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Diffstat (limited to 'xorg-server/dix/region.c')
| -rw-r--r-- | xorg-server/dix/region.c | 1659 |
1 files changed, 1659 insertions, 0 deletions
diff --git a/xorg-server/dix/region.c b/xorg-server/dix/region.c new file mode 100644 index 000000000..c0add6ca9 --- /dev/null +++ b/xorg-server/dix/region.c @@ -0,0 +1,1659 @@ +/***********************************************************
+
+Copyright 1987, 1988, 1989, 1998 The Open Group
+
+Permission to use, copy, modify, distribute, and sell this software and its
+documentation for any purpose is hereby granted without fee, provided that
+the above copyright notice appear in all copies and that both that
+copyright notice and this permission notice appear in supporting
+documentation.
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+Except as contained in this notice, the name of The Open Group shall not be
+used in advertising or otherwise to promote the sale, use or other dealings
+in this Software without prior written authorization from The Open Group.
+
+
+Copyright 1987, 1988, 1989 by
+Digital Equipment Corporation, Maynard, Massachusetts.
+
+ All Rights Reserved
+
+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 and that
+both that copyright notice and this permission notice appear in
+supporting documentation, and that the name of Digital not be
+used in advertising or publicity pertaining to distribution of the
+software without specific, written prior permission.
+
+DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
+ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
+DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
+ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+SOFTWARE.
+
+******************************************************************/
+
+/* The panoramix components contained the following notice */
+/*****************************************************************
+
+Copyright (c) 1991, 1997 Digital Equipment Corporation, Maynard, Massachusetts.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software.
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+DIGITAL EQUIPMENT CORPORATION BE LIABLE FOR ANY CLAIM, DAMAGES, INCLUDING,
+BUT NOT LIMITED TO CONSEQUENTIAL OR INCIDENTAL DAMAGES, OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+Except as contained in this notice, the name of Digital Equipment Corporation
+shall not be used in advertising or otherwise to promote the sale, use or other
+dealings in this Software without prior written authorization from Digital
+Equipment Corporation.
+
+******************************************************************/
+
+#ifdef HAVE_DIX_CONFIG_H
+#include <dix-config.h>
+#endif
+
+#include "regionstr.h"
+#include <X11/Xprotostr.h>
+#include <X11/Xfuncproto.h>
+#include "gc.h"
+#include <pixman.h>
+
+#undef assert
+#ifdef REGION_DEBUG
+#define assert(expr) { \
+ CARD32 *foo = NULL; \
+ if (!(expr)) { \
+ ErrorF("Assertion failed file %s, line %d: %s\n", \
+ __FILE__, __LINE__, #expr); \
+ *foo = 0xdeadbeef; /* to get a backtrace */ \
+ } \
+ }
+#else
+#define assert(expr)
+#endif
+
+#define good(reg) assert(RegionIsValid(reg))
+
+/*
+ * The functions in this file implement the Region abstraction used extensively
+ * throughout the X11 sample server. A Region is simply a set of disjoint
+ * (non-overlapping) rectangles, plus an "extent" rectangle which is the
+ * smallest single rectangle that contains all the non-overlapping rectangles.
+ *
+ * A Region is implemented as a "y-x-banded" array of rectangles. This array
+ * imposes two degrees of order. First, all rectangles are sorted by top side
+ * y coordinate first (y1), and then by left side x coordinate (x1).
+ *
+ * Furthermore, the rectangles are grouped into "bands". Each rectangle in a
+ * band has the same top y coordinate (y1), and each has the same bottom y
+ * coordinate (y2). Thus all rectangles in a band differ only in their left
+ * and right side (x1 and x2). Bands are implicit in the array of rectangles:
+ * there is no separate list of band start pointers.
+ *
+ * The y-x band representation does not minimize rectangles. In particular,
+ * if a rectangle vertically crosses a band (the rectangle has scanlines in
+ * the y1 to y2 area spanned by the band), then the rectangle may be broken
+ * down into two or more smaller rectangles stacked one atop the other.
+ *
+ * ----------- -----------
+ * | | | | band 0
+ * | | -------- ----------- --------
+ * | | | | in y-x banded | | | | band 1
+ * | | | | form is | | | |
+ * ----------- | | ----------- --------
+ * | | | | band 2
+ * -------- --------
+ *
+ * An added constraint on the rectangles is that they must cover as much
+ * horizontal area as possible: no two rectangles within a band are allowed
+ * to touch.
+ *
+ * Whenever possible, bands will be merged together to cover a greater vertical
+ * distance (and thus reduce the number of rectangles). Two bands can be merged
+ * only if the bottom of one touches the top of the other and they have
+ * rectangles in the same places (of the same width, of course).
+ *
+ * Adam de Boor wrote most of the original region code. Joel McCormack
+ * substantially modified or rewrote most of the core arithmetic routines,
+ * and added RegionValidate in order to support several speed improvements
+ * to miValidateTree. Bob Scheifler changed the representation to be more
+ * compact when empty or a single rectangle, and did a bunch of gratuitous
+ * reformatting.
+ */
+
+/* true iff two Boxes overlap */
+#define EXTENTCHECK(r1,r2) \
+ (!( ((r1)->x2 <= (r2)->x1) || \
+ ((r1)->x1 >= (r2)->x2) || \
+ ((r1)->y2 <= (r2)->y1) || \
+ ((r1)->y1 >= (r2)->y2) ) )
+
+/* true iff (x,y) is in Box */
+#define INBOX(r,x,y) \
+ ( ((r)->x2 > x) && \
+ ((r)->x1 <= x) && \
+ ((r)->y2 > y) && \
+ ((r)->y1 <= y) )
+
+/* true iff Box r1 contains Box r2 */
+#define SUBSUMES(r1,r2) \
+ ( ((r1)->x1 <= (r2)->x1) && \
+ ((r1)->x2 >= (r2)->x2) && \
+ ((r1)->y1 <= (r2)->y1) && \
+ ((r1)->y2 >= (r2)->y2) )
+
+#define xallocData(n) malloc(RegionSizeof(n))
+#define xfreeData(reg) if ((reg)->data && (reg)->data->size) free((reg)->data)
+
+#define RECTALLOC_BAIL(pReg,n,bail) \
+if (!(pReg)->data || (((pReg)->data->numRects + (n)) > (pReg)->data->size)) \
+ if (!RegionRectAlloc(pReg, n)) { goto bail; }
+
+#define RECTALLOC(pReg,n) \
+if (!(pReg)->data || (((pReg)->data->numRects + (n)) > (pReg)->data->size)) \
+ if (!RegionRectAlloc(pReg, n)) { return FALSE; }
+
+#define ADDRECT(pNextRect,nx1,ny1,nx2,ny2) \
+{ \
+ pNextRect->x1 = nx1; \
+ pNextRect->y1 = ny1; \
+ pNextRect->x2 = nx2; \
+ pNextRect->y2 = ny2; \
+ pNextRect++; \
+}
+
+#define NEWRECT(pReg,pNextRect,nx1,ny1,nx2,ny2) \
+{ \
+ if (!(pReg)->data || ((pReg)->data->numRects == (pReg)->data->size))\
+ { \
+ if (!RegionRectAlloc(pReg, 1)) \
+ return FALSE; \
+ pNextRect = RegionTop(pReg); \
+ } \
+ ADDRECT(pNextRect,nx1,ny1,nx2,ny2); \
+ pReg->data->numRects++; \
+ assert(pReg->data->numRects<=pReg->data->size); \
+}
+
+
+#define DOWNSIZE(reg,numRects) \
+if (((numRects) < ((reg)->data->size >> 1)) && ((reg)->data->size > 50)) \
+{ \
+ RegDataPtr NewData; \
+ NewData = (RegDataPtr)realloc((reg)->data, RegionSizeof(numRects)); \
+ if (NewData) \
+ { \
+ NewData->size = (numRects); \
+ (reg)->data = NewData; \
+ } \
+}
+
+
+BoxRec RegionEmptyBox = {0, 0, 0, 0};
+RegDataRec RegionEmptyData = {0, 0};
+
+RegDataRec RegionBrokenData = {0, 0};
+static RegionRec RegionBrokenRegion = { { 0, 0, 0, 0 }, &RegionBrokenData };
+
+void
+InitRegions (void)
+{
+ pixman_region_set_static_pointers (&RegionEmptyBox, &RegionEmptyData, &RegionBrokenData);
+}
+
+/*****************************************************************
+ * RegionCreate(rect, size)
+ * This routine does a simple malloc to make a structure of
+ * REGION of "size" number of rectangles.
