gfx/cairo/pixman-image-transform.patch

   1 # HG changeset patch
   2 # User Jeff Muizelaar <jmuizelaar@mozilla.com>
   3 # Date 1299543337 18000
   4 # Node ID 57f411f16517fa3abc31b6b081dd31420c4d9b45
   5 # Parent  e56ecd8b3a68c158025207c5fd081d043e28f5ce
   6 Bug 637828. Reset the transform on the dest image. r=joe
   7
   8 We can get into a situation where the destination image has a transform
   9 because we use it as source. The transform set when the image is a source
  10 sticks around and when we use it as a destination pixman gets confused.
  11
  12 It seems like the code at fault here is really pixman. I think that pixman
  13 should probably not be using a transformed fetch on the destination image under
  14 any circumstances.
  15
  16 For example, in this case we're fetching destination pixels from a different
  17 part of the image than we're storing them to. I can't see any reason for
  18 wanting this behaviour.
  19
  20 However, reseting the transform seemed like the easiest solution.
  21
  22 diff --git a/gfx/cairo/cairo/src/cairo-image-surface.c b/gfx/cairo/cairo/src/cairo-image-surface.c
  23 --- a/gfx/cairo/cairo/src/cairo-image-surface.c
  24 +++ b/gfx/cairo/cairo/src/cairo-image-surface.c
  25 @@ -1138,16 +1138,27 @@ _cairo_image_surface_composite (cairo_op
  26         return status;
  27
  28      status = _cairo_image_surface_set_attributes (src, &src_attr,
  29                                                   dst_x + width / 2.,
  30                                                   dst_y + height / 2.);
  31      if (unlikely (status))
  32         goto CLEANUP_SURFACES;
  33
  34 +    /* we sometimes get destinations with transforms.
  35 +     * we're not equiped to deal with this */
  36 +    {
  37 +        static const pixman_transform_t id = {
  38 +           {{ pixman_fixed_1, 0, 0 },
  39 +            { 0, pixman_fixed_1, 0 },
  40 +            { 0, 0, pixman_fixed_1 }}
  41 +        };
  42 +        pixman_image_set_transform (dst->pixman_image, &id);
  43 +    }
  44 +
  45      if (mask) {
  46         status = _cairo_image_surface_set_attributes (mask, &mask_attr,
  47                                                       dst_x + width / 2.,
  48                                                       dst_y + height / 2.);
  49         if (unlikely (status))
  50             goto CLEANUP_SURFACES;
  51
  52         pixman_image_composite (_pixman_operator (op),