Added tonemapping and sector based exposure control

src/CMakeLists.txt

@@ -1108,6 +1108,7 @@ set( FASTMATH_SOURCES
 	gl/shaders/gl_presentshader.cpp
 	gl/shaders/gl_bloomshader.cpp
 	gl/shaders/gl_blurshader.cpp
+	gl/shaders/gl_tonemapshader.cpp
 	gl/system/gl_interface.cpp
 	gl/system/gl_framebuffer.cpp
 	gl/system/gl_menu.cpp

src/gl/renderer/gl_renderbuffers.cpp

@@ -97,10 +97,16 @@ void FGLRenderBuffers::Clear()
 		glDeleteTextures(1, &mSceneTexture);
 	if (mSceneDepthStencil != 0)
 		glDeleteRenderbuffers(1, &mSceneDepthStencil);
+	if (mHudFB != 0)
+		glDeleteFramebuffers(1, &mHudFB);
+	if (mHudTexture != 0)
+		glDeleteTextures(1, &mHudTexture);
 
 	mSceneFB = 0;
 	mSceneTexture = 0;
 	mSceneDepthStencil = 0;
+	mHudFB = 0;
+	mHudTexture = 0;
 	mWidth = 0;
 	mHeight = 0;
 }
@@ -122,7 +128,9 @@ void FGLRenderBuffers::Setup(int width, int height)
 	glActiveTexture(GL_TEXTURE0);
 
 	glGenFramebuffers(1, &mSceneFB);
+	glGenFramebuffers(1, &mHudFB);
 	glGenTextures(1, &mSceneTexture);
+	glGenTextures(1, &mHudTexture);
 	glGenRenderbuffers(1, &mSceneDepthStencil);
 
 	glBindTexture(GL_TEXTURE_2D, mSceneTexture);
@@ -139,6 +147,16 @@ void FGLRenderBuffers::Setup(int width, int height)
 	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mSceneTexture, 0);
 	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, mSceneDepthStencil);
 
+	glBindTexture(GL_TEXTURE_2D, mHudTexture);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16, width, height, 0, GL_RGBA, GL_UNSIGNED_SHORT, nullptr);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+
+	glBindFramebuffer(GL_FRAMEBUFFER, mHudFB);
+	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mHudTexture, 0);
+
 	int bloomWidth = MAX(width / 2, 1);
 	int bloomHeight = MAX(height / 2, 1);
 	for (int i = 0; i < NumBloomLevels; i++)
@@ -191,6 +209,17 @@ void FGLRenderBuffers::BindSceneFB()
 	glBindFramebuffer(GL_FRAMEBUFFER, mSceneFB);
 }
 
+//==========================================================================
+//
+// Makes the 2D/HUD frame buffer active 
+//
+//==========================================================================
+
+void FGLRenderBuffers::BindHudFB()
+{
+	glBindFramebuffer(GL_FRAMEBUFFER, mHudFB);
+}
+
 //==========================================================================
 //
 // Makes the screen frame buffer active
@@ -213,3 +242,15 @@ void FGLRenderBuffers::BindSceneTexture(int index)
 	glActiveTexture(GL_TEXTURE0 + index);
 	glBindTexture(GL_TEXTURE_2D, mSceneTexture);
 }
+
+//==========================================================================
+//
+// Binds the 2D/HUD frame buffer texture to the specified texture unit
+//
+//==========================================================================
+
+void FGLRenderBuffers::BindHudTexture(int index)
+{
+	glActiveTexture(GL_TEXTURE0 + index);
+	glBindTexture(GL_TEXTURE_2D, mHudTexture);
+}

src/gl/renderer/gl_renderbuffers.h

@@ -22,8 +22,10 @@ public:
 
 	void Setup(int width, int height);
 	void BindSceneFB();
+	void BindHudFB();
 	void BindOutputFB();
 	void BindSceneTexture(int index);
+	void BindHudTexture(int index);
 
 	static bool IsSupported() { return gl.version >= 3.3f; }
 
@@ -39,6 +41,8 @@ private:
 	GLuint mSceneTexture = 0;
 	GLuint mSceneDepthStencil = 0;
 	GLuint mSceneFB = 0;
+	GLuint mHudTexture = 0;
+	GLuint mHudFB = 0;
 	GLuint mOutputFB = 0;
 };
 

