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+/*
+*class++
+* Name:
+* ZoomMap
+
+* Purpose:
+* Zoom coordinates about the origin.
+
+* Constructor Function:
+c astZoomMap
+f AST_ZOOMMAP
+
+* Description:
+* The ZoomMap class implements a Mapping which performs a "zoom"
+* transformation by multiplying all coordinate values by the same
+* scale factor (the inverse transformation is performed by
+* dividing by this scale factor). The number of coordinate values
+* representing each point is unchanged.
+
+* Inheritance:
+* The ZoomMap class inherits from the Mapping class.
+
+* Attributes:
+* In addition to those attributes common to all Mappings, every
+* ZoomMap also has the following attributes:
+*
+* - Zoom: ZoomMap scale factor
+
+* Functions:
+c The ZoomMap class does not define any new functions beyond those
+f The ZoomMap class does not define any new routines beyond those
+* which are applicable to all Mappings.
+
+* Copyright:
+* Copyright (C) 1997-2006 Council for the Central Laboratory of the
+* Research Councils
+
+* 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:
+* RFWS: R.F. Warren-Smith (Starlink)
+* DSB: David S. Berry (Starlink)
+
+* History:
+* 1-FEB-1996 (RFWS):
+* Original version.
+* 18-JUL-1996 (RFWS):
+* Updated to support attributes and an external interface.
+* 10-SEP-1996 (RFWS):
+* Added I/O facilities.
+* 4-JUN-1997 (RFWS):
+* Over-ride the MapMerge method to provide ZoomMap
+* simplification facilities.
+* 8-JAN-2003 (DSB):
+* Changed private InitVtab method to protected astInitZoomMapVtab
+* method.
+* 10-MAY-2006 (DSB):
+* Override astEqual.
+*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 ZoomMap
+
+/* 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 "globals.h" /* Thread-safe global data access */
+#include "object.h" /* Base Object class */
+#include "pointset.h" /* Sets of points/coordinates */
+#include "mapping.h" /* Coordinate mappings (parent class) */
+#include "channel.h" /* I/O channels */
+#include "unitmap.h" /* Unit Mappings */
+#include "matrixmap.h" /* Matrix Mappings */
+#include "zoommap.h" /* Interface definition for this class */
+
+/* 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 const char *(* parent_getattrib)( AstObject *, const char *, int * );
+static int (* parent_testattrib)( AstObject *, const char *, int * );
+static void (* parent_clearattrib)( AstObject *, const char *, int * );
+static void (* parent_setattrib)( AstObject *, const char *, int * );
+
+/* Define macros for accessing each item of thread specific global data. */
+#ifdef THREAD_SAFE
+
+/* Define how to initialise thread-specific globals. */
+#define GLOBAL_inits \
+ globals->Class_Init = 0; \
+ globals->GetAttrib_Buff[ 0 ] = 0;
+
+/* Create the function that initialises global data for this module. */
+astMAKE_INITGLOBALS(ZoomMap)
+
+/* Define macros for accessing each item of thread specific global data. */
+#define class_init astGLOBAL(ZoomMap,Class_Init)
+#define class_vtab astGLOBAL(ZoomMap,Class_Vtab)
+#define getattrib_buff astGLOBAL(ZoomMap,GetAttrib_Buff)
+
+
+
+/* If thread safety is not needed, declare and initialise globals at static
+ variables. */
+#else
+
+static char getattrib_buff[ 101 ];
+
+
+/* Define the class virtual function table and its initialisation flag
+ as static variables. */
+static AstZoomMapVtab 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. */
+AstZoomMap *astZoomMapId_( int, double, const char *, ... );
+
+/* Prototypes for Private Member Functions. */
+/* ======================================== */
+static AstPointSet *Transform( AstMapping *, AstPointSet *, int, AstPointSet *, int * );
+static const char *GetAttrib( AstObject *, const char *, int * );static double GetZoom( AstZoomMap *, int * );
+static double Rate( AstMapping *, double *, int, int, int * );
+static int *MapSplit( AstMapping *, int, const int *, AstMapping **, int * );
+static int Equal( AstObject *, AstObject *, int * );
+static int GetIsLinear( AstMapping *, int * );
+static int MapMerge( AstMapping *, int, int, int *, AstMapping ***, int **, int * );
+static int TestAttrib( AstObject *, const char *, int * );
+static int TestZoom( AstZoomMap *, int * );
+static void ClearAttrib( AstObject *, const char *, int * );
+static void ClearZoom( AstZoomMap *, int * );
+static void Dump( AstObject *, AstChannel *, int * );
+static void SetAttrib( AstObject *, const char *, int * );
+static void SetZoom( AstZoomMap *, double, int * );
+
+/* Member functions. */
+/* ================= */
+static void ClearAttrib( AstObject *this_object, const char *attrib, int *status ) {
+/*
+* Name:
+* ClearAttrib
+
+* Purpose:
+* Clear an attribute value for a ZoomMap.
+
+* Type:
+* Private function.
+
+* Synopsis:
+* #include "zoommap.h"
+* void ClearAttrib( AstObject *this, const char *attrib, int *status )
+
+* Class Membership:
+* ZoomMap member function (over-rides the astClearAttrib protected
+* method inherited from the Mapping class).
+
+* Description:
+* This function clears the value of a specified attribute for a
+* ZoomMap, so that the default value will subsequently be used.
+
+* Parameters:
+* this
+* Pointer to the ZoomMap.
+* attrib
+* Pointer to a null-terminated string specifying the attribute
+* name. This should be in lower case with no surrounding white
+* space.
+* status
+* Pointer to the inherited status variable.
+*/
+
+/* Local Variables: */
+ AstZoomMap *this; /* Pointer to the ZoomMap structure */
+
+/* Check the global error status. */
+ if ( !astOK ) return;
+
+/* Obtain a pointer to the ZoomMap structure. */
+ this = (AstZoomMap *) this_object;
+
+/* Check the attribute name and clear the appropriate attribute. */
+
+/* Zoom. */
+/* ----- */
+ if ( !strcmp( attrib, "zoom" ) ) {
+ astClearZoom( this );
+
+/* If the attribute is still not recognised, pass it on to the parent
+ method for further interpretation. */
+ } else {
+ (*parent_clearattrib)( this_object, attrib, status );
+ }
+}
+
+static int Equal( AstObject *this_object, AstObject *that_object, int *status ) {
+/*
+* Name:
+* Equal
+
+* Purpose:
+* Test if two ZoomMaps are equivalent.
+
+* Type:
+* Private function.
+
+* Synopsis:
+* #include "zoommap.h"
+* int Equal( AstObject *this, AstObject *that, int *status )
+
+* Class Membership:
+* ZoomMap member function (over-rides the astEqual protected
+* method inherited from the astMapping class).
