invoked with the
+* AST error status set, or if it should fail for any reason.
+
+* Implementation Notes:
+* - This function is simply a wrap-up for the OverlapX function
+* which performs the required processing but swaps the order of the
+* two arguments. This is a trick to allow the astOverlap
+* method to be over-ridden by derived classes on the basis of the
+* class of either of the two arguments.
+*/
+
+/* Check the inherited status. */
+ if ( !astOK ) return 0;
+
+/* Invoke the private "OverlapX" member function with the two arguments
+ swapped. */
+ return OverlapX( that, this, status );
+}
+
+static int OverlapX( AstRegion *that, AstRegion *this, int *status ){
+/*
+* Name:
+* OverlapX
+
+* Purpose:
+* Test if two regions overlap each other.
+
+* Type:
+* Private function.
+
+* Synopsis:
+* #include "nullregion.h"
+* int OverlapX( AstRegion *that, AstRegion *this )
+
+* Class Membership:
+* NullRegion member function (over-rides the astOverlapX method inherited
+* from the Region class).
+
+* Description:
+* This function performs the processing for the public astOverlap
+* method (as inherited from the Region class and over-ridden by the
+* NullRegion class) and has exactly the same interface except that
+* the order of the two arguments is swapped. This is a trick
+* to allow the astOverlap method to be over-ridden by derived
+* classes on the basis of the class of either of its two
+* arguments.
+*
+* See the astOverlap method for details of the interface.
+
+*/
+
+/* Local Variables: */
+ AstFrameSet *fs; /* FrameSet connecting Region Frames */
+ int result; /* Returned value */
+
+/* Initialise. */
+ result = 0;
+
+/* Check the global error status. */
+ if ( !astOK ) return result;
+
+/* Check that the Regions can be compared meaningfully. */
+ fs = astConvert( this, that, "" );
+ if( fs ) {
+ fs = astAnnul( fs );
+
+/* If both the supplied Regions are NullRegion... */
+ if( astIsANullRegion( this ) && astIsANullRegion( that ) ) {
+
+/* If the Negated attributes are equal, the Regions are identical.
+ Otherwise they are mutually exclusive. */
+ if( astGetNegated( this ) == astGetNegated( that ) ) {
+ result = 5;
+ } else {
+ result = 6;
+ }
+
+/* If one of the supplied Region is a NullRegion containing no points,
+ then there is no overlap. */
+ } else if( ( astIsANullRegion( this ) && !astGetNegated( this ) ) ||
+ ( astIsANullRegion( that ) && !astGetNegated( that ) ) ) {
+ result = 1;
+
+/* If "that" is infinite and "this" is not infinite, then "this" is
+ entirely inside "that". */
+ } else if( astIsANullRegion( that ) && astGetNegated( that ) ) {
+ result = 2;
+
+/* If "this" is infinite and "that" is not infinite, then "that" is
+ entirely inside "this". */
+ } else if( astIsANullRegion( this ) && astGetNegated( this ) ){
+ result = 3;
+
+/* Otherwise there is partial overlap. */
+ } else {
+ result = 4;
+ }
+ }
+
+/* If not OK, return zero. */
+ if( !astOK ) result = 0;
+
+/* 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 "nullregion.h"
+* void RegBaseBox( AstRegion *this, double *lbnd, double *ubnd, int *status )
+
+* Class Membership:
+* NullRegion 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: */
+ AstNullRegion *this; /* Pointer to NullRegion structure */
+ 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 NullRegion structure */
+ this = (AstNullRegion *) this_region;
+
+/* Get the number of base Frame axes. */
+ nc = astGetNin( this_region->frameset );
+
+/* Set the upper bound less than the lower bound to indicate that the region
+ contains no points. */
+ for( i = 0; i < nc; i++ ) {
+ lbnd[ i ] = 1.0;
+ ubnd[ i ] = -1.0;
+ }
+
+}
+
+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 "nullregion.h"
+* AstPointSet *astRegBaseMesh( AstRegion *this, int *status )
+
+* Class Membership:
+* NullRegion 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. Note, a NullRegion has no boundary. This
+* is indicated by returned a PointSet containing a single point with a
+* value of AST__BAD on every axis.
