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.
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.