Add Gambatte color GLSL port by RiskyJumps

handheld/gbc-gambatte-color.glslp

+shaders = 1
+
+shader0 = shaders/color/gbc-gambatte-color.glsl
+filter_linear0 = false
+scale_type_0 = source
+scale0 = 1.0

handheld/shaders/color/gbc-gambatte-color.glsl

+/*
+   Gambatte Color
+   A GLSL port of the color correction option on Gambatte emulator
+   Ported by: RiskyJumps
+   License: Public domain
+*/
+
+/*
+OPTIONS:
+
+INT_OPS (default: Disabled)
+It's supposed to be more "accurate" but it's a waste. Not recommended
+*/
+//#define INT_OPS
+
+/*
+SIMULATE_INT (default: Disabled)
+Only meaningful if INT_OPS is disabled. It truncates floats. Then
+again, it's supposed to be more "accurate" but it looks just
+too similar. It's still a waste. Not recommended.
+*/
+//#define SIMULATE_INT
+
+// Compatibility #ifdefs needed for parameters
+#ifdef GL_ES
+#define COMPAT_PRECISION mediump
+#else
+#define COMPAT_PRECISION
+#endif
+
+#if defined(VERTEX)
+
+#if __VERSION__ >= 130
+#define COMPAT_VARYING out
+#define COMPAT_ATTRIBUTE in
+#define COMPAT_TEXTURE texture
+#else
+#define COMPAT_VARYING varying 
+#define COMPAT_ATTRIBUTE attribute 
+#define COMPAT_TEXTURE texture2D
+#endif
+
+#ifdef GL_ES
+#define COMPAT_PRECISION mediump
+#else
+#define COMPAT_PRECISION
+#endif
+
+COMPAT_ATTRIBUTE vec4 VertexCoord;
+COMPAT_ATTRIBUTE vec4 COLOR;
+COMPAT_ATTRIBUTE vec4 TexCoord;
+COMPAT_VARYING vec4 COL0;
+COMPAT_VARYING vec4 TEX0;
+
+uniform mat4 MVPMatrix;
+uniform COMPAT_PRECISION int FrameDirection;
+uniform COMPAT_PRECISION int FrameCount;
+uniform COMPAT_PRECISION vec2 OutputSize;
+uniform COMPAT_PRECISION vec2 TextureSize;
+uniform COMPAT_PRECISION vec2 InputSize;
+
+void main()
+{
+     gl_Position = MVPMatrix * VertexCoord;
+     COL0 = COLOR;
+     TEX0.xy = TexCoord.xy;
+}
+
+#elif defined(FRAGMENT)
+
+#if __VERSION__ >= 130
+#define COMPAT_VARYING in
+#define COMPAT_TEXTURE texture
+out vec4 FragColor;
+#else
+#define COMPAT_VARYING varying
+#define FragColor gl_FragColor
+#define COMPAT_TEXTURE texture2D
+#endif
+
+#ifdef GL_ES
+#ifdef GL_FRAGMENT_PRECISION_HIGH
+precision highp float;
+#else
+precision mediump float;
+#endif
+#define COMPAT_PRECISION mediump
+#else
+#define COMPAT_PRECISION
+#endif
+
+uniform COMPAT_PRECISION int FrameDirection;
+uniform COMPAT_PRECISION int FrameCount;
+uniform COMPAT_PRECISION vec2 OutputSize;
+uniform COMPAT_PRECISION vec2 TextureSize;
+uniform COMPAT_PRECISION vec2 InputSize;
+uniform sampler2D Texture;
+COMPAT_VARYING vec4 TEX0;
+
+// compatibility #defines
+#define Source Texture
+#define vTexCoord TEX0.xy
+
+#define SourceSize vec4(TextureSize, 1.0 / TextureSize) //either TextureSize or InputSize
+#define outsize vec4(OutputSize, 1.0 / OutputSize)
+
+void main()
+{
+     vec4 color = COMPAT_TEXTURE(Texture, TEX0.xy);
+
+#ifdef INT_OPS
+     color.rgb *= 255.0;
+
+     int r = (int)color.r;
+     int g = (int)color.g;
+     int b = (int)color.b;
+
+     int R = (r * 13 + g * 2 + b) >> 4;
+     int G = (g *  3 + b) >> 2;
+     int B = (r *  3 + g * 2 + b * 11) >> 4;
+
+     color.rgb = vec3((float)R, (float)G, (float)B);
+     color.rgb /= 255.0;
+
+     FragColor = color;
+     return;
+
+#else
+     mat3 color_correction = mat3(
+         13.0,  2.0,   1.0,
+          0.0,  3.0,   1.0,
+          3.0,  2.0,  11.0
+     );
+
+     mat3 scale = mat3(
+         1.0/16.0,      0.0,       0.0,
+              0.0,  1.0/4.0,       0.0,
+              0.0,      0.0,  1.0/16.0
+     );
+
+     color_correction *= scale;
+
+#ifdef SIMULATE_INT
+     color.rgb *= 255.0;
+     color.rgb = floor(color.rgb);
+     color.rgb *= color_correction;
+     color.rgb = floor(color.rgb);
+     color.rgb /= 255.0;
+     FragColor = color;
+     return;
+
+#else
+     color.rgb *= color_correction;
+     FragColor = color;
+     return;
+
+#endif
+
+#endif
+}
+#endif