Rendering in geode

[Jonathan Morton]

On Tue, 2010-06-22 at 17:40 +0800, Huang, FrankR wrote:
> We do need a complete description on the condition that the Source
> coordinates are outside the image. Because when I fixed this, another
> rendering issue in firefox is appearing with my patch. Some characters
> are missing in the rendering in firefox.

Assuming that you are rejecting all attributes that you cannot handle at
all (eg. transforms, component-alpha, etc.), the situation with
coordinates is not very complex.  The handling of coordinates outside a
source image's native rectangle depends entirely on the Repeat attribute
and the operation being performed, as I have already described.

The one remaining subtlety is that the same rules apply to images
provided as masks.  All of the same attributes apply separately to mask
images as to source images.  As a result, if coordinates land outside
the mask image with it's Repeat attribute cleared, these areas will also
become no-ops in Over mode or zero-fills in Src mode.

Finally, remember that source images with 1x1 dimensions and the Repeat
attribute set are very common, especially during text rendering, and are
to be treated as solid colours.  Mask images with these properties are
less common but still legal.  Both of these conditions can be detected
at setup time.

-- 
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From: Jonathan Morton
      jonathan.morton at movial.com