#version 450 /* * gizmo98 bayer 4x4 dithering shader * Copyright (C) 2023 gizmo98 * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free * Software Foundation; either version 2 of the License, or (at your option) * any later version. * * version 0.1, 16.05.2023 * --------------------------------------------------------------------------------------- * - initial commit * * https://github.com/gizmo98/gizmo-crt-shader * * uses parts of texture anti-aliasing shader from Ikaros https://www.shadertoy.com/view/ldsSRX */ layout(push_constant) uniform Push { vec4 SourceSize; vec4 OriginalSize; vec4 OutputSize; uint FrameCount; float COLOR_DEPTH; float DITHER_TUNE; float EGA_PALETTE; } params; layout(std140, set = 0, binding = 0) uniform UBO { mat4 MVP; } global; #pragma parameter COLOR_DEPTH "Color depth in Bits" 1.0 1.0 8.0 1.0 #pragma parameter DITHER_TUNE "Tune dithering" 0.0 -64.0 64.0 1.0 #pragma parameter EGA_PALETTE "EGA palette" 0.0 0.0 1.0 1.0 #pragma stage vertex layout(location = 0) in vec4 Position; layout(location = 1) in vec2 TexCoord; layout(location = 0) out vec2 vTexCoord; void main() { gl_Position = global.MVP * Position; vTexCoord = TexCoord; } #pragma stage fragment layout(location = 0) in vec2 vTexCoord; layout(location = 0) out vec4 FragColor; layout(set = 0, binding = 2) uniform sampler2D Source; vec4 DitherPattern(vec4 col, vec2 coord) { mat4 bayerMatrix; bayerMatrix[0] = vec4(0.0, 8.0, 2.0, 10.0); bayerMatrix[1] = vec4(12.0, 4.0, 14.0, 6.0); bayerMatrix[2] = vec4(3.0, 11.0, 1.0, 9.0); bayerMatrix[3] = vec4(15.0, 7.0, 13.0, 5.0); ivec2 st = ivec2(fract(coord.xy / 4.0) * 4.0); float threshold = bayerMatrix[st.x][st.y]; float multiplier = pow(2.0,8.0 - params.COLOR_DEPTH) - 1.0; threshold = (threshold / 15.0) - 0.5; threshold *= ((multiplier + params.DITHER_TUNE) / 255.0); col.rgb += threshold; return col; } vec2 saturateA(in vec2 x) { return clamp(x, 0.0, 1.0); } vec2 magnify(in vec2 uv, in vec2 res) { uv *= res; return (saturateA(fract(uv) / saturateA(fwidth(uv))) + floor(uv) - 0.5) / res.xy; } vec4 textureAA(in vec2 uv){ vec2 texSize = vec2(textureSize(Source, 0)); uv = magnify(uv,texSize.xy); vec2 uv1 = uv*texSize.xy; vec2 iuv = floor(uv1); vec4 col = texture( Source, uv ); col = DitherPattern( col , iuv - 0.5); return col; } vec4 ColorDepthReduction(vec4 col) { float divider = pow(2.0,params.COLOR_DEPTH) - 1.0; col.rgb *= divider; col.rgb = floor(col.rgb) + step(0.5, fract(col.rgb)); col.rgb /= divider; return col; } vec4 EGAPalette(vec4 col) { float divider = 3.0; vec3 c = floor(col.rgb * divider) + step(0.5, fract(col.rgb * divider)); if (c.rgb == vec3(0.0,0.0,0.0) || c.rgb == vec3(1.0,1.0,1.0) || c.rgb == vec3(2.0,2.0,2.0) || c.rgb == vec3(3.0,3.0,3.0) || c.rgb == vec3(2.0,1.0,0.0)) col.rgb = col.rgb; // bright green else if (c.rgb == vec3(0.0,3.0,0.0)|| c.rgb == vec3(0.0,3.0,2.0)|| c.rgb == vec3(2.0,3.0,0.0)|| c.rgb == vec3(0.0,3.0,1.0)|| c.rgb == vec3(1.0,3.0,1.0)|| c.rgb == vec3(1.0,3.0,0.0)|| c.rgb == vec3(2.0,3.0,1.0)|| c.rgb == vec3(2.0,3.0,2.0)) col.rgb = vec3(1.0,3.0,1.0) / divider; // green else if (c.rgb == vec3(0.0,2.0,0.0)|| c.rgb == vec3(0.0,2.0,1.0)|| c.rgb == vec3(0.0,1.0,0.0)|| c.rgb == vec3(0.0,1.0,1.0)|| c.rgb == vec3(1.0,2.0,1.0)|| c.rgb == vec3(1.0,2.0,0.0)|| c.rgb == vec3(0.0,1.0,1.0)) col.rgb = vec3(0.0,2.0,0.0) / divider; // bright red else if (c.rgb == vec3(3.0,0.0,0.0)|| c.rgb == vec3(3.0,0.0,1.0)|| c.rgb == vec3(3.0,1.0,0.0)|| c.rgb == vec3(3.0,1.0,1.0)) col.rgb = vec3(3.0,1.0,1.0) / divider; // red else if (c.rgb == vec3(2.0,0.0,0.0)|| c.rgb == vec3(2.0,0.0,1.0)|| c.rgb == vec3(1.0,0.0,0.0)) col.rgb = vec3(2.0,0.0,0.0) / divider; // bright cyan else if (c.rgb == vec3(0.0,3.0,3.0)|| c.rgb == vec3(1.0,3.0,3.0)|| c.rgb == vec3(2.0,3.0,3.0)) col.rgb = vec3(1.0,3.0,3.0) / divider; // cyan else if (c.rgb == vec3(0.0,2.0,2.0)|| c.rgb == vec3(1.0,2.0,2.0)) col.rgb = vec3(0.0,2.0,2.0) / divider; // bright blue else if (c.rgb == vec3(0.0,2.0,3.0)|| c.rgb == vec3(1.0,2.0,3.0)|| c.rgb == vec3(0.0,0.0,3.0)) col.rgb = vec3(1.0,1.0,3.0) / divider; // blue else if (c.rgb == vec3(0.0,0.0,2.0)|| c.rgb == vec3(0.0,0.0,1.0)|| c.rgb == vec3(0.0,1.0,2.0)|| c.rgb == vec3(1.0,1.0,3.0)|| c.rgb == vec3(0.0,1.0,3.0)) col.rgb = vec3(0.0,0.0,2.0) / divider; // brown else if (c.rgb == vec3(2.0,1.0,0.0)|| c.rgb == vec3(2.0,1.0,1.0)|| c.rgb == vec3(1.0,1.0,0.0)) col.rgb = vec3(2.0,1.0,0.0) / divider; // bright yellow else if (c.rgb == vec3(3.0,3.0,0.0)|| c.rgb == vec3(3.0,3.0,1.0)|| c.rgb == vec3(3.0,3.0,2.0)|| c.rgb == vec3(2.0,2.0,0.0)|| c.rgb == vec3(2.0,2.0,1.0)) col.rgb = vec3(3.0,3.0,1.0) / divider; // magenta else if (c.rgb == vec3(2.0,0.0,2.0)|| c.rgb == vec3(2.0,0.0,3.0)|| c.rgb == vec3(2.0,1.0,2.0)|| c.rgb == vec3(2.0,1.0,3.0)) col.rgb = vec3(2.0,0.0,2.0) / divider; // bright magenta else if (c.rgb == vec3(3.0,0.0,2.0)|| c.rgb == vec3(3.0,0.0,3.0)|| c.rgb == vec3(3.0,2.0,3.0)|| c.rgb == vec3(3.0,1.0,3.0)|| c.rgb == vec3(3.0,1.0,2.0)) col.rgb = vec3(3.0,1.0,3.0) / divider; else if (c.r == 0.0) col.gb = step(2.0,c.gb) * 2.0 / divider; else if (c.g == 0.0) col.rb = step(2.0,c.rb) * 2.0 / divider; else if (c.b == 0.0) col.rg = step(2.0,c.rg) * 2.0 / divider; else if (c.r == 3.0) col.gb = step(1.0,c.gb) / divider; else if (c.g == 3.0) col.rb = step(1.0,c.rb) / divider; else if (c.b == 3.0) col.rg = step(1.0,c.rg) / divider; return col; } void main() { vec2 texcoord = vTexCoord.xy; FragColor = textureAA(texcoord); FragColor = ColorDepthReduction(FragColor); if (params.EGA_PALETTE == 1.0) FragColor = EGAPalette(FragColor); }