+ *****************************************************************/
+
+RegionPtr
+RegionCreate(BoxPtr rect, int size)
+{
+ RegionPtr pReg;
+
+ pReg = (RegionPtr)malloc(sizeof(RegionRec));
+ if (!pReg)
+ return &RegionBrokenRegion;
+
+ RegionInit (pReg, rect, size);
+
+ return pReg;
+}
+
+void
+RegionDestroy(RegionPtr pReg)
+{
+ pixman_region_fini (pReg);
+ if (pReg != &RegionBrokenRegion)
+ free(pReg);
+}
+
+void
+RegionPrint(RegionPtr rgn)
+{
+ int num, size;
+ int i;
+ BoxPtr rects;
+
+ num = RegionNumRects(rgn);
+ size = RegionSize(rgn);
+ rects = RegionRects(rgn);
+ ErrorF("[mi] num: %d size: %d\n", num, size);
+ ErrorF("[mi] extents: %d %d %d %d\n",
+ rgn->extents.x1, rgn->extents.y1, rgn->extents.x2, rgn->extents.y2);
+ for (i = 0; i < num; i++)
+ ErrorF("[mi] %d %d %d %d \n",
+ rects[i].x1, rects[i].y1, rects[i].x2, rects[i].y2);
+ ErrorF("[mi] \n");
+}
+
+#ifdef DEBUG
+Bool
+RegionIsValid(RegionPtr reg)
+{
+ int i, numRects;
+
+ if ((reg->extents.x1 > reg->extents.x2) ||
+ (reg->extents.y1 > reg->extents.y2))
+ return FALSE;
+ numRects = RegionNumRects(reg);
+ if (!numRects)
+ return ((reg->extents.x1 == reg->extents.x2) &&
+ (reg->extents.y1 == reg->extents.y2) &&
+ (reg->data->size || (reg->data == &RegionEmptyData)));
+ else if (numRects == 1)
+ return !reg->data;
+ else
+ {
+ BoxPtr pboxP, pboxN;
+ BoxRec box;
+
+ pboxP = RegionRects(reg);
+ box = *pboxP;
+ box.y2 = pboxP[numRects-1].y2;
+ pboxN = pboxP + 1;
+ for (i = numRects; --i > 0; pboxP++, pboxN++)
+ {
+ if ((pboxN->x1 >= pboxN->x2) ||
+ (pboxN->y1 >= pboxN->y2))
+ return FALSE;
+ if (pboxN->x1 < box.x1)
+ box.x1 = pboxN->x1;
+ if (pboxN->x2 > box.x2)
+ box.x2 = pboxN->x2;
+ if ((pboxN->y1 < pboxP->y1) ||
+ ((pboxN->y1 == pboxP->y1) &&
+ ((pboxN->x1 < pboxP->x2) || (pboxN->y2 != pboxP->y2))))
+ return FALSE;
+ }
+ return ((box.x1 == reg->extents.x1) &&
+ (box.x2 == reg->extents.x2) &&
+ (box.y1 == reg->extents.y1) &&
+ (box.y2 == reg->extents.y2));
+ }
+}
+#endif /* DEBUG */
+
+Bool
+RegionBreak (RegionPtr pReg)
+{
+ xfreeData (pReg);
+ pReg->extents = RegionEmptyBox;
+ pReg->data = &RegionBrokenData;
+ return FALSE;
+}
+
+Bool
+RegionRectAlloc(RegionPtr pRgn, int n)
+{
+ RegDataPtr data;
+
+ if (!pRgn->data)
+ {
+ n++;
+ pRgn->data = xallocData(n);
+ if (!pRgn->data)
+ return RegionBreak (pRgn);
+ pRgn->data->numRects = 1;
+ *RegionBoxptr(pRgn) = pRgn->extents;
+ }
+ else if (!pRgn->data->size)
+ {
+ pRgn->data = xallocData(n);
+ if (!pRgn->data)
+ return RegionBreak (pRgn);
+ pRgn->data->numRects = 0;
+ }
+ else
+ {
+ if (n == 1)
+ {
+ n = pRgn->data->numRects;
+ if (n > 500) /* XXX pick numbers out of a hat */
+ n = 250;
+ }
+ n += pRgn->data->numRects;
+ data = (RegDataPtr)realloc(pRgn->data, RegionSizeof(n));
+ if (!data)
+ return RegionBreak (pRgn);
+ pRgn->data = data;
+ }
+ pRgn->data->size = n;
+ return TRUE;
+}
+
+/*======================================================================
+ * Generic Region Operator
+ *====================================================================*/
+
+/*-
+ *-----------------------------------------------------------------------
+ * RegionCoalesce --
+ * Attempt to merge the boxes in the current band with those in the
+ * previous one. We are guaranteed that the current band extends to
+ * the end of the rects array. Used only by RegionOp.
+ *
+ * Results:
+ * The new index for the previous band.
+ *
+ * Side Effects:
+ * If coalescing takes place:
+ * - rectangles in the previous band will have their y2 fields
+ * altered.
+ * - pReg->data->numRects will be decreased.
