annotate sdr/dither.p.glsl @ 2:c45c7a1f7d9d
foo
| author |
John Tsiombikas <nuclear@member.fsf.org> |
| date |
Wed, 09 Jan 2013 02:37:05 +0200 |
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2d27bfd21fc5 |
| children |
403ec1be3a1a |
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line source |
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1 uniform sampler2D framebuf, dither_tex;
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2 uniform int dither_levels, dither_size;
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3
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4 void main()
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5 {
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6 float levels = float(dither_levels);
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7
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8 vec4 pixel = texture2D(framebuf, gl_TexCoord[0].xy);
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9 float lum = dot(pixel.xyz, vec3(0.2126, 0.7152, 0.0722));
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10 // gamma correct luminance?
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11 //lum = pow(lum, 1.0 / 2.2);
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12 float coord_shift = floor(lum * levels) / levels;
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13
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14 vec2 dsz2 = vec2(float(dither_size), float(dither_size));
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15
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16 vec2 coord = mod(gl_FragCoord.xy, dsz2) / float(dither_size);
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17 coord.y = coord.y / levels + coord_shift;
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18 float val = texture2D(dither_tex, coord).x;
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19
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20 const vec3 dark_col = vec3(0.043, 0.286, 0.337);
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21 const vec3 bright_col = vec3(0.965, 0.778, 0.555);
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22
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23 gl_FragColor = vec4(mix(dark_col, bright_col, val), 1.0);
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24 }
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