+
+* Description:
+* This function returns a boolean result (0 or 1) to indicate whether
+* two ZoomMaps are equivalent.
+
+* Parameters:
+* this
+* Pointer to the first Object (a ZoomMap).
+* that
+* Pointer to the second Object.
+* status
+* Pointer to the inherited status variable.
+
+* Returned Value:
+* One if the ZoomMaps are equivalent, zero otherwise.
+
+* 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: */
+ AstZoomMap *that;
+ AstZoomMap *this;
+ int nin;
+ int nout;
+ int result;
+
+/* Initialise. */
+ result = 0;
+
+/* Check the global error status. */
+ if ( !astOK ) return result;
+
+/* Obtain pointers to the two ZoomMap structures. */
+ this = (AstZoomMap *) this_object;
+ that = (AstZoomMap *) that_object;
+
+/* Check the second object is a ZoomMap. We know the first is a
+ ZoomMap since we have arrived at this implementation of the virtual
+ function. */
+ if( astIsAZoomMap( that ) ) {
+
+/* Get the number of inputs and outputs and check they are the same for both. */
+ nin = astGetNin( this );
+ nout = astGetNout( this );
+ if( astGetNin( that ) == nin && astGetNout( that ) == nout ) {
+
+/* If the Invert flags for the two ZoomMaps differ, it may still be possible
+ for them to be equivalent. First compare the ZoomMaps if their Invert
+ flags are the same. In this case all the attributes of the two ZoomMaps
+ must be identical. */
+ if( astGetInvert( this ) == astGetInvert( that ) ) {
+ result = ( astEQUAL( this->zoom, that->zoom ) );
+
+/* If the Invert flags for the two ZoomMaps differ, the attributes of the two
+ ZoomMaps must be inversely related to each other. */
+ } else {
+ result = ( astEQUAL( this->zoom, 1.0/that->zoom ) );
+
+ }
+ }
+ }
+
+/* If an error occurred, clear the result value. */
+ if ( !astOK ) result = 0;
+
+/* Return the result, */
+ return result;
+}
+
+static const char *GetAttrib( AstObject *this_object, const char *attrib, int *status ) {
+/*
+* Name:
+* GetAttrib
+
+* Purpose:
+* Get the value of a specified attribute for a ZoomMap.
+
+* Type:
+* Private function.
+
+* Synopsis:
+* #include "zoommap.h"
+* const char *GetAttrib( AstObject *this, const char *attrib, int *status )
+
+* Class Membership:
+* ZoomMap member function (over-rides the protected astGetAttrib
+* method inherited from the Mapping class).
+
+* Description:
+* This function returns a pointer to the value of a specified
+* attribute for a ZoomMap, formatted as a character string.
+
+* Parameters:
+* this
+* Pointer to the ZoomMap.
+* attrib
+* Pointer to a null-terminated string containing the name of
+* the attribute whose value is required. This name should be in
+* lower case, with all white space removed.
+* status
+* Pointer to the inherited status variable.
+
+* Returned Value:
+* - Pointer to a null-terminated string containing the attribute
+* value.
+
+* Notes:
+* - The returned string pointer may point at memory allocated
+* within the ZoomMap, or at static memory. The contents of the
+* string may be over-written or the pointer may become invalid
+* following a further invocation of the same function or any
+* modification of the ZoomMap. A copy of the string should
+* therefore be made if necessary.
+* - A NULL pointer will be returned if this function is invoked
+* with the global error status set, or if it should fail for any
+* reason.
+*/
+
+/* Local Variables: */
+ astDECLARE_GLOBALS /* Pointer to thread-specific global data */
+ AstZoomMap *this; /* Pointer to the ZoomMap structure */
+ const char *result; /* Pointer value to return */
+ double zoom; /* Zoom attribute value */
+
+/* Initialise. */
+ result = NULL;
+
+/* Check the global error status. */
+ if ( !astOK ) return result;
+
+/* Get a pointer to the thread specific global data structure. */
+ astGET_GLOBALS(this_object);
+
+/* Obtain a pointer to the ZoomMap structure. */
+ this = (AstZoomMap *) this_object;
+
+/* Compare "attrib" with each recognised attribute name in turn,
+ obtaining the value of the required attribute. If necessary, write
+ the value into "getattrib_buff" as a null-terminated string in an appropriate
+ format. Set "result" to point at the result string. */
+
+/* Zoom. */
+/* ----- */
+ if ( !strcmp( attrib, "zoom" ) ) {
+ zoom = astGetZoom( this );
+ if ( astOK ) {
+ (void) sprintf( getattrib_buff, "%.*g", DBL_DIG, zoom );
+ result = getattrib_buff;
+ }
+
+/* If the attribute name was not recognised, pass it on to the parent
+ method for further interpretation. */
+ } else {
+ result = (*parent_getattrib)( this_object, attrib, status );
+ }
+
+/* Return the result. */
+ return result;
+}
+
+static int GetIsLinear( AstMapping *this_mapping, int *status ){
+/*
+* Name:
+* GetIsLinear
+
+* Purpose:
+* Return the value of the IsLinear attribute for a ZoomMap.
+
+* Type:
+* Private function.
+
+* Synopsis:
+* #include "mapping.h"
+* void GetIsLinear( AstMapping *this, int *status )
+
+* Class Membership:
+* ZoomMap member function (over-rides the protected astGetIsLinear
+* method inherited from the Mapping class).
+
+* Description:
+* This function returns the value of the IsLinear attribute for a
+* Frame, which is always one.
+
+* Parameters:
+* this
+* Pointer to the ZoomMap.
+* status
+* Pointer to the inherited status variable.
+*/
+ return 1;
+}
+
+void astInitZoomMapVtab_( AstZoomMapVtab *vtab, const char *name, int *status ) {
+/*
+*+
+* Name:
+* astInitZoomMapVtab
+
+* Purpose:
+* Initialise a virtual function table for a ZoomMap.
+
+* Type:
+* Protected function.
+
+* Synopsis:
+* #include "zoommap.h"
+* void astInitZoomMapVtab( AstZoomMapVtab *vtab, const char *name )
+
+* Class Membership:
+* ZoomMap vtab initialiser.
