bsnes/shaders/AANN.shader/AANN.fs

94 lines
2.4 KiB
GLSL

#version 150
// AntiAliased Nearest Neighbor
// by jimbo1qaz and wareya
// Licensed MIT
precision highp float;
uniform sampler2D source[];
uniform vec4 sourceSize[];
uniform vec4 targetSize[];
in Vertex {
vec2 texCoord;
};
out vec4 fragColor;
#define NOT(fl) (1-fl)
#define YES(fl) fl
vec4 vpow(vec4 n, float e)
{
return vec4(pow(n.x, e), pow(n.y, e), pow(n.z, e), pow(n.w, e));
}
vec4 getLQV(vec3 mine) {
return vec4
( mine.r
, mine.g
, mine.b
, mine.r*0.2989 + mine.g*0.5870 + mine.b*0.1140);
}
vec3 fromLQV(vec4 mine) {
float f = mine.w/(mine.r*0.2989 + mine.g*0.5870 + mine.b*0.1140);
return vec3(mine.rgb)*f;
}
vec3 percent(float ssize, float tsize, float coord) {
float minfull = (coord*tsize - 0.5) /tsize*ssize;
float maxfull = (coord*tsize + 0.5) /tsize*ssize;
float realfull = floor(maxfull);
if (minfull > realfull) {
return vec3(1, (realfull+0.5)/ssize, (realfull+0.5)/ssize);
}
return vec3(
(maxfull - realfull) / (maxfull - minfull),
(realfull-0.5) / ssize,
(realfull+0.5) / ssize
);
}
void main() {
float cheapsrgb = 2.1;
float gamma = 3.0;
vec3 xstuff = percent(sourceSize[0].x, targetSize[0].x, texCoord.x);
vec3 ystuff = percent(sourceSize[0].y, targetSize[0].y, texCoord.y);
float xkeep = xstuff[0];
float ykeep = ystuff[0];
// get points to interpolate across, in linear rgb
vec4 a = getLQV(vpow(texture(source[0],vec2(xstuff[1],ystuff[1])), cheapsrgb).rgb);
vec4 b = getLQV(vpow(texture(source[0],vec2(xstuff[2],ystuff[1])), cheapsrgb).rgb);
vec4 c = getLQV(vpow(texture(source[0],vec2(xstuff[1],ystuff[2])), cheapsrgb).rgb);
vec4 d = getLQV(vpow(texture(source[0],vec2(xstuff[2],ystuff[2])), cheapsrgb).rgb);
// use perceptual gamma for luminance component
a.w = pow(a.w, 1/gamma);
b.w = pow(b.w, 1/gamma);
c.w = pow(c.w, 1/gamma);
d.w = pow(d.w, 1/gamma);
// interpolate
vec4 gammaLQVresult =
NOT(xkeep)*NOT(ykeep)*a +
YES(xkeep)*NOT(ykeep)*b +
NOT(xkeep)*YES(ykeep)*c +
YES(xkeep)*YES(ykeep)*d;
// change luminance gamma back to linear
vec4 LQVresult = gammaLQVresult;
LQVresult.w = pow(gammaLQVresult.w, gamma);
// convert back to srgb; lqv -> lrgb -> srgb
vec4 c1 = vpow(vec4(fromLQV(LQVresult), 1), 1/cheapsrgb);
fragColor = c1;
}