src/gl/renderer/gl_renderer.cpp

@@ -64,6 +64,7 @@
 #include "gl/shaders/gl_shader.h"
 #include "gl/shaders/gl_bloomshader.h"
 #include "gl/shaders/gl_blurshader.h"
+#include "gl/shaders/gl_tonemapshader.h"
 #include "gl/shaders/gl_presentshader.h"
 #include "gl/textures/gl_texture.h"
 #include "gl/textures/gl_translate.h"
@@ -115,6 +116,7 @@ void FGLRenderer::Initialize()
 	mBloomExtractShader = new FBloomExtractShader();
 	mBloomCombineShader = new FBloomCombineShader();
 	mBlurShader = new FBlurShader();
+	mTonemapShader = new FTonemapShader();
 	mPresentShader = new FPresentShader();
 
 	// Only needed for the core profile, because someone decided it was a good idea to remove the default VAO.
@@ -168,6 +170,7 @@ FGLRenderer::~FGLRenderer()
 	if (mBloomExtractShader) delete mBloomExtractShader;
 	if (mBloomCombineShader) delete mBloomCombineShader;
 	if (mBlurShader) delete mBlurShader;
+	if (mTonemapShader) delete mTonemapShader;
 }
 
 //==========================================================================
@@ -235,7 +238,10 @@ void FGLRenderer::Begin2D()
 	if (FGLRenderBuffers::IsSupported())
 	{
 		mBuffers->Setup(framebuffer->GetWidth(), framebuffer->GetHeight());
-		mBuffers->BindSceneFB();
+		if (mDrawingScene2D)
+			mBuffers->BindSceneFB();
+		else
+			mBuffers->BindHudFB();
 		glViewport(0, 0, mOutputViewport.width, mOutputViewport.height);
 	}
 	else

src/gl/renderer/gl_renderer.h

@@ -22,6 +22,7 @@ class FGLRenderBuffers;
 class FBloomExtractShader;
 class FBloomCombineShader;
 class FBlurShader;
+class FTonemapShader;
 class FPresentShader;
 
 inline float DEG2RAD(float deg)
@@ -88,6 +89,7 @@ public:
 	FBloomExtractShader *mBloomExtractShader;
 	FBloomCombineShader *mBloomCombineShader;
 	FBlurShader *mBlurShader;
+	FTonemapShader *mTonemapShader;
 	FPresentShader *mPresentShader;
 
 	FTexture *gllight;
@@ -106,6 +108,8 @@ public:
 
 	GL_IRECT mOutputViewportLB;
 	GL_IRECT mOutputViewport;
+	bool mDrawingScene2D = false;
+	float mCameraExposure = 1.0f;
 
 	FGLRenderer(OpenGLFrameBuffer *fb);
 	~FGLRenderer() ;
@@ -154,6 +158,7 @@ public:
 	void WriteSavePic (player_t *player, FILE *file, int width, int height);
 	void EndDrawScene(sector_t * viewsector);
 	void BloomScene();
+	void TonemapScene();
 	void Flush();
 
 	void SetProjection(float fov, float ratio, float fovratio);

src/gl/scene/gl_scene.cpp

@@ -74,6 +74,7 @@
 #include "gl/shaders/gl_shader.h"
 #include "gl/shaders/gl_bloomshader.h"
 #include "gl/shaders/gl_blurshader.h"
+#include "gl/shaders/gl_tonemapshader.h"
 #include "gl/shaders/gl_presentshader.h"
 #include "gl/stereo3d/gl_stereo3d.h"
 #include "gl/stereo3d/scoped_view_shifter.h"
@@ -219,11 +220,9 @@ void FGLRenderer::BloomScene()
 
 	const float blurAmount = 4.0f;
 	int sampleCount = 5; // Note: must be uneven number 3 to 15
-	float exposure = 2.0f;
+	float exposure = mCameraExposure;
 
