--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/qt3support/other/q3polygonscanner.cpp Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,939 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the Qt3Support module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "q3polygonscanner.h"
+#include "q3pointarray.h"
+#include <stdlib.h>
+
+QT_BEGIN_NAMESPACE
+
+// Based on Xserver code miFillGeneralPoly...
+/*
+ *
+ * Written by Brian Kelleher; Oct. 1985
+ *
+ * Routine to fill a polygon. Two fill rules are
+ * supported: frWINDING and frEVENODD.
+ *
+ * See fillpoly.h for a complete description of the algorithm.
+ */
+
+/*
+ * These are the data structures needed to scan
+ * convert regions. Two different scan conversion
+ * methods are available -- the even-odd method, and
+ * the winding number method.
+ * The even-odd rule states that a point is inside
+ * the polygon if a ray drawn from that point in any
+ * direction will pass through an odd number of
+ * path segments.
+ * By the winding number rule, a point is decided
+ * to be inside the polygon if a ray drawn from that
+ * point in any direction passes through a different
+ * number of clockwise and counterclockwise path
+ * segments.
+ *
+ * These data structures are adapted somewhat from
+ * the algorithm in (Foley/Van Dam) for scan converting
+ * polygons.
+ * The basic algorithm is to start at the top (smallest y)
+ * of the polygon, stepping down to the bottom of
+ * the polygon by incrementing the y coordinate. We
+ * keep a list of edges which the current scanline crosses,
+ * sorted by x. This list is called the Active Edge Table (AET)
+ * As we change the y-coordinate, we update each entry in
+ * in the active edge table to reflect the edges new xcoord.
+ * This list must be sorted at each scanline in case
+ * two edges intersect.
+ * We also keep a data structure known as the Edge Table (ET),
+ * which keeps track of all the edges which the current
+ * scanline has not yet reached. The ET is basically a
+ * list of ScanLineList structures containing a list of
+ * edges which are entered at a given scanline. There is one
+ * ScanLineList per scanline at which an edge is entered.
+ * When we enter a new edge, we move it from the ET to the AET.
+ *
+ * From the AET, we can implement the even-odd rule as in
+ * (Foley/Van Dam).
+ * The winding number rule is a little trickier. We also
+ * keep the EdgeTableEntries in the AET linked by the
+ * nextWETE (winding EdgeTableEntry) link. This allows
+ * the edges to be linked just as before for updating
+ * purposes, but only uses the edges linked by the nextWETE
+ * link as edges representing spans of the polygon to
+ * drawn (as with the even-odd rule).
+ */
+
+/* $XConsortium: miscanfill.h,v 1.5 94/04/17 20:27:50 dpw Exp $ */
+/*
+
+Copyright (c) 1987 X Consortium
+
+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, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+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 X CONSORTIUM 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 X Consortium 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 X Consortium.
+
+*/
+
+
+/*
+ * scanfill.h
+ *
+ * Written by Brian Kelleher; Jan 1985
+ *
+ * This file contains a few macros to help track
+ * the edge of a filled object. The object is assumed
+ * to be filled in scanline order, and thus the
+ * algorithm used is an extension of Bresenham's line
+ * drawing algorithm which assumes that y is always the
+ * major axis.
+ * Since these pieces of code are the same for any filled shape,
+ * it is more convenient to gather the library in one
+ * place, but since these pieces of code are also in
+ * the inner loops of output primitives, procedure call
+ * overhead is out of the question.
+ * See the author for a derivation if needed.
+ */
+
+/*
+ * In scan converting polygons, we want to choose those pixels
+ * which are inside the polygon. Thus, we add .5 to the starting
+ * x coordinate for both left and right edges. Now we choose the
+ * first pixel which is inside the pgon for the left edge and the
+ * first pixel which is outside the pgon for the right edge.
+ * Draw the left pixel, but not the right.
+ *
+ * How to add .5 to the starting x coordinate:
+ * If the edge is moving to the right, then subtract dy from the
+ * error term from the general form of the algorithm.
