Scanlines rendering?

[vanfanel]

Hi,

Many engines reimplementations of 320x games nowadays implement scanlines, and games look awesome like that.
Coud you please implement the tv2x scanline method used by scummvm? It works nice along with SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "linear");
while other implementations don't, thus giving a VERY nive look to those games.

[Falcury]

Sounds interesting. I wonder how we could implement that.
Maybe scale up 320x200 to 640x400 first, then blend a texture that contains the scanlines into that. Then scale that further to the window size.
Or maybe we would have to migrate from SDL's Renderer API to OpenGL (so we could write our own scaling shaders). Don't know how easy or hard that would be.

[vanfanel]

@Falcury : I believe the tv2x filter in scummvm does precissely that (scale to double res, then apply an scanlines blend), and it looks great even in my 1380x768 monitor.
The shaders way...well... it would be better to port to RetroArch and then use the myriad of filters already available there: let another solid API take care of the shaders instead of writting a new renderer.