-	auto vbo = GLRenderer->mVBO;
-
-	// TODO: Need a better way to share state with other parts of the pipeline
+	// TBD: Maybe need a better way to share state with other parts of the pipeline
 	GLboolean blendEnabled, scissorEnabled;
 	GLint currentProgram, blendEquationRgb, blendEquationAlpha, blendSrcRgb, blendSrcAlpha, blendDestRgb, blendDestAlpha;
 	glGetBooleanv(GL_BLEND, &blendEnabled);
@@ -251,12 +250,12 @@ void FGLRenderer::BloomScene()
 	mBloomExtractShader->SceneTexture.Set(0);
 	mBloomExtractShader->Exposure.Set(exposure);
 	{
-		FFlatVertex *ptr = vbo->GetBuffer();
+		FFlatVertex *ptr = mVBO->GetBuffer();
 		ptr->Set(-1.0f, -1.0f, 0, 0.0f, 0.0f); ptr++;
 		ptr->Set(-1.0f, 1.0f, 0, 0.0f, 1.0f); ptr++;
 		ptr->Set(1.0f, -1.0f, 0, 1.0f, 0.0f); ptr++;
 		ptr->Set(1.0f, 1.0f, 0, 1.0f, 1.0f); ptr++;
-		vbo->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
+		mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
 	}
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
@@ -266,8 +265,8 @@ void FGLRenderer::BloomScene()
 	{
 		const auto &level = mBuffers->BloomLevels[i];
 		const auto &next = mBuffers->BloomLevels[i + 1];
-		mBlurShader->BlurHorizontal(vbo, blurAmount, sampleCount, level.VTexture, level.HFramebuffer, level.Width, level.Height);
-		mBlurShader->BlurVertical(vbo, blurAmount, sampleCount, level.HTexture, next.VFramebuffer, next.Width, next.Height);
+		mBlurShader->BlurHorizontal(mVBO, blurAmount, sampleCount, level.VTexture, level.HFramebuffer, level.Width, level.Height);
+		mBlurShader->BlurVertical(mVBO, blurAmount, sampleCount, level.HTexture, next.VFramebuffer, next.Width, next.Height);
 	}
 
 	// Blur and upscale:
@@ -276,8 +275,8 @@ void FGLRenderer::BloomScene()
 		const auto &level = mBuffers->BloomLevels[i];
 		const auto &next = mBuffers->BloomLevels[i - 1];
 
-		mBlurShader->BlurHorizontal(vbo, blurAmount, sampleCount, level.VTexture, level.HFramebuffer, level.Width, level.Height);
-		mBlurShader->BlurVertical(vbo, blurAmount, sampleCount, level.HTexture, level.VFramebuffer, level.Width, level.Height);
+		mBlurShader->BlurHorizontal(mVBO, blurAmount, sampleCount, level.VTexture, level.HFramebuffer, level.Width, level.Height);
+		mBlurShader->BlurVertical(mVBO, blurAmount, sampleCount, level.HTexture, level.VFramebuffer, level.Width, level.Height);
 
 		// Linear upscale:
 		glBindFramebuffer(GL_FRAMEBUFFER, next.VFramebuffer);
@@ -289,17 +288,17 @@ void FGLRenderer::BloomScene()
 		mBloomCombineShader->Bind();
 		mBloomCombineShader->BloomTexture.Set(0);
 		{
-			FFlatVertex *ptr = vbo->GetBuffer();
+			FFlatVertex *ptr = mVBO->GetBuffer();
 			ptr->Set(-1.0f, -1.0f, 0, 0.0f, 0.0f); ptr++;
 			ptr->Set(-1.0f, 1.0f, 0, 0.0f, 1.0f); ptr++;
 			ptr->Set(1.0f, -1.0f, 0, 1.0f, 0.0f); ptr++;
 			ptr->Set(1.0f, 1.0f, 0, 1.0f, 1.0f); ptr++;
-			vbo->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
+			mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
 		}
 	}
 
-	mBlurShader->BlurHorizontal(vbo, blurAmount, sampleCount, level0.VTexture, level0.HFramebuffer, level0.Width, level0.Height);
-	mBlurShader->BlurVertical(vbo, blurAmount, sampleCount, level0.HTexture, level0.VFramebuffer, level0.Width, level0.Height);
+	mBlurShader->BlurHorizontal(mVBO, blurAmount, sampleCount, level0.VTexture, level0.HFramebuffer, level0.Width, level0.Height);
+	mBlurShader->BlurVertical(mVBO, blurAmount, sampleCount, level0.HTexture, level0.VFramebuffer, level0.Width, level0.Height);
 
 	// Add bloom back to scene texture:
 	mBuffers->BindSceneFB();
@@ -314,12 +313,12 @@ void FGLRenderer::BloomScene()
 	mBloomCombineShader->Bind();
 	mBloomCombineShader->BloomTexture.Set(0);
 	{
-		FFlatVertex *ptr = vbo->GetBuffer();
+		FFlatVertex *ptr = mVBO->GetBuffer();
 		ptr->Set(-1.0f, -1.0f, 0, 0.0f, 0.0f); ptr++;
 		ptr->Set(-1.0f, 1.0f, 0, 0.0f, 1.0f); ptr++;
 		ptr->Set(1.0f, -1.0f, 0, 1.0f, 0.0f); ptr++;
 		ptr->Set(1.0f, 1.0f, 0, 1.0f, 1.0f); ptr++;
-		vbo->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
+		mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
 	}
 
 	if (blendEnabled)
@@ -332,7 +331,41 @@ void FGLRenderer::BloomScene()
 
