stk-code_catmod/data/shaders/mlaa_neigh3.frag
vincentlj fa068d7810 OGL32CTX: Ask #version 130 for all our shaders
git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@14919 178a84e3-b1eb-0310-8ba1-8eac791a3b58
2014-01-05 00:08:00 +00:00

40 lines
1.3 KiB
GLSL

#version 130
varying vec4 offset[2];
uniform sampler2D blendMap;
uniform sampler2D colorMap;
void main() {
// Fetch the blending weights for current pixel:
vec4 topLeft = texture2D(blendMap, gl_TexCoord[0].xy);
float bottom = texture2D(blendMap, offset[1].zw).g;
float right = texture2D(blendMap, offset[1].xy).a;
vec4 a = vec4(topLeft.r, bottom, topLeft.b, right);
// Up to 4 lines can be crossing a pixel (one in each edge). So, we perform
// a weighted average, where the weight of each line is 'a' cubed, which
// favors blending and works well in practice.
vec4 w = a * a * a;
// There is some blending weight with a value greater than 0.0?
float sum = dot(w, vec4(1.0));
if (sum < 1e-5)
discard;
vec4 color = vec4(0.0);
// Add the contributions of the possible 4 lines that can cross this pixel:
vec4 C = texture2D(colorMap, gl_TexCoord[0].xy);
vec4 Cleft = texture2D(colorMap, offset[0].xy);
vec4 Ctop = texture2D(colorMap, offset[0].zw);
vec4 Cright = texture2D(colorMap, offset[1].xy);
vec4 Cbottom = texture2D(colorMap, offset[1].zw);
color = mix(C, Ctop, a.r) * w.r + color;
color = mix(C, Cbottom, a.g) * w.g + color;
color = mix(C, Cleft, a.b) * w.b + color;
color = mix(C, Cright, a.a) * w.a + color;
// Normalize the resulting color and we are finished!
gl_FragColor = color / sum;
}