Optimizes FBO usages for LOSTexture and water shore foam.

Tested By: Stan
Differential Revision: https://code.wildfiregames.com/D4418
This was SVN commit r26180.

source/graphics/LOSTexture.cpp

@@ -60,8 +60,7 @@ static const size_t g_BlurSize = 7;
 static const size_t g_SubTextureAlignment = 4;
 
 CLOSTexture::CLOSTexture(CSimulation2& simulation)
-	: m_Simulation(simulation), m_Dirty(true), m_ShaderInitialized(false),
+	: m_Simulation(simulation)
-	m_SmoothFBO(0), m_MapSize(0), m_WhichTex(true)
 {
 	if (CRenderer::IsInitialised() && g_RenderingOptions.GetSmoothLOS())
 		CreateShader();
@@ -69,8 +68,10 @@ CLOSTexture::CLOSTexture(CSimulation2& simulation)
 
 CLOSTexture::~CLOSTexture()
 {
-	if (m_SmoothFBO)
+	if (m_SmoothFBO1)
-		glDeleteFramebuffersEXT(1, &m_SmoothFBO);
+		glDeleteFramebuffersEXT(1, &m_SmoothFBO1);
+	if (m_SmoothFBO2)
+		glDeleteFramebuffersEXT(1, &m_SmoothFBO2);
 
 	if (m_Texture)
 		DeleteTexture();
@@ -79,10 +80,10 @@ CLOSTexture::~CLOSTexture()
 // Create the LOS texture engine. Should be ran only once.
 bool CLOSTexture::CreateShader()
 {
-	m_smoothShader = g_Renderer.GetShaderManager().LoadEffect(str_los_interp);
+	m_SmoothTech = g_Renderer.GetShaderManager().LoadEffect(str_los_interp);
-	CShaderProgramPtr shader = m_smoothShader->GetShader();
+	CShaderProgramPtr shader = m_SmoothTech->GetShader();
 
-	m_ShaderInitialized = m_smoothShader && shader;
+	m_ShaderInitialized = m_SmoothTech && shader;
 
 	if (!m_ShaderInitialized)
 	{
@@ -91,7 +92,8 @@ bool CLOSTexture::CreateShader()
 		return false;
 	}
 
-	glGenFramebuffersEXT(1, &m_SmoothFBO);
+	glGenFramebuffersEXT(1, &m_SmoothFBO1);
+	glGenFramebuffersEXT(1, &m_SmoothFBO2);
 	return true;
 }
 
@@ -139,18 +141,10 @@ void CLOSTexture::InterpolateLOS(Renderer::Backend::GL::CDeviceCommandContext* d
 	if (skipSmoothLOS)
 		return;
 
-	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m_SmoothFBO);
+	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, (m_WhichTex ? m_SmoothFBO2 : m_SmoothFBO1));
-	glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D,
-			   (m_WhichTex ? m_TextureSmooth2 : m_TextureSmooth1)->GetHandle(), 0);
 
-	GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
+	m_SmoothTech->BeginPass();
-	if (status != GL_FRAMEBUFFER_COMPLETE_EXT)
+	CShaderProgramPtr shader = m_SmoothTech->GetShader();
-	{
-		LOGWARNING("LOS framebuffer object incomplete: 0x%04X", status);
-	}
-
-	m_smoothShader->BeginPass();
-	CShaderProgramPtr shader = m_smoothShader->GetShader();
 
 	glDisable(GL_BLEND);
 
@@ -198,9 +192,7 @@ void CLOSTexture::InterpolateLOS(Renderer::Backend::GL::CDeviceCommandContext* d
 	g_Renderer.SetViewport(oldVp);
 
 	shader->Unbind();
-	m_smoothShader->EndPass();
+	m_SmoothTech->EndPass();
-
-	glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, 0, 0);
 
 	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
 
@@ -256,6 +248,20 @@ void CLOSTexture::ConstructTexture(Renderer::Backend::GL::CDeviceCommandContext*
 		m_TextureSmooth2 = Renderer::Backend::GL::CTexture::Create2D(
 			Renderer::Backend::Format::A8, textureSize, textureSize, defaultSamplerDesc);
 