+
+* Description:
+* This function initialises the component of a virtual function
+* table which is used by the ZoomMap 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 */
+ AstObjectVtab *object; /* Pointer to Object component of Vtab */
+ AstMappingVtab *mapping; /* Pointer to Mapping 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. */
+ astInitMappingVtab( (AstMappingVtab *) vtab, name );
+
+/* Store a unique "magic" value in the virtual function table. This
+ will be used (by astIsAZoomMap) 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 = &(((AstMappingVtab *) vtab)->id);
+
+/* Initialise member function pointers. */
+/* ------------------------------------ */
+/* Store pointers to the member functions (implemented here) that provide
+ virtual methods for this class. */
+ vtab->ClearZoom = ClearZoom;
+ vtab->GetZoom = GetZoom;
+ vtab->SetZoom = SetZoom;
+ vtab->TestZoom = TestZoom;
+
+/* 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;
+
+ parent_clearattrib = object->ClearAttrib;
+ object->ClearAttrib = ClearAttrib;
+ parent_getattrib = object->GetAttrib;
+ object->GetAttrib = GetAttrib;
+ parent_setattrib = object->SetAttrib;
+ object->SetAttrib = SetAttrib;
+ parent_testattrib = object->TestAttrib;
+ object->TestAttrib = TestAttrib;
+
+ parent_transform = mapping->Transform;
+ mapping->Transform = Transform;
+
+/* Store replacement pointers for methods which will be over-ridden by
+ new member functions implemented here. */
+ object->Equal = Equal;
+ mapping->MapMerge = MapMerge;
+ mapping->MapSplit = MapSplit;
+ mapping->Rate = Rate;
+ mapping->GetIsLinear = GetIsLinear;
+
+/* Declare the class dump function. There is no copy constructor or
+ destructor. */
+ astSetDump( vtab, Dump, "ZoomMap", "Zoom about the origin" );
+
+/* 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 ZoomMap.
+
+* 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:
+* ZoomMap method (over-rides the protected astMapMerge method
+* inherited from the Mapping class).
+
+* Description:
+* This function attempts to simplify a sequence of Mappings by
+* merging a nominated ZoomMap 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 ZoomMap with one 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 ZoomMap which is to be merged with
+* its neighbours. This should be a cloned copy of the ZoomMap
+* pointer contained in the array element "(*map_list)[where]"
+* (see below). This pointer will not be annulled, and the
+* ZoomMap it identifies will not be modified by this function.
+* where
+* Index in the "*map_list" array (below) at which the pointer
+* to the nominated ZoomMap 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: */
+ AstMapping *map; /* Pointer to Mapping */
+ AstMapping *new; /* Pointer to replacement Mapping */
+ const char *class; /* Pointer to Mapping class string */
+ double *zooms; /* Pointer to zoom factor array */
+ double maxzoom; /* Maximum zoom factor */
+ double minzoom; /* Minimum zoom factor */
+ double zoom; /* Zoom factor */
+ int coord; /* Loop counter for coordinates */
+ int imap1; /* Index of first ZoomMap */
+ int imap2; /* Index of last ZoomMap */
+ int imap; /* Loop counter for Mappings */
+ int ncoord; /* Number of input/output coordinates */
+ int ngone; /* Number of Mappings eliminated */
+ int nin; /* Total number of input coordinates */
+ int nzoom; /* Number of zoom factors */
+ int result; /* Result value to return */
+ int simpler; /* Mapping(s) simplified? */
+ int single; /* Replacement is a single ZoomMap? */
+ int unit; /* Replacement Mapping is a UnitMap? */
+
+/* Initialise the returned result. */
+ result = -1;
+
+/* Check the global error status. */
+ if ( !astOK ) return result;
+
+/* Further initialisation. */
+ new = NULL;
+ ngone = 0;
+ simpler = 0;
+
+/* In series. */
+/* ---------- */
+/* Handle the case where the Mappings are connected in series. */
+ if ( series ) {
+
+/* Obtain the effective zoom factor of the nominated Mapping (which is
+ a ZoomMap) when its Invert attribute is set to the value given. */
+ zoom = astGetZoom( ( *map_list )[ where ] );
+ if ( ( *invert_list )[ where ] ) zoom = 1.0 / zoom;
+
+/* Search adjacent lower-numbered Mappings and identify the class to
+ which they belong. */
+ imap1 = where;
+ while ( astOK && ( ( imap1 - 1 ) >= 0 ) ) {
+ map = ( *map_list )[ imap1 - 1 ];
+ class = astGetClass( map );
+ if ( astOK ) {
+
+/* For each ZoomMap found, obtain the effective zoom factor (taking
+ account of the associated invert flag value), and accumulate the
+ overall zoom factor to be used for the simplified Mapping. */
+ if ( !strcmp( class, "ZoomMap" ) ) {
+ if ( ( *invert_list )[ imap1 - 1 ] ) {
+ zoom /= astGetZoom( map );
+ } else {
+ zoom *= astGetZoom( map );
+ }
+
+/* UnitMaps have an effective zoom factor of unity, so we include them
+ but they so have no effect. Quit looping when the first Mapping is
+ found which is not a ZoomMap or a UnitMap. */
+ } else if ( strcmp( class, "UnitMap" ) ) {
+ break;
+ }
+ imap1--;
+ }
+ }
+
+/* Similarly search adjacent higher-numbered ZoomMaps and UnitMaps and
+ accumulate their effective zoom factors. */
+ imap2 = where;
+ while ( astOK && ( ( imap2 + 1 ) < *nmap ) ) {
+ map = ( *map_list )[ imap2 + 1 ];
+ class = astGetClass( map );
+ if ( astOK ) {
+ if ( !strcmp( class, "ZoomMap" ) ) {
+ if ( ( *invert_list )[ imap2 + 1 ] ) {
+ zoom /= astGetZoom( map );
+ } else {
+ zoom *= astGetZoom( map );
+ }
+ } else if ( strcmp( class, "UnitMap" ) ) {
+ break;
+ }
+ imap2++;
+ }
+ }
+
+/* Determine how many Mappings can be eliminated by condensing those
+ found above into a single Mapping. */
+ ngone = imap2 - imap1;
+
+/* Determine if the replacement Mapping can be a UnitMap. This will be
+ the case only if the accumulated zoom factor is unity (within some
+ tolerable error). */
+ unit = ( fabs( zoom - 1.0 ) <= ( 8.0 * DBL_EPSILON ) );
+
+/* Determine if simplification is possible. This will be so if (a)
+ Mappings can be eliminated ("ngone" is non-zero), or (b) the
+ replacement can be a UnitMap, or (c) where there was initially only
+ one ZoomMap, its invert flag was set (it will always be cleared in
+ the replacement Mapping). */