+ * If the edge is moving to the left, then add dy to the error term.
+ *
+ * The reason for the difference between edges moving to the left
+ * and edges moving to the right is simple: If an edge is moving
+ * to the right, then we want the algorithm to flip immediately.
+ * If it is moving to the left, then we don't want it to flip until
+ * we traverse an entire pixel.
+ */
+#define BRESINITPGON(dy, x1, x2, xStart, d, m, m1, incr1, incr2) { \
+ int dx; /* local storage */ \
+\
+ /* \
+ * if the edge is horizontal, then it is ignored \
+ * and assumed not to be processed. Otherwise, do this stuff. \
+ */ \
+ if ((dy) != 0) { \
+ xStart = (x1); \
+ dx = (x2) - xStart; \
+ if (dx < 0) { \
+ m = dx / (dy); \
+ m1 = m - 1; \
+ incr1 = -2 * dx + 2 * (dy) * m1; \
+ incr2 = -2 * dx + 2 * (dy) * m; \
+ d = 2 * m * (dy) - 2 * dx - 2 * (dy); \
+ } else { \
+ m = dx / (dy); \
+ m1 = m + 1; \
+ incr1 = 2 * dx - 2 * (dy) * m1; \
+ incr2 = 2 * dx - 2 * (dy) * m; \
+ d = -2 * m * (dy) + 2 * dx; \
+ } \
+ } \
+}
+
+#define BRESINCRPGON(d, minval, m, m1, incr1, incr2) { \
+ if (m1 > 0) { \
+ if (d > 0) { \
+ minval += m1; \
+ d += incr1; \
+ } \
+ else { \
+ minval += m; \
+ d += incr2; \
+ } \
+ } else {\
+ if (d >= 0) { \
+ minval += m1; \
+ d += incr1; \
+ } \
+ else { \
+ minval += m; \
+ d += incr2; \
+ } \
+ } \
+}
+
+
+/*
+ * This structure contains all of the information needed
+ * to run the bresenham algorithm.
+ * The variables may be hardcoded into the declarations
+ * instead of using this structure to make use of
+ * register declarations.
+ */
+typedef struct {
+ int minor; /* minor axis */
+ int d; /* decision variable */
+ int m, m1; /* slope and slope+1 */
+ int incr1, incr2; /* error increments */
+} BRESINFO;
+
+
+#define BRESINITPGONSTRUCT(dmaj, min1, min2, bres) \
+ BRESINITPGON(dmaj, min1, min2, bres.minor, bres.d, \
+ bres.m, bres.m1, bres.incr1, bres.incr2)
+
+#define BRESINCRPGONSTRUCT(bres) \
+ BRESINCRPGON(bres.d, bres.minor, bres.m, bres.m1, bres.incr1, bres.incr2)
+
+
+typedef struct _EdgeTableEntry {
+ int ymax; /* ycoord at which we exit this edge. */
+ BRESINFO bres; /* Bresenham info to run the edge */
+ struct _EdgeTableEntry *next; /* next in the list */
+ struct _EdgeTableEntry *back; /* for insertion sort */
+ struct _EdgeTableEntry *nextWETE; /* for winding num rule */
+ int ClockWise; /* flag for winding number rule */
+} EdgeTableEntry;
+
+
+typedef struct _ScanLineList{
+ int scanline; /* the scanline represented */
+ EdgeTableEntry *edgelist; /* header node */
+ struct _ScanLineList *next; /* next in the list */
+} ScanLineList;
+
+
+typedef struct {
+ int ymax; /* ymax for the polygon */
+ int ymin; /* ymin for the polygon */
+ ScanLineList scanlines; /* header node */
+} EdgeTable;
+
+
+/*
+ * Here is a struct to help with storage allocation
+ * so we can allocate a big chunk at a time, and then take
+ * pieces from this heap when we need to.
