Files
magic/database/DBcellbox.c
T
R. Timothy Edwards 957d7edd64 A number of things in one commit:
1) Added a "*showmem" "wizard" command to get a dump of all memory
   being used by tiles in the database.
2) Made a slight correction to the way magic detects exact overlap
   of instances of the same cell.  This probably does not make any
   actual difference in practice.
3) Corrected an uninitialized variable in dbReComputeBboxFunc().
4) Changes DBSrCellPlaneArea() to use a static BPEnum variable, so
   that it does not waste time allocating and freeing memory for
   the same thing over and over again.
5) Corrected a memory leak in the tech file "extract" section that
   loses memory every time the extraction style is changed.
6) Corrected the tile join routines to fix a bad memory leak in the
   tile allocation and recovery---a fix which was mentioned in issue
   #414 but which had not yet been implemented.  This has now been
   tested and confirmed to work.
2025-11-07 11:00:22 -05:00

870 lines
24 KiB
C

/*
* DBcellbox.c --
*
* Procedures for calculating and changing cell bounding boxes,
* and for manipulating arrays of cells.
*
* *********************************************************************
* * Copyright (C) 1985, 1990 Regents of the University of California. *
* * Permission to use, copy, modify, and distribute this *
* * software and its documentation for any purpose and without *
* * fee is hereby granted, provided that the above copyright *
* * notice appear in all copies. The University of California *
* * makes no representations about the suitability of this *
* * software for any purpose. It is provided "as is" without *
* * express or implied warranty. Export of this software outside *
* * of the United States of America may require an export license. *
* *********************************************************************
*/
#ifndef lint
static char rcsid[] __attribute__ ((unused)) = "$Header: /usr/cvsroot/magic-8.0/database/DBcellbox.c,v 1.3 2008/12/11 18:36:43 tim Exp $";
#endif /* not lint */
#include <stdio.h>
#include "utils/magic.h"
#include "utils/geometry.h"
#include "utils/geofast.h"
#include "tiles/tile.h"
#include "utils/hash.h"
#include "database/database.h"
#include "database/databaseInt.h"
#include "windows/windows.h"
#include "dbwind/dbwind.h"
#include "utils/undo.h"
/*
*-----------------------------------------------------------------------------
*
* DBPrintUseId --
*
* Generate the print name of the use identifier indicated by the supplied
* SearchContext.
*
* Results:
* Returns a pointer to the NULL byte at the end of the string
* generated.
*
* Side effects:
* The character string pointed to by name is set to contain the use
* id of scx->scx_use followed by any array indices. If scx->scx_use
* is a two dimensional array, the array indices are of the form [y,x],
* otherwise there is a single array index either of the form [y] or [x].
* The array indices are taken from scx->scx_x and scx->scx_y. At most
* size characters are copied into the string pointed to by name.
*
*-----------------------------------------------------------------------------
*/
char *
DBPrintUseId(
SearchContext *scx, /* Pointer to current search context, specifying a
* cell use and X,Y array indices.
*/
char *name, /* Pointer to string into which we will copy the
* print name of this instance.
*/
int size, /* Maximum number of characters to copy into string. */
bool display_only) /* TRUE if called for displaying only */
{
CellUse *use = scx->scx_use;
char *sp, *id, *ep;
char indices[100];
if ((id = use->cu_id) == (char *) NULL)
{
name[0] = '\0';
return (name);
}
sp = name;
if (display_only && (use->cu_flags & CU_LOCKED))
*sp++ = CULOCKCHAR;
for (ep = &name[size]; (sp < ep) && *id; *sp++ = *id++)
/* Nothing */;
if (use->cu_xlo != use->cu_xhi || use->cu_ylo != use->cu_yhi)
{
if (use->cu_xlo == use->cu_xhi)
(void) sprintf(indices, "[%d]", scx->scx_y);
else if (use->cu_ylo == use->cu_yhi)
(void) sprintf(indices, "[%d]", scx->scx_x);
else
(void) sprintf(indices, "[%d,%d]", scx->scx_y, scx->scx_x);
for (id = indices; (sp < ep) && *id; *sp++ = *id++)
/* Nothing */;
}
if (sp == ep)
sp--;
*sp = '\0';
return (sp);
}
/*
* ----------------------------------------------------------------------------
*
* DBCellSetAvail --
* DBCellClearAvail --
*
* Mark a cell as available/unavailable.
