[cairo] Gradient mesh rasterizer

[Adrian Johnson]

Andrea Canciani wrote:
> I'm working on extending cairo patterns to handle tensor product
> shading patterns (type 7 in pdf reference).
> Right now I can rasterize them, but my code isn't fast and clean as it
> should, anyway Adrian Johnson suggested me to post it here as there
> are performance expert reading this list.
> In the comments I tried to point out known performance problems and
> possible solutions.
> The code should be linked to cairo and libm. Please pay attantion when
> running it because it overwrites the file "mesh.png" in the current
> directory with a rendering of a gradient mesh (hardcoded in the main
> function).
> Please notify me about any glitches you get.
> Andrea Canciani


This looks fantastic. Last year I started work on coding the Type 7 
gradient mesh API discussed at the cairo summit along with support for 
the PDF backend. I'll dig out that code and add your rasterizer so the 
output can be compared with the PDF output rendered with Adobe Reader. 
This will also make it easier to write test cases and measure the 
performance of your rasterizer.