+		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m_SmoothFBO1);
+		glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D,
+			m_TextureSmooth1->GetHandle(), 0);
+		GLenum status1 = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
+		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m_SmoothFBO2);
+		glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D,
+			m_TextureSmooth2->GetHandle(), 0);
+		GLenum status2 = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
+		if (status1 != GL_FRAMEBUFFER_COMPLETE_EXT || status2 != GL_FRAMEBUFFER_COMPLETE_EXT)
+		{
+			LOGWARNING("LOS framebuffer object incomplete: 0x%04X 0x%04X", status1, status2);
+		}
+		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+
 		deviceCommandContext->UploadTexture(m_TextureSmooth1.get(), Renderer::Backend::Format::A8, texData.get(), textureSize * textureSize);
 		deviceCommandContext->UploadTexture(m_TextureSmooth2.get(), Renderer::Backend::Format::A8, texData.get(), textureSize * textureSize);
 	}

source/graphics/LOSTexture.h

@@ -84,19 +84,22 @@ private:
 
 	CSimulation2& m_Simulation;
 
-	bool m_Dirty;
+	bool m_Dirty = true;
 
-	bool m_ShaderInitialized;
+	bool m_ShaderInitialized = false;
 
 	std::unique_ptr<Renderer::Backend::GL::CTexture>
 		m_Texture, m_TextureSmooth1, m_TextureSmooth2;
 
-	bool m_WhichTex;
+	bool m_WhichTex = true;
 
-	GLuint m_SmoothFBO;
+	// We update textures once a frame, so we change a FBO once a frame. That
-	CShaderTechniquePtr m_smoothShader;
+	// allows us to use two ping-pong FBOs instead of checking completeness of
+	// FBO each frame.
+	GLuint m_SmoothFBO1 = 0, m_SmoothFBO2 = 0;
+	CShaderTechniquePtr m_SmoothTech;
 
-	size_t m_MapSize; // vertexes per side
+	size_t m_MapSize = 0; // vertexes per side
 
 	CMatrix3D m_TextureMatrix;
 	CMatrix3D m_MinimapTextureMatrix;

source/renderer/SceneRenderer.cpp

@@ -880,11 +880,15 @@ void CSceneRenderer::RenderSubmissions(
 	{
 		if (waterScissor.GetVolume() > 0 && m->waterManager.WillRenderFancyWater())
 		{
+			m->waterManager.UpdateQuality();
+
 			PROFILE3_GPU("water scissor");
 			RenderReflections(context, waterScissor);
 
 			if (g_RenderingOptions.GetWaterRefraction())
 				RenderRefractions(context, waterScissor);
+
+			m->terrainRenderer.RenderWaterFoamOccluders(cullGroup);
 		}
 	}
 

source/renderer/TerrainRenderer.cpp

@@ -51,7 +51,8 @@
  * TerrainRenderer keeps track of which phase it is in, to detect
  * when Submit, PrepareForRendering etc. are called in the wrong order.
  */
-enum Phase {
+enum Phase
+{
 	Phase_Submit,
 	Phase_Render
 };
@@ -400,38 +401,6 @@ bool TerrainRenderer::RenderFancyWater(const CShaderDefines& context, int cullGr
 	const double time = waterManager.m_WaterTexTimer;
 	const float repeatPeriod = waterManager.m_RepeatPeriod;
 
