Add ssao quality setting

src/gl/renderer/gl_postprocess.cpp

@@ -99,7 +99,12 @@ CVAR(Float, gl_lens_k, -0.12f, 0)
 CVAR(Float, gl_lens_kcube, 0.1f, 0)
 CVAR(Float, gl_lens_chromatic, 1.12f, 0)
 
-CVAR(Bool, gl_ssao, false, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
+CUSTOM_CVAR(Int, gl_ssao, 0, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
+{
+	if (self < 0 || self > 3)
+		self = 0;
+}
+
 CVAR(Float, gl_ssao_strength, 0.7, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
 CVAR(Bool, gl_ssao_debug, false, 0)
 CVAR(Float, gl_ssao_bias, 0.5f, 0)

src/gl/scene/gl_scene.cpp

@@ -158,10 +158,11 @@ void FGLRenderer::Set3DViewport(bool mainview)
 {
 	if (mainview && mBuffers->Setup(mScreenViewport.width, mScreenViewport.height, mSceneViewport.width, mSceneViewport.height))
 	{
-		mBuffers->BindSceneFB(gl_ssao);
+		bool useSSAO = (gl_ssao != 0);
+		mBuffers->BindSceneFB(useSSAO);
 		GLenum buffers[] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1 };
-		glDrawBuffers(gl_ssao ? 2 : 1, buffers);
-		gl_RenderState.SetPassType(gl_ssao ? GBUFFER_PASS : NORMAL_PASS);
+		glDrawBuffers(useSSAO ? 2 : 1, buffers);
+		gl_RenderState.SetPassType(useSSAO ? GBUFFER_PASS : NORMAL_PASS);
 		gl_RenderState.Apply();
 	}
 
@@ -494,7 +495,7 @@ void FGLRenderer::DrawScene(int drawmode)
 	GLRenderer->mClipPortal = NULL;	// this must be reset before any portal recursion takes place.
 
 	// If SSAO is active, switch to gbuffer shaders and use the gbuffer framebuffer
-	bool applySSAO = gl_ssao && FGLRenderBuffers::IsEnabled() && drawmode == DM_MAINVIEW;
+	bool applySSAO = gl_ssao != 0 && FGLRenderBuffers::IsEnabled() && drawmode == DM_MAINVIEW;
 	if (applySSAO)
 	{
 		GLenum buffers[] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1 };

src/gl/shaders/gl_ambientshader.cpp

@@ -74,32 +74,47 @@ void FLinearDepthShader::Bind(bool multisample)
 
 void FSSAOShader::Bind()
 {
-	if (!mShader)
+	auto &shader = mShader[gl_ssao];
+	if (!shader)
 	{
-		const char *defines = R"(
-			#define USE_RANDOM_TEXTURE
-			#define RANDOM_TEXTURE_WIDTH 4.0
-			#define NUM_DIRECTIONS 8.0
-			#define NUM_STEPS 4.0
-		)";
-
-		mShader.Compile(FShaderProgram::Vertex, "shaders/glsl/screenquad.vp", "", 330);
-		mShader.Compile(FShaderProgram::Fragment, "shaders/glsl/ssao.fp", defines, 330);
-		mShader.SetFragDataLocation(0, "FragColor");
-		mShader.Link("shaders/glsl/ssao");
-		mShader.SetAttribLocation(0, "PositionInProjection");
-		DepthTexture.Init(mShader, "DepthTexture");
-		RandomTexture.Init(mShader, "RandomTexture");
-		UVToViewA.Init(mShader, "UVToViewA");
-		UVToViewB.Init(mShader, "UVToViewB");
-		InvFullResolution.Init(mShader, "InvFullResolution");
-		NDotVBias.Init(mShader, "NDotVBias");
-		NegInvR2.Init(mShader, "NegInvR2");
-		RadiusToScreen.Init(mShader, "RadiusToScreen");
-		AOMultiplier.Init(mShader, "AOMultiplier");
-		AOStrength.Init(mShader, "AOStrength");
+		shader.Compile(FShaderProgram::Vertex, "shaders/glsl/screenquad.vp", "", 330);
+		shader.Compile(FShaderProgram::Fragment, "shaders/glsl/ssao.fp", GetDefines(gl_ssao), 330);
+		shader.SetFragDataLocation(0, "FragColor");
+		shader.Link("shaders/glsl/ssao");
+		shader.SetAttribLocation(0, "PositionInProjection");
+		DepthTexture.Init(shader, "DepthTexture");
+		RandomTexture.Init(shader, "RandomTexture");
+		UVToViewA.Init(shader, "UVToViewA");
+		UVToViewB.Init(shader, "UVToViewB");
+		InvFullResolution.Init(shader, "InvFullResolution");
+		NDotVBias.Init(shader, "NDotVBias");
+		NegInvR2.Init(shader, "NegInvR2");
+		RadiusToScreen.Init(shader, "RadiusToScreen");
+		AOMultiplier.Init(shader, "AOMultiplier");
+		AOStrength.Init(shader, "AOStrength");
 	}
-	mShader.Bind();
+	shader.Bind();
+}
+
+FString FSSAOShader::GetDefines(int mode)
+{
+	int numDirections, numSteps;
+	switch (gl_ssao)
+	{
+	default:
+	case LowQuality:    numDirections = 2; numSteps = 4; break;
+	case MediumQuality: numDirections = 4; numSteps = 4; break;
+	case HighQuality:   numDirections = 8; numSteps = 4; break;
+	}
+
+	FString defines;
+	defines.Format(R"(
+		#define USE_RANDOM_TEXTURE
+		#define RANDOM_TEXTURE_WIDTH 4.0
+		#define NUM_DIRECTIONS %d.0
+		#define NUM_STEPS %d.0
+	)", numDirections, numSteps);
+	return defines;
 }
 
 void FDepthBlurShader::Bind(bool vertical)

src/gl/shaders/gl_ambientshader.h

@@ -39,7 +39,18 @@ public:
 	FBufferedUniform1f AOStrength;
 
 private:
-	FShaderProgram mShader;
+	enum Quality
+	{
+		Off,
+		LowQuality,
+		MediumQuality,
+		HighQuality,
+		NumQualityModes
+	};
+
+	FString GetDefines(int mode);
+
+	FShaderProgram mShader[NumQualityModes];
 };
 
 class FDepthBlurShader

src/gl/system/gl_cvars.h

@@ -50,7 +50,7 @@ EXTERN_CVAR(Bool, gl_lens)
 EXTERN_CVAR(Float, gl_lens_k)
 EXTERN_CVAR(Float, gl_lens_kcube)
 EXTERN_CVAR(Float, gl_lens_chromatic)
-EXTERN_CVAR(Bool, gl_ssao)
+EXTERN_CVAR(Int, gl_ssao)
 EXTERN_CVAR(Float, gl_ssao_strength)
 EXTERN_CVAR(Bool, gl_ssao_debug)
 EXTERN_CVAR(Float, gl_ssao_bias)