forked from AuroraMiddleware/gtk
af917c4ade
Note: We interpolate premultiplied colors as per the CSS spec. This i different from Cairo, which interpolates unpremultiplied. So in testcases with translucent gradients, it's actually Cairo that is wrong.
34 lines
795 B
GLSL
34 lines
795 B
GLSL
#version 420 core
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struct ColorStop {
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float offset;
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vec4 color;
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};
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layout(location = 0) in float inGradientPos;
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layout(location = 1) in flat int inRepeating;
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layout(location = 2) in flat int inStopCount;
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layout(location = 3) in flat ColorStop inStops[8];
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layout(location = 0) out vec4 outColor;
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void main()
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{
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float pos;
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if (inRepeating != 0)
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pos = fract (inGradientPos);
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else
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pos = clamp (inGradientPos, 0, 1);
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vec4 color = inStops[0].color;
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int n = clamp (inStopCount, 2, 8);
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for (int i = 1; i < n; i++)
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{
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if (inStops[i].offset > inStops[i-1].offset)
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color = mix (color, inStops[i].color, clamp((pos - inStops[i-1].offset) / (inStops[i].offset - inStops[i-1].offset), 0, 1));
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}
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//outColor = vec4(pos, pos, pos, 1.0);
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outColor = color;
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}
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