+++ /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);
-}