 //-----------------------------------------------------------------------------
 //
-// Run post processing steps and copy to frame buffer
+// Tonemap scene texture and place the result in the HUD/2D texture
+//
+//-----------------------------------------------------------------------------
+
+void FGLRenderer::TonemapScene()
+{
+	GLboolean blendEnabled, scissorEnabled;
+	glGetBooleanv(GL_BLEND, &blendEnabled);
+	glGetBooleanv(GL_SCISSOR_TEST, &scissorEnabled);
+
+	glDisable(GL_BLEND);
+	glDisable(GL_SCISSOR_TEST);
+
+	mBuffers->BindHudFB();
+	mBuffers->BindSceneTexture(0);
+	mTonemapShader->Bind();
+	mTonemapShader->SceneTexture.Set(0);
+	mTonemapShader->Exposure.Set(mCameraExposure);
+	
+	FFlatVertex *ptr = mVBO->GetBuffer();
+	ptr->Set(-1.0f, -1.0f, 0, 0.0f, 0.0f); ptr++;
+	ptr->Set(-1.0f, 1.0f, 0, 0.0f, 1.0f); ptr++;
+	ptr->Set(1.0f, -1.0f, 0, 1.0f, 0.0f); ptr++;
+	ptr->Set(1.0f, 1.0f, 0, 1.0f, 1.0f); ptr++;
+	mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
+
+	if (blendEnabled)
+		glEnable(GL_BLEND);
+	if (scissorEnabled)
+		glEnable(GL_SCISSOR_TEST);
+}
+
+//-----------------------------------------------------------------------------
+//
+// Gamma correct while copying to frame buffer
 //
 //-----------------------------------------------------------------------------
 
@@ -406,7 +439,7 @@ void FGLRenderer::Flush()
 			mPresentShader->Contrast.Set(clamp<float>(vid_contrast, 0.1f, 3.f));
 			mPresentShader->Brightness.Set(clamp<float>(vid_brightness, -0.8f, 0.8f));
 		}
-		mBuffers->BindSceneTexture(0);
+		mBuffers->BindHudTexture(0);
 
 		FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
 		ptr->Set(-1.0f, -1.0f, 0, 0.0f, 0.0f); ptr++;
@@ -938,6 +971,7 @@ void FGLRenderer::EndDrawScene(sector_t * viewsector)
 	glDisable(GL_SCISSOR_TEST);
 
 	BloomScene();
+	TonemapScene();
 }
 
 
@@ -1042,6 +1076,13 @@ sector_t * FGLRenderer::RenderViewpoint (AActor * camera, GL_IRECT * bounds, flo
 		mViewActor=camera;
 	}
 
+	if (toscreen)
+	{
+		float light = viewsector->lightlevel / 255.0f;
+		float exposure = MAX(1.0f + (1.0f - light * light) * 1.5f, 0.5f);
+		mCameraExposure = mCameraExposure * 0.98f + exposure * 0.02f;
+	}
+
 	// 'viewsector' will not survive the rendering so it cannot be used anymore below.
 	retval = viewsector;
 
@@ -1056,6 +1097,7 @@ sector_t * FGLRenderer::RenderViewpoint (AActor * camera, GL_IRECT * bounds, flo
 		// TODO: stereo specific viewport - needed when implementing side-by-side modes etc.
 		SetOutputViewport(bounds);
 		Set3DViewport();
+		mDrawingScene2D = true;
 		mCurrentFoV = fov;
 		// Stereo mode specific perspective projection
 		SetProjection( eye->GetProjection(fov, ratio, fovratio) );
@@ -1073,6 +1115,7 @@ sector_t * FGLRenderer::RenderViewpoint (AActor * camera, GL_IRECT * bounds, flo
 
