xorg-server-1.4/fb/fbarc.c

   1 /*
   2  * Copyright © 1998 Keith Packard
   3  *
   4  * Permission to use, copy, modify, distribute, and sell this software and its
   5  * documentation for any purpose is hereby granted without fee, provided that
   6  * the above copyright notice appear in all copies and that both that
   7  * copyright notice and this permission notice appear in supporting
   8  * documentation, and that the name of Keith Packard not be used in
   9  * advertising or publicity pertaining to distribution of the software without
  10  * specific, written prior permission.  Keith Packard makes no
  11  * representations about the suitability of this software for any purpose.  It
  12  * is provided "as is" without express or implied warranty.
  13  *
  14  * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  15  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  16  * EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  17  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  18  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  19  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  20  * PERFORMANCE OF THIS SOFTWARE.
  21  */
  22
  23 #ifdef HAVE_DIX_CONFIG_H
  24 #include <dix-config.h>
  25 #endif
  26
  27 #include "fb.h"
  28 #include "mizerarc.h"
  29 #include <limits.h>
  30
  31 typedef void    (*FbArc) (FbBits    *dst,
  32                           FbStride  dstStride,
  33                           int       dstBpp,
  34                           xArc      *arc,
  35                           int       dx,
  36                           int       dy,
  37                           FbBits    and,
  38                           FbBits    xor);
  39
  40 void
  41 fbPolyArc (DrawablePtr  pDrawable,
  42            GCPtr        pGC,
  43            int          narcs,
  44            xArc         *parcs)
  45 {
  46     FbArc       arc;
  47
  48     if (pGC->lineWidth == 0)
  49     {
  50 #ifndef FBNOPIXADDR
  51         arc = 0;
  52         if (pGC->lineStyle == LineSolid && pGC->fillStyle == FillSolid)
  53         {
  54             switch (pDrawable->bitsPerPixel)
  55             {
  56             case 8:     arc = fbArc8; break;
  57             case 16:    arc = fbArc16; break;
  58 #ifdef FB_24BIT
  59             case 24:    arc = fbArc24; break;
  60 #endif
  61             case 32:    arc = fbArc32; break;
  62             }
  63         }
  64         if (arc)
  65         {
  66             FbGCPrivPtr pPriv = fbGetGCPrivate (pGC);
  67             FbBits      *dst;
  68             FbStride    dstStride;
  69             int         dstBpp;
  70             int         dstXoff, dstYoff;
  71             BoxRec      box;
  72             int         x2, y2;
  73             RegionPtr   cclip;
  74
  75             cclip = fbGetCompositeClip (pGC);
  76             fbGetDrawable (pDrawable, dst, dstStride, dstBpp, dstXoff, dstYoff);
  77             while (narcs--)
  78             {
  79                 if (miCanZeroArc (parcs))
  80                 {
  81                     box.x1 = parcs->x + pDrawable->x;
  82                     box.y1 = parcs->y + pDrawable->y;
  83                     /*
  84                      * Because box.x2 and box.y2 get truncated to 16 bits, and the
  85                      * RECT_IN_REGION test treats the resulting number as a signed
  86                      * integer, the RECT_IN_REGION test alone can go the wrong way.
  87                      * This can result in a server crash because the rendering
  88                      * routines in this file deal directly with cpu addresses
  89                      * of pixels to be stored, and do not clip or otherwise check
  90                      * that all such addresses are within their respective pixmaps.
  91                      * So we only allow the RECT_IN_REGION test to be used for
  92                      * values that can be expressed correctly in a signed short.
  93                      */
  94                     x2 = box.x1 + (int)parcs->width + 1;
  95                     box.x2 = x2;
  96                     y2 = box.y1 + (int)parcs->height + 1;
  97                     box.y2 = y2;
  98                     if ( (x2 <= SHRT_MAX) && (y2 <= SHRT_MAX) &&
  99                         (RECT_IN_REGION(pDrawable->pScreen, cclip, &box) == rgnIN) )
 100                         (*arc) (dst, dstStride, dstBpp,
 101                                 parcs, pDrawable->x + dstXoff, pDrawable->y + dstYoff,
 102                                 pPriv->and, pPriv->xor);
 103                     else
 104                         miZeroPolyArc(pDrawable, pGC, 1, parcs);
 105                 }
 106                 else
 107                     miPolyArc(pDrawable, pGC, 1, parcs);
 108                 parcs++;
 109             }
 110             fbFinishAccess (pDrawable);
 111         }
 112         else
 113 #endif
 114             miZeroPolyArc (pDrawable, pGC, narcs, parcs);
 115     }
 116     else
 117         miPolyArc (pDrawable, pGC, narcs, parcs);
 118 }