mirror of
https://github.com/italicsjenga/slang-shaders.git
synced 2024-11-24 08:31:31 +11:00
80 lines
2.4 KiB
Plaintext
80 lines
2.4 KiB
Plaintext
#version 450
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layout(push_constant) uniform Push
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{
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vec4 SourceSize;
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vec4 OriginalSize;
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vec4 OutputSize;
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uint FrameCount;
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float frequency;
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} params;
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#pragma parameter frequency "CMYK HalfTone Dot Density" 275.0 50.0 500.0 25.0
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#define frequency params.frequency
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#define mul(a,b) (b*a)
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layout(std140, set = 0, binding = 0) uniform UBO
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{
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mat4 MVP;
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} global;
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#pragma stage vertex
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layout(location = 0) in vec4 Position;
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layout(location = 1) in vec2 TexCoord;
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layout(location = 0) out vec2 vTexCoord;
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void main()
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{
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gl_Position = global.MVP * Position;
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vTexCoord = TexCoord;
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}
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#pragma stage fragment
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layout(location = 0) in vec2 vTexCoord;
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layout(location = 0) out vec4 FragColor;
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layout(set = 0, binding = 2) uniform sampler2D Source;
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void main()
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{
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// Distance to nearest point in a grid of
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// (frequency x frequency) points over the unit square
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mat2 rotation_matrix = mat2(0.707, 0.707, -0.707, 0.707);
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vec2 st2 = mul(rotation_matrix , vTexCoord);
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vec2 nearest = 2.0 * fract(frequency * st2) - 1.0;
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float dist = length(nearest);
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vec3 texcolor = texture(Source, vTexCoord).rgb; // Unrotated coords
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vec3 black = texcolor; // kinda cheating, but it makes the colors look much better
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// Perform a rough RGB-to-CMYK conversion
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vec4 cmyk;
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cmyk.xyz = 1.0 - texcolor;
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cmyk.w = min(cmyk.x, min(cmyk.y, cmyk.z)); // Create K
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mat2 k_matrix = mat2(0.707, 0.707, -0.707, 0.707);
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vec2 Kst = frequency * mul(k_matrix , vTexCoord);
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vec2 Kuv = 2.0 * fract(Kst) - 1.0;
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float k = step(0.0, sqrt(cmyk.w) - length(Kuv));
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mat2 c_matrix = mat2(0.966, 0.259, -0.259, 0.966);
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vec2 Cst = frequency * mul(c_matrix , vTexCoord);
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vec2 Cuv = 2.0 * fract(Cst) - 1.0;
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float c = step(0.0, sqrt(cmyk.x) - length(Cuv));
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mat2 m_matrix = mat2(0.966, -0.259, 0.259, 0.966);
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vec2 Mst = frequency * mul(m_matrix , vTexCoord);
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vec2 Muv = 2.0 * fract(Mst) - 1.0;
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float m = step(0.0, sqrt(cmyk.y) - length(Muv));
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vec2 Yst = frequency * vTexCoord; // 0 deg
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vec2 Yuv = 2.0 * fract(Yst) - 1.0;
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float y = step(0.0, sqrt(cmyk.z) - length(Yuv));
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vec3 rgbscreen = 1.0 - vec3(c,m,y);
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rgbscreen = mix(rgbscreen, black, k);
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float afwidth = 2.0 * frequency * length(params.OutputSize.zw);
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float blend = smoothstep(0.0, 1.0, afwidth);
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vec4 color = vec4(mix(rgbscreen , texcolor, blend), 1.0);
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color = (max(texcolor.r, max(texcolor.g, texcolor.b)) < 0.01) ? vec4(0.,0.,0.,0.) : color; // make blacks actually black
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FragColor = color;
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} |