+
+* Parameters:
+* this
+* Pointer to the Region.
+* status
+* Pointer to the inherited status variable.
+
+* Returned Value:
+* Pointer to a new PointSet containing a single point with value of
+* AST__BAD on every axis.
+
+*-
+*/
+
+/* Local Variables: */
+ AstPointSet *result;
+ double **ptr;
+ int i;
+ int nc;
+
+/* Initialise */
+ result = NULL;
+
+/* Check the inherited 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 number of base Frame axes */
+ nc = astGetNin( this->frameset );
+
+/* Create the PointSet. */
+ result = astPointSet( 1, nc, "", status );
+
+/* Get a pointer to the axis values. */
+ ptr = astGetPoints( result );
+
+/* If OK, store AST__BAD on every axis. */
+ if( ptr ) for( i = 0; i < nc; i++ ) ptr[ i ][ 0 ] = AST__BAD;
+
+/* 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 );
+
+ }
+
+/* Return the result. */
+ return result;
+}
+
+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 "nullregion.h"
+* AstRegion *RegBasePick( AstRegion *this, int naxes, const int *axes,
+* int *status )
+
+* Class Membership:
+* NullRegion 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 */
+ AstRegion *bunc; /* The uncertainty in the supplied Region */
+ AstRegion *result; /* Returned Region */
+ AstRegion *unc; /* The uncertainty in the 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;
+ }
+
+/* Create the new NullRegion. */
+ result = (AstRegion *) astNullRegion( frm, unc, "", status );
+
+/* Free resources */
+ frm = astAnnul( frm );
+ bfrm = astAnnul( bfrm );
+ if( unc ) unc = astAnnul( unc );
+
+/* Return a NULL pointer if an error has occurred. */
+ if( !astOK ) result = astAnnul( result );
+
+/* Return the result. */
+ return result;
+}
+
+static void GetRegionBounds( AstRegion *this_region, double *lbnd, double *ubnd, int *status ){
+/*
+* Name:
+* GetRegionBounds
+
+* Purpose:
+* Returns the bounding box of an un-negated Region in the current Frame of
+* the encapsulated FrameSet.
+
+* Type:
+* Private function.
+
+* Synopsis:
+* #include "nullregion.h"
+* void astGetRegionBounds( AstRegion *this, double *lbnd, double *ubnd, int *status )
+
+* Class Membership:
+* NullRegion member function (over-rides the astGetRegionBounds protected
+* method inherited from the Region class).
+
+* Description:
+* This function returns the upper and lower axis bounds of a Region in
+* the current 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 current Frame of the encapsulated
+* FrameSet. It should have at least as many elements as there are
+* axes in the Region.
+* ubnd
+* Pointer to an array in which to return the upper axis bounds
+* covered by the Region in the current Frame of the encapsulated
+* FrameSet. It should have at least as many elements as there are
+* axes in the Region.
+* status
+* Pointer to the inherited status variable.
+
+*/
+
+/* Local Variables: */
+ AstNullRegion *this; /* Pointer to NullRegion structure */
+ 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 NullRegion structure */
+ this = (AstNullRegion *) this_region;
+
+/* Get the number of base Frame axes. */
+ nc = astGetNin( this_region->frameset );
+
+/* Set the upper bound less than the lower bound to indicate that the region
+ contains no points. */
+ for( i = 0; i < nc; i++ ) {
+ lbnd[ i ] = 1.0;
+ ubnd[ i ] = -1.0;
+ }
+
+}
+
+static AstPointSet *RegMesh( AstRegion *this, int *status ){
+/*
+* Name:
+* RegMesh
+
+* Purpose:
+* Return a PointSet containing points spread over the boundary of a
+* Region.
+
+* Type:
+* Private function.
