tightvnc-1.3dev5-vncviewer-alpha-cursor.patch

   1 --- vnc_unixsrc.orig/vncviewer/cursor.c 2003-01-15 04:46:52.000000000 -0500
   2 +++ vnc_unixsrc/vncviewer/cursor.c      2005-02-05 12:28:10.000000000 -0500
   3 @@ -472,6 +472,140 @@
   4    int offset, bytesPerPixel;
   5    char *pos;
   6
   7 +#define alphahack
   8 +#ifdef alphahack
   9 +  /* hack to have cursor transparency at 32bpp <runge@karlrunge.com> */
  10 +  static int alphablend = -1;
  11 +
  12 +  if (alphablend < 0) {
  13 +       /* you have to set NO_ALPHABLEND=1 in your environment to disable */
  14 +       if (getenv("NO_ALPHABLEND")) {
  15 +               alphablend = 0;
  16 +       } else {
  17 +               alphablend = 1;
  18 +       }
  19 +  }
  20 +
  21 +  bytesPerPixel = myFormat.bitsPerPixel / 8;
  22 +
  23 +  if (alphablend && bytesPerPixel == 4) {
  24 +       unsigned long pixel, put, *upos, *upix;
  25 +       int got_alpha = 0, rsX, rsY, rsW, rsH;
  26 +       static XImage *image = NULL;
  27 +       static int iwidth = 128;
  28 +
  29 +       if (! image) {
  30 +               /* watch out for tiny fb (rare) */
  31 +               if (iwidth > si.framebufferWidth) {
  32 +                       iwidth = si.framebufferWidth;
  33 +               }
  34 +               if (iwidth > si.framebufferHeight) {
  35 +                       iwidth = si.framebufferHeight;
  36 +               }
  37 +
  38 +               /* initialize an XImage with a chunk of desktopWin */
  39 +               image = XGetImage(dpy, desktopWin, 0, 0, iwidth, iwidth,
  40 +                   AllPlanes, ZPixmap);
  41 +       }
  42 +
  43 +       /* first check if there is any non-zero alpha channel data at all: */
  44 +       for (y = 0; y < rcHeight; y++) {
  45 +               for (x = 0; x < rcWidth; x++) {
  46 +                       int alpha;
  47 +
  48 +                       offset = y * rcWidth + x;
  49 +                       pos = (char *)&rcSource[offset * bytesPerPixel];
  50 +
  51 +                       upos = (unsigned long *) pos;
  52 +                       alpha = (*upos & 0xff000000) >> 24;
  53 +                       if (alpha) {
  54 +                               got_alpha = 1;
  55 +                               break;
  56 +                       }
  57 +               }
  58 +               if (got_alpha) {
  59 +                       break;
  60 +               }
  61 +       }
  62 +
  63 +       if (!got_alpha) {
  64 +               /* no alpha channel data, fallback to the old way */
  65 +               goto oldway;
  66 +       }
  67 +
  68 +       /* load the saved fb patch in to image (faster way?) */
  69 +       XGetSubImage(dpy, rcSavedArea, 0, 0, rcWidth, rcHeight,
  70 +           AllPlanes, ZPixmap, image, 0, 0);
  71 +       upix = (unsigned long *)image->data;
  72 +
  73 +       /* if the richcursor is clipped, the fb patch will be smaller */
  74 +       rsW = rcWidth;
  75 +       rsX = 0;        /* used to denote a shift from the left side */
  76 +       x = rcCursorX - rcHotX;
  77 +       if (x < 0) {
  78 +               rsW += x;
  79 +               rsX = -x;
  80 +       } else if (x + rsW > si.framebufferWidth) {
  81 +               rsW = si.framebufferWidth - x;
  82 +       }
  83 +       rsH = rcHeight;
  84 +       rsY = 0;        /* used to denote a shift from the top side */
  85 +       y = rcCursorY - rcHotY;
  86 +       if (y < 0) {
  87 +               rsH += y;
  88 +               rsY = -y;
  89 +       } else if (y + rsH > si.framebufferHeight) {
  90 +               rsH = si.framebufferHeight - y;
  91 +       }
  92 +
  93 +       /*
  94 +        * now loop over the cursor data, blend in the fb values,
  95 +        * and then overwrite the fb (CopyDataToScreen())
  96 +        */
  97 +       for (y = 0; y < rcHeight; y++) {
  98 +               y0 = rcCursorY - rcHotY + y;
  99 +               if (y0 < 0 || y0 >= si.framebufferHeight) {
 100 +                       continue;       /* clipped */
 101 +               }
 102 +               for (x = 0; x < rcWidth; x++) {
 103 +                       int alpha, color_curs, color_fb, i;
 104 +
 105 +                       x0 = rcCursorX - rcHotX + x;
 106 +                       if (x0 < 0 || x0 >= si.framebufferWidth) {
 107 +                               continue;       /* clipped */
 108 +                       }
 109 +
 110 +                       offset = y * rcWidth + x;
 111 +                       pos = (char *)&rcSource[offset * bytesPerPixel];
 112 +
 113 +                       /* extract secret alpha byte from rich cursor: */
 114 +                       upos = (unsigned long *) pos;
 115 +                       alpha = (*upos & 0xff000000) >> 24;     /* XXX MSB? */
 116 +
 117 +                       /* extract the pixel from the fb: */
 118 +                       pixel = *(upix + (y-rsY)*iwidth + (x-rsX));
 119 +
 120 +                       put = 0;
 121 +                       /* for simplicity, blend all 4 bytes */
 122 +                       for (i = 0; i < 4; i++) {
 123 +                               int sh = i*8;
 124 +                               color_curs = ((0xff << sh) & *upos) >> sh;
 125 +                               color_fb   = ((0xff << sh) & pixel) >> sh;
 126 +
 127 +                               /* XXX assumes pre-multipled color_curs */
 128 +                               color_fb = color_curs
 129 +                                   + ((0xff - alpha) * color_fb)/0xff;
 130 +                               put |= color_fb << sh;
 131 +                       }
 132 +                       /* place in the fb: */
 133 +                       CopyDataToScreen((char *)&put, x0, y0, 1, 1);
 134 +               }
 135 +       }
 136 +       return;
 137 +  }
 138 +oldway:
 139 +#endif
 140 +
 141    bytesPerPixel = myFormat.bitsPerPixel / 8;
 142
 143    /* FIXME: Speed optimization is possible. */