+ simpler = ngone || unit || ( *invert_list )[ where ];
+
+/* Do nothing more unless simplification is possible. */
+ if ( simpler ) {
+
+/* Obtain the number of input/output coordinates for the replacement
+ Mapping and create the appropriate replacement. */
+ nin = astGetNin( ( *map_list )[ where ] );
+ if ( unit ) {
+ new = (AstMapping *) astUnitMap( nin, "", status );
+ } else {
+ new = (AstMapping *) astZoomMap( nin, zoom, "", status );
+ }
+ }
+
+/* In parallel. */
+/* ------------ */
+/* Handle the case where the Mappings are connected in parallel. */
+ } else {
+
+/* Obtain the number of input/output coordinates for the nominated Mapping. */
+ nin = astGetNin( ( *map_list )[ where ] );
+
+/* Search adjacent lower-numbered Mappings and identify the class to
+ which they belong. */
+ imap1 = where;
+ while ( astOK && ( ( imap1 - 1 ) >= 0 ) ) {
+ map = ( *map_list )[ imap1 - 1 ];
+ class = astGetClass( map );
+ if ( astOK ) {
+
+/* Quit looping when the first Mapping is found which is not a ZoomMap
+ or a UnitMap. */
+ if ( strcmp( class, "ZoomMap" ) &&
+ strcmp( class, "UnitMap" ) ) break;
+
+/* Accumulate the total number of input/output coordinates for each
+ adjacent ZoomMap and UnitMap found. */
+ nin += astGetNin( map );
+ imap1--;
+ }
+ }
+
+/* Similarly search adjacent higher-numbered Mappings and accumulate
+ the number of input/output coordinates.*/
+ imap2 = where;
+ while ( astOK && ( ( imap2 + 1 ) < *nmap ) ) {
+ map = ( *map_list )[ imap2 + 1 ];
+ class = astGetClass( map );
+ if ( astOK ) {
+ if ( strcmp( class, "ZoomMap" ) &&
+ strcmp( class, "UnitMap" ) ) break;
+ nin += astGetNin( map );
+ imap2++;
+ }
+ }
+
+/* Allocate memory for an array of zoom factors, one for each
+ input/output coordinate in the replacement Mapping. */
+ zooms = astMalloc( sizeof( double ) * (size_t) nin );
+ if ( astOK ) {
+
+/* Initialise. */
+ nzoom = 0;
+ minzoom = DBL_MAX;
+ maxzoom = -DBL_MAX;
+
+/* Loop through all the ZoomMaps and UnitMaps being merged and again
+ identify the class to which they belong. */
+ for ( imap = imap1; astOK && ( imap <= imap2 ); imap++ ) {
+ map = ( *map_list )[ imap ];
+ class = astGetClass( map );
+ if ( astOK ) {
+
+/* Set a default zoom factor of unity (for UnitMaps). If the Mapping
+ is a ZoomMap, replace this with the effective zoom factor, taking
+ account of the associated invert flag. */
+ zoom = 1.0;
+ if ( !strcmp( class, "ZoomMap" ) ) {
+ if ( ( *invert_list )[ imap ] ) {
+ zoom = 1.0 / astGetZoom( map );
+ } else {
+ zoom = astGetZoom( map );
+ }
+ }
+
+/* Replicate the zoom factor in the zoom factor array, once for each
+ input/output coordinate associated with the current Mapping. */
+ ncoord = astGetNin( map );
+ for ( coord = 0; coord < ncoord; coord++ ) {
+ zooms[ nzoom++ ] = zoom;
+ }
+
+/* Store the minimum and maximum zoom factors encountered. */
+ if ( zoom < minzoom ) minzoom = zoom;
+ if ( zoom > maxzoom ) maxzoom = zoom;
+ }
+ }
+
+/* Determine how many Mappings can be eliminated by condensing those
+ found above into a single Mapping. */
+ ngone = imap2 - imap1;
+
+/* Determine whether the replacement Mapping can be a single
+ ZoomMap. This will be so if all the effective zoom factors were the
+ same. */
+ single = ( minzoom == maxzoom );
+
+/* Determine if the replacement Mapping can be a UnitMap. This will be
+ so if all the effective zoom factors were equal to unity. */
+ unit = single && ( minzoom == 1.0 );
+
+/* Determine if simplification is possible. This will be so if (a)
+ Mappings can be eliminated ("ngone" is non-zero), or (b) the
+ replacement can be a UnitMap, or (c) where there was initially only
+ one ZoomMap, its invert flag was set (it will always be cleared in
+ the replacement Mapping). */
+ simpler = ngone || unit || ( *invert_list )[ where ];
+
+/* Do nothing more unless simplification is possible. */
+ if ( simpler ) {
+
+/* Create a replacement UnitMap or ZoomMap if appropriate. */
+ if ( unit ) {
+ new = (AstMapping *) astUnitMap( nin, "", status );
+ } else if ( single ) {
+ new = (AstMapping *) astZoomMap( nin, minzoom, "", status );
+
+/* Otherwise, replace the original ZoomMaps and UnitMaps with a
+ diagonal MatrixMap containing the zoom factors as its diagonal
+ elements. */
+ } else {
+ new = (AstMapping *) astMatrixMap( nin, nin, 1, zooms, "", status );
+ }
+ }
+ }
+
+/* Free the array of zoom factors. */
+ zooms = astFree( zooms );
+ }
+
+/* If OK, and simplification is possible, we now have a replacement
+ Mapping and can insert it into the Mapping list. */
+ if ( astOK ) {
+ if ( simpler ) {
+
+/* Annul the pointers to all the ZoomMaps that are being replaced. */
+ for ( imap = imap1; imap <= imap2; imap++ ) {
+ ( *map_list )[ imap ] = astAnnul( ( *map_list )[ imap ] );
+ }
+
+/* Insert the new pointer and the associated invert flag. */
+ ( *map_list )[ imap1 ] = new;
+ ( *invert_list )[ imap1 ] = 0;
+
+/* Loop to close the resulting gap by moving subsequent elements down
+ in the arrays. */
+ for ( imap = imap2 + 1; imap < *nmap; imap++ ) {
+ ( *map_list )[ imap - ngone ] = ( *map_list )[ imap ];
+ ( *invert_list )[ imap - ngone ] = ( *invert_list )[ imap ];
+ }
+
+/* Clear the vacated elements at the end. */
+ for ( imap = *nmap - ngone; imap < *nmap; imap++ ) {
+ ( *map_list )[ imap ] = NULL;
+ ( *invert_list )[ imap ] = 0;
+ }
+
+/* Decrement the Mapping count and return the index of the first
+ modified element. */
+ ( *nmap ) -= ngone;
+ result = imap1;
+ }
+
+/* If an error occurred, but a new Mapping has been created, then
+ annul it. */
+ } else {
+ if ( new ) new = astAnnul( new );
+ }
+
+/* If an error occurred, clear the returned result. */
+ if ( !astOK ) result = -1;
+
+/* Return the result. */
+ return result;
+}
+
+static int *MapSplit( AstMapping *this_map, int nin, const int *in, AstMapping **map, int *status ){
+/*
+* Name:
+* MapSplit
+
+* Purpose:
+* Create a Mapping representing a subset of the inputs of an existing
+* ZoomMap.
+
+* Type:
+* Private function.
+
+* Synopsis:
+* #include "zoommap.h"
+* int *MapSplit( AstMapping *this, int nin, const int *in, AstMapping **map, int *status )
+
+* Class Membership:
+* ZoomMap method (over-rides the protected astMapSplit method
+* inherited from the Mapping class).