+
+* Synopsis:
+* #include "nullregion.h"
+* AstPointSet *astRegMesh( AstRegion *this, int *status )
+
+* Class Membership:
+* NullRegion member function (over-rides the astRegMesh 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 current Frame of
+* the encapsulated FrameSet. Note, a NullRegion has no boundary and
+* so an error is reported if this function is called.
+
+* Parameters:
+* this
+* Pointer to the Region.
+* status
+* Pointer to the inherited status variable.
+
+* Returned Value:
+* NULL pointer.
+
+* Notes:
+* - This implementation reports and error and returns NULL since a
+* NullRegion has no boundary.
+*-
+*/
+
+ astError( AST__INTER, "astRegMesh(%s): The %s class does not implement "
+ "the astRegMesh method inherited from the Region class "
+ "(internal AST programming error).", status, astGetClass( this ),
+ astGetClass( this ) );
+ return NULL;
+}
+
+static AstMapping *Simplify( AstMapping *this_mapping, int *status ) {
+/*
+* Name:
+* Simplify
+
+* Purpose:
+* Simplify the Mapping represented by a Region.
+
+* Type:
+* Private function.
+
+* Synopsis:
+* #include "nullregion.h"
+* AstMapping *Simplify( AstMapping *this, int *status )
+
+* Class Membership:
+* NullRegion method (over-rides the astSimplify method inherited
+* from the Region class).
+
+* Description:
+* This function invokes the parent Region Simplify method, and then
+* performs any further region-specific simplification.
+*
+* If the Mapping from base to current Frame is not a UnitMap, this
+* will include attempting to fit a new Region to the boundary defined
+* in the current Frame.
+
+* Parameters:
+* this
+* Pointer to the original Region.
+* status
+* Pointer to the inherited status variable.
+
+* Returned Value:
+* A pointer to the simplified Region. A cloned pointer to the
+* supplied Region will be returned if no simplication could be
+* performed.
+
+* Notes:
+* - A NULL pointer value will be returned if this function is
+* invoked with the AST error status set, or if it should fail for
+* any reason.
+*/
+
+/* Local Variables: */
+ AstFrame *frm; /* Current Frame */
+ AstMapping *map; /* Base->current Mapping */
+ AstMapping *result; /* Result pointer to return */
+ AstRegion *new; /* Simplified Region */
+ AstRegion *this; /* Pointer to supplied Region structure */
+
+/* Initialise. */
+ result = NULL;
+
+/* Check the global error status. */
+ if ( !astOK ) return result;
+
+/* Get a pointer to the supplied Region structure. */
+ this = (AstRegion *) this_mapping;
+
+/* Invoke the parent Simplify method inherited from the Region class. This
+ will simplify the encapsulated FrameSet and uncertainty Region. */
+ new = (AstRegion *) (*parent_simplify)( this_mapping, status );
+
+/* Is the Mapping from base Frame to current Frame in the Region a
+ UnitMap? If so, no simplification is possible. */
+ map = astGetMapping( new->frameset, AST__BASE, AST__CURRENT );
+ if( astIsAUnitMap( map ) ){
+ result = astClone( new );
+
+ } else {
+
+/* Create a NullRegion from the current Frame. */
+ frm = astGetFrame( new->frameset, AST__CURRENT );
+ result = (AstMapping *) astNullRegion( frm, astGetUnc( new, 0 ), "", status );
+
+/* Free resources. */
+ frm = astAnnul( frm );
+
+ }
+ map = astAnnul( map );
+ new = astAnnul( new );
+
+/* 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( result != this_mapping ) astRegOverlay( result, this, 1 );
+
+/* If an error occurred, annul the returned pointer. */
+ if ( !astOK ) result = astAnnul( result );
+
+/* Return the result. */
+ return result;
+}
+
+static AstPointSet *Transform( AstMapping *this_mapping, AstPointSet *in,
+ int forward, AstPointSet *out, int *status ) {
+/*
+* Name:
+* Transform
+
+* Purpose:
+* Apply a NullRegion to transform a set of points.