+ *
+ *-----------------------------------------------------------------------
+ */
+_X_INLINE static int
+RegionCoalesce (
+ RegionPtr pReg, /* Region to coalesce */
+ int prevStart, /* Index of start of previous band */
+ int curStart) /* Index of start of current band */
+{
+ BoxPtr pPrevBox; /* Current box in previous band */
+ BoxPtr pCurBox; /* Current box in current band */
+ int numRects; /* Number rectangles in both bands */
+ int y2; /* Bottom of current band */
+ /*
+ * Figure out how many rectangles are in the band.
+ */
+ numRects = curStart - prevStart;
+ assert(numRects == pReg->data->numRects - curStart);
+
+ if (!numRects) return curStart;
+
+ /*
+ * The bands may only be coalesced if the bottom of the previous
+ * matches the top scanline of the current.
+ */
+ pPrevBox = RegionBox(pReg, prevStart);
+ pCurBox = RegionBox(pReg, curStart);
+ if (pPrevBox->y2 != pCurBox->y1) return curStart;
+
+ /*
+ * Make sure the bands have boxes in the same places. This
+ * assumes that boxes have been added in such a way that they
+ * cover the most area possible. I.e. two boxes in a band must
+ * have some horizontal space between them.
+ */
+ y2 = pCurBox->y2;
+
+ do {
+ if ((pPrevBox->x1 != pCurBox->x1) || (pPrevBox->x2 != pCurBox->x2)) {
+ return curStart;
+ }
+ pPrevBox++;
+ pCurBox++;
+ numRects--;
+ } while (numRects);
+
+ /*
+ * The bands may be merged, so set the bottom y of each box
+ * in the previous band to the bottom y of the current band.
+ */
+ numRects = curStart - prevStart;
+ pReg->data->numRects -= numRects;
+ do {
+ pPrevBox--;
+ pPrevBox->y2 = y2;
+ numRects--;
+ } while (numRects);
+ return prevStart;
+}
+
+
+/* Quicky macro to avoid trivial reject procedure calls to RegionCoalesce */
+
+#define Coalesce(newReg, prevBand, curBand) \
+ if (curBand - prevBand == newReg->data->numRects - curBand) { \
+ prevBand = RegionCoalesce(newReg, prevBand, curBand); \
+ } else { \
+ prevBand = curBand; \
+ }
+
+/*-
+ *-----------------------------------------------------------------------
+ * RegionAppendNonO --
+ * Handle a non-overlapping band for the union and subtract operations.
+ * Just adds the (top/bottom-clipped) rectangles into the region.
+ * Doesn't have to check for subsumption or anything.
+ *
+ * Results:
+ * None.
+ *
+ * Side Effects:
+ * pReg->data->numRects is incremented and the rectangles overwritten
+ * with the rectangles we're passed.
+ *
+ *-----------------------------------------------------------------------
+ */
+
+_X_INLINE static Bool
+RegionAppendNonO (
+ RegionPtr pReg,
+ BoxPtr r,
+ BoxPtr rEnd,
+ int y1,
+ int y2)
+{
+ BoxPtr pNextRect;
+ int newRects;
+
+ newRects = rEnd - r;
+
+ assert(y1 < y2);
+ assert(newRects != 0);
+
+ /* Make sure we have enough space for all rectangles to be added */
+ RECTALLOC(pReg, newRects);
+ pNextRect = RegionTop(pReg);
+ pReg->data->numRects += newRects;
+ do {
+ assert(r->x1 < r->x2);
+ ADDRECT(pNextRect, r->x1, y1, r->x2, y2);
+ r++;
+ } while (r != rEnd);
+
+ return TRUE;
+}
+
+#define FindBand(r, rBandEnd, rEnd, ry1) \
+{ \
+ ry1 = r->y1; \
+ rBandEnd = r+1; \
+ while ((rBandEnd != rEnd) && (rBandEnd->y1 == ry1)) { \
+ rBandEnd++; \
+ } \
+}
+
+#define AppendRegions(newReg, r, rEnd) \
+{ \
+ int newRects; \
+ if ((newRects = rEnd - r)) { \
+ RECTALLOC(newReg, newRects); \
+ memmove((char *)RegionTop(newReg),(char *)r, \
+ newRects * sizeof(BoxRec)); \
+ newReg->data->numRects += newRects; \
+ } \
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * RegionOp --
+ * Apply an operation to two regions. Called by RegionUnion, RegionInverse,
+ * RegionSubtract, RegionIntersect.... Both regions MUST have at least one
+ * rectangle, and cannot be the same object.
+ *
+ * Results:
+ * TRUE if successful.
+ *
+ * Side Effects:
+ * The new region is overwritten.
+ * pOverlap set to TRUE if overlapFunc ever returns TRUE.
+ *
+ * Notes:
+ * The idea behind this function is to view the two regions as sets.
+ * Together they cover a rectangle of area that this function divides
+ * into horizontal bands where points are covered only by one region
+ * or by both. For the first case, the nonOverlapFunc is called with
+ * each the band and the band's upper and lower extents. For the
+ * second, the overlapFunc is called to process the entire band. It
+ * is responsible for clipping the rectangles in the band, though
+ * this function provides the boundaries.
+ * At the end of each band, the new region is coalesced, if possible,
+ * to reduce the number of rectangles in the region.
+ *
+ *-----------------------------------------------------------------------
+ */
+
+typedef Bool (*OverlapProcPtr)(
+ RegionPtr pReg,
+ BoxPtr r1,
+ BoxPtr r1End,
+ BoxPtr r2,
+ BoxPtr r2End,
+ short y1,
+ short y2,
+ Bool *pOverlap);
+
+static Bool
+RegionOp(
+ RegionPtr newReg, /* Place to store result */
+ RegionPtr reg1, /* First region in operation */
+ RegionPtr reg2, /* 2d region in operation */
+ OverlapProcPtr overlapFunc, /* Function to call for over-
+ * lapping bands */
+ Bool appendNon1, /* Append non-overlapping bands */
+ /* in region 1 ? */
+ Bool appendNon2, /* Append non-overlapping bands */
+ /* in region 2 ? */
+ Bool *pOverlap)
+{
+ BoxPtr r1; /* Pointer into first region */
+ BoxPtr r2; /* Pointer into 2d region */
+ BoxPtr r1End; /* End of 1st region */
+ BoxPtr r2End; /* End of 2d region */
+ short ybot; /* Bottom of intersection */
+ short ytop; /* Top of intersection */
+ RegDataPtr oldData; /* Old data for newReg */
+ int prevBand; /* Index of start of
+ * previous band in newReg */
+ int curBand; /* Index of start of current
+ * band in newReg */
+ BoxPtr r1BandEnd; /* End of current band in r1 */
+ BoxPtr r2BandEnd; /* End of current band in r2 */
+ short top; /* Top of non-overlapping band */
+ short bot; /* Bottom of non-overlapping band*/
+ int r1y1; /* Temps for r1->y1 and r2->y1 */
+ int r2y1;
+ int newSize;
+ int numRects;
+
+ /*
+ * Break any region computed from a broken region
+ */
+ if (RegionNar (reg1) || RegionNar(reg2))
+ return RegionBreak (newReg);
+
+ /*
+ * Initialization:
+ * set r1, r2, r1End and r2End appropriately, save the rectangles
+ * of the destination region until the end in case it's one of
+ * the two source regions, then mark the "new" region empty, allocating
+ * another array of rectangles for it to use.
