slang-shaders/dithering/shaders/blue_noise_dynamic.slang
Stefan 7d9f561673
add blue noise dithering (#432)
* add blue noise dithering
2023-05-18 13:46:17 -05:00

249 lines
8.1 KiB
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#version 450
/*
* gizmo98 blue noise 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
* uses blue noise texture from http://momentsingraphics.de/BlueNoise.html
*/
layout(push_constant) uniform Push
{
vec4 SourceSize;
vec4 OriginalSize;
vec4 OutputSize;
uint FrameCount;
float COLOR_DEPTH;
float DITHER_TUNE;
float MONOCHROME;
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 MONOCHROME "Monochrome" 0.0 0.0 1.0 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;
layout(set = 0, binding = 3) uniform sampler2D BlueNoiseTexture0;
vec4 DitherPattern(vec4 col, vec2 coord)
{
float count = floor(fract(params.FrameCount / 11.0) * 11.0);
vec2 texSize = vec2(textureSize(BlueNoiseTexture0,0));
coord = fract(coord/ texSize) * texSize;
vec4 color;
if (count == 0.0)
color = texelFetch(BlueNoiseTexture0,ivec2(coord),0);
else if (count == 1.0)
color = texelFetch(BlueNoiseTexture0,ivec2(coord.y,coord.x),0).brga;
else if (count == 2.0)
color = texelFetch(BlueNoiseTexture0,ivec2(coord),0).gbra;
else if (count == 3.0)
color = texelFetch(BlueNoiseTexture0,ivec2(coord.y,coord.x),0).rbga;
else if (count == 4.0)
color = texelFetch(BlueNoiseTexture0,ivec2(coord),0).bgra;
else if (count == 5.0)
color = texelFetch(BlueNoiseTexture0,ivec2(coord.y,coord.x),0).grba;
else if (count == 6.0)
color = texelFetch(BlueNoiseTexture0,ivec2(texSize - coord),0);
else if (count == 7.0)
color = texelFetch(BlueNoiseTexture0,ivec2(texSize.y - coord.y,texSize.x - coord.x),0).brga;
else if (count == 8.0)
color = texelFetch(BlueNoiseTexture0,ivec2(texSize - coord),0).gbra;
else if (count == 9.0)
color = texelFetch(BlueNoiseTexture0,ivec2(texSize.y - coord.y,texSize.x - coord.x),0).rbga;
else if (count == 10.0)
color = texelFetch(BlueNoiseTexture0,ivec2(texSize - coord),0).bgra;
else if (count == 11.0)
color = texelFetch(BlueNoiseTexture0,ivec2(texSize.y - coord.y,texSize.x - coord.x),0).grba;
if (params.MONOCHROME == 1.0)
color.rgb = color.rrr;
vec3 threshold = color.rgb;
float multiplier = pow(2.0,8.0 - params.COLOR_DEPTH) - 1.0;
threshold = threshold - 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 = textureSize(Source,0);
vec2 st = uv*texSize.xy;
vec2 ist = floor(st);
vec4 col = texture(Source, uv);
if (params.MONOCHROME == 1.0)
col.rgb = vec3(col.r + col.g + col.b) / 3.0;
col = DitherPattern(col , ist + 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);
}