+
+* Type:
+* Private function.
+
+* Synopsis:
+* #include "nullregion.h"
+* AstPointSet *Transform( AstMapping *this, AstPointSet *in,
+* int forward, AstPointSet *out, int *status )
+
+* Class Membership:
+* NullRegion member function (over-rides the astTransform protected
+* method inherited from the Mapping class).
+
+* Description:
+* This function takes a NullRegion 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 NullRegion.
+* 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 NullRegion.
+* - 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: */
+ AstNullRegion *this; /* Pointer to NullRegion */
+ AstPointSet *result; /* Pointer to output PointSet */
+ double **ptr_out; /* Pointer to output coordinate data */
+ double *p; /* Pointer to next axis value */
+ int coord; /* Zero-based index for coordinates */
+ int ncoord_out; /* No. of coordinates per output point */
+ int npoint_out; /* No. of points */
+ int point; /* Loop counter for points */
+
+/* Check the global error status. */
+ if ( !astOK ) return NULL;
+
+/* Obtain a pointer to the NullRegion structure. */
+ this = (AstNullRegion *) this_mapping;
+
+/* Apply the parent mapping using the stored pointer to the Transform member
+ function inherited from the parent Region class. This function validates
+ all arguments and generates an output PointSet if necessary,
+ containing a copy of the input PointSet. */
+ result = (*parent_transform)( this_mapping, in, forward, out, status );
+
+/* We will now extend the parent astTransform method by performing the
+ calculations needed to generate the output coordinate values. */
+
+/* If the NullRegion has been inverted, it represents an infinite region
+ which includes all points, so just retain the copy of the supplied
+ PointSet created by the parent Transform method above. If the NullRegion
+ has not been inverted, it contains no points and so set all output points
+ bad. */
+ if( !astGetNegated( this ) ) {
+ ncoord_out = astGetNcoord( result );
+ npoint_out = astGetNpoint( result );
+ ptr_out = astGetPoints( result );
+ if ( astOK ) {
+ for ( coord = 0; coord < ncoord_out; coord++ ) {
+ p = ptr_out[ coord ];
+ for ( point = 0; point < npoint_out; point++ ) {
+ *(p++) = AST__BAD;
+ }
+ }
+ }
+ }
+
+/* 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. */
+/* ----------------- */
+/* None */
+
+/* Destructor. */
+/* ----------- */
+/* None */
+
+/* Dump function. */
+/* -------------- */
+static void Dump( AstObject *this_object, AstChannel *channel, int *status ) {
+/*
+* Name:
+* Dump
+
+* Purpose:
+* Dump function for NullRegion 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 NullRegion class to an output Channel.
+
+* Parameters:
+* this
+* Pointer to the NullRegion whose data are being written.
+* channel
+* Pointer to the Channel to which the data are being written.
+* status
+* Pointer to the inherited status variable.
+*/
+
+/* Local Variables: */
+ AstNullRegion *this; /* Pointer to the NullRegion structure */
+
+/* Check the global error status. */
+ if ( !astOK ) return;
+
+/* Obtain a pointer to the NullRegion structure. */
+ this = (AstNullRegion *) this_object;
+
+/* Write out values representing the instance variables for the
+ NullRegion 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 astIsANullRegion and astCheckNullRegion functions using the macros
+ defined for this purpose in the "object.h" header file. */
+astMAKE_ISA(NullRegion,Region)
+astMAKE_CHECK(NullRegion)
+
+AstNullRegion *astNullRegion_( void *frame_void, AstRegion *unc, const char *options, int *status, ...) {
+/*
+*++
+* Name:
+c astNullRegion
+f AST_NULLREGION
+
+* Purpose:
+* Create a NullRegion.
+
+* Type:
+* Public function.
+
+* Synopsis:
+c #include "nullregion.h"
+c AstNullRegion *astNullRegion( AstFrame *frame, AstRegion *unc, const char *options, ... )
+f RESULT = AST_NULLREGION( FRAME, UNC, OPTIONS, STATUS )
+
+* Class Membership:
+* NullRegion constructor.