+ */
+
+ r1 = RegionRects(reg1);
+ newSize = RegionNumRects(reg1);
+ r1End = r1 + newSize;
+ numRects = RegionNumRects(reg2);
+ r2 = RegionRects(reg2);
+ r2End = r2 + numRects;
+ assert(r1 != r1End);
+ assert(r2 != r2End);
+
+ oldData = NULL;
+ if (((newReg == reg1) && (newSize > 1)) ||
+ ((newReg == reg2) && (numRects > 1)))
+ {
+ oldData = newReg->data;
+ newReg->data = &RegionEmptyData;
+ }
+ /* guess at new size */
+ if (numRects > newSize)
+ newSize = numRects;
+ newSize <<= 1;
+ if (!newReg->data)
+ newReg->data = &RegionEmptyData;
+ else if (newReg->data->size)
+ newReg->data->numRects = 0;
+ if (newSize > newReg->data->size)
+ if (!RegionRectAlloc(newReg, newSize))
+ return FALSE;
+
+ /*
+ * Initialize ybot.
+ * In the upcoming loop, ybot and ytop serve different functions depending
+ * on whether the band being handled is an overlapping or non-overlapping
+ * band.
+ * In the case of a non-overlapping band (only one of the regions
+ * has points in the band), ybot is the bottom of the most recent
+ * intersection and thus clips the top of the rectangles in that band.
+ * ytop is the top of the next intersection between the two regions and
+ * serves to clip the bottom of the rectangles in the current band.
+ * For an overlapping band (where the two regions intersect), ytop clips
+ * the top of the rectangles of both regions and ybot clips the bottoms.
+ */
+
+ ybot = min(r1->y1, r2->y1);
+
+ /*
+ * prevBand serves to mark the start of the previous band so rectangles
+ * can be coalesced into larger rectangles. qv. RegionCoalesce, above.
+ * In the beginning, there is no previous band, so prevBand == curBand
+ * (curBand is set later on, of course, but the first band will always
+ * start at index 0). prevBand and curBand must be indices because of
+ * the possible expansion, and resultant moving, of the new region's
+ * array of rectangles.
+ */
+ prevBand = 0;
+
+ do {
+ /*
+ * This algorithm proceeds one source-band (as opposed to a
+ * destination band, which is determined by where the two regions
+ * intersect) at a time. r1BandEnd and r2BandEnd serve to mark the
+ * rectangle after the last one in the current band for their
+ * respective regions.
+ */
+ assert(r1 != r1End);
+ assert(r2 != r2End);
+
+ FindBand(r1, r1BandEnd, r1End, r1y1);
+ FindBand(r2, r2BandEnd, r2End, r2y1);
+
+ /*
+ * First handle the band that doesn't intersect, if any.
+ *
+ * Note that attention is restricted to one band in the
+ * non-intersecting region at once, so if a region has n
+ * bands between the current position and the next place it overlaps
+ * the other, this entire loop will be passed through n times.
+ */
+ if (r1y1 < r2y1) {
+ if (appendNon1) {
+ top = max(r1y1, ybot);
+ bot = min(r1->y2, r2y1);
+ if (top != bot) {
+ curBand = newReg->data->numRects;
+ RegionAppendNonO(newReg, r1, r1BandEnd, top, bot);
+ Coalesce(newReg, prevBand, curBand);
+ }
+ }
+ ytop = r2y1;
+ } else if (r2y1 < r1y1) {
+ if (appendNon2) {
+ top = max(r2y1, ybot);
+ bot = min(r2->y2, r1y1);
+ if (top != bot) {
+ curBand = newReg->data->numRects;
+ RegionAppendNonO(newReg, r2, r2BandEnd, top, bot);
+ Coalesce(newReg, prevBand, curBand);
+ }
+ }
+ ytop = r1y1;
+ } else {
+ ytop = r1y1;
+ }
+
+ /*
+ * Now see if we've hit an intersecting band. The two bands only
+ * intersect if ybot > ytop
+ */
+ ybot = min(r1->y2, r2->y2);
+ if (ybot > ytop) {
+ curBand = newReg->data->numRects;
+ (* overlapFunc)(newReg, r1, r1BandEnd, r2, r2BandEnd, ytop, ybot,
+ pOverlap);
+ Coalesce(newReg, prevBand, curBand);
+ }
+
+ /*
+ * If we've finished with a band (y2 == ybot) we skip forward
+ * in the region to the next band.
+ */
+ if (r1->y2 == ybot) r1 = r1BandEnd;
+ if (r2->y2 == ybot) r2 = r2BandEnd;
+
+ } while (r1 != r1End && r2 != r2End);
+
+ /*
+ * Deal with whichever region (if any) still has rectangles left.
+ *
+ * We only need to worry about banding and coalescing for the very first
+ * band left. After that, we can just group all remaining boxes,
+ * regardless of how many bands, into one final append to the list.
+ */
+
+ if ((r1 != r1End) && appendNon1) {
+ /* Do first nonOverlap1Func call, which may be able to coalesce */
+ FindBand(r1, r1BandEnd, r1End, r1y1);
+ curBand = newReg->data->numRects;
+ RegionAppendNonO(newReg, r1, r1BandEnd, max(r1y1, ybot), r1->y2);
+ Coalesce(newReg, prevBand, curBand);
+ /* Just append the rest of the boxes */
+ AppendRegions(newReg, r1BandEnd, r1End);
+
+ } else if ((r2 != r2End) && appendNon2) {
+ /* Do first nonOverlap2Func call, which may be able to coalesce */
+ FindBand(r2, r2BandEnd, r2End, r2y1);
+ curBand = newReg->data->numRects;
+ RegionAppendNonO(newReg, r2, r2BandEnd, max(r2y1, ybot), r2->y2);
+ Coalesce(newReg, prevBand, curBand);
+ /* Append rest of boxes */
+ AppendRegions(newReg, r2BandEnd, r2End);
+ }
+
+ free(oldData);
+
+ if (!(numRects = newReg->data->numRects))
+ {
+ xfreeData(newReg);
+ newReg->data = &RegionEmptyData;
+ }
+ else if (numRects == 1)
+ {
+ newReg->extents = *RegionBoxptr(newReg);
+ xfreeData(newReg);
+ newReg->data = NULL;
+ }
+ else
+ {
+ DOWNSIZE(newReg, numRects);
+ }
+
+ return TRUE;
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * RegionSetExtents --
+ * Reset the extents of a region to what they should be. Called by
+ * Subtract and Intersect as they can't figure it out along the
+ * way or do so easily, as Union can.
