On Fri, Aug 27, 2010 at 10:18 AM, Chris Marrin <cmar...@apple.com> wrote: > > Hi Ken, > It would help me, and I think many others, if we could have a discussion of > how exactly your tessellation logic works and what it is intended to do. For > instance, is the algorithm you're using based on Loop-Blinn? I'm a bit > familiar with that algorithm and some of the problems it has with rendering > this type of geometry. For instance, there are typically anti-aliasing > artifacts at the points where the interior triangles touch the edges. These > are described in section 5.1 of the paper and the authors added additional > (and not well described) logic to solve the problem. > If you could describe your algorithm a bit and show some expected results > with typical cases, that would be really helpful. > For those not familiar with Loop-Blinn, here is a link to their original > paper, presented at Siggraph 2005: > Resolution Independent Curve Rendering using Programmable Graphics ... > It's a great algorithm for rendering resolution independent 2D objects using > the GPU. It has potential to render both 2D shapes (as used in Canvas and > SVG) and text glyphs. It's advantage is that once you generate the triangles > for the shape, you can render the shape at any resolution. It's disadvantage > is that the triangle generation is quite expensive, so mutating shapes can > potentially be slower than a simpler resolution dependent tessellation.
I think there's a variant of the algorithm that uses the stencil buffer polygon rendering method ( http://zrusin.blogspot.com/2006/07/hardware-accelerated-polygon-rendering.html ) instead of triangulation. The paper I think I read on that only covered quadratic splines, but maybe somehow has extended that method to cubic splines by now? Nico > ----- > ~Chris > cmar...@apple.com > > > > > _______________________________________________ > webkit-dev mailing list > webkit-dev@lists.webkit.org > http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev > > _______________________________________________ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