+
+* Description:
+* This function creates a new NullRegion and optionally initialises its
+* attributes.
+*
+* A NullRegion is a Region with no bounds. If the Negated attribute of a
+* NullRegion is false, the NullRegion represents a Region containing no
+* points. If the Negated attribute of a NullRegion is true, the NullRegion
+* represents an infinite Region containing all points within the
+* coordinate system.
+
+* 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 unc
+f UNC = INTEGER (Given)
+* An optional pointer to an existing Region which specifies the
+* uncertainties associated with positions in the supplied Frame.
+* The uncertainty in any point in the Frame is found by shifting the
+* supplied "uncertainty" Region so that it is centred at the point
+* being considered. The area covered by the shifted uncertainty
+* Region then represents the uncertainty in the 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 NullRegion. Alternatively,
+f a null Object pointer (AST__NULL)
+c a NULL Object pointer
+* may be supplied, in which case a default uncertainty of zero is
+* used.
+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 NullRegion. 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 NullRegion. 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 astNullRegion()
+f AST_NULLREGION = INTEGER
+* A pointer to the new NullRegion.
+
+* Notes:
+* - A null Object pointer (AST__NULL) will be returned if this
+c function is invoked with the AST error status set, or if it
+f function is invoked with STATUS set to an error value, or if it
+* should fail for any reason.
+*--
+*/
+
+/* Local Variables: */
+ astDECLARE_GLOBALS /* Pointer to thread-specific global data */
+ AstFrame *frame; /* Pointer to Frame structure */
+ AstNullRegion *new; /* Pointer to new NullRegion */
+ 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 NullRegion, allocating memory and initialising the
+ virtual function table as well if necessary. */
+ new = astInitNullRegion( NULL, sizeof( AstNullRegion ), !class_init,
+ &class_vtab, "NullRegion", frame, 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 NullRegion'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 NullRegion. */
+ return new;
+}
+
+AstNullRegion *astNullRegionId_( void *frame_void, void *unc_void,
+ const char *options, ... ) {
+/*
+* Name:
+* astNullRegionId_
+
+* Purpose:
+* Create a NullRegion.
+
+* Type:
+* Private function.
+
+* Synopsis:
+* #include "nullregion.h"
+* AstNullRegion *astNullRegionId_( AstFrame *frame, AstRegion *unc, const char *options, ... )
+
+* Class Membership:
+* NullRegion constructor.
+
+* Description:
+* This function implements the external (public) interface to the
+* astNullRegion constructor function. It returns an ID value (instead
+* of a true C pointer) to external users, and must be provided
+* because astNullRegion_ 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 astNullRegion_ 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 astNullRegion_.
+
+* Returned Value:
+* The ID value associated with the new NullRegion.
+*/
+
+/* Local Variables: */
+ astDECLARE_GLOBALS /* Pointer to thread-specific global data */
+ AstFrame *frame; /* Pointer to Frame structure */
+ AstNullRegion *new; /* Pointer to new NullRegion */
+ 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 NullRegion, allocating memory and initialising the
+ virtual function table as well if necessary. */
+ new = astInitNullRegion( NULL, sizeof( AstNullRegion ), !class_init,
+ &class_vtab, "NullRegion", frame, 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 NullRegion'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 NullRegion. */
+ return astMakeId( new );
+}
+
+AstNullRegion *astInitNullRegion_( void *mem, size_t size, int init,
+ AstNullRegionVtab *vtab, const char *name,
+ AstFrame *frame, AstRegion *unc, int *status ) {
+/*
+*+
+* Name:
+* astInitNullRegion
+
+* Purpose:
+* Initialise a NullRegion.
+
+* Type:
+* Protected function.
+
+* Synopsis:
+* #include "nullregion.h"
+* AstNullRegion *astInitNullRegion_( void *mem, size_t size, int init,
+* AstNullRegionVtab *vtab, const char *name,
+* AstFrame *frame, AstRegion *unc )
+
+* Class Membership:
+* NullRegion initialiser.
