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kryx94
05-15-2014, 08:00 AM
hi everybody,

I'm starting in creating shaders with glsl and I have a problem:

I must use this shader (FXAA):


#version 120
#define FXAA_REDUCE_MIN (1.0/128.0)
#define FXAA_REDUCE_MUL (1.0/8.0)
#define FXAA_SPAN_MAX 8.0
uniform sampler2D sampler0;
uniform vec2 resolution;

void main(){
vec2 inverse_resolution=vec2(1.0/resolution.x,1.0/resolution.y);
vec3 rgbNW = texture2D(sampler0, (gl_FragCoord.xy + vec2(-1.0,-1.0)) * inverse_resolution).xyz;
vec3 rgbNE = texture2D(sampler0, (gl_FragCoord.xy + vec2(1.0,-1.0)) * inverse_resolution).xyz;
vec3 rgbSW = texture2D(sampler0, (gl_FragCoord.xy + vec2(-1.0,1.0)) * inverse_resolution).xyz;
vec3 rgbSE = texture2D(sampler0, (gl_FragCoord.xy + vec2(1.0,1.0)) * inverse_resolution).xyz;
vec3 rgbM = texture2D(sampler0, gl_FragCoord.xy * inverse_resolution).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)) * inverse_resolution;
vec3 rgbA = 0.5 * (texture2D(sampler0, gl_FragCoord.xy * inverse_resolution + dir * (1.0/3.0 - 0.5)).xyz + texture2D(sampler0, gl_FragCoord.xy * inverse_resolution + dir * (2.0/3.0 - 0.5)).xyz);
vec3 rgbB = rgbA * 0.5 + 0.25 * (texture2D(sampler0, gl_FragCoord.xy * inverse_resolution + dir * - 0.5).xyz + texture2D(sampler0, gl_FragCoord.xy * inverse_resolution + dir * 0.5).xyz);
float lumaB = dot(rgbB, luma);
if((lumaB < lumaMin) || (lumaB > lumaMax)) {
gl_FragColor = vec4(rgbA,1.0);
} else {
gl_FragColor = vec4(rgbB,1.0);
}
}

It work fine if I apply this on the window as a filtre. But I would like to execute it on a off-screen rendering.
I think I must change gl_FragCoord.xy by gl_TexCoord[0].xy but it don't work...

Thank you for halping me,

Kryx

kryx94
05-15-2014, 08:16 AM
I have found the change:


#version 120
#define FXAA_REDUCE_MIN (1.0/128.0)
#define FXAA_REDUCE_MUL (1.0/8.0)
#define FXAA_SPAN_MAX 8.0
uniform sampler2D sampler0;
uniform vec2 resolution;

void main(){
vec2 inverse_resolution=vec2(1.0/resolution.x,1.0/resolution.y);
vec3 rgbNW = texture2D(sampler0, gl_TexCoord[0].xy + (vec2(-1.0,-1.0)) * inverse_resolution).xyz;
vec3 rgbNE = texture2D(sampler0, gl_TexCoord[0].xy + (vec2(1.0,-1.0)) * inverse_resolution).xyz;
vec3 rgbSW = texture2D(sampler0, gl_TexCoord[0].xy + (vec2(-1.0,1.0)) * inverse_resolution).xyz;
vec3 rgbSE = texture2D(sampler0, gl_TexCoord[0].xy + (vec2(1.0,1.0)) * inverse_resolution).xyz;
vec3 rgbM = texture2D(sampler0, gl_TexCoord[0].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)) * inverse_resolution;
vec3 rgbA = 0.5 * (texture2D(sampler0, gl_TexCoord[0].xy + dir * (1.0/3.0 - 0.5)).xyz + texture2D(sampler0, gl_TexCoord[0].xy + dir * (2.0/3.0 - 0.5)).xyz);
vec3 rgbB = rgbA * 0.5 + 0.25 * (texture2D(sampler0, gl_TexCoord[0].xy + dir * - 0.5).xyz + texture2D(sampler0, gl_TexCoord[0].xy + dir * 0.5).xyz);
float lumaB = dot(rgbB, luma);
if((lumaB < lumaMin) || (lumaB > lumaMax)) {
gl_FragColor = vec4(rgbA,1.0);
} else {
gl_FragColor = vec4(rgbB,1.0);
}
}