* These exist mainly to create a cell for the first time, and to
* allow a cell to be 'flushed' via the "flush" command.
*
* Results:
* None.
*
* Side effects:
* Modifies flags in cellDef.
*
* ----------------------------------------------------------------------------
*/
void
DBCellSetAvail(cellDef)
CellDef *cellDef; /* Pointer to definition of cell we wish to
* mark as available.
*/
{
cellDef->cd_flags &= ~CDNOTFOUND;
cellDef->cd_flags |= CDAVAILABLE;
}
void
DBCellClearAvail(cellDef)
CellDef *cellDef; /* Pointer to definition of cell we wish to
* mark as available.
*/
{
cellDef->cd_flags &= ~(CDNOTFOUND|CDAVAILABLE);
}
/*
* ----------------------------------------------------------------------------
*
* DBCellGetModified --
* DBCellSetModified --
*
* Get/set the CDMODIFIED status of a cell.
* DBCellGetModified returns TRUE if the cell has been modified, FALSE
* if not. DBCellSetModified marks the cell as having been modified
* if its argument is TRUE, and marks it as having been unmodified if
* its argument is FALSE.
*
* Results:
* DBCellGetModified: TRUE or FALSE.
* DBCellSetModified: None.
*
* Side effects:
* DBCellGetModified: None.
* DBCellSetModified: modifies cellDef->cd_flags.
*
* ----------------------------------------------------------------------------
*/
bool
DBCellGetModified(cellDef)
CellDef *cellDef; /* Pointer to definition of cell */
{
return ((cellDef->cd_flags & CDMODIFIED) != 0);
}
void
DBCellSetModified(cellDef, ismod)
CellDef *cellDef;
bool ismod; /* If TRUE, mark the cell as modified; if FALSE,
* mark it as unmodified.
*/
{
cellDef->cd_flags &= ~CDMODIFIED|CDGETNEWSTAMP;
if (ismod)
cellDef->cd_flags |= CDMODIFIED|CDGETNEWSTAMP;
}
/*
* ----------------------------------------------------------------------------
*
* DBComputeUseBbox --
*
* Compute the bounding box for a CellUse in coordinates of its parent.
*
* Results:
* None.
*
* Side effects:
* Sets cellUse->cu_bbox to be the bounding box for the indicated CellUse
* in coordinates of that CellUse's parent, and cellUse->cu_extended
* to the bounding box of the cell use including all rendered text labels.