 		ProcessScene(toscreen);
 		if (mainview) EndDrawScene(retval);	// do not call this for camera textures.
+		mDrawingScene2D = false;
 		eye->TearDown();
 	}
 	stereo3dMode.TearDown();

src/gl/shaders/gl_blurshader.cpp

@@ -80,32 +80,29 @@ void FBlurShader::BlurHorizontal(FFlatVertexBuffer *vbo, float blurAmount, int s
 
 void FBlurShader::Blur(FFlatVertexBuffer *vbo, float blurAmount, int sampleCount, GLuint inputTexture, GLuint outputFrameBuffer, int width, int height, bool vertical)
 {
-	int error = glGetError();
 	BlurSetup *setup = GetSetup(blurAmount, sampleCount);
-	error = glGetError();
 	if (vertical)
 		setup->VerticalShader->Bind();
 	else
 		setup->HorizontalShader->Bind();
-	error = glGetError();
+
 	glActiveTexture(GL_TEXTURE0);
 	glBindTexture(GL_TEXTURE_2D, inputTexture);
 	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);
-	error = glGetError();
+
 	glBindFramebuffer(GL_FRAMEBUFFER, outputFrameBuffer);
 	glViewport(0, 0, width, height);
 	glDisable(GL_BLEND);
-	error = glGetError();
+
 	FFlatVertex *ptr = vbo->GetBuffer();
 	ptr->Set(-1.0f, -1.0f, 0, 0.0f, 0.0f); ptr++;
 	ptr->Set(-1.0f, 1.0f, 0, 0.0f, 1.0f); ptr++;
 	ptr->Set(1.0f, -1.0f, 0, 1.0f, 0.0f); ptr++;
 	ptr->Set(1.0f, 1.0f, 0, 1.0f, 1.0f); ptr++;
 	vbo->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
-	error = glGetError();
 }
 
 //==========================================================================
@@ -138,9 +135,7 @@ FBlurShader::BlurSetup *FBlurShader::GetSetup(float blurAmount, int sampleCount)
 	blurSetup.VerticalShader->SetAttribLocation(0, "PositionInProjection");
 	blurSetup.VerticalShader->Link("vertical blur");
 	blurSetup.VerticalShader->Bind();
-	int error = glGetError();
 	glUniform1i(glGetUniformLocation(*blurSetup.VerticalShader.get(), "SourceTexture"), 0);
-	error = glGetError();
 
 	blurSetup.HorizontalShader = std::make_shared<FShaderProgram>();
 	blurSetup.HorizontalShader->Compile(FShaderProgram::Vertex, "horizontal blur vertex shader", vertexCode);

src/gl/shaders/gl_tonemapshader.cpp

@@ -0,0 +1,65 @@
+/*
+** gl_tonemapshader.cpp
+** Converts a HDR texture to 0-1 range by applying a tonemap operator
+**
+**---------------------------------------------------------------------------
+** Copyright 2016 Magnus Norddahl
+** All rights reserved.
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions
+** are met:
+**
+** 1. Redistributions of source code must retain the above copyright
+**    notice, this list of conditions and the following disclaimer.
+** 2. Redistributions in binary form must reproduce the above copyright
+**    notice, this list of conditions and the following disclaimer in the
+**    documentation and/or other materials provided with the distribution.
+** 3. The name of the author may not be used to endorse or promote products
+**    derived from this software without specific prior written permission.
+** 4. When not used as part of GZDoom or a GZDoom derivative, this code will be
+**    covered by the terms of the GNU Lesser General Public License as published
+**    by the Free Software Foundation; either version 2.1 of the License, or (at
+**    your option) any later version.
+** 5. Full disclosure of the entire project's source code, except for third
+**    party libraries is mandatory. (NOTE: This clause is non-negotiable!)
+**
+** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+**---------------------------------------------------------------------------
+**
+*/
+
+#include "gl/system/gl_system.h"
+#include "files.h"
+#include "m_swap.h"
+#include "v_video.h"
+#include "gl/gl_functions.h"
+#include "vectors.h"
+#include "gl/system/gl_interface.h"
+#include "gl/system/gl_framebuffer.h"
+#include "gl/system/gl_cvars.h"
+#include "gl/shaders/gl_tonemapshader.h"
+
+void FTonemapShader::Bind()
+{
+	if (!mShader)
+	{
+		mShader.Compile(FShaderProgram::Vertex, "shaders/glsl/tonemap.vp");
+		mShader.Compile(FShaderProgram::Fragment, "shaders/glsl/tonemap.fp");
+		mShader.SetFragDataLocation(0, "FragColor");
+		mShader.Link("shaders/glsl/tonemap");
+		mShader.SetAttribLocation(0, "PositionInProjection");
+		SceneTexture.Init(mShader, "InputTexture");
+		Exposure.Init(mShader, "ExposureAdjustment");
+	}
+	mShader.Bind();
+}

