Aaron Spike wrote:
Joshua A. Andler wrote:
On Thu, 2009-12-24 at 08:14 -0600, Aaron Spike wrote:
Color in SVG includes an alpha channel. I've been told that rendering of Coons patch meshes is ambiguous when this is the case. Does this also affect Tensor-product patch meshes?
I'm curious about the ambiguity. Do you recall why that was said? I'm sure it's more technical, but if it works how I imagine it could, it could afford great artistic leverage.
IIRC extreme bends in the control beziers can cause the fill to self overlap. Transparent or semi-transparent colors would allow the deeper parts of the fill to bleed through. And once again, remember that I don't know what I'm talking about. :-)
There is an experimental implementation of mesh gradients for cairo at: http://cgit.freedesktop.org/~ajohnson/cairo/log/?h=mesh
This branch makes it easy to write a few test cases help understand how PDF Type 6 and 7 gradients work.
Some sample output (including self overlapping and transparency) is at: http://people.freedesktop.org/~ajohnson/mesh/