+ */
+#define SLLSPERBLOCK 25
+
+typedef struct _ScanLineListBlock {
+ ScanLineList SLLs[SLLSPERBLOCK];
+ struct _ScanLineListBlock *next;
+} ScanLineListBlock;
+
+/*
+ * number of points to buffer before sending them off
+ * to scanlines() : Must be an even number
+ */
+#define NUMPTSTOBUFFER 200
+
+/*
+ *
+ * a few macros for the inner loops of the fill code where
+ * performance considerations don't allow a procedure call.
+ *
+ * Evaluate the given edge at the given scanline.
+ * If the edge has expired, then we leave it and fix up
+ * the active edge table; otherwise, we increment the
+ * x value to be ready for the next scanline.
+ * The winding number rule is in effect, so we must notify
+ * the caller when the edge has been removed so he
+ * can reorder the Winding Active Edge Table.
+ */
+#define EVALUATEEDGEWINDING(pAET, pPrevAET, y, fixWAET) { \
+ if (pAET->ymax == y) { /* leaving this edge */ \
+ pPrevAET->next = pAET->next; \
+ pAET = pPrevAET->next; \
+ fixWAET = 1; \
+ if (pAET) \
+ pAET->back = pPrevAET; \
+ } \
+ else { \
+ BRESINCRPGONSTRUCT(pAET->bres); \
+ pPrevAET = pAET; \
+ pAET = pAET->next; \
+ } \
+}
+
+
+/*
+ * Evaluate the given edge at the given scanline.
+ * If the edge has expired, then we leave it and fix up
+ * the active edge table; otherwise, we increment the
+ * x value to be ready for the next scanline.
+ * The even-odd rule is in effect.
+ */
+#define EVALUATEEDGEEVENODD(pAET, pPrevAET, y) { \
+ if (pAET->ymax == y) { /* leaving this edge */ \
+ pPrevAET->next = pAET->next; \
+ pAET = pPrevAET->next; \
+ if (pAET) \
+ pAET->back = pPrevAET; \
+ } \
+ else { \
+ BRESINCRPGONSTRUCT(pAET->bres) \
+ pPrevAET = pAET; \
+ pAET = pAET->next; \
+ } \
+}
+
+/***********************************************************
+
+Copyright (c) 1987 X Consortium
+
+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, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+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
+X CONSORTIUM 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 X Consortium 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 X Consortium.
+
+
+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.
+
+******************************************************************/
+
+#define MAXINT 0x7fffffff
+#define MININT -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.
+ *
+ */
+static bool
+miInsertEdgeInET(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 *)malloc(sizeof(ScanLineListBlock));
+ if (!tmpSLLBlock)
+ return false;
+ (*SLLBlock)->next = tmpSLLBlock;
+ tmpSLLBlock->next = 0;
+ *SLLBlock = tmpSLLBlock;
+ *iSLLBlock = 0;
+ }
+ pSLL = &((*SLLBlock)->SLLs[(*iSLLBlock)++]);
+
+ pSLL->next = pPrevSLL->next;
+ pSLL->edgelist = 0;
+ pPrevSLL->next = pSLL;
+ }
+ pSLL->scanline = scanline;
+
+ /*
+ * now insert the edge in the right bucket
+ */
+ prev = 0;
+ 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.
+ *
+ */
+
+typedef struct {
+#if defined(Q_OS_MAC)
+ int y, x;
+#else
+ int x, y;
+#endif
+
+} DDXPointRec, *DDXPointPtr;
+
+/*
+ * Clean up our act.
+ */
+static void
+miFreeStorage(ScanLineListBlock *pSLLBlock)
+{
+ register ScanLineListBlock *tmpSLLBlock;
+
+ while (pSLLBlock)
+ {
+ tmpSLLBlock = pSLLBlock->next;
+ free(pSLLBlock);
+ pSLLBlock = tmpSLLBlock;
+ }
+}
+
+static bool
+miCreateETandAET(int count, DDXPointPtr pts, EdgeTable *ET,
+ EdgeTableEntry *AET, 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 = 0;
+ AET->back = 0;
+ AET->nextWETE = 0;
+ AET->bres.minor = MININT;
+
+ /*
+ * initialize the Edge Table.
