Custom PPSSPP shaders

[LunaMoo]

@bdszoke I guess you're cutting way too much from the distance in the clamp function. 0.5 is the center of the screen, so if you -0.7 the result is ALWAYS outside of the screen, and so you'll never see any changes to the effect itself, only the non affected portion will change.

Basically in:
float distance = dot(v_texcoord0 - 0.5, v_texcoord0 - 0.5);
distance = clamp(distance - 0.7, 0.0, 1.0);
float vignette = 1.0 + 0.7 * (distance * 3.0);

change "3.0" to increase/decrease brightness of the effect, and change "0.7"(in second line) to lower values like 0.25 or something to actually see the effect on the screen, as I explained anything above 0.5 will remove the effect totally(effect of your shader, not of the one in game).

Edit: also mathematically 1.0 + 0.7 * (distance * 3.0) equals to 1.0 + distance * 2,1 so you can simplify this

Another Edit: you should check this:3 might be better than your shader tries.