Add Palette LUT tonemap mode

src/gl/renderer/gl_postprocess.cpp

@@ -55,6 +55,7 @@
 #include "r_utility.h"
 #include "a_hexenglobal.h"
 #include "p_local.h"
+#include "colormatcher.h"
 #include "gl/gl_functions.h"
 #include "gl/system/gl_interface.h"
 #include "gl/system/gl_framebuffer.h"
@@ -89,7 +90,7 @@ CVAR(Float, gl_exposure, 0.0f, 0)
 
 CUSTOM_CVAR(Int, gl_tonemap, 0, CVAR_ARCHIVE|CVAR_GLOBALCONFIG)
 {
-	if (self < 0 || self > 4)
+	if (self < 0 || self > 5)
 		self = 0;
 }
 
@@ -222,13 +223,61 @@ void FGLRenderer::TonemapScene()
 	mBuffers->BindCurrentTexture(0);
 	mTonemapShader->Bind();
 	mTonemapShader->SceneTexture.Set(0);
-	mTonemapShader->Exposure.Set(mCameraExposure);
+
+	if (mTonemapShader->IsPaletteMode())
+	{
+		mTonemapShader->PaletteLUT.Set(1);
+		BindTonemapPalette(1);
+	}
+	else
+	{
+		mTonemapShader->Exposure.Set(mCameraExposure);
+	}
+
 	RenderScreenQuad();
 	mBuffers->NextTexture();
 
 	FGLDebug::PopGroup();
 }
 
+void FGLRenderer::BindTonemapPalette(int texunit)
+{
+	if (mTonemapPalette)
+	{
+		mTonemapPalette->Bind(texunit, 0, false);
+	}
+	else
+	{
+		TArray<unsigned char> lut;
+		lut.Resize(512 * 512 * 4);
+		for (int r = 0; r < 64; r++)
+		{
+			for (int g = 0; g < 64; g++)
+			{
+				for (int b = 0; b < 64; b++)
+				{
+					PalEntry color = GPalette.BaseColors[ColorMatcher.Pick((r << 2) | (r >> 1), (g << 2) | (g >> 1), (b << 2) | (b >> 1))];
+					int index = ((r * 64 + g) * 64 + b) * 4;
+					lut[index] = color.r;
+					lut[index + 1] = color.g;
+					lut[index + 2] = color.b;
+					lut[index + 3] = 255;
+				}
+			}
+		}
+
+		mTonemapPalette = new FHardwareTexture(512, 512, true);
+		mTonemapPalette->CreateTexture(&lut[0], 512, 512, texunit, false, 0, "mTonemapPalette");
+
+		glActiveTexture(GL_TEXTURE0 + texunit);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+		glActiveTexture(GL_TEXTURE0);
+	}
+}
+
 //-----------------------------------------------------------------------------
 //
 // Apply lens distortion and place the result in the HUD/2D texture

src/gl/renderer/gl_postprocessstate.cpp

@@ -62,8 +62,12 @@ FGLPostProcessState::FGLPostProcessState()
 	glBindTexture(GL_TEXTURE_2D, 0);
 	if (gl.flags & RFL_SAMPLER_OBJECTS)
 	{
-		glGetIntegerv(GL_SAMPLER_BINDING, &samplerBinding);
+		glGetIntegerv(GL_SAMPLER_BINDING, &samplerBinding[0]);
 		glBindSampler(0, 0);
+		glActiveTexture(GL_TEXTURE0 + 1);
+		glGetIntegerv(GL_SAMPLER_BINDING, &samplerBinding[1]);
+		glBindSampler(1, 0);
+		glActiveTexture(GL_TEXTURE0);
 	}
 
 	glGetBooleanv(GL_BLEND, &blendEnabled);
@@ -120,7 +124,10 @@ FGLPostProcessState::~FGLPostProcessState()
 	glActiveTexture(GL_TEXTURE0);
 	glBindTexture(GL_TEXTURE_2D, 0);
 	if (gl.flags & RFL_SAMPLER_OBJECTS)
-		glBindSampler(0, samplerBinding);
+	{
+		glBindSampler(0, samplerBinding[0]);
+		glBindSampler(1, samplerBinding[1]);
+	}
 	glBindTexture(GL_TEXTURE_2D, textureBinding);
 	glActiveTexture(activeTex);
 }

src/gl/renderer/gl_postprocessstate.h

@@ -20,7 +20,7 @@ private:
 
 	GLint activeTex;
 	GLint textureBinding;
-	GLint samplerBinding;
+	GLint samplerBinding[2];
 	GLboolean blendEnabled;
 	GLboolean scissorEnabled;
 	GLboolean depthEnabled;

src/gl/renderer/gl_renderer.cpp

@@ -123,6 +123,7 @@ void FGLRenderer::Initialize(int width, int height)
 	mBloomCombineShader = new FBloomCombineShader();
 	mBlurShader = new FBlurShader();
 	mTonemapShader = new FTonemapShader();
+	mTonemapPalette = nullptr;
 	mLensShader = new FLensShader();
 	mPresentShader = new FPresentShader();
 	m2DDrawer = new F2DDrawer;
@@ -181,6 +182,7 @@ FGLRenderer::~FGLRenderer()
 	if (mBloomCombineShader) delete mBloomCombineShader;
 	if (mBlurShader) delete mBlurShader;
 	if (mTonemapShader) delete mTonemapShader;
+	if (mTonemapPalette) delete mTonemapPalette;
 	if (mLensShader) delete mLensShader;
 }
 

