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A comment on The Littlest CPU Rasterizer. Parent comment

Re:The Littlest CPU Rasterizer by ginko on Monday March 10, 2014 @07:20PM (#7376353)
For concave shapes like letters the best choice would probably be a scanline-based rasterization algorithm.

Sort all polygon edges from top to bottom and walk through that list line-by-line, keeping track of all active edges for each scanline. For those you can then find all intersections and fill the ranges in-between. By using an even-odd rule you can make sure that concave polygons and polygons with holes are filled properly.

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Re:The Littlest CPU Rasterizer by ginsweater on Monday March 10, 2014 @10:16PM (#7377033)
I wrote one of those once! It was a nightmare morass of one-pixel errors. Maybe there was some clever simplification I missed that would have made it all easy, but these days I use the libraries. :P

I know that's how stb_truetype's renderer works, incidentally. Don't know if Freetype is the same, but I'd be mildly surprised to find it wasn't.

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