Apply exposure even when tonemapping is off

Multiply the pixel color by r_toneMappingExposure even when tone mapping
is disabled. For the next release the cvar should be renamed to reflect
its separation from tone mapping.

Fixes #1628.

Author: slipher

src/engine/renderer/glsl_source/cameraEffects_fp.glsl

@@ -88,9 +88,11 @@ void main()
 		convertToSRGB( color.rgb );
 	}
 
+	color.rgb *= u_TonemapExposure;
+
 #if defined(r_highPrecisionRendering) && defined(HAVE_ARB_texture_float)
 	if( u_Tonemap ) {
-		color.rgb = TonemapLottes( color.rgb * u_TonemapExposure );
+		color.rgb = TonemapLottes( color.rgb );
 	}
 #endif
 

src/engine/renderer/tr_backend.cpp

@@ -1737,14 +1737,14 @@ void RB_CameraPostFX() {
 	gl_cameraEffectsShader->SetUniform_InverseGamma( 1.0 / r_gamma->value );
 
 	gl_cameraEffectsShader->SetUniform_SRGB( tr.worldLinearizeTexture );
+	gl_cameraEffectsShader->SetUniform_TonemapExposure( r_toneMappingExposure.Get() );
 
 	const bool tonemap = r_toneMapping.Get() && r_highPrecisionRendering.Get() && glConfig.textureFloatAvailable;
 	if ( tonemap ) {
 		vec4_t tonemapParms { r_toneMappingContrast.Get(), r_toneMappingHighlightsCompressionSpeed.Get() };
 		ComputeTonemapParams( tonemapParms[0], tonemapParms[1], r_toneMappingHDRMax.Get(),
 			r_toneMappingDarkAreaPointHDR.Get(), r_toneMappingDarkAreaPointLDR.Get(), tonemapParms[2], tonemapParms[3] );
 		gl_cameraEffectsShader->SetUniform_TonemapParms( tonemapParms );
-		gl_cameraEffectsShader->SetUniform_TonemapExposure( r_toneMappingExposure.Get() );
 	}
 	gl_cameraEffectsShader->SetUniform_Tonemap( tonemap );
 
@@ -2889,14 +2889,14 @@ static void SetFrameUniforms() {
 
 	globalUBOProxy->SetUniform_ColorModulate( tr.viewParms.gradingWeights );
 	globalUBOProxy->SetUniform_InverseGamma( 1.0f / r_gamma->value );
+	globalUBOProxy->SetUniform_TonemapExposure( r_toneMappingExposure.Get() );
 
 	const bool tonemap = r_toneMapping.Get() && r_highPrecisionRendering.Get() && glConfig.textureFloatAvailable;
 	if ( tonemap ) {
 		vec4_t tonemapParms{ r_toneMappingContrast.Get(), r_toneMappingHighlightsCompressionSpeed.Get() };
 		ComputeTonemapParams( tonemapParms[0], tonemapParms[1], r_toneMappingHDRMax.Get(),
 			r_toneMappingDarkAreaPointHDR.Get(), r_toneMappingDarkAreaPointLDR.Get(), tonemapParms[2], tonemapParms[3] );
 		globalUBOProxy->SetUniform_TonemapParms( tonemapParms );
-		globalUBOProxy->SetUniform_TonemapExposure( r_toneMappingExposure.Get() );
 	}
 	globalUBOProxy->SetUniform_Tonemap( tonemap );
 

src/engine/renderer/tr_init.cpp

@@ -186,8 +186,9 @@ Cvar::Cvar<int> r_rendererAPI( "r_rendererAPI", "Renderer API: 0: OpenGL, 1: Vul
 
 	Cvar::Cvar<bool> r_toneMapping(
 		"r_toneMapping", "Use  HDR->LDR tonemapping", Cvar::NONE, true );
+	// TODO(0.56): rename because it can be used without tone mapping now
 	Cvar::Cvar<float> r_toneMappingExposure(
-		"r_toneMappingExposure", "Tonemap exposure", Cvar::NONE, 1.0f );
+		"r_toneMappingExposure", "Exposure (brightness adjustment)", Cvar::NONE, 1.0f );
 	Cvar::Range<Cvar::Cvar<float>> r_toneMappingContrast(
 		"r_toneMappingContrast", "Makes dark areas light up faster",
 		Cvar::NONE, 1.6f, 1.0f, 10.0f );