--- /dev/null
+/***********************************************************
+
+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.
+
+******************************************************************/
+/* $XConsortium: mipolycon.c,v 5.1 94/04/17 20:27:43 keith Exp $ */
+#include "gcstruct.h"
+#include "pixmap.h"
+#include "miscanfill.h"
+
+static int getPolyYBounds();
+
+/*
+ * convexpoly.c
+ *
+ * Written by Brian Kelleher; Dec. 1985.
+ *
+ * Fill a convex polygon. If the given polygon
+ * is not convex, then the result is undefined.
+ * The algorithm is to order the edges from smallest
+ * y to largest by partitioning the array into a left
+ * edge list and a right edge list. The algorithm used
+ * to traverse each edge is an extension of Bresenham's
+ * line algorithm with y as the major axis.
+ * For a derivation of the algorithm, see the author of
+ * this code.
+ */
+Bool
+miFillConvexPoly(dst, pgc, count, ptsIn)
+ DrawablePtr dst;
+ GCPtr pgc;
+ int count; /* number of points */
+ DDXPointPtr ptsIn; /* the points */
+{
+ register int xl, xr; /* x vals of left and right edges */
+ register int dl, dr; /* decision variables */
+ register int ml, m1l; /* left edge slope and slope+1 */
+ int mr, m1r; /* right edge slope and slope+1 */
+ int incr1l, incr2l; /* left edge error increments */
+ int incr1r, incr2r; /* right edge error increments */
+ int dy; /* delta y */
+ int y; /* current scanline */
+ int left, right; /* indices to first endpoints */
+ int i; /* loop counter */
+ int nextleft, nextright; /* indices to second endpoints */
+ DDXPointPtr ptsOut, FirstPoint; /* output buffer */
+ int *width, *FirstWidth; /* output buffer */
+ int imin; /* index of smallest vertex (in y) */
+ int ymin; /* y-extents of polygon */
+ int ymax;
+
+ /*
+ * find leftx, bottomy, rightx, topy, and the index
+ * of bottomy. Also translate the points.
+ */
+ imin = getPolyYBounds(ptsIn, count, &ymin, &ymax);
+
+ dy = ymax - ymin + 1;
+ if ((count < 3) || (dy < 0))
+ return(TRUE);
+ ptsOut = FirstPoint = (DDXPointPtr )ALLOCATE_LOCAL(sizeof(DDXPointRec)*dy);
+ width = FirstWidth = (int *)ALLOCATE_LOCAL(sizeof(int) * dy);
+ if(!FirstPoint || !FirstWidth)
+ {
+ if (FirstWidth) DEALLOCATE_LOCAL(FirstWidth);
+ if (FirstPoint) DEALLOCATE_LOCAL(FirstPoint);
+ return(FALSE);
+ }
+
+ nextleft = nextright = imin;
+ y = ptsIn[nextleft].y;
+
+ /*
+ * loop through all edges of the polygon
+ */
+ do {
+ /*
+ * add a left edge if we need to
+ */
+ if (ptsIn[nextleft].y == y) {
+ left = nextleft;
+
+ /*
+ * find the next edge, considering the end
+ * conditions of the array.
+ */
+ nextleft++;
+ if (nextleft >= count)
+ nextleft = 0;
+
+ /*
+ * now compute all of the random information
+ * needed to run the iterative algorithm.
+ */
+ BRESINITPGON(ptsIn[nextleft].y-ptsIn[left].y,
+ ptsIn[left].x,ptsIn[nextleft].x,
+ xl, dl, ml, m1l, incr1l, incr2l);
+ }
+
+ /*
+ * add a right edge if we need to
+ */
+ if (ptsIn[nextright].y == y) {
+ right = nextright;
+
+ /*
+ * find the next edge, considering the end
+ * conditions of the array.
+ */
+ nextright--;
+ if (nextright < 0)
+ nextright = count-1;
+
+ /*
+ * now compute all of the random information
+ * needed to run the iterative algorithm.
+ */
+ BRESINITPGON(ptsIn[nextright].y-ptsIn[right].y,
+ ptsIn[right].x,ptsIn[nextright].x,
+ xr, dr, mr, m1r, incr1r, incr2r);
+ }
+
+ /*
+ * generate scans to fill while we still have
+ * a right edge as well as a left edge.
+ */
+ i = min(ptsIn[nextleft].y, ptsIn[nextright].y) - y;
+ /* in case we're called with non-convex polygon */
+ if(i < 0)
+ {
+ DEALLOCATE_LOCAL(FirstWidth);
+ DEALLOCATE_LOCAL(FirstPoint);
+ return(TRUE);
+ }
+ while (i-- > 0)
+ {
+ ptsOut->y = y;
+
+ /*
+ * reverse the edges if necessary
+ */
+ if (xl < xr)
+ {
+ *(width++) = xr - xl;
+ (ptsOut++)->x = xl;
+ }
+ else
+ {
+ *(width++) = xl - xr;
+ (ptsOut++)->x = xr;
+ }
+ y++;
+
+ /* increment down the edges */
+ BRESINCRPGON(dl, xl, ml, m1l, incr1l, incr2l);
+ BRESINCRPGON(dr, xr, mr, m1r, incr1r, incr2r);
+ }
+ } while (y != ymax);
+
+ /*
+ * Finally, fill the <remaining> spans
+ */
+ (*pgc->ops->FillSpans)(dst, pgc,
+ ptsOut-FirstPoint,FirstPoint,FirstWidth,
+ 1);
+ DEALLOCATE_LOCAL(FirstWidth);
+ DEALLOCATE_LOCAL(FirstPoint);
+ return(TRUE);
+}
+
+\f
+/*
+ * Find the index of the point with the smallest y.
+ */
+static
+int
+getPolyYBounds(pts, n, by, ty)
+ DDXPointPtr pts;
+ int n;
+ int *by, *ty;
+{
+ register DDXPointPtr ptMin;
+ int ymin, ymax;
+ DDXPointPtr ptsStart = pts;
+
+ ptMin = pts;
+ ymin = ymax = (pts++)->y;
+
+ while (--n > 0) {
+ if (pts->y < ymin)
+ {
+ ptMin = pts;
+ ymin = pts->y;
+ }
+ if(pts->y > ymax)
+ ymax = pts->y;
+
+ pts++;
+ }
+
+ *by = ymin;
+ *ty = ymax;
+ return(ptMin-ptsStart);
+}
projects / rdpsrv / blobdiff