37 lines
1.3 KiB
GLSL
37 lines
1.3 KiB
GLSL
// pathfinder/shaders/gles2/ssaa-subpixel-resolve.fs.glsl
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//
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// Copyright (c) 2017 The Pathfinder Project Developers.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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//! Performs subpixel antialiasing for LCD screens by converting a
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//! 3x-oversampled RGBA color buffer to an RGB framebuffer, applying the
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//! FreeType color defringing filter as necessary.
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precision mediump float;
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/// The alpha coverage texture.
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uniform sampler2D uSource;
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/// The dimensions of the alpha coverage texture, in texels.
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uniform ivec2 uSourceDimensions;
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uniform vec4 uKernel;
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varying vec2 vTexCoord;
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void main() {
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float onePixel = 1.0 / float(uSourceDimensions.x);
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vec4 shadesL, shadesR;
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float shadeC;
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sample9Tap(shadesL, shadeC, shadesR, uSource, vTexCoord, onePixel, uKernel);
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vec3 shades = vec3(convolve7Tap(shadesL, vec3(shadeC, shadesR.xy), uKernel),
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convolve7Tap(vec4(shadesL.yzw, shadeC), shadesR.xyz, uKernel),
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convolve7Tap(vec4(shadesL.zw, shadeC, shadesR.x), shadesR.yzw, uKernel));
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gl_FragColor = vec4(shades, 1.0);
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}
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