+ *
+ * Results:
+ * None.
+ *
+ * Side Effects:
+ * The region's 'extents' structure is overwritten.
+ *
+ *-----------------------------------------------------------------------
+ */
+static void
+RegionSetExtents (RegionPtr pReg)
+{
+ BoxPtr pBox, pBoxEnd;
+
+ if (!pReg->data)
+ return;
+ if (!pReg->data->size)
+ {
+ pReg->extents.x2 = pReg->extents.x1;
+ pReg->extents.y2 = pReg->extents.y1;
+ return;
+ }
+
+ pBox = RegionBoxptr(pReg);
+ pBoxEnd = RegionEnd(pReg);
+
+ /*
+ * Since pBox is the first rectangle in the region, it must have the
+ * smallest y1 and since pBoxEnd is the last rectangle in the region,
+ * it must have the largest y2, because of banding. Initialize x1 and
+ * x2 from pBox and pBoxEnd, resp., as good things to initialize them
+ * to...
+ */
+ pReg->extents.x1 = pBox->x1;
+ pReg->extents.y1 = pBox->y1;
+ pReg->extents.x2 = pBoxEnd->x2;
+ pReg->extents.y2 = pBoxEnd->y2;
+
+ assert(pReg->extents.y1 < pReg->extents.y2);
+ while (pBox <= pBoxEnd) {
+ if (pBox->x1 < pReg->extents.x1)
+ pReg->extents.x1 = pBox->x1;
+ if (pBox->x2 > pReg->extents.x2)
+ pReg->extents.x2 = pBox->x2;
+ pBox++;
+ };
+
+ assert(pReg->extents.x1 < pReg->extents.x2);
+}
+
+/*======================================================================
+ * Region Intersection
+ *====================================================================*/
+/*-
+ *-----------------------------------------------------------------------
+ * RegionIntersectO --
+ * Handle an overlapping band for RegionIntersect.
+ *
+ * Results:
+ * TRUE if successful.
+ *
+ * Side Effects:
+ * Rectangles may be added to the region.
+ *
+ *-----------------------------------------------------------------------
+ */
+/*ARGSUSED*/
+
+#define MERGERECT(r) \
+{ \
+ if (r->x1 <= x2) { \
+ /* Merge with current rectangle */ \
+ if (r->x1 < x2) *pOverlap = TRUE; \
+ if (x2 < r->x2) x2 = r->x2; \
+ } else { \
+ /* Add current rectangle, start new one */ \
+ NEWRECT(pReg, pNextRect, x1, y1, x2, y2); \
+ x1 = r->x1; \
+ x2 = r->x2; \
+ } \
+ r++; \
+}
+
+/*======================================================================
+ * Region Union
+ *====================================================================*/
+
+/*-
+ *-----------------------------------------------------------------------
+ * RegionUnionO --
+ * Handle an overlapping band for the union operation. Picks the
+ * left-most rectangle each time and merges it into the region.
+ *
+ * Results:
+ * TRUE if successful.
+ *
+ * Side Effects:
+ * pReg is overwritten.
+ * pOverlap is set to TRUE if any boxes overlap.
+ *
+ *-----------------------------------------------------------------------
+ */
+static Bool
+RegionUnionO (
+ RegionPtr pReg,
+ BoxPtr r1,
+ BoxPtr r1End,
+ BoxPtr r2,
+ BoxPtr r2End,
+ short y1,
+ short y2,
+ Bool *pOverlap)
+{
+ BoxPtr pNextRect;
+ int x1; /* left and right side of current union */
+ int x2;
+
+ assert (y1 < y2);
+ assert(r1 != r1End && r2 != r2End);
+
+ pNextRect = RegionTop(pReg);
+
+ /* Start off current rectangle */
+ if (r1->x1 < r2->x1)
+ {
+ x1 = r1->x1;
+ x2 = r1->x2;
+ r1++;
+ }
+ else
+ {
+ x1 = r2->x1;
+ x2 = r2->x2;
+ r2++;
+ }
+ while (r1 != r1End && r2 != r2End)
+ {
+ if (r1->x1 < r2->x1) MERGERECT(r1) else MERGERECT(r2);
+ }
+
+ /* Finish off whoever (if any) is left */
+ if (r1 != r1End)
+ {
+ do
+ {
+ MERGERECT(r1);
+ } while (r1 != r1End);
+ }
+ else if (r2 != r2End)
+ {
+ do
+ {
+ MERGERECT(r2);
+ } while (r2 != r2End);
+ }
+
+ /* Add current rectangle */
+ NEWRECT(pReg, pNextRect, x1, y1, x2, y2);
+
+ return TRUE;
+}
+
+/*======================================================================
+ * Batch Rectangle Union
+ *====================================================================*/
+
+/*-
+ *-----------------------------------------------------------------------
+ * RegionAppend --
+ *
+ * "Append" the rgn rectangles onto the end of dstrgn, maintaining
+ * knowledge of YX-banding when it's easy. Otherwise, dstrgn just
+ * becomes a non-y-x-banded random collection of rectangles, and not
+ * yet a true region. After a sequence of appends, the caller must
+ * call RegionValidate to ensure that a valid region is constructed.
+ *
+ * Results:
+ * TRUE if successful.
+ *
+ * Side Effects:
+ * dstrgn is modified if rgn has rectangles.
