I've been working on trying to render trimmed NURBS in WebGL for a CAD project (not a game, I know). I've got all the help I need on the math side of this, but core of the method I'm working with makes me divide things up into monotone polygons. My approach is to triangulate the monotone polygons using the method in this PPT by Garey et. al., then throw that into my shader via VBOs and index buffers.
My real worry is that this could potentially generate 100s of small monotone polygons, which means 100s of VBOs and index buffers that I would have to link to a single surface object. The upside is that I'd only have to do this once per surface, so once it's done, it's up to the shaders to move things around.
I guess I'm just looking for potential gotchas with this as far as performance or maybe there's a better way to do things than the way I'm thinking. I've tried to find a way to offload the work to the shader, but I can't find a good way. Maybe there's a way to stitch the monotone polygons together...I'm not sure. I'm throwing this to the community for feedback.