*
* ----------------------------------------------------------------------------
*/
void
DBComputeUseBbox(use)
CellUse *use;
{
Rect *box, *extended;
Rect childRect, childExtend;
int xdelta, ydelta;
xdelta = use->cu_xsep * (use->cu_xhi - use->cu_xlo);
ydelta = use->cu_ysep * (use->cu_yhi - use->cu_ylo);
if (xdelta < 0) xdelta = (-xdelta);
if (ydelta < 0) ydelta = (-ydelta);
box = &(use->cu_def->cd_bbox);
extended = &(use->cu_def->cd_extended);
if (use->cu_xsep < 0)
{
childRect.r_xbot = box->r_xbot - xdelta;
childRect.r_xtop = box->r_xtop;
childExtend.r_xbot = extended->r_xbot - xdelta;
childExtend.r_xtop = extended->r_xtop;
}
else
{
childRect.r_xbot = box->r_xbot;
childRect.r_xtop = box->r_xtop + xdelta;
childExtend.r_xbot = extended->r_xbot;
childExtend.r_xtop = extended->r_xtop + xdelta;
}
if (use->cu_ysep < 0)
{
childRect.r_ybot = box->r_ybot - ydelta;
childRect.r_ytop = box->r_ytop;
childExtend.r_ybot = extended->r_ybot - ydelta;
childExtend.r_ytop = extended->r_ytop;
}
else
{
childRect.r_ybot = box->r_ybot;
childRect.r_ytop = box->r_ytop + ydelta;
childExtend.r_ybot = extended->r_ybot;
childExtend.r_ytop = extended->r_ytop + ydelta;
}
GeoTransRect(&use->cu_transform, &childRect, &use->cu_bbox);
GeoTransRect(&use->cu_transform, &childExtend, &use->cu_extended);
}
/*
* ----------------------------------------------------------------------------
*
* DBIsChild --
*
* Test to see if cu1 is a child of cu2.
*
* Results:
* TRUE if cu1 is a child of cu2, FALSE otherwise.
*
* Side effects:
* None.
*
* ----------------------------------------------------------------------------
*/
bool
DBIsChild(cu1, cu2)
CellUse *cu1, *cu2;
{
return (cu1->cu_parent == cu2->cu_def);
}
/*
* ----------------------------------------------------------------------------
*
* DBSetArray --
*
* Copy the array information from fromCellUse to toCellUse
*
* Results:
* None.
*
* Side Effects:
* The array information if toCellUse is modified.
*
* ----------------------------------------------------------------------------
*/
void
DBSetArray(fromCellUse, toCellUse)
CellUse *fromCellUse;
CellUse *toCellUse;
{
toCellUse->cu_xlo = fromCellUse->cu_xlo;
toCellUse->cu_ylo = fromCellUse->cu_ylo;
toCellUse->cu_xhi = fromCellUse->cu_xhi;
toCellUse->cu_yhi = fromCellUse->cu_yhi;
toCellUse->cu_xsep = fromCellUse->cu_xsep;
toCellUse->cu_ysep = fromCellUse->cu_ysep;
}
/*
* ----------------------------------------------------------------------------
*
* DBSetTrans --
*
* Change the transform for cellUse to that supplied.
*
* Results:
* None.
*
* Side Effects:
* Updates cellUse->cu_trans and cellUse->cu_bbox
*
* ----------------------------------------------------------------------------
*/
void
DBSetTrans(cellUse, trans)
CellUse *cellUse;
Transform *trans;
{
cellUse->cu_transform = *trans;
DBComputeUseBbox(cellUse);
}
/*
* ----------------------------------------------------------------------------
*
* DBMakeArray --
*
* Turn cellUse into an array whose X indices run from xlo through xhi
* and whose Y indices run from ylo through yhi. The separation between
* adjacent array elements is xsep in the X direction, and ysep in the
* Y direction.
*
* The X and Y information is in coordinates of the root cell def.
* It gets transformed down to the def of cellUse according to the
* transform supplied. What we do guarantee is that the array
* indices will appear, in root coordinates, to run from xlo to xhi
* left-to-right, and from ylo to yhi bottom-to-top.
*
* Results:
* None.
*
* Side Effects:
* The array information if toCellUse is modified.
*
* ----------------------------------------------------------------------------
*/
void
DBMakeArray(cellUse, rootToCell, xlo, ylo, xhi, yhi, xsep, ysep)
CellUse *cellUse;
Transform *rootToCell;
int xlo, ylo;
int xhi, yhi;
int xsep, ysep;
{
int t;
cellUse->cu_xsep = rootToCell->t_a * xsep + rootToCell->t_b * ysep;
cellUse->cu_ysep = rootToCell->t_d * xsep + rootToCell->t_e * ysep;
/*
* Now transform the indices.
