[ysuter]

has anyone already implemented a trifiller on the j2me platform? which algorithm would you sugest to use? scanline filling? recursive is not possible, as you might geht a stack overflow..

[remonvv]

I dont see how you would use recursion for a trifiller anyway. I have java code that scans triangles. It' pretty straightforward, especially if you limit it to just triangles :

1) Sort vertices by y coord.
2) determine long edge (over y axis)
3) Use modified bresenham line algorithm to scan top short edge against long edge
4) Use modified bresenham line algorithm to scan bottom short edge against long edge
5) Store coords in array
6) Draw horizontal spans

Easy..

[ysuter]

yeah sure.. well, if you want to implement a substitute function for polyfill (not just a triangle) when you might think about recursive filling. =) But you're right that for simple triangles there is no need of resursion.

[remonvv]

no you dont, recursion is not a viable approach for any graphical primitive. It's not a "flood fill" kinda thing. With more edges the only thing that gets more complicated is the edge sorting, if you want to support complex polies (self intersecting etc.) the span algorithm wil also complicate somewhat. However, you never use recursion for something such as this, for the simple reason that you'll get stack overflows or out of memory exceptions whenever you render a complicated scene, not to mention that it's horribly slow.