Triangle Sweep-Line Algorithm
void ScanTriangle(Triangle T, Color rgba){
for each edge pair {
initialize xL, xR;
compute dxL/dyL and dxR/dyR;
for each scanline at y for (int x = xL; x <= xR; x++)
SetPixel(x, y, rgba);
xL += dxL/dyL;
xR += dxR/dyR;
}
}