+ */
+ ET->scanlines.next = 0;
+ ET->ymax = MININT;
+ ET->ymin = MAXINT;
+ pSLLBlock->next = 0;
+
+ 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 = qMax(ET->ymax, PrevPt->y);
+ ET->ymin = qMin(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.
+ *
+ */
+
+static void
+miloadAET(EdgeTableEntry *AET, EdgeTableEntry *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---> ...
+ *
+ */
+static void
+micomputeWAET(EdgeTableEntry *AET)
+{
+ register EdgeTableEntry *pWETE;
+ register int inside = 1;
+ register int isInside = 0;
+
+ AET->nextWETE = 0;
+ 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 = 0;
+}
+
+/*
+ * InsertionSort
+ *
+ * Just a simple insertion sort using
+ * pointers and back pointers to sort the Active
+ * Edge Table.
+ *
+ */
+
+static int
+miInsertionSort(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;
+}
+
+/*!
+ \overload
+*/
+void Q3PolygonScanner::scan(const Q3PointArray& pa, bool winding, int index, int npoints)
+{
+ scan(pa, winding, index, npoints, true);
+}
+
+/*!
+ \overload
+
+ If \a stitchable is false, the right and bottom edges of the
+ polygon are included. This causes adjacent polygons to overlap.
+*/
+void Q3PolygonScanner::scan(const Q3PointArray& pa, bool winding, int index, int npoints, bool stitchable)
+{
+ scan(pa, winding, index, npoints,
+ stitchable ? Edge(Left+Top) : Edge(Left+Right+Top+Bottom));
+}
+
+/*!
+ Calls processSpans() for all scanlines of the polygon defined by
+ \a npoints starting at \a index in \a pa.
+
+ If \a winding is true, the Winding algorithm rather than the
+ Odd-Even rule is used.
+
+ The \a edges is any bitwise combination of:
+ \list
+ \i Q3PolygonScanner::Left
+ \i Q3PolygonScanner::Right
+ \i Q3PolygonScanner::Top
+ \i Q3PolygonScanner::Bottom
+ \endlist
+ \a edges determines which edges are included.
+
+ \warning The edges feature does not work properly.
+
+*/
+void Q3PolygonScanner::scan(const Q3PointArray& pa, bool winding, int index, int npoints, Edge edges)
+{
+
+
+ DDXPointPtr ptsIn = (DDXPointPtr)pa.data();
+ ptsIn += index;
+ register EdgeTableEntry *pAET; /* the Active Edge Table */
+ register int y; /* the current scanline */
+ register int nPts = 0; /* number of pts in buffer */
+ register EdgeTableEntry *pWETE; /* Winding Edge Table */
+ register ScanLineList *pSLL; /* Current ScanLineList */
+ register DDXPointPtr ptsOut; /* ptr to output buffers */
+ int *width;
+ DDXPointRec FirstPoint[NUMPTSTOBUFFER]; /* the output buffers */
+ int FirstWidth[NUMPTSTOBUFFER];
+ EdgeTableEntry *pPrevAET; /* previous AET entry */
+ EdgeTable ET; /* Edge Table header node */
+ EdgeTableEntry AET; /* Active ET header node */
+ EdgeTableEntry *pETEs; /* Edge Table Entries buff */
+ ScanLineListBlock SLLBlock; /* header for ScanLineList */
+ int fixWAET = 0;
+ int edge_l = (edges & Left) ? 1 : 0;
+ int edge_r = (edges & Right) ? 1 : 0;
+ int edge_t = 1; //#### (edges & Top) ? 1 : 0;
+ int edge_b = (edges & Bottom) ? 1 : 0;
+
+ if (npoints == -1)
+ npoints = pa.size();
+
+ if (npoints < 3)
+ return;
+
+ if(!(pETEs = (EdgeTableEntry *)
+ malloc(sizeof(EdgeTableEntry) * npoints)))
+ return;
+ ptsOut = FirstPoint;
+ width = FirstWidth;
+ if (!miCreateETandAET(npoints, ptsIn, &ET, &AET, pETEs, &SLLBlock))
+ {
+ free(pETEs);
+ return;
+ }
+ pSLL = ET.scanlines.next;
+
+ if (!winding)
+ {
+ /*
+ * for each scanline
+ */
+ for (y = ET.ymin+1-edge_t; y < ET.ymax+edge_b; y++)
+ {
+ /*
+ * Add a new edge to the active edge table when we
+ * get to the next edge.
