6b67cfe63f
This is primarily done to lower the GTK version dependency below GTK 3.22, since GTK 3.22 is unlikely to be widely availale any time soon.
36 lines
1.0 KiB
GLSL
36 lines
1.0 KiB
GLSL
//-----------------------------------------------------------------------------
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// Edge rendering shader
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//
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// Copyright 2016 Aleksey Egorov
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//-----------------------------------------------------------------------------
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const float feather = 0.5;
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uniform vec4 color;
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uniform float pixel;
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uniform float width;
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uniform float patternLen;
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uniform float patternScale;
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uniform sampler2D pattern;
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varying vec3 fragLoc;
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void main() {
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// lookup distance texture
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vec4 v = texture2D(pattern, vec2(fragLoc.z / patternScale, 0.0));
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// decode distance value
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float val = dot(v, vec4(1.0, 1.0 / 255.0, 1.0 / 65025.0, 1.0 / 160581375.0));
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// calculate cap
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float dist = length(vec2(val * patternScale / (patternLen * width) + abs(fragLoc.x), fragLoc.y));
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// perform antialising
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float k = smoothstep(1.0 - 2.0 * feather * pixel / (width + feather * pixel), 1.0, abs(dist));
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// perfrom alpha-test
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if(k == 1.0) discard;
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// write resulting color
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gl_FragColor = vec4(color.rgb, color.a * (1.0 - k));
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}
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