FreonLinux/system/tinyx/fb/fbarc.c

/*
 *
 * Copyright © 1998 Keith Packard
 *
 * 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, and that the name of Keith Packard not be used in
 * advertising or publicity pertaining to distribution of the software without
 * specific, written prior permission.  Keith Packard makes no
 * representations about the suitability of this software for any purpose.  It
 * is provided "as is" without express or implied warranty.
 *
 * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL KEITH PACKARD 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 "fb.h"
#include "mizerarc.h"
#include <limits.h>

typedef void (*FbArc) (FbBits * dst,
                       FbStride dstStride,
                       int dstBpp,
                       xArc * arc, int dx, int dy, FbBits and, FbBits xor);

void
fbPolyArc(DrawablePtr pDrawable, GCPtr pGC, int narcs, xArc * parcs)
{
    FbArc arc;

    if (pGC->lineWidth == 0) {
        arc = 0;
        if (pGC->lineStyle == LineSolid && pGC->fillStyle == FillSolid) {
            switch (pDrawable->bitsPerPixel) {
            case 8:
                arc = fbArc8;
                break;
            case 16:
                arc = fbArc16;
                break;
            case 24:
                arc = fbArc24;
                break;
            case 32:
                arc = fbArc32;
                break;
            }
        }
        if (arc) {
            FbGCPrivPtr pPriv = fbGetGCPrivate(pGC);

            FbBits *dst;

            FbStride dstStride;

            int dstBpp;

            int dstXoff, dstYoff;

            BoxRec box;

            int x2, y2;

            RegionPtr cclip;

            cclip = fbGetCompositeClip(pGC);
            fbGetDrawable(pDrawable, dst, dstStride, dstBpp, dstXoff, dstYoff);
            while (narcs--) {
                if (miCanZeroArc(parcs)) {
                    box.x1 = parcs->x + pDrawable->x;
                    box.y1 = parcs->y + pDrawable->y;
                    /*
                     * Because box.x2 and box.y2 get truncated to 16 bits, and the
                     * RECT_IN_REGION test treats the resulting number as a signed
                     * integer, the RECT_IN_REGION test alone can go the wrong way.
                     * This can result in a server crash because the rendering
                     * routines in this file deal directly with cpu addresses
                     * of pixels to be stored, and do not clip or otherwise check
                     * that all such addresses are within their respective pixmaps.
                     * So we only allow the RECT_IN_REGION test to be used for
                     * values that can be expressed correctly in a signed short.
                     */
                    x2 = box.x1 + (int) parcs->width + 1;
                    box.x2 = x2;
                    y2 = box.y1 + (int) parcs->height + 1;
                    box.y2 = y2;
                    if ((x2 <= SHRT_MAX) && (y2 <= SHRT_MAX) &&
                        (RECT_IN_REGION(cclip, &box) ==
                         rgnIN))
                        (*arc) (dst, dstStride, dstBpp, parcs,
                                pDrawable->x + dstXoff, pDrawable->y + dstYoff,
                                pPriv->and, pPriv->xor);
                    else
                        miZeroPolyArc(pDrawable, pGC, 1, parcs);
                }
                else
                    miPolyArc(pDrawable, pGC, 1, parcs);
                parcs++;
            }
        }
        else
            miZeroPolyArc(pDrawable, pGC, narcs, parcs);
    }
    else
        miPolyArc(pDrawable, pGC, narcs, parcs);
}