Maxim Shemanarev, the author of the open source anti-grain 2D rendering engine, seems to have tackled the curve stroking (dealing with cusps etc) pragmatically: http://www.antigrain.com/mcseem/index.html http://www.antigrain.com/mcseem/index.html http://www.antigrain.com/research/adaptive_bezier/index.html#PAGE_ADAPTIVE_B...
I did something similar in my car racing game (currently under development, naturally in Haskell ;), where the track is defined with B-splines. I keep subdividing those parts where the cosine of the angle between subsequent segments is below a certain limit. I also found that by adding well-chosen textures, this limit--hence the polygon count--can be decreased drastically without any perceivable loss in quality. Gergely -- http://www.fastmail.fm - Or how I learned to stop worrying and love email again