dbf-udg: sdr/dither.p.glsl annotate

dbf-udg

initial commit

author	John Tsiombikas <nuclear@member.fsf.org>
date	Tue, 08 Jan 2013 03:16:48 +0200
parents
children	c45c7a1f7d9d

rev	line source
nuclear@0	1 uniform sampler2D framebuf, dither_tex;
nuclear@0	2 uniform int dither_levels, dither_size;
nuclear@0	3
nuclear@0	4 void main()
nuclear@0	5 {
nuclear@0	6 float levels = float(dither_levels);
nuclear@0	7
nuclear@0	8 vec4 pixel = texture2D(framebuf, gl_TexCoord[0].xy);
nuclear@0	9 float lum = dot(pixel.xyz, vec3(0.2126, 0.7152, 0.0722));
nuclear@0	10 float coord_shift = floor(lum * levels) / levels;
nuclear@0	11
nuclear@0	12 vec2 dsz2 = vec2(float(dither_size), float(dither_size));
nuclear@0	13
nuclear@0	14 vec2 coord = mod(gl_FragCoord.xy, dsz2) / float(dither_size);
nuclear@0	15 coord.y = coord.y / levels + coord_shift;
nuclear@0	16 float val = texture2D(dither_tex, coord).x;
nuclear@0	17
nuclear@0	18 const vec3 dark_col = vec3(0.043, 0.286, 0.337);
nuclear@0	19 const vec3 bright_col = vec3(0.965, 0.778, 0.555);
nuclear@0	20
nuclear@0	21 gl_FragColor = vec4(mix(dark_col, bright_col, val), 1.0);
nuclear@0	22 }