+
+* Description:
+* This function creates a new Mapping by picking specified inputs from
+* an existing ZoomMap. This is only possible if the specified inputs
+* correspond to some subset of the ZoomMap outputs. That is, there
+* must exist a subset of the ZoomMap outputs for which each output
+* depends only on the selected ZoomMap inputs, and not on any of the
+* inputs which have not been selected. If this condition is not met
+* by the supplied ZoomMap, then a NULL Mapping is returned.
+
+* Parameters:
+* this
+* Pointer to the ZoomMap to be split (the ZoomMap is not actually
+* modified by this function).
+* nin
+* The number of inputs to pick from "this".
+* in
+* Pointer to an array of indices (zero based) for the inputs which
+* are to be picked. This array should have "nin" elements. If "Nin"
+* is the number of inputs of the supplied ZoomMap, then each element
+* should have a value in the range zero to Nin-1.
+* map
+* Address of a location at which to return a pointer to the new
+* Mapping. This Mapping will have "nin" inputs (the number of
+* outputs may be different to "nin"). A NULL pointer will be
+* returned if the supplied ZoomMap has no subset of outputs which
+* depend only on the selected inputs.
+* status
+* Pointer to the inherited status variable.
+
+* Returned Value:
+* A pointer to a dynamically allocated array of ints. The number of
+* elements in this array will equal the number of outputs for the
+* returned Mapping. Each element will hold the index of the
+* corresponding output in the supplied ZoomMap. The array should be
+* freed using astFree when no longer needed. A NULL pointer will
+* be returned if no output Mapping can be created.
+
+* Notes:
+* - If this function is invoked with the global error status set,
+* or if it should fail for any reason, then NULL values will be
+* returned as the function value and for the "map" pointer.
+*/
+
+/* Local Variables: */
+ AstZoomMap *this; /* Pointer to ZoomMap structure */
+ int *result; /* Pointer to returned array */
+ int i; /* Loop count */
+ int iin; /* Mapping input index */
+ int mnin; /* No. of Mapping inputs */
+ int ok; /* Are input indices OK? */
+
+/* Initialise */
+ result = NULL;
+ *map = NULL;
+
+/* Check the global error status. */
+ if ( !astOK ) return result;
+
+/* Get a pointer to the ZoomMap structure. */
+ this = (AstZoomMap *) this_map;
+
+/* Allocate memory for the returned array and create a ZoomMap with the
+ required number of axes. */
+ result = astMalloc( sizeof( int )*(size_t) nin );
+ *map = (AstMapping *) astZoomMap( nin, astGetZoom( this ), "", status );
+
+/* Set its Invert attribute to be like the supplied ZoomMap. */
+ astSetInvert( *map, astGetInvert( this ) );
+
+/* Check pointers can be used safely. */
+ if( astOK ) {
+
+/* Store the required output axis indices. At the same time check that each
+ axis is valid. */
+ mnin = astGetNin( this );
+ ok = 1;
+ for( i = 0; i < nin; i++ ) {
+ iin = in[ i ];
+ if( iin >= 0 && iin < mnin ) {
+ result[ i ] = iin;
+ } else {
+ ok = 0;
+ break;
+ }
+ }
+
+/* If the "in" array contained any invalid values, free the returned
+ resources. */
+ if( !ok ) {
+ result = astFree( result );
+ *map = astAnnul( *map );
+ }
+ }
+
+/* Free returned resources if an error has occurred. */
+ if( !astOK ) {
+ result = astFree( result );
+ *map = astAnnul( *map );
+ }
+
+/* Return the list of output indices. */
+ return result;
+}
+
+static double Rate( AstMapping *this, double *at, int ax1, int ax2, int *status ){
+/*
+* Name:
+* Rate
+
+* Purpose:
+* Calculate the rate of change of a Mapping output.
+
+* Type:
+* Private function.
+
+* Synopsis:
+* #include "zoommap.h"
+* result = Rate( AstMapping *this, double *at, int ax1, int ax2, int *status )
+
+* Class Membership:
+* ZoomMap member function (overrides the astRate method inherited
+* from the Mapping class ).
+
+* Description:
+* This function returns the rate of change of a specified output of
+* the supplied Mapping with respect to a specified input, at a
+* specified input position.
+
+* Parameters:
+* this
+* Pointer to the Mapping to be applied.
+* at
+* The address of an array holding the axis values at the position
+* at which the rate of change is to be evaluated. The number of
+* elements in this array should equal the number of inputs to the
+* Mapping.
+* ax1
+* The index of the Mapping output for which the rate of change is to
+* be found (output numbering starts at 0 for the first output).
+* ax2
+* The index of the Mapping input which is to be varied in order to
+* find the rate of change (input numbering starts at 0 for the first
+* input).
+* status
+* Pointer to the inherited status variable.
+
+* Returned Value:
+* The rate of change of Mapping output "ax1" with respect to input
+* "ax2", evaluated at "at", or AST__BAD if the value cannot be
+* calculated.
+
+*/
+
+/* Local Variables: */
+ double result;
+
+/* Check inherited status */
+ if( !astOK ) return AST__BAD;
+
+/* Result is zero if the axes differ */
+ if( ax1 != ax2 ) {
+ result = 0.0;
+
+/* Otherwise, get the zoom factor. */
+ } else {
+ result = astGetZoom( (AstZoomMap *) this );
+
+/* If the ZoomMap has been inverted, return the reciprocal of the zoom
+ factor. */
+ if ( astGetInvert( this ) ) {
+ if( result != AST__BAD && result != 0.0 ) {
+ result = 1.0/result;
+ } else {
+ result = AST__BAD;
+ }
+ }
+ }
+
+/* Return the result. */
+ return result;
+}
+
+static void SetAttrib( AstObject *this_object, const char *setting, int *status ) {
+/*
+* Name:
+* SetAttrib
+
+* Purpose:
+* Set an attribute value for a ZoomMap.
+
+* Type:
+* Private function.
+
+* Synopsis:
+* #include "zoommap.h"
+* void SetAttrib( AstObject *this, const char *setting )
+
+* Class Membership:
+* ZoomMap member function (over-rides the astSetAttrib protected
+* method inherited from the Mapping class).
+
+* Description:
+* This function assigns an attribute value for a ZoomMap, the
+* attribute and its value being specified by means of a string of
+* the form:
+*
+* "attribute= value "
+*
+* Here, "attribute" specifies the attribute name and should be in
+* lower case with no white space present. The value to the right
+* of the "=" should be a suitable textual representation of the
+* value to be assigned and this will be interpreted according to
+* the attribute's data type. White space surrounding the value is
+* only significant for string attributes.
+
+* Parameters:
+* this
+* Pointer to the ZoomMap.