+ */
+ if (pSLL && y == pSLL->scanline)
+ {
+ miloadAET(&AET, pSLL->edgelist);
+ pSLL = pSLL->next;
+ }
+ pPrevAET = &AET;
+ pAET = AET.next;
+
+ /*
+ * for each active edge
+ */
+ while (pAET)
+ {
+ ptsOut->x = pAET->bres.minor + 1 - edge_l;
+ ptsOut++->y = y;
+ *width++ = pAET->next->bres.minor - pAET->bres.minor
+ - 1 + edge_l + edge_r;
+ nPts++;
+
+ /*
+ * send out the buffer when its full
+ */
+ if (nPts == NUMPTSTOBUFFER)
+ {
+ processSpans(nPts, (QPoint*)FirstPoint, FirstWidth);
+ ptsOut = FirstPoint;
+ width = FirstWidth;
+ nPts = 0;
+ }
+ EVALUATEEDGEEVENODD(pAET, pPrevAET, y)
+ EVALUATEEDGEEVENODD(pAET, pPrevAET, y)
+ }
+ miInsertionSort(&AET);
+ }
+ }
+ else /* default to WindingNumber */
+ {
+ /*
+ * for each scanline
+ */
+ for (y = ET.ymin+1-edge_t; y < ET.ymax+edge_b; y++)
+ {
+ /*
+ * Add a new edge to the active edge table when we
+ * get to the next edge.
+ */
+ if (pSLL && y == pSLL->scanline)
+ {
+ miloadAET(&AET, pSLL->edgelist);
+ micomputeWAET(&AET);
+ pSLL = pSLL->next;
+ }
+ pPrevAET = &AET;
+ pAET = AET.next;
+ pWETE = pAET;
+
+ /*
+ * for each active edge
+ */
+ while (pAET)
+ {
+ /*
+ * if the next edge in the active edge table is
+ * also the next edge in the winding active edge
+ * table.
+ */
+ if (pWETE == pAET)
+ {
+ ptsOut->x = pAET->bres.minor + 1 - edge_l;
+ ptsOut++->y = y;
+ *width++ = pAET->nextWETE->bres.minor - pAET->bres.minor - 1 + edge_l + edge_r;
+ nPts++;
+
+ /*
+ * send out the buffer
+ */
+ if (nPts == NUMPTSTOBUFFER)
+ {
+ processSpans(nPts, (QPoint*)FirstPoint, FirstWidth);
+ ptsOut = FirstPoint;
+ width = FirstWidth;
+ nPts = 0;
+ }
+
+ pWETE = pWETE->nextWETE;
+ while (pWETE != pAET) {
+ EVALUATEEDGEWINDING(pAET, pPrevAET, y, fixWAET)
+ }
+ pWETE = pWETE->nextWETE;
+ }
+ EVALUATEEDGEWINDING(pAET, pPrevAET, y, fixWAET)
+ }
+
+ /*
+ * reevaluate the Winding active edge table if we
+ * just had to resort it or if we just exited an edge.
+ */
+ if (miInsertionSort(&AET) || fixWAET)
+ {
+ micomputeWAET(&AET);
+ fixWAET = 0;
+ }
+ }
+ }
+
+ /*
+ * Get any spans that we missed by buffering
+ */
+
+
+ processSpans(nPts, (QPoint*)FirstPoint, FirstWidth);
+ free(pETEs);
+ miFreeStorage(SLLBlock.next);
+}
+/***** END OF X11-based CODE *****/
+
+QT_END_NAMESPACE