* We should preserve the property that indices in root coordinates
* should appear to run from xlo through xhi, left-to-right, and
* from ylo through yhi, bottom-to-top.
*/
if (rootToCell->t_a == 0)
{
t = xlo; xlo = ylo; ylo = t;
t = xhi; xhi = yhi; yhi = t;
}
cellUse->cu_xlo = xlo;
cellUse->cu_ylo = ylo;
cellUse->cu_xhi = xhi;
cellUse->cu_yhi = yhi;
DBComputeUseBbox(cellUse);
}
/*
* ----------------------------------------------------------------------------
*
* DBArrayOverlap --
*
* Determine which elements of an array overlap the supplied clipping
* rectangle. Assumes that the clipping rectangle overlaps at least
* some part of the array area.
*
* Results:
* None.
*
* WARNING:
* This code is very sensitive to being changed. Make sure you
* understand it before you change it.
*
* Side Effects:
* Sets *pxlo, *pxhi, *pylo, *pyhi to be the inclusive range of array
* indices which overlay the given clipping rectangle.
*
* If there is any overlap in X, *pxlo <= *pxhi; similarly, if there
* is any overlap in Y, *pylo <= *pyhi.
*
* ----------------------------------------------------------------------------
*/
void
DBArrayOverlap(cu, parentRect, pxlo, pxhi, pylo, pyhi)
CellUse *cu; /* Pointer to cell use which may be an array */
Rect *parentRect; /* Clipping rectangle cu->cu_parent coords */
int *pxlo, *pxhi;
int *pylo, *pyhi;
{
int outxlo, outxhi, outylo, outyhi, t;
int xlo, ylo, xhi, yhi, xsep, ysep;
Transform parentToCell;
Rect box, childR;
/* For a non-arrayed element, return the indices of the only element */
if (cu->cu_xlo == cu->cu_xhi && cu->cu_ylo == cu->cu_yhi)
{
*pxlo = *pxhi = cu->cu_xlo;
*pylo = *pyhi = cu->cu_ylo;
return;
}
box = cu->cu_def->cd_bbox;
GEOINVERTTRANS(&cu->cu_transform, &parentToCell);
GEOTRANSRECT(&parentToCell, parentRect, &childR);
xsep = cu->cu_xsep;
ysep = cu->cu_ysep;
/*
* Canonicalize the array indices so that the base element
* of the array has the minimum x and y coordinate, ie,
* so that xlo <= xhi and ylo <= yhi.
*/
if (cu->cu_xlo > cu->cu_xhi) xlo = cu->cu_xhi, xhi = cu->cu_xlo;
else xlo = cu->cu_xlo, xhi = cu->cu_xhi;
if (cu->cu_ylo > cu->cu_yhi) ylo = cu->cu_yhi, yhi = cu->cu_ylo;
else ylo = cu->cu_ylo, yhi = cu->cu_yhi;
/*
* If the separation along one of the coordinate axes is negative,
* flip everything about that axis.
*/
if (xsep < 0)
{
xsep = (-xsep);
t = childR.r_xbot; childR.r_xbot = -childR.r_xtop; childR.r_xtop = -t;
t = box.r_xbot; box.r_xbot = -box.r_xtop; box.r_xtop = -t;
}
if (ysep < 0)
{
ysep = (-ysep);
t = childR.r_ybot; childR.r_ybot = -childR.r_ytop; childR.r_ytop = -t;
t = box.r_ybot; box.r_ybot = -box.r_ytop; box.r_ytop = -t;
}
/*
* The following inequalities are used to derive the equations
* computed below. "Blo" is the lower coordinate of the incident
* box, and "Bhi" is the upper coordinate.
*
* min outlo : (outlo - lo) * sep + top >= Blo
* max outhi : (outhi - lo) * sep + bot <= Bhi
*
* The intent is that "outlo" will be the smaller of the two
* coordinates, and "outhi" the larger.