+ *
+ */
+Bool
+RegionAppend(RegionPtr dstrgn, RegionPtr rgn)
+{
+ int numRects, dnumRects, size;
+ BoxPtr new, old;
+ Bool prepend;
+
+ if (RegionNar(rgn))
+ return RegionBreak (dstrgn);
+
+ if (!rgn->data && (dstrgn->data == &RegionEmptyData))
+ {
+ dstrgn->extents = rgn->extents;
+ dstrgn->data = NULL;
+ return TRUE;
+ }
+
+ numRects = RegionNumRects(rgn);
+ if (!numRects)
+ return TRUE;
+ prepend = FALSE;
+ size = numRects;
+ dnumRects = RegionNumRects(dstrgn);
+ if (!dnumRects && (size < 200))
+ size = 200; /* XXX pick numbers out of a hat */
+ RECTALLOC(dstrgn, size);
+ old = RegionRects(rgn);
+ if (!dnumRects)
+ dstrgn->extents = rgn->extents;
+ else if (dstrgn->extents.x2 > dstrgn->extents.x1)
+ {
+ BoxPtr first, last;
+
+ first = old;
+ last = RegionBoxptr(dstrgn) + (dnumRects - 1);
+ if ((first->y1 > last->y2) ||
+ ((first->y1 == last->y1) && (first->y2 == last->y2) &&
+ (first->x1 > last->x2)))
+ {
+ if (rgn->extents.x1 < dstrgn->extents.x1)
+ dstrgn->extents.x1 = rgn->extents.x1;
+ if (rgn->extents.x2 > dstrgn->extents.x2)
+ dstrgn->extents.x2 = rgn->extents.x2;
+ dstrgn->extents.y2 = rgn->extents.y2;
+ }
+ else
+ {
+ first = RegionBoxptr(dstrgn);
+ last = old + (numRects - 1);
+ if ((first->y1 > last->y2) ||
+ ((first->y1 == last->y1) && (first->y2 == last->y2) &&
+ (first->x1 > last->x2)))
+ {
+ prepend = TRUE;
+ if (rgn->extents.x1 < dstrgn->extents.x1)
+ dstrgn->extents.x1 = rgn->extents.x1;
+ if (rgn->extents.x2 > dstrgn->extents.x2)
+ dstrgn->extents.x2 = rgn->extents.x2;
+ dstrgn->extents.y1 = rgn->extents.y1;
+ }
+ else
+ dstrgn->extents.x2 = dstrgn->extents.x1;
+ }
+ }
+ if (prepend)
+ {
+ new = RegionBox(dstrgn, numRects);
+ if (dnumRects == 1)
+ *new = *RegionBoxptr(dstrgn);
+ else
+ memmove((char *)new,(char *)RegionBoxptr(dstrgn),
+ dnumRects * sizeof(BoxRec));
+ new = RegionBoxptr(dstrgn);
+ }
+ else
+ new = RegionBoxptr(dstrgn) + dnumRects;
+ if (numRects == 1)
+ *new = *old;
+ else
+ memmove((char *)new, (char *)old, numRects * sizeof(BoxRec));
+ dstrgn->data->numRects += numRects;
+ return TRUE;
+}
+
+
+#define ExchangeRects(a, b) \
+{ \
+ BoxRec t; \
+ t = rects[a]; \
+ rects[a] = rects[b]; \
+ rects[b] = t; \
+}
+
+static void
+QuickSortRects(
+ BoxRec rects[],
+ int numRects)
+{
+ int y1;
+ int x1;
+ int i, j;
+ BoxPtr r;
+
+ /* Always called with numRects > 1 */
+
+ do
+ {
+ if (numRects == 2)
+ {
+ if (rects[0].y1 > rects[1].y1 ||
+ (rects[0].y1 == rects[1].y1 && rects[0].x1 > rects[1].x1))
+ ExchangeRects(0, 1);
+ return;
+ }
+
+ /* Choose partition element, stick in location 0 */
+ ExchangeRects(0, numRects >> 1);
+ y1 = rects[0].y1;
+ x1 = rects[0].x1;
+
+ /* Partition array */
+ i = 0;
+ j = numRects;
+ do
+ {
+ r = &(rects[i]);
+ do
+ {
+ r++;
+ i++;
+ } while (i != numRects &&
+ (r->y1 < y1 || (r->y1 == y1 && r->x1 < x1)));
+ r = &(rects[j]);
+ do
+ {
+ r--;
+ j--;
+ } while (y1 < r->y1 || (y1 == r->y1 && x1 < r->x1));
+ if (i < j)
+ ExchangeRects(i, j);
+ } while (i < j);
+
+ /* Move partition element back to middle */
+ ExchangeRects(0, j);
+
+ /* Recurse */
+ if (numRects-j-1 > 1)
+ QuickSortRects(&rects[j+1], numRects-j-1);
+ numRects = j;
+ } while (numRects > 1);
+}
+
+/*-
+ *-----------------------------------------------------------------------
+ * RegionValidate --
+ *
+ * Take a ``region'' which is a non-y-x-banded random collection of
+ * rectangles, and compute a nice region which is the union of all the
+ * rectangles.
+ *
+ * Results:
+ * TRUE if successful.
+ *
+ * Side Effects:
+ * The passed-in ``region'' may be modified.
+ * pOverlap set to TRUE if any retangles overlapped, else FALSE;
+ *
+ * Strategy:
+ * Step 1. Sort the rectangles into ascending order with primary key y1
+ * and secondary key x1.
+ *
+ * Step 2. Split the rectangles into the minimum number of proper y-x
+ * banded regions. This may require horizontally merging
+ * rectangles, and vertically coalescing bands. With any luck,
+ * this step in an identity tranformation (ala the Box widget),
+ * or a coalescing into 1 box (ala Menus).
+ *
+ * Step 3. Merge the separate regions down to a single region by calling
+ * Union. Maximize the work each Union call does by using
+ * a binary merge.
+ *
+ *-----------------------------------------------------------------------
+ */
+
+Bool
+RegionValidate(RegionPtr badreg, Bool *pOverlap)
+{
+ /* Descriptor for regions under construction in Step 2. */
+ typedef struct {
+ RegionRec reg;
+ int prevBand;
+ int curBand;
+ } RegionInfo;
+
+ int numRects; /* Original numRects for badreg */
+ RegionInfo *ri; /* Array of current regions */
+ int numRI; /* Number of entries used in ri */
+ int sizeRI; /* Number of entries available in ri */
+ int i; /* Index into rects */
+ int j; /* Index into ri */
+ RegionInfo *rit; /* &ri[j] */
+ RegionPtr reg; /* ri[j].reg */
+ BoxPtr box; /* Current box in rects */
+ BoxPtr riBox; /* Last box in ri[j].reg */
+ RegionPtr hreg; /* ri[j_half].reg */
+ Bool ret = TRUE;
+
+ *pOverlap = FALSE;
+ if (!badreg->data)
+ {
+ good(badreg);
+ return TRUE;
+ }
+ numRects = badreg->data->numRects;
+ if (!numRects)
+ {
+ if (RegionNar(badreg))
+ return FALSE;
+ good(badreg);
+ return TRUE;
+ }
+ if (badreg->extents.x1 < badreg->extents.x2)
+ {
+ if ((numRects) == 1)
+ {
+ xfreeData(badreg);
+ badreg->data = (RegDataPtr) NULL;
+ }
+ else
+ {
+ DOWNSIZE(badreg, numRects);
+ }
+ good(badreg);
+ return TRUE;
+ }
+
+ /* Step 1: Sort the rects array into ascending (y1, x1) order */
+ QuickSortRects(RegionBoxptr(badreg), numRects);
