add LUT tonemapping shader

reshade/lut.slangp

@@ -0,0 +1,8 @@
+shaders = 1
+
+shader0 = shaders/LUT/LUT.slang
+
+textures = SamplerLUT
+
+SamplerLUT = shaders/LUT/16.png
+SamplerLUT_linear = true

reshade/shaders/LUT/LUT.slang

@@ -0,0 +1,44 @@
+#version 450
+
+layout(push_constant) uniform Push
+{
+	vec4 SourceSize;
+	vec4 OriginalSize;
+	vec4 OutputSize;
+	uint FrameCount;
+	float LUT_Size;
+} params;
+
+#pragma parameter LUT_Size "LUT Size" 16.0 16.0 64.0 1.0
+
+layout(std140, set = 0, binding = 0) uniform UBO
+{
+	mat4 MVP;
+} 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 = 0) out vec4 FragColor;
+layout(set = 0, binding = 2) uniform sampler2D Source;
+layout(set = 0, binding = 3) uniform sampler2D SamplerLUT;
+
+void main()
+{
+	vec4 imgColor = texture(Source, vTexCoord.xy);
+    float red = ( imgColor.r * (params.LUT_Size - 1.0) + 0.5 ) / (params.LUT_Size * params.LUT_Size);
+    float green = ( imgColor.g * (params.LUT_Size - 1.0) + 0.5 ) / params.LUT_Size;
+    float blue = floor( imgColor.b  * (params.LUT_Size - 1.0) ) / params.LUT_Size;
+    vec4 color = texture( SamplerLUT, vec2( blue + red, green ));
+   FragColor = color;
+}