+* setting
+* Pointer to a null-terminated string specifying the new attribute
+* value.
+*/
+
+/* Local Variables: */
+ AstZoomMap *this; /* Pointer to the ZoomMap structure */
+ double zoom; /* Zoom attribute value */
+ int len; /* Length of setting string */
+ int nc; /* Number of characters read by astSscanf */
+
+/* Check the global error status. */
+ if ( !astOK ) return;
+
+/* Obtain a pointer to the ZoomMap structure. */
+ this = (AstZoomMap *) this_object;
+
+/* Obtain the length of the setting string. */
+ len = (int) strlen( setting );
+
+/* Test for each recognised attribute in turn, using "astSscanf" to parse
+ the setting string and extract the attribute value (or an offset to
+ it in the case of string values). In each case, use the value set
+ in "nc" to check that the entire string was matched. Once a value
+ has been obtained, use the appropriate method to set it. */
+
+/* Zoom. */
+/* ----- */
+ if ( nc = 0,
+ ( 1 == astSscanf( setting, "zoom= %lf %n", &zoom, &nc ) )
+ && ( nc >= len ) ) {
+ astSetZoom( this, zoom );
+
+/* If the attribute is still not recognised, pass it on to the parent
+ method for further interpretation. */
+ } else {
+ (*parent_setattrib)( this_object, setting, status );
+ }
+}
+
+static int TestAttrib( AstObject *this_object, const char *attrib, int *status ) {
+/*
+* Name:
+* TestAttrib
+
+* Purpose:
+* Test if a specified attribute value is set for a ZoomMap.
+
+* Type:
+* Private function.
+
+* Synopsis:
+* #include "zoommap.h"
+* int TestAttrib( AstObject *this, const char *attrib, int *status )
+
+* Class Membership:
+* ZoomMap member function (over-rides the astTestAttrib protected
+* method inherited from the Mapping class).
+
+* Description:
+* This function returns a boolean result (0 or 1) to indicate whether
+* a value has been set for one of a ZoomMap's attributes.
+
+* Parameters:
+* this
+* Pointer to the ZoomMap.
+* attrib
+* Pointer to a null-terminated string specifying the attribute
+* name. This should be in lower case with no surrounding white
+* space.
+* status
+* Pointer to the inherited status variable.
+
+* Returned Value:
+* One if a value has been set, otherwise zero.
+
+* Notes:
+* - A value of zero will be returned if this function is invoked
+* with the global status set, or if it should fail for any reason.
+*/
+
+/* Local Variables: */
+ AstZoomMap *this; /* Pointer to the ZoomMap structure */
+ int result; /* Result value to return */
+
+/* Initialise. */
+ result = 0;
+
+/* Check the global error status. */
+ if ( !astOK ) return result;
+
+/* Obtain a pointer to the ZoomMap structure. */
+ this = (AstZoomMap *) this_object;
+
+/* Check the attribute name and test the appropriate attribute. */
+
+/* Zoom. */
+/* ----- */
+ if ( !strcmp( attrib, "zoom" ) ) {
+ result = astTestZoom( this );
+
+/* If the attribute is still not recognised, pass it on to the parent
+ method for further interpretation. */
+ } else {
+ result = (*parent_testattrib)( this_object, attrib, status );
+ }
+
+/* Return the result, */
+ return result;
+}
+
+static AstPointSet *Transform( AstMapping *this, AstPointSet *in,
+ int forward, AstPointSet *out, int *status ) {
+/*
+* Name:
+* Transform
+
+* Purpose:
+* Apply a ZoomMap to transform a set of points.
+
+* Type:
+* Private function.
+
+* Synopsis:
+* #include "zoommap.h"
+* AstPointSet *Transform( AstMapping *this, AstPointSet *in,
+* int forward, AstPointSet *out, int *status )
+
+* Class Membership:
+* ZoomMap member function (over-rides the astTransform protected
+* method inherited from the Mapping class).
+
+* Description:
+* This function takes a ZoomMap and a set of points encapsulated in a
+* PointSet and transforms the points so as to apply the required zoom
+* factor.
+
+* Parameters:
+* this
+* Pointer to the ZoomMap.
+* 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:
+* - 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 coordinates for the ZoomMap being applied.
+* - 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: */
+ AstPointSet *result; /* Pointer to output PointSet */
+ AstZoomMap *map; /* Pointer to ZoomMap to be applied */
+ double **ptr_in; /* Pointer to input coordinate data */
+ double **ptr_out; /* Pointer to output coordinate data */
+ double scale; /* Scale factor to implement zoom */
+ int coord; /* Loop counter for coordinates */
+ int ncoord_in; /* Number of coordinates per input point */
+ int npoint; /* Number of points */
+ int point; /* Loop counter for points */
+
+/* Check the global error status. */
+ if ( !astOK ) return NULL;
+
+/* Obtain a pointer to the ZoomMap. */
+ map = (AstZoomMap *) this;
+
+/* Apply the parent mapping using the stored pointer to the Transform member
+ function inherited from the parent Mapping class. This function validates
+ all arguments and generates an output PointSet if necessary, but does not
+ actually transform any coordinate values. */
+ 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. */
+
+/* Determine the numbers of points and coordinates per point from the input
+ PointSet and obtain pointers for accessing the input and output coordinate
+ values. */
+ ncoord_in = astGetNcoord( in );
+ npoint = astGetNpoint( in );
+ ptr_in = astGetPoints( in );
+ ptr_out = astGetPoints( result );
+
+/* Determine whether to apply the forward or inverse mapping, according to the
+ direction specified and whether the mapping has been inverted. */
+ if ( astGetInvert( map ) ) forward = !forward;
+
+/* Perform coordinate arithmetic. */
+/* ------------------------------ */
+/* Generate the coordinate scale factor, according to the direction
+ of mapping required. */
+ scale = astGetZoom( map );
+ if ( !forward && astOK ) scale = 1.0 / scale;
+
+/* Loop to apply the scale factor to all the coordinate values, checking for
+ (and propagating) bad values in the process. */
+ if ( astOK ) {
+ for ( coord = 0; coord < ncoord_in; coord++ ) {
+ for ( point = 0; point < npoint; point++ ) {
+ if ( ptr_in[ coord ][ point ] == AST__BAD ) {
+ ptr_out[ coord ][ point ] = AST__BAD;
+ } else {
+ ptr_out[ coord ][ point ] = ptr_in[ coord ][ point ] * scale;
+ }
+ }
+ }
+ }
+
+/* Return a pointer to the output PointSet. */
+ return result;
+}
+
+/* Functions which access class attributes. */
+/* ---------------------------------------- */
+/* Implement member functions to access the attributes associated with
+ this class using the macros defined for this purpose in the
+ "object.h" file. For a description of each attribute, see the class
+ interface (in the associated .h file). */
+
+/*
+*att++
+* Name:
+* Zoom
+
+* Purpose:
+* ZoomMap scale factor.
