mirror of
https://github.com/curioustorvald/Terrarum.git
synced 2026-03-12 14:51:51 +09:00
74 lines
2.6 KiB
GLSL
74 lines
2.6 KiB
GLSL
varying vec4 v_color;
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varying vec2 v_texCoords;
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uniform sampler2D u_texture;
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// "steps" of R, G and B. Must be integer && equal or greater than 2
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uniform float rcount = 4.0;
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uniform float gcount = 4.0;
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uniform float bcount = 4.0;
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uniform float acount = 1.0;
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/*int bayer[8][8] = {
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{ 0,32, 8,40, 2,34,10,42}, // 8x8 bayer ordered dithering
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{48,16,56,24,50,18,58,26}, // pattern. Each input pixel
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{12,44, 4,36,14,46, 6,38}, // is scaled to the 0..63 range
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{60,28,52,20,62,30,54,22}, // before looking in this table
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{ 3,35,11,43, 1,33, 9,41}, // to determine the action
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{51,19,59,27,49,17,57,25},
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{15,47, 7,39,13,45, 5,37},
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{63,31,55,23,61,29,53,21} }; // fun fact: you can calculate bayer value on-the-fly but LUT is faster
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float bayerSize = 8.0;*/
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int bayer[12][12] = {
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{0 ,96 ,64 ,8 ,104,72 ,2 ,98 ,66 ,10 ,106,74 }, // 12x12 bayer ordered dithering
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{112,80 ,16 ,120,88 ,24 ,114,82 ,18 ,122,90 ,26 }, // pattern. Each input pixel
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{48 ,32 ,128,56 ,40 ,136,50 ,34 ,130,58 ,42 ,138}, // is scaled to the 0..143 range
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{12 ,108,76 ,4 ,100,68 ,14 ,110,78 ,6 ,102,70 }, // before looking in this table
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{124,92 ,28 ,116,84 ,20 ,126,94 ,30 ,118,86 ,22 }, // to determine the action
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{60 ,44 ,140,52 ,36 ,132,62 ,46 ,142,54 ,38 ,134},
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{3 ,99 ,67 ,11 ,107,75 ,1 ,97 ,65 ,9 ,105,73 },
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{115,83 ,19 ,123,91 ,27 ,113,81 ,17 ,121,89 ,25 },
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{51 ,35 ,131,59 ,43 ,139,49 ,33 ,129,57 ,41 ,137},
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{15 ,111,79 ,7 ,103,71 ,13 ,109,77 ,5 ,101,69 },
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{127,95 ,31 ,119,87 ,23 ,125,93 ,29 ,117,85 ,21 },
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{63 ,47 ,143,55 ,39 ,135,61 ,45 ,141,53 ,37 ,133}};
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float bayerSize = 12.0;
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float bayerDivider = bayerSize * bayerSize;
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vec4 nearestColour(vec4 incolor) {
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vec4 rgbaCounts = vec4(rcount, gcount, bcount, acount);
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vec4 color = incolor;
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color.r = floor((rgbaCounts.r - 1.0) * color.r + 0.5) / (rgbaCounts.r - 1.0);
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color.g = floor((rgbaCounts.g - 1.0) * color.g + 0.5) / (rgbaCounts.g - 1.0);
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color.b = floor((rgbaCounts.b - 1.0) * color.b + 0.5) / (rgbaCounts.b - 1.0);
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if (rgbaCounts.a >= 2.0) {
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color.a = floor((rgbaCounts.a - 1.0) * color.a + 0.5) / (rgbaCounts.a - 1.0);
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}
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else {
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color.a = 1.0;
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}
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return color;
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}
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void main(void) {
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float spread = 1.0 / (0.299 * (rcount - 1.0) + 0.587 * (gcount - 1.0) + 0.114 * (bcount - 1.0)); // this spread value is optimised one -- try your own values for various effects!
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// create texture coordinates based on pixelSize //
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vec4 inColor = texture2D(u_texture, v_texCoords);
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vec2 entry = mod(gl_FragCoord.xy, vec2(bayerSize, bayerSize));
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gl_FragColor = nearestColour(inColor + spread * (bayer[int(entry.y)][int(entry.x)] / bayerDivider - 0.5));
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//gl_FragColor = nearestColour(inColor);
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} |