/* $XFree86: xc/programs/Xserver/mi/mipolyutil.c,v 1.9 2001/12/14 20:00:26 dawes 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. ******************************************************************/ /* $Xorg: mipolyutil.c,v 1.4 2001/02/09 02:05:21 xorgcvs Exp $ */ #ifdef HAVE_DIX_CONFIG_H #include #endif #include "regionstr.h" #include "gc.h" #include "miscanfill.h" #include "mipoly.h" #include /* MAXINT */ /* * fillUtils.c * * Written by Brian Kelleher; Oct. 1985 * * This module contains all of the utility functions * needed to scan convert a polygon. * */ /* * 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. * */ Bool miInsertEdgeInET(ET, ETE, scanline, SLLBlock, iSLLBlock) 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 *)xalloc(sizeof(ScanLineListBlock)); if (!tmpSLLBlock) return FALSE; (*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 < ETE->bres.minor)) { prev = start; start = start->next; } ETE->next = start; if (prev) prev->next = ETE; else pSLL->edgelist = ETE; return TRUE; } /* * 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. * */ Bool miCreateETandAET(count, pts, ET, AET, pETEs, pSLLBlock) register int count; register DDXPointPtr pts; EdgeTable *ET; EdgeTableEntry *AET; register EdgeTableEntry *pETEs; ScanLineListBlock *pSLLBlock; { register DDXPointPtr top, bottom; register DDXPointPtr PrevPt, CurrPt; int iSLLBlock = 0; int dy; if (count < 2) return TRUE; /* * initialize the Active Edge Table */ AET->next = (EdgeTableEntry *)NULL; AET->back = (EdgeTableEntry *)NULL; AET->nextWETE = (EdgeTableEntry *)NULL; AET->bres.minor = MININT; /* * initialize the Edge Table. */ ET->scanlines.next = (ScanLineList *)NULL; ET->ymax = MININT; ET->ymin = MAXINT; 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); if (!miInsertEdgeInET(ET, pETEs, top->y, &pSLLBlock, &iSLLBlock)) { miFreeStorage(pSLLBlock->next); return FALSE; } ET->ymax = max(ET->ymax, PrevPt->y); ET->ymin = min(ET->ymin, PrevPt->y); pETEs++; } PrevPt = CurrPt; } return TRUE; } /* * loadAET * * This routine moves EdgeTableEntries from the * EdgeTable into the Active Edge Table, * leaving them sorted by smaller x coordinate. * */ void miloadAET(AET, ETEs) register EdgeTableEntry *AET, *ETEs; { register EdgeTableEntry *pPrevAET; register EdgeTableEntry *tmp; pPrevAET = AET; AET = AET->next; while (ETEs) { while (AET && (AET->bres.minor < ETEs->bres.minor)) { 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---> ... * */ void micomputeWAET(AET) 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. * */ int miInsertionSort(AET) 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 > AET->bres.minor) 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. */ void miFreeStorage(pSLLBlock) register ScanLineListBlock *pSLLBlock; { register ScanLineListBlock *tmpSLLBlock; while (pSLLBlock) { tmpSLLBlock = pSLLBlock->next; xfree(pSLLBlock); pSLLBlock = tmpSLLBlock; } }