-	// Render normals and foam to a framebuffer if we're in fancy effects
-	if (waterManager.m_WaterFancyEffects)
-	{
-		// Save the post-processing framebuffer.
-		GLint fbo;
-		glGetIntegerv(GL_FRAMEBUFFER_BINDING_EXT, &fbo);
-
-		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, waterManager.m_FancyEffectsFBO);
-
-		glDisable(GL_BLEND);
-		glEnable(GL_DEPTH_TEST);
-		glDepthFunc(GL_LEQUAL);
-
-		glDisable(GL_CULL_FACE);
-		// Overwrite waves that would be behind the ground.
-		CShaderTechniquePtr dummyTech = g_Renderer.GetShaderManager().LoadEffect(str_solid);
-		dummyTech->BeginPass();
-		CShaderProgramPtr dummyShader = dummyTech->GetShader();
-
-		dummyShader->Uniform(str_transform, sceneRenderer.GetViewCamera().GetViewProjection());
-		dummyShader->Uniform(str_color, 0.0f, 0.0f, 0.0f, 0.0f);
-		std::vector<CPatchRData*>& visiblePatches = m->visiblePatches[cullGroup];
-		for (size_t i = 0; i < visiblePatches.size(); ++i)
-		{
-			CPatchRData* data = visiblePatches[i];
-			data->RenderWater(dummyShader, true, true);
-		}
-		dummyTech->EndPass();
-
-		glEnable(GL_CULL_FACE);
-		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo);
-	}
 	glEnable(GL_BLEND);
 	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 	glEnable(GL_DEPTH_TEST);
@@ -580,9 +549,7 @@ void TerrainRenderer::RenderSimpleWater(int cullGroup)
 // Render water that is part of the terrain
 void TerrainRenderer::RenderWater(const CShaderDefines& context, int cullGroup, ShadowMap* shadow)
 {
-	WaterManager& waterManager = g_Renderer.GetSceneRenderer().GetWaterManager();
+	const WaterManager& waterManager = g_Renderer.GetSceneRenderer().GetWaterManager();
-
-	waterManager.UpdateQuality();
 
 	if (!waterManager.WillRenderFancyWater())
 		RenderSimpleWater(cullGroup);
@@ -590,6 +557,36 @@ void TerrainRenderer::RenderWater(const CShaderDefines& context, int cullGroup,
 		RenderFancyWater(context, cullGroup, shadow);
 }
 
+void TerrainRenderer::RenderWaterFoamOccluders(int cullGroup)
+{
+	CSceneRenderer& sceneRenderer = g_Renderer.GetSceneRenderer();
+	const WaterManager& waterManager = sceneRenderer.GetWaterManager();
+	if (!waterManager.WillRenderFancyWater())
+		return;
+
+	// Render normals and foam to a framebuffer if we're using fancy effects.
+	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, waterManager.m_FancyEffectsFBO);
+
+	glDisable(GL_BLEND);
+	glEnable(GL_DEPTH_TEST);
+	glDepthFunc(GL_LEQUAL);
+
+	glDisable(GL_CULL_FACE);
+	// Overwrite waves that would be behind the ground.
+	CShaderTechniquePtr dummyTech = g_Renderer.GetShaderManager().LoadEffect(str_solid);
+	dummyTech->BeginPass();
+	CShaderProgramPtr dummyShader = dummyTech->GetShader();
+
+	dummyShader->Uniform(str_transform, sceneRenderer.GetViewCamera().GetViewProjection());
+	dummyShader->Uniform(str_color, 0.0f, 0.0f, 0.0f, 0.0f);
+	for (CPatchRData* data : m->visiblePatches[cullGroup])
+		data->RenderWater(dummyShader, true, true);
+	dummyTech->EndPass();
+
+	glEnable(GL_CULL_FACE);
+	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+}
+
 void TerrainRenderer::RenderPriorities(int cullGroup)
 {
 	PROFILE("priorities");

source/renderer/TerrainRenderer.h

@@ -1,4 +1,4 @@
-/* Copyright (C) 2021 Wildfire Games.
+/* Copyright (C) 2022 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -130,6 +130,11 @@ public:
 	 */
 	void RenderWater(const CShaderDefines& context, int cullGroup, ShadowMap* shadow);
 
+	/**
+	 * Renders terrain to a framebuffer to occlude shore foams.
+	 */
+	void RenderWaterFoamOccluders(int cullGroup);
+
 	/**
 	 * Calculate a scissor rectangle for the visible water patches.
 	 */