add HDR tonemapping shader

misc/tonemapping.slang

@@ -0,0 +1,129 @@
+#version 450
+
+layout(push_constant) uniform Push
+{
+	vec4 SourceSize;
+	vec4 OriginalSize;
+	vec4 OutputSize;
+	uint FrameCount;
+	float MAP;
+} params;
+
+#pragma parameter MAP "Tone Map Method" 0.0 0.0 6.0 1.0
+
+layout(std140, set = 0, binding = 0) uniform UBO
+{
+	mat4 MVP;
+} global;
+
+/*
+This shader experiments the effect of different tone mapping operators.
+This is still a work in progress.
+More info:
+http://slideshare.net/ozlael/hable-john-uncharted2-hdr-lighting
+http://filmicgames.com/archives/75
+http://filmicgames.com/archives/183
+http://filmicgames.com/archives/190
+http://imdoingitwrong.wordpress.com/2010/08/19/why-reinhard-desaturates-my-blacks-3/
+http://mynameismjp.wordpress.com/2010/04/30/a-closer-look-at-tone-mapping/
+http://renderwonk.com/publications/s2010-color-course/
+--
+Zavie
+*/
+
+float gamma = 2.2;
+
+vec3 linearToneMapping(vec3 color)
+{
+	float exposure = 1.;
+	color = clamp(exposure * color, 0., 1.);
+	color = pow(color, vec3(1. / gamma));
+	return color;
+}
+
+vec3 simpleReinhardToneMapping(vec3 color)
+{
+	float exposure = 1.5;
+	color *= exposure/(1. + color / exposure);
+	color = pow(color, vec3(1. / gamma));
+	return color;
+}
+
+vec3 lumaBasedReinhardToneMapping(vec3 color)
+{
+	float luma = dot(color, vec3(0.2126, 0.7152, 0.0722));
+	float toneMappedLuma = luma / (1. + luma);
+	color *= toneMappedLuma / luma;
+	color = pow(color, vec3(1. / gamma));
+	return color;
+}
+
+vec3 whitePreservingLumaBasedReinhardToneMapping(vec3 color)
+{
+	float white = 2.;
+	float luma = dot(color, vec3(0.2126, 0.7152, 0.0722));
+	float toneMappedLuma = luma * (1. + luma / (white*white)) / (1. + luma);
+	color *= toneMappedLuma / luma;
+	color = pow(color, vec3(1. / gamma));
+	return color;
+}
+
+vec3 RomBinDaHouseToneMapping(vec3 color)
+{
+    color = exp( -1.0 / ( 2.72*color + 0.15 ) );
+	color = pow(color, vec3(1. / gamma));
+	return color;
+}
+
+vec3 filmicToneMapping(vec3 color)
+{
+	color = max(vec3(0.), color - vec3(0.004));
+	color = (color * (6.2 * color + .5)) / (color * (6.2 * color + 1.7) + 0.06);
+	return color;
+}
+
+vec3 Uncharted2ToneMapping(vec3 color)
+{
+	float A = 0.15;
+	float B = 0.50;
+	float C = 0.10;
+	float D = 0.20;
+	float E = 0.02;
+	float F = 0.30;
+	float W = 11.2;
+	float exposure = 2.;
+	color *= exposure;
+	color = ((color * (A * color + C * B) + D * E) / (color * (A * color + B) + D * F)) - E / F;
+	float white = ((W * (A * W + C * B) + D * E) / (W * (A * W + B) + D * F)) - E / F;
+	color /= white;
+	color = pow(color, vec3(1. / gamma));
+	return color;
+}
+
+#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;
+
+void main()
+{
+    vec3 color = COMPAT_TEXTURE(Texture, TEX0.xy).rgb;
+if (MAP == 0.0) FragColor = vec4(linearToneMapping(color), 1.0);
+if (MAP == 1.0) FragColor = vec4(simpleReinhardToneMapping(color), 1.0);
+if (MAP == 2.0) FragColor = vec4(lumaBasedReinhardToneMapping(color), 1.0);
+if (MAP == 3.0) FragColor = vec4(whitePreservingLumaBasedReinhardToneMapping(color), 1.0);
+if (MAP == 4.0) FragColor = vec4(RomBinDaHouseToneMapping(color), 1.0);
+if (MAP == 5.0) FragColor = vec4(filmicToneMapping(color), 1.0);
+if (MAP == 6.0) FragColor = vec4(Uncharted2ToneMapping(color), 1.0);
+}