ppsspp/assets/shaders/fxaa.fsh
Henrik Rydgard 7d8aed096a Add proper support for upscaling shaders, add Spline36 upscaling
Spline36 isn't as amazing as I had hoped heh. And it will need work to
work in GLSL ES. Anyway...

This also renames u_texcoordDelta to u_texelDelta to fit in with u_pixelDelta.
2013-10-22 12:18:49 +02:00

69 lines
2.5 KiB
GLSL

// PPSSPP: Grabbed from Processing and slightly modified.
// FXAA shader, GLSL code adapted from:
// http://horde3d.org/wiki/index.php5?title=Shading_Technique_-_FXAA
// Whitepaper describing the technique:
// http://developer.download.nvidia.com/assets/gamedev/files/sdk/11/FXAA_WhitePaper.pdf
#ifdef GL_ES
precision mediump float;
precision mediump int;
#endif
uniform sampler2D sampler0;
// The inverse of the texture dimensions along X and Y
uniform vec2 u_texelDelta;
varying vec2 v_texcoord0;
void main() {
// The parameters are hardcoded for now, but could be
// made into uniforms to control fromt he program.
float FXAA_SPAN_MAX = 8.0;
float FXAA_REDUCE_MUL = 1.0/8.0;
float FXAA_REDUCE_MIN = (1.0/128.0);
vec3 rgbNW = texture2D(sampler0, v_texcoord0.xy + (vec2(-1.0, -1.0) * u_texelDelta)).xyz;
vec3 rgbNE = texture2D(sampler0, v_texcoord0.xy + (vec2(+1.0, -1.0) * u_texelDelta)).xyz;
vec3 rgbSW = texture2D(sampler0, v_texcoord0.xy + (vec2(-1.0, +1.0) * u_texelDelta)).xyz;
vec3 rgbSE = texture2D(sampler0, v_texcoord0.xy + (vec2(+1.0, +1.0) * u_texelDelta)).xyz;
vec3 rgbM = texture2D(sampler0, v_texcoord0.xy).xyz;
vec3 luma = vec3(0.299, 0.587, 0.114);
float lumaNW = dot(rgbNW, luma);
float lumaNE = dot(rgbNE, luma);
float lumaSW = dot(rgbSW, luma);
float lumaSE = dot(rgbSE, luma);
float lumaM = dot( rgbM, luma);
float lumaMin = min(lumaM, min(min(lumaNW, lumaNE), min(lumaSW, lumaSE)));
float lumaMax = max(lumaM, max(max(lumaNW, lumaNE), max(lumaSW, lumaSE)));
vec2 dir;
dir.x = -((lumaNW + lumaNE) - (lumaSW + lumaSE));
dir.y = ((lumaNW + lumaSW) - (lumaNE + lumaSE));
float dirReduce = max((lumaNW + lumaNE + lumaSW + lumaSE) * (0.25 * FXAA_REDUCE_MUL), FXAA_REDUCE_MIN);
float rcpDirMin = 1.0/(min(abs(dir.x), abs(dir.y)) + dirReduce);
dir = min(vec2(FXAA_SPAN_MAX, FXAA_SPAN_MAX),
max(vec2(-FXAA_SPAN_MAX, -FXAA_SPAN_MAX), dir * rcpDirMin)) * u_texelDelta;
vec3 rgbA = (1.0/2.0) * (
texture2D(sampler0, v_texcoord0.xy + dir * (1.0/3.0 - 0.5)).xyz +
texture2D(sampler0, v_texcoord0.xy + dir * (2.0/3.0 - 0.5)).xyz);
vec3 rgbB = rgbA * (1.0/2.0) + (1.0/4.0) * (
texture2D(sampler0, v_texcoord0.xy + dir * (0.0/3.0 - 0.5)).xyz +
texture2D(sampler0, v_texcoord0.xy + dir * (3.0/3.0 - 0.5)).xyz);
float lumaB = dot(rgbB, luma);
if((lumaB < lumaMin) || (lumaB > lumaMax)){
gl_FragColor.xyz=rgbA;
} else {
gl_FragColor.xyz=rgbB;
}
gl_FragColor.a = 1.0;
}