+
+* Type:
+* Public attribute.
+
+* Synopsis:
+* Double precision.
+
+* Description:
+* This attribute holds the ZoomMap scale factor, by which
+* coordinate values are multiplied (by the forward transformation)
+* or divided (by the inverse transformation). The default value
+* is unity.
+*
+c Note that if a ZoomMap is inverted (e.g. by using astInvert),
+f Note that if a ZoomMap is inverted (e.g. by using AST_INVERT),
+* then the reciprocal of this zoom factor will, in effect, be
+* used.
+*
+* In general, Mapping attributes cannot be changed after the Mapping
+* has been created (the exception to this is the Invert attribute,
+* which can be changed at any time). However, several of the oldest
+* Mapping classes - including the ZoomMap class - were introduced
+* into the AST library before this restriction was enforced. To
+* reduce the chances of breaking existing software, the attributes of
+* such Mappings may still be changed, but only for Mapping instances
+* that have exactly one active reference. In other words, an error will
+* be reported if an attempt is made to set or clear an attribute of a
+* Mapping (other than the Invert attribute) if that Mapping has been
+* cloned. Mappings are cloned when they are incorporated into another
+* object such as a CmpMap or FrameSet, or when the
+c astClone
+f AST_CLONE
+* function is used.
+
+* Applicability:
+* ZoomMap
+* All ZoomMaps have this attribute.
+
+* Notes:
+* - The Zoom attribute may not be set to zero.
+*att--
+*/
+/* This ia a double value with a value of 0.0 when undefined but
+ yielding a default of 1.0. Setting it explicitly to 0.0 is not
+ permitted except via astClearZoom. */
+astMAKE_CLEAR1(ZoomMap,Zoom,zoom,0.0)
+astMAKE_GET(ZoomMap,Zoom,double,1.0,( ( this->zoom == 0.0 ) ?
+ 1.0 : this->zoom ))
+
+/* Check for an attempt to set a value of zero and report an error if
+ necessary (leaving the Zoom value unchanged). */
+astMAKE_SET1(ZoomMap,Zoom,double,zoom,(
+ ( value != 0.0 ) ?
+ value :
+ ( astError( AST__ZOOMI,
+ "astSetZoom(%s): A zoom factor of zero is not allowed.", status,
+ astGetClass( this ) ),
+ this->zoom ) ))
+astMAKE_TEST(ZoomMap,Zoom,( this->zoom != 0.0 ))
+
+/* Copy constructor. */
+/* ----------------- */
+/* No copy constructor is needed, as a byte-by-byte copy suffices. */
+
+/* Destructor. */
+/* ----------- */
+/* No destructor is needed as no memory, etc. needs freeing. */
+
+/* Dump function. */
+/* -------------- */
+static void Dump( AstObject *this_object, AstChannel *channel, int *status ) {
+/*
+* Name:
+* Dump
+
+* Purpose:
+* Dump function for ZoomMap 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 ZoomMap class to an output Channel.
+
+* Parameters:
+* this
+* Pointer to the ZoomMap 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: */
+ AstZoomMap *this; /* Pointer to the ZoomMap structure */
+ double dval; /* Double value */
+ int set; /* Attribute value set? */
+
+/* Check the global error status. */
+ if ( !astOK ) return;
+
+/* Obtain a pointer to the ZoomMap structure. */
+ this = (AstZoomMap *) this_object;
+
+/* Write out values representing the instance variables for the
+ ZoomMap 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. */
+
+/* Zoom. */
+/* ----- */
+ set = TestZoom( this, status );
+ dval = set ? GetZoom( this, status ) : astGetZoom( this );
+ astWriteDouble( channel, "Zoom", set, 1, dval, "Zoom factor" );
+}
+
+/* Standard class functions. */
+/* ========================= */
+/* Implement the astIsAZoomMap and astCheckZoomMap functions using the macros
+ defined for this purpose in the "object.h" header file. */
+astMAKE_ISA(ZoomMap,Mapping)
+astMAKE_CHECK(ZoomMap)
+
+AstZoomMap *astZoomMap_( int ncoord, double zoom, const char *options, int *status, ...) {
+/*
+*++
+* Name:
+c astZoomMap
+f AST_ZOOMMAP
+
+* Purpose:
+* Create a ZoomMap.
+
+* Type:
+* Public function.
+
+* Synopsis:
+c #include "zoommap.h"
+c AstZoomMap *astZoomMap( int ncoord, double zoom,
+c const char *options, ... )
+f RESULT = AST_ZOOMMAP( NCOORD, ZOOM, OPTIONS, STATUS )
+
+* Class Membership:
+* ZoomMap constructor.
+
+* Description:
+* This function creates a new ZoomMap and optionally initialises its
+* attributes.
+*
+* A ZoomMap is a Mapping which "zooms" a set of points about the
+* origin by multiplying all coordinate values by the same scale
+* factor (the inverse transformation is performed by dividing by
+* this scale factor).
+
+* Parameters:
+c ncoord
+f NCOORD = INTEGER (Given)
+* The number of coordinate values for each point to be
+* transformed (i.e. the number of dimensions of the space in
+* which the points will reside). The same number is applicable
+* to both input and output points.
+c zoom
+f ZOOM = DOUBLE PRECISION (Given)
+* Initial scale factor by which coordinate values should be
+* multiplied (by the forward transformation) or divided (by the
+* inverse transformation). This factor may subsequently be
+* changed via the ZoomMap's Zoom attribute. It may be positive
+* or negative, but should not be zero.
+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 ZoomMap. 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 ZoomMap. 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 astZoomMap()
+f AST_ZOOMMAP = INTEGER
+* A pointer to the new ZoomMap.
+
+* 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 */
+ AstZoomMap *new; /* Pointer to new ZoomMap */
+ 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;
+
+/* Initialise the ZoomMap, allocating memory and initialising the
+ virtual function table as well if necessary. */
+ new = astInitZoomMap( NULL, sizeof( AstZoomMap ), !class_init, &class_vtab,
+ "ZoomMap", ncoord, zoom );
+
+/* 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 ZoomMap'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 ZoomMap. */
+ return new;
+}
+
+AstZoomMap *astZoomMapId_( int ncoord, double zoom,
+ const char *options, ... ) {
+/*
+* Name:
+* astZoomMapId_
+
+* Purpose:
+* Create a ZoomMap.
+
+* Type:
+* Private function.
+
+* Synopsis:
+* #include "zoommap.h"
+* AstZoomMap *astZoomMapId_( int ncoord, double zoom,
+* const char *options, ... )
+
+* Class Membership:
+* ZoomMap constructor.