*/
/* Even though it should never happen, handle zero spacings
* gracefully.
*/
if (xsep != 0)
{
outxlo = xlo + (childR.r_xbot - box.r_xtop + xsep - 1) / xsep;
outxhi = xlo + (childR.r_xtop - box.r_xbot) / xsep;
}
else
{
outxlo = xlo;
outxhi = xhi;
}
if (ysep != 0)
{
outylo = ylo + (childR.r_ybot - box.r_ytop + ysep - 1) / ysep;
outyhi = ylo + (childR.r_ytop - box.r_ybot) / ysep;
}
else
{
outylo = ylo;
outyhi = yhi;
}
/*
* Clip against the canonicalized array indices.
* Note that this may result in rxlo > rxhi or rylo > ryhi, in which
* case the rectangle doesn't intersect the array at all.
*/
if (outxlo < xlo) outxlo = xlo;
if (outxhi > xhi) outxhi = xhi;
if (outylo < ylo) outylo = ylo;
if (outyhi > yhi) outyhi = yhi;
/*
* Convert canonicalized array indices back into actual
* array indices for output.
*/
if (cu->cu_xlo > cu->cu_xhi)
{
*pxhi = cu->cu_xhi + cu->cu_xlo - outxlo;
*pxlo = cu->cu_xhi + cu->cu_xlo - outxhi;
}
else
{
*pxlo = outxlo;
*pxhi = outxhi;
}
if (cu->cu_ylo > cu->cu_yhi)
{
*pyhi = cu->cu_yhi + cu->cu_ylo - outylo;
*pylo = cu->cu_yhi + cu->cu_ylo - outyhi;
}
else
{
*pylo = outylo;
*pyhi = outyhi;
}
}
/*
* ----------------------------------------------------------------------------
*
* DBReComputeBbox --
* DBReComputeBboxVert --
*
* Propagate changes to bounding boxes.
* The former is the default procedure; the latter should be used
* when the tile planes of a cell are organized into maximal vertical
* strips instead of maximal horizontal.
*
* Results:
* None.
*
* Side Effects:
* These procedures re-examine cellDef to see if its bounding box
* has gotten larger or smaller. If so, the bounding box is
* modified, and the change is reflected upwards in the
* hierarchy to parents of cellDef. This occurs recursively
* until the top of the hierarchy is reached.
*
* Also modifies the CellUse bounding boxes of parents as
* appropriate (cu_bbox).
*
* WARNING
*
* In order to preserve consistency, if it is discovered that a
* cell contains no material of any kind, its bounding box is
* set to a default of (0,0) :: (1,1). If the cell contains
* labels but still has a zero-size bounding box, then the bounding
* box is enlarged by one unit to give it non-zero area.
*
* ----------------------------------------------------------------------------
*/
void dbReComputeBboxFunc();
void
DBReComputeBbox(cellDef)
CellDef *cellDef; /* Cell def whose bounding box may have changed */
{
extern bool DBBoundPlane();
dbReComputeBboxFunc(cellDef, DBBoundPlane, DBReComputeBbox);
}
void
DBReComputeBboxVert(cellDef)
CellDef *cellDef; /* Cell def whose bounding box may have changed */
{
extern bool DBBoundPlaneVert();
dbReComputeBboxFunc(cellDef, DBBoundPlaneVert, DBReComputeBboxVert);
}
void
dbReComputeBboxFunc(cellDef, boundProc, recurseProc)
CellDef *cellDef; /* Cell def whose bounding box may have changed */
bool (*boundProc)();
void (*recurseProc)();
{
bool degenerate;
Rect rect, area, extended, *box;
Rect redisplayArea;
CellUse *use;
CellDef *parent, *last;
Label *label;
bool foundAny;
int pNum;
/*
* Include area of subcells separately
*/
if (!((foundAny = DBBoundCellPlane(cellDef, &extended, &rect)) > 0))
extended = GeoNullRect;
area = rect;
for (pNum = PL_PAINTBASE; pNum < DBNumPlanes; pNum++)
if (pNum != PL_DRC_CHECK)
if ((*boundProc)(cellDef->cd_planes[pNum], &rect))
{
if (foundAny)
(void) GeoInclude(&rect, &area);
else
area = rect;
foundAny = TRUE;
}
/*
* Include the area of label anchors, too.