+
+ /* Step 2: Scatter the sorted array into the minimum number of regions */
+
+ /* Set up the first region to be the first rectangle in badreg */
+ /* Note that step 2 code will never overflow the ri[0].reg rects array */
+ ri = (RegionInfo *) malloc(4 * sizeof(RegionInfo));
+ if (!ri)
+ return RegionBreak (badreg);
+ sizeRI = 4;
+ numRI = 1;
+ ri[0].prevBand = 0;
+ ri[0].curBand = 0;
+ ri[0].reg = *badreg;
+ box = RegionBoxptr(&ri[0].reg);
+ ri[0].reg.extents = *box;
+ ri[0].reg.data->numRects = 1;
+
+ /* Now scatter rectangles into the minimum set of valid regions. If the
+ next rectangle to be added to a region would force an existing rectangle
+ in the region to be split up in order to maintain y-x banding, just
+ forget it. Try the next region. If it doesn't fit cleanly into any
+ region, make a new one. */
+
+ for (i = numRects; --i > 0;)
+ {
+ box++;
+ /* Look for a region to append box to */
+ for (j = numRI, rit = ri; --j >= 0; rit++)
+ {
+ reg = &rit->reg;
+ riBox = RegionEnd(reg);
+
+ if (box->y1 == riBox->y1 && box->y2 == riBox->y2)
+ {
+ /* box is in same band as riBox. Merge or append it */
+ if (box->x1 <= riBox->x2)
+ {
+ /* Merge it with riBox */
+ if (box->x1 < riBox->x2) *pOverlap = TRUE;
+ if (box->x2 > riBox->x2) riBox->x2 = box->x2;
+ }
+ else
+ {
+ RECTALLOC_BAIL(reg, 1, bail);
+ *RegionTop(reg) = *box;
+ reg->data->numRects++;
+ }
+ goto NextRect; /* So sue me */
+ }
+ else if (box->y1 >= riBox->y2)
+ {
+ /* Put box into new band */
+ if (reg->extents.x2 < riBox->x2) reg->extents.x2 = riBox->x2;
+ if (reg->extents.x1 > box->x1) reg->extents.x1 = box->x1;
+ Coalesce(reg, rit->prevBand, rit->curBand);
+ rit->curBand = reg->data->numRects;
+ RECTALLOC_BAIL(reg, 1, bail);
+ *RegionTop(reg) = *box;
+ reg->data->numRects++;
+ goto NextRect;
+ }
+ /* Well, this region was inappropriate. Try the next one. */
+ } /* for j */
+
+ /* Uh-oh. No regions were appropriate. Create a new one. */
+ if (sizeRI == numRI)
+ {
+ /* Oops, allocate space for new region information */
+ sizeRI <<= 1;
+ rit = (RegionInfo *) realloc(ri, sizeRI * sizeof(RegionInfo));
+ if (!rit)
+ goto bail;
+ ri = rit;
+ rit = &ri[numRI];
+ }
+ numRI++;
+ rit->prevBand = 0;
+ rit->curBand = 0;
+ rit->reg.extents = *box;
+ rit->reg.data = NULL;
+ if (!RegionRectAlloc(&rit->reg, (i+numRI) / numRI)) /* MUST force allocation */
+ goto bail;
+NextRect: ;
+ } /* for i */
+
+ /* Make a final pass over each region in order to Coalesce and set
+ extents.x2 and extents.y2 */
+
+ for (j = numRI, rit = ri; --j >= 0; rit++)
+ {
+ reg = &rit->reg;
+ riBox = RegionEnd(reg);
+ reg->extents.y2 = riBox->y2;
+ if (reg->extents.x2 < riBox->x2) reg->extents.x2 = riBox->x2;
+ Coalesce(reg, rit->prevBand, rit->curBand);
+ if (reg->data->numRects == 1) /* keep unions happy below */
+ {
+ xfreeData(reg);
+ reg->data = NULL;
+ }
+ }
+
+ /* Step 3: Union all regions into a single region */
+ while (numRI > 1)
+ {
+ int half = numRI/2;
+ for (j = numRI & 1; j < (half + (numRI & 1)); j++)
+ {
+ reg = &ri[j].reg;
+ hreg = &ri[j+half].reg;
+ if (!RegionOp(reg, reg, hreg, RegionUnionO, TRUE, TRUE, pOverlap))
+ ret = FALSE;
+ if (hreg->extents.x1 < reg->extents.x1)
+ reg->extents.x1 = hreg->extents.x1;
+ if (hreg->extents.y1 < reg->extents.y1)
+ reg->extents.y1 = hreg->extents.y1;
+ if (hreg->extents.x2 > reg->extents.x2)
+ reg->extents.x2 = hreg->extents.x2;
+ if (hreg->extents.y2 > reg->extents.y2)
+ reg->extents.y2 = hreg->extents.y2;
+ xfreeData(hreg);
+ }
+ numRI -= half;
+ }
+ *badreg = ri[0].reg;
+ free(ri);
+ good(badreg);
+ return ret;
+bail:
+ for (i = 0; i < numRI; i++)
+ xfreeData(&ri[i].reg);
+ free(ri);
+ return RegionBreak (badreg);
+}
+
+RegionPtr
+RegionFromRects(int nrects, xRectangle *prect, int ctype)
+{
+
+ RegionPtr pRgn;
+ RegDataPtr pData;
+ BoxPtr pBox;
+ int i;
+ int x1, y1, x2, y2;
+
+ pRgn = RegionCreate(NullBox, 0);
+ if (RegionNar (pRgn))
+ return pRgn;
+ if (!nrects)
+ return pRgn;
+ if (nrects == 1)
+ {
+ x1 = prect->x;
+ y1 = prect->y;
+ if ((x2 = x1 + (int) prect->width) > MAXSHORT)
+ x2 = MAXSHORT;
+ if ((y2 = y1 + (int) prect->height) > MAXSHORT)
+ y2 = MAXSHORT;
+ if (x1 != x2 && y1 != y2)
+ {
+ pRgn->extents.x1 = x1;
+ pRgn->extents.y1 = y1;
+ pRgn->extents.x2 = x2;
+ pRgn->extents.y2 = y2;
+ pRgn->data = NULL;
+ }
+ return pRgn;
+ }
+ pData = xallocData(nrects);
+ if (!pData)
+ {
+ RegionBreak (pRgn);
+ return pRgn;
+ }
+ pBox = (BoxPtr) (pData + 1);
+ for (i = nrects; --i >= 0; prect++)
+ {
+ x1 = prect->x;
+ y1 = prect->y;
+ if ((x2 = x1 + (int) prect->width) > MAXSHORT)
+ x2 = MAXSHORT;
+ if ((y2 = y1 + (int) prect->height) > MAXSHORT)
+ y2 = MAXSHORT;
+ if (x1 != x2 && y1 != y2)
+ {
+ pBox->x1 = x1;
+ pBox->y1 = y1;
+ pBox->x2 = x2;
+ pBox->y2 = y2;
+ pBox++;
+ }
+ }
+ if (pBox != (BoxPtr) (pData + 1))
+ {
+ pData->size = nrects;
+ pData->numRects = pBox - (BoxPtr) (pData + 1);
+ pRgn->data = pData;
+ if (ctype != CT_YXBANDED)
+ {
+ Bool overlap; /* result ignored */
+ pRgn->extents.x1 = pRgn->extents.x2 = 0;
+ RegionValidate(pRgn, &overlap);
+ }
+ else
+ RegionSetExtents(pRgn);
+ good(pRgn);
+ }
+ else
+ {
+ free(pData);
+ }
+ return pRgn;
+}
+
+#define ExchangeSpans(a, b) \
+{ \
+ DDXPointRec tpt; \
+ int tw; \
+ \
+ tpt = spans[a]; spans[a] = spans[b]; spans[b] = tpt; \
+ tw = widths[a]; widths[a] = widths[b]; widths[b] = tw; \
+}
+
+/* ||| I should apply the merge sort code to rectangle sorting above, and see
+ if mapping time can be improved. But right now I've been at work 12 hours,
+ so forget it.