src/gl/shaders/gl_tonemapshader.h

@@ -0,0 +1,18 @@
+#ifndef __GL_TONEMAPSHADER_H
+#define __GL_TONEMAPSHADER_H
+
+#include "gl_shaderprogram.h"
+
+class FTonemapShader
+{
+public:
+	void Bind();
+
+	FBufferedUniform1i SceneTexture;
+	FBufferedUniform1f Exposure;
+
+private:
+	FShaderProgram mShader;
+};
+
+#endif

src/gl/system/gl_wipe.cpp

@@ -158,7 +158,7 @@ bool OpenGLFrameBuffer::WipeStartScreen(int type)
 
 	if (FGLRenderBuffers::IsSupported())
 	{
-		GLRenderer->mBuffers->BindSceneFB();
+		GLRenderer->mBuffers->BindHudFB();
 		glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, Width, Height);
 	}
 	else
@@ -193,7 +193,7 @@ void OpenGLFrameBuffer::WipeEndScreen()
 	wipeendscreen->Bind(0, false, false);
 
 	if (FGLRenderBuffers::IsSupported())
-		GLRenderer->mBuffers->BindSceneFB();
+		GLRenderer->mBuffers->BindHudFB();
 
 	glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, Width, Height);
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
@@ -232,7 +232,7 @@ bool OpenGLFrameBuffer::WipeDo(int ticks)
 
 	if (FGLRenderBuffers::IsSupported())
 	{
-		GLRenderer->mBuffers->BindSceneFB();
+		GLRenderer->mBuffers->BindHudFB();
 		glViewport(0, 0, GLRenderer->mOutputViewport.width, GLRenderer->mOutputViewport.height);
 	}
 

wadsrc/static/shaders/glsl/tonemap.fp

@@ -0,0 +1,65 @@
+
+#version 330
+
+in vec2 TexCoord;
+out vec4 FragColor;
+
+uniform sampler2D InputTexture;
+uniform float ExposureAdjustment;
+
+vec3 Linear(vec3 c)
+{
+	//return pow(c, 2.2);
+	return c * c; // cheaper, but assuming gamma of 2.0 instead of 2.2
+}
+
+vec3 sRGB(vec3 c)
+{
+	//return pow(c, vec3(1.0 / 2.2));
+	return sqrt(c); // cheaper, but assuming gamma of 2.0 instead of 2.2
+}
+
+vec3 TonemapLinear(vec3 color)
+{
+	return sRGB(color);
+}
+
+vec3 TonemapReinhard(vec3 color)
+{
+	color = color / (1 + color);
+	return sRGB(color);
+}
+
+vec3 TonemapHejlDawson(vec3 color)
+{
+	vec3 x = max(vec3(0), color - 0.004);
+	return (x * (6.2 * x + 0.5)) / (x * (6.2 * x + 1.7) + 0.06); // no sRGB needed
+}
+
+vec3 Uncharted2Tonemap(vec3 x)
+{
+	float A = 0.15;
+	float B = 0.50;
+	float C = 0.10;
+	float D = 0.20;
+	float E = 0.02;
+	float F = 0.30;
+	return ((x * (A * x + C * B) + D * E) / (x * (A * x + B) + D * F)) - E / F;
+}
+
+vec3 TonemapUncharted2(vec3 color)
+{
+	float W = 11.2;
+	float ExposureBias = 2.0;
+	vec3 curr = Uncharted2Tonemap(ExposureBias * color);
+	vec3 whiteScale = vec3(1) / Uncharted2Tonemap(vec3(W));
+	return sRGB(curr * whiteScale);
+}
+
+void main()
+{
+	vec3 color = texture(InputTexture, TexCoord).rgb;
+	color = color * ExposureAdjustment;
+	color = Linear(color); // needed because gzdoom's scene texture is not linear at the moment
+	FragColor = vec4(TonemapUncharted2(color), 1.0);
+}

wadsrc/static/shaders/glsl/tonemap.vp

@@ -0,0 +1,11 @@
+
+#version 330
+
+in vec4 PositionInProjection;
+out vec2 TexCoord;
+
+void main()
+{
+	gl_Position = PositionInProjection;
+	TexCoord = PositionInProjection.xy * 0.5 + 0.5;
+}