*/
for (label = cellDef->cd_labels; label != NULL; label = label->lab_next)
{
if (foundAny)
{
if (label->lab_rect.r_xbot < area.r_xbot)
area.r_xbot = label->lab_rect.r_xbot;
if (label->lab_rect.r_ybot < area.r_ybot)
area.r_ybot = label->lab_rect.r_ybot;
if (label->lab_rect.r_xtop > area.r_xtop)
area.r_xtop = label->lab_rect.r_xtop;
if (label->lab_rect.r_ytop > area.r_ytop)
area.r_ytop = label->lab_rect.r_ytop;
}
else
{
area = label->lab_rect;
foundAny = TRUE;
}
}
/* Make sure the extended bounding box includes the area of all
* paint material just found, then include the area of all text
* in the current cell.
*/
GeoInclude(&area, &extended);
if (foundAny)
{
for (label = cellDef->cd_labels; label != NULL; label = label->lab_next)
if (label->lab_font >= 0)
GeoInclude(&label->lab_bbox, &extended);
}
/*
* If there is nothing at all, produce a 1x1 box with its
* lower left corner at the origin.
*/
if (!foundAny)
{
degenerate = TRUE;
area.r_xbot = area.r_ybot = 0;
area.r_xtop = area.r_ytop = 1;
extended = area;
}
else degenerate = FALSE;
/*
* Canonicalize degeneracy in all other directions by
* expanding the box by one unit in the degenerate
* direction.
*/
if (area.r_xbot == area.r_xtop)
area.r_xtop = area.r_xbot + 1;
if (area.r_ybot == area.r_ytop)
area.r_ytop = area.r_ybot + 1;
if (extended.r_xbot == extended.r_xtop)
extended.r_xtop = extended.r_xbot + 1;
if (extended.r_ybot == extended.r_ytop)
extended.r_ytop = extended.r_ybot + 1;
/* Did the bounding box change? If not then there's no need to
* recompute the parents. If the cell has no material, then
* we must always propagate upwards. This is because DBClearCellDef
* sets the bounding box to the degenerate size WITHOUT propagating
* (it isn't safe for DBClearCellDef to propagate). At this point
* the propagation must be done.
*/
box = &cellDef->cd_extended;
if ((area.r_xbot == box->r_xbot && area.r_ybot == box->r_ybot
&& area.r_xtop == box->r_xtop && area.r_ytop == box->r_ytop)
&& !degenerate)
return;
/*
* Alas, the cell's bounding box has actually changed. Thus
* we must recompute the areas of all the parents of this
* cell recursively. We must rip up the child cell and place
* it down again to insure that the subcell tile planes in the
* parents are all correct.
*
* The undo package is disabled around this since it will already
* insure that DBReComputeBbox will be called at the appropriate
* times.
*/
UndoDisable();
for (use = cellDef->cd_parents; use != NULL; use = use->cu_nextuse)
if (use->cu_parent != (CellDef *) NULL)
{
/* DBDeleteCell trashes the parent pointer, but we restore
* it so we'll know where to put the cell back later.
*/
parent = use->cu_parent;
DBDeleteCellNoModify(use);
use->cu_parent = parent;
}
cellDef->cd_bbox = area;
cellDef->cd_extended = extended;
/*
* Relink each of the uses into the subcell tile planes
* of their respective parents. Also, redisplay the use
* in each parent, in each window where the cell isn't
* expanded (i.e. the bounding box is no longer correct).