+*/
+
+static void QuickSortSpans(
+ DDXPointRec spans[],
+ int widths[],
+ int numSpans)
+{
+ int y;
+ int i, j, m;
+ DDXPointPtr r;
+
+ /* Always called with numSpans > 1 */
+ /* Sorts only by y, doesn't bother to sort by x */
+
+ do
+ {
+ if (numSpans < 9)
+ {
+ /* Do insertion sort */
+ int yprev;
+
+ yprev = spans[0].y;
+ i = 1;
+ do
+ { /* while i != numSpans */
+ y = spans[i].y;
+ if (yprev > y)
+ {
+ /* spans[i] is out of order. Move into proper location. */
+ DDXPointRec tpt;
+ int tw, k;
+
+ for (j = 0; y >= spans[j].y; j++) {}
+ tpt = spans[i];
+ tw = widths[i];
+ for (k = i; k != j; k--)
+ {
+ spans[k] = spans[k-1];
+ widths[k] = widths[k-1];
+ }
+ spans[j] = tpt;
+ widths[j] = tw;
+ y = spans[i].y;
+ } /* if out of order */
+ yprev = y;
+ i++;
+ } while (i != numSpans);
+ return;
+ }
+
+ /* Choose partition element, stick in location 0 */
+ m = numSpans / 2;
+ if (spans[m].y > spans[0].y) ExchangeSpans(m, 0);
+ if (spans[m].y > spans[numSpans-1].y) ExchangeSpans(m, numSpans-1);
+ if (spans[m].y > spans[0].y) ExchangeSpans(m, 0);
+ y = spans[0].y;
+
+ /* Partition array */
+ i = 0;
+ j = numSpans;
+ do
+ {
+ r = &(spans[i]);
+ do
+ {
+ r++;
+ i++;
+ } while (i != numSpans && r->y < y);
+ r = &(spans[j]);
+ do
+ {
+ r--;
+ j--;
+ } while (y < r->y);
+ if (i < j)
+ ExchangeSpans(i, j);
+ } while (i < j);
+
+ /* Move partition element back to middle */
+ ExchangeSpans(0, j);
+
+ /* Recurse */
+ if (numSpans-j-1 > 1)
+ QuickSortSpans(&spans[j+1], &widths[j+1], numSpans-j-1);
+ numSpans = j;
+ } while (numSpans > 1);
+}
+
+#define NextBand() \
+{ \
+ clipy1 = pboxBandStart->y1; \
+ clipy2 = pboxBandStart->y2; \
+ pboxBandEnd = pboxBandStart + 1; \
+ while (pboxBandEnd != pboxLast && pboxBandEnd->y1 == clipy1) { \
+ pboxBandEnd++; \
+ } \
+ for (; ppt != pptLast && ppt->y < clipy1; ppt++, pwidth++) {} \
+}
+
+/*
+ Clip a list of scanlines to a region. The caller has allocated the
+ space. FSorted is non-zero if the scanline origins are in ascending
+ order.
+ returns the number of new, clipped scanlines.
+*/
+
+int
+RegionClipSpans(
+ RegionPtr prgnDst,
+ DDXPointPtr ppt,
+ int *pwidth,
+ int nspans,
+ DDXPointPtr pptNew,
+ int *pwidthNew,
+ int fSorted)
+{
+ DDXPointPtr pptLast;
+ int *pwidthNewStart; /* the vengeance of Xerox! */
+ int y, x1, x2;
+ int numRects;
+
+ good(prgnDst);
+ pptLast = ppt + nspans;
+ pwidthNewStart = pwidthNew;
+
+ if (!prgnDst->data)
+ {
+ /* Do special fast code with clip boundaries in registers(?) */
+ /* It doesn't pay much to make use of fSorted in this case,
+ so we lump everything together. */
+
+ int clipx1, clipx2, clipy1, clipy2;
+
+ clipx1 = prgnDst->extents.x1;
+ clipy1 = prgnDst->extents.y1;
+ clipx2 = prgnDst->extents.x2;
+ clipy2 = prgnDst->extents.y2;
+
+ for (; ppt != pptLast; ppt++, pwidth++)
+ {
+ y = ppt->y;
+ x1 = ppt->x;
+ if (clipy1 <= y && y < clipy2)
+ {
+ x2 = x1 + *pwidth;
+ if (x1 < clipx1) x1 = clipx1;
+ if (x2 > clipx2) x2 = clipx2;
+ if (x1 < x2)
+ {
+ /* part of span in clip rectangle */
+ pptNew->x = x1;
+ pptNew->y = y;
+ *pwidthNew = x2 - x1;
+ pptNew++;
+ pwidthNew++;
+ }
+ }
+ } /* end for */
+
+ }
+ else if ((numRects = prgnDst->data->numRects))
+ {
+ /* Have to clip against many boxes */
+ BoxPtr pboxBandStart, pboxBandEnd;
+ BoxPtr pbox;
+ BoxPtr pboxLast;
+ int clipy1, clipy2;
+
+ /* In this case, taking advantage of sorted spans gains more than
+ the sorting costs. */
+ if ((! fSorted) && (nspans > 1))
+ QuickSortSpans(ppt, pwidth, nspans);
+
+ pboxBandStart = RegionBoxptr(prgnDst);
+ pboxLast = pboxBandStart + numRects;
+
+ NextBand();
+
+ for (; ppt != pptLast; )
+ {
+ y = ppt->y;
+ if (y < clipy2)
+ {
+ /* span is in the current band */
+ pbox = pboxBandStart;
+ x1 = ppt->x;
+ x2 = x1 + *pwidth;
+ do
+ { /* For each box in band */
+ int newx1, newx2;
+
+ newx1 = x1;
+ newx2 = x2;
+ if (newx1 < pbox->x1) newx1 = pbox->x1;
+ if (newx2 > pbox->x2) newx2 = pbox->x2;
+ if (newx1 < newx2)
+ {
+ /* Part of span in clip rectangle */
+ pptNew->x = newx1;
+ pptNew->y = y;
+ *pwidthNew = newx2 - newx1;
+ pptNew++;
+ pwidthNew++;
+ }
+ pbox++;
+ } while (pbox != pboxBandEnd);
+ ppt++;
+ pwidth++;
+ }
+ else
+ {
+ /* Move to next band, adjust ppt as needed */
+ pboxBandStart = pboxBandEnd;
+ if (pboxBandStart == pboxLast)
+ break; /* We're completely done */
+ NextBand();
+ }
+ }
+ }
+ return pwidthNew - pwidthNewStart;
+}
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