By scanline rasterizer I assumed a system similar to the original Quake scene rasterizer best described in Michael Abrash's Graphics Programming Black Book.
The method allows saving substantially on any overdraw since fillrate is really the primary bottleneck here.
I did a quick check on your page and it seems the implementation describes a per triangle setup vs the more complicated solution by Carmack and his team? Could still work well for larger triangles, maybe with a check on triangle size to avoid really small ones.
Quake did after all utilize 3 different rasterizers to optimize performance depending on use case.
The method allows saving substantially on any overdraw since fillrate is really the primary bottleneck here.
I did a quick check on your page and it seems the implementation describes a per triangle setup vs the more complicated solution by Carmack and his team? Could still work well for larger triangles, maybe with a check on triangle size to avoid really small ones.
Quake did after all utilize 3 different rasterizers to optimize performance depending on use case.