add blue noise dithering (#432)

* add blue noise dithering

dithering/blue_noise.slangp

@@ -0,0 +1,12 @@
+shaders = "1"
+shader0 = "shaders/blue_noise.slang"
+filter_linear0 = "false"
+scale_type0 = viewport
+
+parameters = "COLOR_DEPTH;DITHER_TUNE;EGA_PALETTE"
+COLOR_DEPTH = "2.0"
+DITHER_TUNE = "0.0"
+EGA_PALETTE = "0.0"
+
+textures = "BlueNoiseTexture"
+BlueNoiseTexture = shaders/blue-noise/LDR_RGB1_0.png

dithering/blue_noise_dynamic_4Bit.slangp

@@ -0,0 +1,13 @@
+shaders = "1"
+shader0 = "shaders/blue_noise_dynamic.slang"
+filter_linear0 = "false"
+scale_type0 = viewport
+
+parameters = "COLOR_DEPTH;DITHER_TUNE;EGA_PALETTE"
+COLOR_DEPTH = "4.0"
+DITHER_TUNE = "0.0"
+EGA_PALETTE = "0.0"
+
+textures = "BlueNoiseTexture0"
+BlueNoiseTexture0 = shaders/blue-noise/LDR_RGB1_0.png
+

dithering/blue_noise_dynamic_monochrome.slangp

@@ -0,0 +1,14 @@
+shaders = "1"
+shader0 = "shaders/blue_noise_dynamic.slang"
+filter_linear0 = "false"
+scale_type0 = viewport
+
+parameters = "COLOR_DEPTH;DITHER_TUNE;MONOCHROME;EGA_PALETTE"
+COLOR_DEPTH = "2.0"
+DITHER_TUNE = "0.0"
+MONOCHROME = "1.0"
+EGA_PALETTE = "0.0"
+
+textures = "BlueNoiseTexture0"
+BlueNoiseTexture0 = shaders/blue-noise/LDR_RGB1_0.png
+

dithering/shaders/blue_noise.slang

@@ -0,0 +1,220 @@
+#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 BlueNoiseTexture;
+
+vec4 DitherPattern(vec4 col, vec2 coord)
+{
+    vec4 color = texelFetch(BlueNoiseTexture,ivec2(coord),0);
+    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);
+}

dithering/shaders/blue_noise_dynamic.slang

@@ -0,0 +1,248 @@
+#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);
+}