Translated gba-color.cg.

No obvious bugs were spotted.

handheld/gba-color.slang

@@ -0,0 +1,77 @@
+#version 450
+/*
+   Author: Pokefan531
+   License: Public domain
+*/
+
+// Shader that replicates the LCD dynamics from a GameBoy Advance
+
+layout(std140, set = 0, binding = 0) uniform UBO
+{
+    mat4 MVP;
+    vec4 OutputSize;
+    vec4 OriginalSize;
+    vec4 SourceSize;
+} global;
+
+#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 = 1) in vec2 FragCoord;
+layout(location = 0) out vec4 FragColor;
+layout(set = 0, binding = 2) uniform sampler2D Source;
+
+
+vec3 grayscale(vec3 col)
+{
+    // Non-conventional way to do grayscale,
+    // but bSNES uses this as grayscale value.
+    return vec3(dot(col, vec3(0.2126, 0.7152, 0.0722)));
+}
+
+void main()
+{
+//part 1
+    float saturation    = 1.0;
+    float Display_gamma = 1.02;
+    float CRT_gamma     = 2.4;
+    float luminance     = 1.0;
+
+    vec3 gamma  = vec3(CRT_gamma / Display_gamma);
+    vec3 res    = texture(Source, vTexCoord).xyz;
+    res         = mix(grayscale(res), res, saturation); // Apply saturation
+    res         = pow(res, gamma.rgb); // Apply gamma
+    vec4 c      = vec4(clamp(res * luminance, 0.0, 1.0), 1.0);
+
+//part 2
+    float r = c.x;
+    float g = c.y;
+    float b = c.z;
+    float a = c.w;
+    float w = r * 0.714 + g * 0.251 + b * 0.000;
+    float q = r * 0.071 + g * 0.643 + b * 0.216;
+    float e = r * 0.071 + g * 0.216 + b * 0.643;
+
+//part 3
+    saturation      = 1.0;
+    Display_gamma   = 3.6;
+    CRT_gamma       = 2.4;
+    luminance       = 1.01;
+
+    res     = vec3(w, q, e);
+    gamma   = gamma = vec3(CRT_gamma / Display_gamma);
+    res     = mix(grayscale(res), res, saturation); // Apply saturation
+    res     = pow(res, gamma.rgb); // Apply gamma
+    
+    FragColor = vec4(clamp(res * luminance, 0.0, 1.0), 1.0);
+}