> I'm working on Giga/PicoDrive, a Megadrive emulator, a bit at the moment. When I
> did a few measurements a few weeks ago I found 4ms was used on cpu, and 20ms
> used on graphics rendering on a GP32.
>
> So I thought I may take a bit of time to jump up and down on the tile rendering
> and make it a bit more efficent. It's a line by line renderer at the moment,
> which I'm keen to hold onto for at long as possible because it makes raster
> effects so easy. But I may have to lose that at some point or at least make two
> graphics engines.

Why? You could simply use a normal tile engine and add some stuff to make clipping efficient, e.g. only parse the needed parts of the tilemap.