+
+* Description:
+* This function is provided for use by class implementations to initialise
+* a new NullRegion object. It allocates memory (if necessary) to accommodate
+* the NullRegion plus any additional data associated with the derived class.
+* It then initialises a NullRegion 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 NullRegion at the start of the memory passed via the
+* "vtab" parameter.
+
+* Parameters:
+* mem
+* A pointer to the memory in which the NullRegion is to be initialised.
+* This must be of sufficient size to accommodate the NullRegion data
+* (sizeof(NullRegion)) 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 NullRegion (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 NullRegion
+* structure, so a valid value must be supplied even if not required for
+* allocating memory.
+* init
+* A logical flag indicating if the NullRegion'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 NullRegion.
+* 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.
+* unc
+* A pointer to a Region which specifies the uncertainty of positions
+* within the supplied Frame. A NULL pointer can be supplied, in which
+* case default uncertainties of zero 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). 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 NullRegion.
+
+* 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: */
+ AstNullRegion *new; /* Pointer to new NullRegion */
+
+/* Check the global status. */
+ if ( !astOK ) return NULL;
+
+/* If necessary, initialise the virtual function table. */
+ if ( init ) astInitNullRegionVtab( vtab, name );
+
+/* Initialise a Region structure (the parent class) as the first component
+ within the NullRegion structure, allocating memory if necessary. */
+ new = (AstNullRegion *) astInitRegion( mem, size, 0, (AstRegionVtab *) vtab,
+ name, frame, NULL, unc );
+
+/* If an error occurred, clean up by deleting the new NullRegion. */
+ if ( !astOK ) new = astDelete( new );
+
+/* Return a pointer to the new NullRegion. */
+ return new;
+}
+
+AstNullRegion *astLoadNullRegion_( void *mem, size_t size, AstNullRegionVtab *vtab,
+ const char *name, AstChannel *channel, int *status ) {
+/*
+*+
+* Name:
+* astLoadNullRegion
+
+* Purpose:
+* Load a NullRegion.
+
+* Type:
+* Protected function.
+
+* Synopsis:
+* #include "nullregion.h"
+* AstNullRegion *astLoadNullRegion( void *mem, size_t size, AstNullRegionVtab *vtab,
+* const char *name, AstChannel *channel )
+
+* Class Membership:
+* NullRegion loader.
+
+* Description:
+* This function is provided to load a new NullRegion 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
+* NullRegion 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 NullRegion at the start of the memory
+* passed via the "vtab" parameter.
+
+* Parameters:
+* mem
+* A pointer to the memory into which the NullRegion is to be
+* loaded. This must be of sufficient size to accommodate the
+* NullRegion data (sizeof(NullRegion)) 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 NullRegion (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 NullRegion 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(AstNullRegion) is used instead.
+* vtab
+* Pointer to the start of the virtual function table to be
+* associated with the new NullRegion. If this is NULL, a pointer
+* to the (static) virtual function table for the NullRegion 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 "NullRegion" is used instead.
+
+* Returned Value:
+* A pointer to the new NullRegion.
+
+* 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 */
+ AstNullRegion *new; /* Pointer to the new NullRegion */
+
+/* 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 NullRegion. In this case the
+ NullRegion belongs to this class, so supply appropriate values to be
+ passed to the parent class loader (and its parent, etc.). */
+ if ( !vtab ) {
+ size = sizeof( AstNullRegion );
+ vtab = &class_vtab;
+ name = "NullRegion";
+
+/* If required, initialise the virtual function table for this class. */
+ if ( !class_init ) {
+ astInitNullRegionVtab( 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 NullRegion. */
+ 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, "NullRegion" );
+
+/* 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. */
+/* ---------------------------- */
+
+/* If an error occurred, clean up by deleting the new NullRegion. */
+ if ( !astOK ) new = astDelete( new );
+ }
+
+/* Return the new NullRegion 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. */
+
+
+
+
+
+
+
+
+
+