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Diffstat (limited to 'libX11/src/PolyReg.c')
| -rw-r--r-- | libX11/src/PolyReg.c | 640 |
1 files changed, 640 insertions, 0 deletions
diff --git a/libX11/src/PolyReg.c b/libX11/src/PolyReg.c new file mode 100644 index 000000000..d6f4c74b1 --- /dev/null +++ b/libX11/src/PolyReg.c @@ -0,0 +1,640 @@ +/* $Xorg: PolyReg.c,v 1.5 2001/02/09 02:03:35 xorgcvs Exp $ */ +/************************************************************************ + +Copyright 1987, 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 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. + +************************************************************************/ +/* $XFree86: xc/lib/X11/PolyReg.c,v 1.6 2001/12/14 19:54:03 dawes Exp $ */ + +#define LARGE_COORDINATE 1000000 +#define SMALL_COORDINATE -LARGE_COORDINATE + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif +#include "Xlibint.h" +#include "Xutil.h" +#include <X11/Xregion.h> +#include "poly.h" + +/* + * InsertEdgeInET + * + * Insert the given edge into the edge table. + * First we must find the correct bucket in the + * Edge table, then find the right slot in the + * bucket. Finally, we can insert it. + * + */ +static void +InsertEdgeInET( + EdgeTable *ET, + EdgeTableEntry *ETE, + int scanline, + ScanLineListBlock **SLLBlock, + int *iSLLBlock) +{ + register EdgeTableEntry *start, *prev; + register ScanLineList *pSLL, *pPrevSLL; + ScanLineListBlock *tmpSLLBlock; + + /* + * find the right bucket to put the edge into + */ + pPrevSLL = &ET->scanlines; + pSLL = pPrevSLL->next; + while (pSLL && (pSLL->scanline < scanline)) + { + pPrevSLL = pSLL; + pSLL = pSLL->next; + } + + /* + * reassign pSLL (pointer to ScanLineList) if necessary + */ + if ((!pSLL) || (pSLL->scanline > scanline)) + { + if (*iSLLBlock > SLLSPERBLOCK-1) + { + tmpSLLBlock = + (ScanLineListBlock *)Xmalloc(sizeof(ScanLineListBlock)); + (*SLLBlock)->next = tmpSLLBlock; + tmpSLLBlock->next = (ScanLineListBlock *)NULL; + *SLLBlock = tmpSLLBlock; + *iSLLBlock = 0; + } + pSLL = &((*SLLBlock)->SLLs[(*iSLLBlock)++]); + + pSLL->next = pPrevSLL->next; + pSLL->edgelist = (EdgeTableEntry *)NULL; + pPrevSLL->next = pSLL; + } + pSLL->scanline = scanline; + + /* + * now insert the edge in the right bucket + */ + prev = (EdgeTableEntry *)NULL; + start = pSLL->edgelist; + while (start && (start->bres.minor_axis < ETE->bres.minor_axis)) + { + prev = start; + start = start->next; + } + ETE->next = start; + + if (prev) + prev->next = ETE; + else + pSLL->edgelist = ETE; +} + +/* + * CreateEdgeTable + * + * This routine creates the edge table for + * scan converting polygons. + * The Edge Table (ET) looks like: + * + * EdgeTable + * -------- + * | ymax | ScanLineLists + * |scanline|-->------------>-------------->... + * -------- |scanline| |scanline| + * |edgelist| |edgelist| + * --------- --------- + * | | + * | | + * V V + * list of ETEs list of ETEs + * + * where ETE is an EdgeTableEntry data structure, + * and there is one ScanLineList per scanline at + * which an edge is initially entered. + * + */ + +static void +CreateETandAET( + register int count, + register XPoint *pts, + EdgeTable *ET, + EdgeTableEntry *AET, + register EdgeTableEntry *pETEs, + ScanLineListBlock *pSLLBlock) +{ + register XPoint *top, *bottom; + register XPoint *PrevPt, *CurrPt; + int iSLLBlock = 0; + int dy; + + if (count < 2) return; + + /* + * initialize the Active Edge Table + */ + AET->next = (EdgeTableEntry *)NULL; + AET->back = (EdgeTableEntry *)NULL; + AET->nextWETE = (EdgeTableEntry *)NULL; + AET->bres.minor_axis = SMALL_COORDINATE; + + /* + * initialize the Edge Table. + */ + ET->scanlines.next = (ScanLineList *)NULL; + ET->ymax = SMALL_COORDINATE; + ET->ymin = LARGE_COORDINATE; + pSLLBlock->next = (ScanLineListBlock *)NULL; + + PrevPt = &pts[count-1]; + + /* + * for each vertex in the array of points. + * In this loop we are dealing with two vertices at + * a time -- these make up one edge of the polygon. + */ + while (count--) + { + CurrPt = pts++; + + /* + * find out which point is above and which is below. + */ + if (PrevPt->y > CurrPt->y) + { + bottom = PrevPt, top = CurrPt; + pETEs->ClockWise = 0; + } + else + { + bottom = CurrPt, top = PrevPt; + pETEs->ClockWise = 1; + } + + /* + * don't add horizontal edges to the Edge table. + */ + if (bottom->y != top->y) + { + pETEs->ymax = bottom->y-1; /* -1 so we don't get last scanline */ + + /* + * initialize integer edge algorithm + */ + dy = bottom->y - top->y; + BRESINITPGONSTRUCT(dy, top->x, bottom->x, pETEs->bres); + + InsertEdgeInET(ET, pETEs, top->y, &pSLLBlock, &iSLLBlock); + + if (PrevPt->y > ET->ymax) + ET->ymax = PrevPt->y; + if (PrevPt->y < ET->ymin) + ET->ymin = PrevPt->y; + pETEs++; + } + + PrevPt = CurrPt; + } +} + +/* + * loadAET + * + * This routine moves EdgeTableEntries from the + * EdgeTable into the Active Edge Table, + * leaving them sorted by smaller x coordinate. + * + */ + +static void +loadAET( + register EdgeTableEntry *AET, + register EdgeTableEntry *ETEs) +{ + register EdgeTableEntry *pPrevAET; + register EdgeTableEntry *tmp; + + pPrevAET = AET; + AET = AET->next; + while (ETEs) + { + while (AET && (AET->bres.minor_axis < ETEs->bres.minor_axis)) + { + pPrevAET = AET; + AET = AET->next; + } + tmp = ETEs->next; + ETEs->next = AET; + if (AET) + AET->back = ETEs; + ETEs->back = pPrevAET; + pPrevAET->next = ETEs; + pPrevAET = ETEs; + + ETEs = tmp; + } +} + +/* + * computeWAET + * + * This routine links the AET by the + * nextWETE (winding EdgeTableEntry) link for + * use by the winding number rule. The final + * Active Edge Table (AET) might look something + * like: + * + * AET + * ---------- --------- --------- + * |ymax | |ymax | |ymax | + * | ... | |... | |... | + * |next |->|next |->|next |->... + * |nextWETE| |nextWETE| |nextWETE| + * --------- --------- ^-------- + * | | | + * V-------------------> V---> ... + * + */ +static void +computeWAET( + register EdgeTableEntry *AET) +{ + register EdgeTableEntry *pWETE; + register int inside = 1; + register int isInside = 0; + + AET->nextWETE = (EdgeTableEntry *)NULL; + pWETE = AET; + AET = AET->next; + while (AET) + { + if (AET->ClockWise) + isInside++; + else + isInside--; + + if ((!inside && !isInside) || + ( inside && isInside)) + { + pWETE->nextWETE = AET; + pWETE = AET; + inside = !inside; + } + AET = AET->next; + } + pWETE->nextWETE = (EdgeTableEntry *)NULL; +} + +/* + * InsertionSort + * + * Just a simple insertion sort using + * pointers and back pointers to sort the Active + * Edge Table. + * + */ + +static int +InsertionSort( + register EdgeTableEntry *AET) +{ + register EdgeTableEntry *pETEchase; + register EdgeTableEntry *pETEinsert; + register EdgeTableEntry *pETEchaseBackTMP; + register int changed = 0; + + AET = AET->next; + while (AET) + { + pETEinsert = AET; + pETEchase = AET; + while (pETEchase->back->bres.minor_axis > AET->bres.minor_axis) + pETEchase = pETEchase->back; + + AET = AET->next; + if (pETEchase != pETEinsert) + { + pETEchaseBackTMP = pETEchase->back; + pETEinsert->back->next = AET; + if (AET) + AET->back = pETEinsert->back; + pETEinsert->next = pETEchase; + pETEchase->back->next = pETEinsert; + pETEchase->back = pETEinsert; + pETEinsert->back = pETEchaseBackTMP; + changed = 1; + } + } + return(changed); +} + +/* + * Clean up our act. + */ +static void +FreeStorage( + register ScanLineListBlock *pSLLBlock) +{ + register ScanLineListBlock *tmpSLLBlock; + + while (pSLLBlock) + { + tmpSLLBlock = pSLLBlock->next; + Xfree((char *)pSLLBlock); + pSLLBlock = tmpSLLBlock; + } +} + +/* + * Create an array of rectangles from a list of points. + * If indeed these things (POINTS, RECTS) are the same, + * then this proc is still needed, because it allocates + * storage for the array, which was allocated on the + * stack by the calling procedure. + * + */ +static int PtsToRegion( + register int numFullPtBlocks, + register int iCurPtBlock, + POINTBLOCK *FirstPtBlock, + REGION *reg) +{ + register BOX *rects; + register XPoint *pts; + register POINTBLOCK *CurPtBlock; + register int i; + register BOX *extents; + register int numRects; + BOX *prevRects = reg->rects; + + extents = ®->extents; + + numRects = ((numFullPtBlocks * NUMPTSTOBUFFER) + iCurPtBlock) >> 1; + + if (!(reg->rects = (BOX *)Xrealloc((char *)reg->rects, + (unsigned) (sizeof(BOX) * numRects)))) { + Xfree(prevRects); + return(0); + } + + reg->size = numRects; + CurPtBlock = FirstPtBlock; + rects = reg->rects - 1; + numRects = 0; + extents->x1 = MAXSHORT, extents->x2 = MINSHORT; + + for ( ; numFullPtBlocks >= 0; numFullPtBlocks--) { + /* the loop uses 2 points per iteration */ + i = NUMPTSTOBUFFER >> 1; + if (!numFullPtBlocks) + i = iCurPtBlock >> 1; + for (pts = CurPtBlock->pts; i--; pts += 2) { + if (pts->x == pts[1].x) + continue; + if (numRects && pts->x == rects->x1 && pts->y == rects->y2 && + pts[1].x == rects->x2 && + (numRects == 1 || rects[-1].y1 != rects->y1) && + (i && pts[2].y > pts[1].y)) { + rects->y2 = pts[1].y + 1; + continue; + } + numRects++; + rects++; + rects->x1 = pts->x; rects->y1 = pts->y; + rects->x2 = pts[1].x; rects->y2 = pts[1].y + 1; + if (rects->x1 < extents->x1) + extents->x1 = rects->x1; + if (rects->x2 > extents->x2) + extents->x2 = rects->x2; + } + CurPtBlock = CurPtBlock->next; + } + + if (numRects) { + extents->y1 = reg->rects->y1; + extents->y2 = rects->y2; + } else { + extents->x1 = 0; + extents->y1 = 0; + extents->x2 = 0; + extents->y2 = 0; + } + reg->numRects = numRects; + + return(TRUE); +} + +/* + * polytoregion + * + * Scan converts a polygon by returning a run-length + * encoding of the resultant bitmap -- the run-length + * encoding is in the form of an array of rectangles. + */ +Region +XPolygonRegion( + XPoint *Pts, /* the pts */ + int Count, /* number of pts */ + int rule) /* winding rule */ +{ + Region region; + register EdgeTableEntry *pAET; /* Active Edge Table */ + register int y; /* current scanline */ + register int iPts = 0; /* number of pts in buffer */ + register EdgeTableEntry *pWETE; /* Winding Edge Table Entry*/ + register ScanLineList *pSLL; /* current scanLineList */ + register XPoint *pts; /* output buffer */ + EdgeTableEntry *pPrevAET; /* ptr to previous AET */ + EdgeTable ET; /* header node for ET */ + EdgeTableEntry AET; /* header node for AET */ + EdgeTableEntry *pETEs; /* EdgeTableEntries pool */ + ScanLineListBlock SLLBlock; /* header for scanlinelist */ + int fixWAET = FALSE; + POINTBLOCK FirstPtBlock, *curPtBlock; /* PtBlock buffers */ + POINTBLOCK *tmpPtBlock; + int numFullPtBlocks = 0; + + if (! (region = XCreateRegion())) return (Region) NULL; + + /* special case a rectangle */ + pts = Pts; + if (((Count == 4) || + ((Count == 5) && (pts[4].x == pts[0].x) && (pts[4].y == pts[0].y))) && + (((pts[0].y == pts[1].y) && + (pts[1].x == pts[2].x) && + (pts[2].y == pts[3].y) && + (pts[3].x == pts[0].x)) || + ((pts[0].x == pts[1].x) && + (pts[1].y == pts[2].y) && + (pts[2].x == pts[3].x) && + (pts[3].y == pts[0].y)))) { + region->extents.x1 = min(pts[0].x, pts[2].x); + region->extents.y1 = min(pts[0].y, pts[2].y); + region->extents.x2 = max(pts[0].x, pts[2].x); + region->extents.y2 = max(pts[0].y, pts[2].y); + if ((region->extents.x1 != region->extents.x2) && + (region->extents.y1 != region->extents.y2)) { + region->numRects = 1; + *(region->rects) = region->extents; + } + return(region); + } + + if (Count < 2) return region; + + if (! (pETEs = (EdgeTableEntry *) + Xmalloc((unsigned) (sizeof(EdgeTableEntry) * Count)))) { + XDestroyRegion(region); + return (Region) NULL; + } + + pts = FirstPtBlock.pts; + CreateETandAET(Count, Pts, &ET, &AET, pETEs, &SLLBlock); + pSLL = ET.scanlines.next; + curPtBlock = &FirstPtBlock; + + if (rule == EvenOddRule) { + /* + * for each scanline + */ + for (y = ET.ymin; y < ET.ymax; y++) { + /* + * Add a new edge to the active edge table when we + * get to the next edge. + */ + if (pSLL != NULL && y == pSLL->scanline) { + loadAET(&AET, pSLL->edgelist); + pSLL = pSLL->next; + } + pPrevAET = &AET; + pAET = AET.next; + + /* + * for each active edge + */ + while (pAET) { + pts->x = pAET->bres.minor_axis, pts->y = y; + pts++, iPts++; + + /* + * send out the buffer + */ + if (iPts == NUMPTSTOBUFFER) { + tmpPtBlock = (POINTBLOCK *)Xmalloc(sizeof(POINTBLOCK)); + curPtBlock->next = tmpPtBlock; + curPtBlock = tmpPtBlock; + pts = curPtBlock->pts; + numFullPtBlocks++; + iPts = 0; + } + EVALUATEEDGEEVENODD(pAET, pPrevAET, y); + } + (void) InsertionSort(&AET); + } + } + else { + /* + * for each scanline + */ + for (y = ET.ymin; y < ET.ymax; y++) { + /* + * Add a new edge to the active edge table when we + * get to the next edge. + */ + if (pSLL != NULL && y == pSLL->scanline) { + loadAET(&AET, pSLL->edgelist); + computeWAET(&AET); + pSLL = pSLL->next; + } + pPrevAET = &AET; + pAET = AET.next; + pWETE = pAET; + + /* + * for each active edge + */ + while (pAET) { + /* + * add to the buffer only those edges that + * are in the Winding active edge table. + */ + if (pWETE == pAET) { + pts->x = pAET->bres.minor_axis, pts->y = y; + pts++, iPts++; + + /* + * send out the buffer + */ + if (iPts == NUMPTSTOBUFFER) { + tmpPtBlock = (POINTBLOCK *)Xmalloc(sizeof(POINTBLOCK)); + curPtBlock->next = tmpPtBlock; + curPtBlock = tmpPtBlock; + pts = curPtBlock->pts; + numFullPtBlocks++; iPts = 0; + } + pWETE = pWETE->nextWETE; + } + EVALUATEEDGEWINDING(pAET, pPrevAET, y, fixWAET); + } + + /* + * recompute the winding active edge table if + * we just resorted or have exited an edge. + */ + if (InsertionSort(&AET) || fixWAET) { + computeWAET(&AET); + fixWAET = FALSE; + } + } + } + FreeStorage(SLLBlock.next); + (void) PtsToRegion(numFullPtBlocks, iPts, &FirstPtBlock, region); + for (curPtBlock = FirstPtBlock.next; --numFullPtBlocks >= 0;) { + tmpPtBlock = curPtBlock->next; + Xfree((char *)curPtBlock); + curPtBlock = tmpPtBlock; + } + Xfree((char *)pETEs); + return(region); +} |