*
* Because more than one cell may be in an array, avoid
* running recurseProc more than once on the same parent.
* The simple way is just wait until the parent cell changes
* to run the process, although this could be done more
* thoroughly.
*/
last = NULL;
for (use = cellDef->cd_parents; use != NULL; use = use->cu_nextuse)
{
redisplayArea = use->cu_extended;
DBComputeUseBbox(use);
if ((parent = use->cu_parent) != (CellDef *) NULL)
{
parent->cd_flags |= CDBOXESCHANGED;
DBPlaceCellNoModify(use, parent);
if (last != parent)
{
if (last != NULL) (*recurseProc)(last);
last = parent;
}
(void) GeoInclude(&use->cu_extended, &redisplayArea);
DBWAreaChanged(parent, &redisplayArea, (int) ~use->cu_expandMask,
&DBAllButSpaceBits);
}
}
if ((last != NULL) && (parent != NULL)) (*recurseProc)(parent);
UndoEnable();
}
/*
* ----------------------------------------------------------------------------
*
* DBComputeArrayArea --
*
* Given an area in native coordinates of a celldef, computes the
* corresponding area in a parent's coordinates, for a particular
* celluse and a particular element of an array.
*
* Results:
* None.
*
* Side Effects:
* Sets *prect to the given area in the given array instance,
* subject to the arraying and transformation inforamtion in
* the given cellUse.
*
* ----------------------------------------------------------------------------
*/
void
DBComputeArrayArea(area, cellUse, x, y, prect)
Rect *area; /* Area to be transformed. */
CellUse *cellUse; /* Cell use whose bounding box is to be computed */
int x, y; /* Indexes of array element whose box is being found */
Rect *prect; /* Pointer to rectangle to be set to bounding
* box of the given array element, in coordinates
* of the def of cellUse.
*/
{
int xdelta, ydelta;
if (cellUse->cu_xlo > cellUse->cu_xhi) x = cellUse->cu_xlo - x;
else x = x - cellUse->cu_xlo;
if (cellUse->cu_ylo > cellUse->cu_yhi) y = cellUse->cu_ylo - y;
else y = y - cellUse->cu_ylo;
xdelta = cellUse->cu_xsep * x;
ydelta = cellUse->cu_ysep * y;
prect->r_xbot = area->r_xbot + xdelta;
prect->r_xtop = area->r_xtop + xdelta;
prect->r_ybot = area->r_ybot + ydelta;
prect->r_ytop = area->r_ytop + ydelta;
}
/*
* ----------------------------------------------------------------------------
*
* DBGetArrayTransform --
*
* This procedure computes the transform from a particular element
* of an array to the coordinates of the array as a whole.
*
* Results:
* The return result is a pointer to a transform describing how
* coordinates of use->cu_def must be transformed in order to
* appear in the (x,y) element location. In other words, if the
* transform for the whole array (use->cu_transform) were
* GeoIdentityTransform, this is the transform from use->cu_def
* to the parent use for the (x,y) element. By the way, the
* return result is a locally-allocated transform that goes away
* the next time this procedure is called, so use it carefully.
*
* Side effects:
* None.
*
* ----------------------------------------------------------------------------
*/
Transform *
DBGetArrayTransform(use, x, y)
CellUse *use;
int x, y; /* Array indices of the desired element.
* These must fall within the range of
* use's array indices.
*/
{
static Transform result;
int xsep, ysep, xbase, ybase;
if (use->cu_xlo > use->cu_xhi) xsep = -use->cu_xsep;
else xsep = use->cu_xsep;
if (use->cu_ylo > use->cu_yhi) ysep = -use->cu_ysep;
else ysep = use->cu_ysep;
xbase = xsep * (x - use->cu_xlo);
ybase = ysep * (y - use->cu_ylo);
GeoTransTranslate(xbase, ybase, &GeoIdentityTransform, &result);
return &result;
}