58 lines
941 B
GLSL
58 lines
941 B
GLSL
#version 130
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uniform sampler2D tex;
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uniform int size;
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uniform vec2 pixel;
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out vec4 FragColor;
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vec4 encdepth(float v) {
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vec4 enc = vec4(1.0, 255.0, 65025.0, 16581375.0) * v;
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enc = fract(enc);
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enc -= enc.yzww * vec4(1.0/255.0, 1.0/255.0, 1.0/255.0, 0.0);
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return enc;
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}
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void main()
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{
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vec2 origtc = gl_TexCoord[0].xy;
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// Get total sum
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float first = 1.0, last = 0.0;
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float lower = 0.0;
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float total = 0.0;
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vec2 tc = pixel * 0.5;
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for (int i = 0; i < size; i++)
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{
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float col = texture(tex, tc).x;
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lower += col * step(tc.y, origtc.y);
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total += col;
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if (col > 0.0001)
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{
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first = min(first, tc.y);
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last = max(last, tc.y);
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}
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tc += pixel;
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}
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float res = (lower / total) - origtc.y;
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// Outside the edges?
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if (origtc.y <= first)
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{
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res = origtc.y * -2.1;
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}
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else if (origtc.y >= last)
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{
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res = (1.0 - origtc.y) * 2.1;
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}
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res = res * 0.5 + 0.5;
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res = clamp(res, 0.01, 0.99);
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FragColor = encdepth(res);
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}
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