+
+* Description:
+* This function implements the external (public) interface to the
+* astZoomMap constructor function. It returns an ID value (instead
+* of a true C pointer) to external users, and must be provided
+* because astZoomMap_ 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 astZoomMap_ 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 astZoomMap_.
+
+* Returned Value:
+* The ID value associated with the new ZoomMap.
+*/
+
+/* Local Variables: */
+ astDECLARE_GLOBALS /* Pointer to thread-specific global data */
+ AstZoomMap *new; /* Pointer to new ZoomMap */
+ va_list args; /* Variable argument list */
+
+ int *status; /* Pointer to inherited status value */
+
+/* Get a pointer to the inherited status value. */
+ status = astGetStatusPtr;
+
+/* Get a pointer to the thread specific global data structure. */
+ astGET_GLOBALS(NULL);
+
+/* Check the global status. */
+ if ( !astOK ) return NULL;
+
+/* Initialise the ZoomMap, allocating memory and initialising the
+ virtual function table as well if necessary. */
+ new = astInitZoomMap( NULL, sizeof( AstZoomMap ), !class_init, &class_vtab,
+ "ZoomMap", ncoord, zoom );
+
+/* 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 ZoomMap'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 ZoomMap. */
+ return astMakeId( new );
+}
+
+AstZoomMap *astInitZoomMap_( void *mem, size_t size, int init,
+ AstZoomMapVtab *vtab, const char *name,
+ int ncoord, double zoom, int *status ) {
+/*
+*+
+* Name:
+* astInitZoomMap
+
+* Purpose:
+* Initialise a ZoomMap.
+
+* Type:
+* Protected function.
+
+* Synopsis:
+* #include "zoommap.h"
+* AstZoomMap *astInitZoomMap( void *mem, size_t size, int init,
+* AstZoomMapVtab *vtab, const char *name,
+* int ncoord, double zoom )
+
+* Class Membership:
+* ZoomMap initialiser.
+
+* Description:
+* This function is provided for use by class implementations to initialise
+* a new ZoomMap object. It allocates memory (if necessary) to accommodate
+* the ZoomMap plus any additional data associated with the derived class.
+* It then initialises a ZoomMap 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 ZoomMap at the start of the memory passed via the
+* "vtab" parameter.
+
+* Parameters:
+* mem
+* A pointer to the memory in which the ZoomMap is to be initialised.
+* This must be of sufficient size to accommodate the ZoomMap data
+* (sizeof(ZoomMap)) 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 ZoomMap (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 ZoomMap
+* structure, so a valid value must be supplied even if not required for
+* allocating memory.
+* init
+* A logical flag indicating if the ZoomMap'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 ZoomMap.
+* 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).
+* ncoord
+* The number of coordinate values per point.
+* zoom
+* The scale factor by which coordinate values are multiplied (by the
+* forward mapping) or divided (by the inverse mapping). This factor may
+* not be zero.
+
+* Returned Value:
+* A pointer to the new ZoomMap.
+
+* 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: */
+ AstZoomMap *new; /* Pointer to new ZoomMap */
+
+/* Check the global status. */
+ if ( !astOK ) return NULL;
+
+/* If necessary, initialise the virtual function table. */
+ if ( init ) astInitZoomMapVtab( vtab, name );
+
+/* Initialise. */
+ new = NULL;
+
+/* Check the initialisation value(s) for validity, reporting an error if
+ necessary. Prefix the error report with the name of the function and the
+ class of object being processed. */
+ if ( zoom == 0.0 ) {
+ astError( AST__ZOOMI, "astInitZoomMap(%s): A zoom factor of zero is not "
+ "allowed.", status, name );
+ } else {
+
+/* Initialise a Mapping structure (the parent class) as the first component
+ within the ZoomMap structure, allocating memory if necessary. Specify that
+ the Mapping should be defined in both the forward and inverse directions. */
+ new = (AstZoomMap *) astInitMapping( mem, size, 0,
+ (AstMappingVtab *) vtab, name,
+ ncoord, ncoord, 1, 1 );
+
+ if ( astOK ) {
+
+/* Initialise the ZoomMap data. */
+/* ---------------------------- */
+/* Store the zoom factor. */
+ new->zoom = zoom;
+
+/* If an error occurred, clean up by deleting the new ZoomMap. */
+ if ( !astOK ) new = astDelete( new );
+ }
+ }
+
+/* Return a pointer to the new ZoomMap. */
+ return new;
+}
+
+AstZoomMap *astLoadZoomMap_( void *mem, size_t size,
+ AstZoomMapVtab *vtab, const char *name,
+ AstChannel *channel, int *status ) {
+/*
+*+
+* Name:
+* astLoadZoomMap
+
+* Purpose:
+* Load a ZoomMap.
+
+* Type:
+* Protected function.
+
+* Synopsis:
+* #include "zoommap.h"
+* AstZoomMap *astLoadZoomMap( void *mem, size_t size,
+* AstZoomMapVtab *vtab, const char *name,
+* AstChannel *channel )
+
+* Class Membership:
+* ZoomMap loader.
+
+* Description:
+* This function is provided to load a new ZoomMap 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
+* ZoomMap 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 ZoomMap at the start of the memory
+* passed via the "vtab" parameter.
+
+
+* Parameters:
+* mem
+* A pointer to the memory into which the ZoomMap is to be
+* loaded. This must be of sufficient size to accommodate the
+* ZoomMap data (sizeof(ZoomMap)) 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 ZoomMap (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 ZoomMap 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(AstZoomMap) is used instead.
+* vtab
+* Pointer to the start of the virtual function table to be
+* associated with the new ZoomMap. If this is NULL, a pointer
+* to the (static) virtual function table for the ZoomMap 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 "ZoomMap" is used instead.
+
+* Returned Value:
+* A pointer to the new ZoomMap.
+
+* 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 */
+ AstZoomMap *new; /* Pointer to the new ZoomMap */
+
+/* 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 ZoomMap. In this case the
+ ZoomMap belongs to this class, so supply appropriate values to be
+ passed to the parent class loader (and its parent, etc.). */
+ if ( !vtab ) {
+ size = sizeof( AstZoomMap );
+ vtab = &class_vtab;
+ name = "ZoomMap";
+
+/* If required, initialise the virtual function table for this class. */
+ if ( !class_init ) {
+ astInitZoomMapVtab( 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 ZoomMap. */
+ new = astLoadMapping( mem, size, (AstMappingVtab *) 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, "ZoomMap" );
+
+/* 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. */
+
+/* Zoom. */
+/* ----- */
+ new->zoom = astReadDouble( channel, "zoom", 0.0 );
+ if ( TestZoom( new, status ) ) SetZoom( new, new->zoom, status );
+
+/* If an error occurred, clean up by deleting the new ZoomMap. */
+ if ( !astOK ) new = astDelete( new );
+ }
+
+/* Return the new ZoomMap 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. */
+
+
+
+
+