mipolygen.c

/***********************************************************

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.

******************************************************************/
#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif

#include <X11/X.h>
#include "gcstruct.h"
#include "miscanfill.h"
#include "mipoly.h"
#include "pixmap.h"
#include "mi.h"

/*
 *
 *     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.
 */

Bool
miFillGeneralPoly(DrawablePtr dst, GCPtr pgc, int count,        /* number of points        */
                  DDXPointPtr ptsIn     /* the points              */
    )
{
    EdgeTableEntry *pAET;       /* the Active Edge Table   */
    int y;                      /* the current scanline    */
    int nPts = 0;               /* number of pts in buffer */
    EdgeTableEntry *pWETE;      /* Winding Edge Table      */
    ScanLineList *pSLL;         /* Current ScanLineList    */
    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;

    if (count < 3)
        return TRUE;

    if (!(pETEs = malloc(sizeof(EdgeTableEntry) * count)))
        return FALSE;
    ptsOut = FirstPoint;
    width = FirstWidth;
    if (!miCreateETandAET(count, ptsIn, &ET, &AET, pETEs, &SLLBlock)) {
        free(pETEs);
        return FALSE;
    }
    pSLL = ET.scanlines.next;

    if (pgc->fillRule == 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 && 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;
                ptsOut++->y = y;
                *width++ = pAET->next->bres.minor - pAET->bres.minor;
                nPts++;

                /*
                 *  send out the buffer when its full
                 */
                if (nPts == NUMPTSTOBUFFER) {
                    (*pgc->ops->FillSpans) (dst, pgc,
                                            nPts, FirstPoint, FirstWidth, 1);
                    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; y < ET.ymax; 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;
                    ptsOut++->y = y;
                    *width++ = pAET->nextWETE->bres.minor - pAET->bres.minor;
                    nPts++;

                    /*
                     *  send out the buffer
                     */
                    if (nPts == NUMPTSTOBUFFER) {
                        (*pgc->ops->FillSpans) (dst, pgc, nPts, FirstPoint,
                                                FirstWidth, 1);
                        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
     */
    (*pgc->ops->FillSpans) (dst, pgc, nPts, FirstPoint, FirstWidth, 1);
    free(pETEs);
    miFreeStorage(SLLBlock.next);
    return TRUE;
}