src/gl/renderer/gl_renderer.h

@@ -26,6 +26,7 @@ class FTonemapShader;
 class FLensShader;
 class FPresentShader;
 class F2DDrawer;
+class FHardwareTexture;
 
 inline float DEG2RAD(float deg)
 {
@@ -92,6 +93,7 @@ public:
 	FBloomCombineShader *mBloomCombineShader;
 	FBlurShader *mBlurShader;
 	FTonemapShader *mTonemapShader;
+	FHardwareTexture *mTonemapPalette;
 	FLensShader *mLensShader;
 	FPresentShader *mPresentShader;
 
@@ -164,6 +166,7 @@ public:
 	void EndDrawScene(sector_t * viewsector);
 	void BloomScene();
 	void TonemapScene();
+	void BindTonemapPalette(int texunit);
 	void LensDistortScene();
 	void CopyToBackbuffer(const GL_IRECT *bounds, bool applyGamma);
 	void Flush() { CopyToBackbuffer(nullptr, true); }

src/gl/shaders/gl_tonemapshader.cpp

@@ -61,10 +61,16 @@ void FTonemapShader::Bind()
 		shader.SetAttribLocation(0, "PositionInProjection");
 		SceneTexture.Init(shader, "InputTexture");
 		Exposure.Init(shader, "ExposureAdjustment");
+		PaletteLUT.Init(shader, "PaletteLUT");
 	}
 	shader.Bind();
 }
 
+bool FTonemapShader::IsPaletteMode()
+{
+	return gl_tonemap == Palette;
+}
+
 const char *FTonemapShader::GetDefines(int mode)
 {
 	switch (mode)
@@ -74,5 +80,6 @@ const char *FTonemapShader::GetDefines(int mode)
 	case Reinhard:   return "#define REINHARD\n";
 	case HejlDawson: return "#define HEJLDAWSON\n";
 	case Uncharted2: return "#define UNCHARTED2\n";
+	case Palette:    return "#define PALETTE\n";
 	}
 }

src/gl/shaders/gl_tonemapshader.h

@@ -10,6 +10,9 @@ public:
 
 	FBufferedUniform1i SceneTexture;
 	FBufferedUniform1f Exposure;
+	FBufferedUniform1i PaletteLUT;
+
+	static bool IsPaletteMode();
 
 private:
 	enum TonemapMode
@@ -19,6 +22,7 @@ private:
 		HejlDawson,
 		Reinhard,
 		Linear,
+		Palette,
 		NumTonemapModes
 	};
 

wadsrc/static/language.enu

@@ -2699,4 +2699,5 @@ OPTVAL_RIGHTEYE 			= "Right Eye";
 OPTVAL_QUADBUFFERED 		= "Quad-buffered";
 OPTVAL_UNCHARTED2			= "Uncharted 2";
 OPTVAL_HEJLDAWSON			= "Hejl Dawson";
-OPTVAL_REINHARD				= "Reinhard";
+OPTVAL_REINHARD				= "Reinhard";
+OPTVAL_PALETTE				= "Palette";

wadsrc/static/menudef.z

@@ -39,6 +39,7 @@ OptionValue "TonemapModes"
 	2, "$OPTVAL_HEJLDAWSON"
 	3, "$OPTVAL_REINHARD"
 	4, "$OPTVAL_LINEAR"
+	5, "$OPTVAL_PALETTE"
 }
 
 OptionValue "TextureFormats"

wadsrc/static/shaders/glsl/tonemap.fp

@@ -42,7 +42,7 @@ vec3 Tonemap(vec3 color)
 	return (x * (6.2 * x + 0.5)) / (x * (6.2 * x + 1.7) + 0.06); // no sRGB needed
 }
 
-#else
+#elif defined(UNCHARTED2)
 
 vec3 Uncharted2Tonemap(vec3 x)
 {
@@ -63,12 +63,33 @@ vec3 Tonemap(vec3 color)
 	return sRGB(curr * whiteScale);
 }
 
+#elif defined(PALETTE)
+
+uniform sampler2D PaletteLUT;
+
+vec3 Tonemap(vec3 color)
+{
+	ivec3 c = ivec3(clamp(color.rgb, vec3(0.0), vec3(1.0)) * 255.0 + 0.5);
+	int index = ((c.r >> 2) * 64 + (c.g >> 2)) * 64 + (c.b >> 2);
+	int tx = index % 512;
+	int ty = index / 512;
+	#if __VERSION__ < 130
+		return texture2D(PaletteLUT, vec2(float(tx) / 512.0, float(ty) / 512.0))).rgb;
+	#else
+		return texelFetch(PaletteLUT, ivec2(tx, ty), 0).rgb;
+	#endif
+}
+
+#else
+#error "Tonemap mode define is missing"
 #endif
 
 void main()
 {
 	vec3 color = texture(InputTexture, TexCoord).rgb;
+#ifndef PALETTE
 	color = color * ExposureAdjustment;
 	color = Linear(color); // needed because gzdoom's scene texture is not linear at the moment
+#endif
 	FragColor = vec4(Tonemap(color), 1.0);
 }