Vignette effect

combine.cc

@@ -17,7 +17,10 @@ T_CombinePass::T_CombinePass(
 		__rw__ T_Texture& bloom )
 	: txImage_( image ) , txBloom_( bloom ) ,
 		bloomStrength_( 0.45 ) ,
-		bloomAttenuation_( 0.3 )
+		bloomAttenuation_( 0.3 ) ,
+		vignette_{
+			1 , 8 , .5 , 1 , 0 , 1
+		}
 {
 	program_ = Globals::Shaders( ).pipeline({
 			"fullscreen.v.glsl" , "combine.f.glsl" });
@@ -30,16 +33,30 @@ void T_CombinePass::render( )
 	glClearColor( 1 , 0 , 1 , 1 );
 	glClear( GL_COLOR_BUFFER_BIT );
 	if ( program_.valid( ) ) {
+		enum {
+			U_MAIN_INPUT ,
+			U_BLOOM_INPUT ,
+			U_OUTPUT_SIZE ,
+			U_BLOOM_PARAMETERS ,
+			U_VIGNETTE_PARAMETERS_1 ,
+			U_VIGNETTE_PARAMETERS_2 ,
+		};
 		auto& tm( Globals::Textures( ) );
 		tm.bind( 0 , txImage_ );
 		tm.bind( 1 , txBloom_ );
 
 		const auto id( program_.program( E_ShaderType::FRAGMENT ) );
 		program_.enable( );
-		glProgramUniform1i( id , 0 , 0 );
+		glProgramUniform1i( id , U_MAIN_INPUT , 0 );
-		glProgramUniform1i( id , 1 , 1 );
+		glProgramUniform1i( id , U_BLOOM_INPUT , 1 );
-		glProgramUniform2f( id , 2 , txImage_.width( ) , txImage_.height( ) );
+		glProgramUniform2f( id , U_OUTPUT_SIZE ,
-		glProgramUniform2f( id , 3 , bloomStrength_ , bloomAttenuation_ );
+				txImage_.width( ) , txImage_.height( ) );
+		glProgramUniform2f( id , U_BLOOM_PARAMETERS ,
+				    bloomStrength_ , bloomAttenuation_ );
+		glProgramUniform4fv( id , U_VIGNETTE_PARAMETERS_1 , 1 ,
+				    vignette_ );
+		glProgramUniform2fv( id , U_VIGNETTE_PARAMETERS_2 , 1 ,
+				    vignette_ + 4 );
 
 		glDrawArrays( GL_TRIANGLE_STRIP , 0 , 4 );
 	}
@@ -52,7 +69,16 @@ void T_CombinePass::makeUI( )
 		return;
 	}
 
-	ImGui::DragFloat( "Bloom strength" , &bloomStrength_ , .001f , 0. , 10 );
+	ImGui::Text( "Bloom" );
-	ImGui::DragFloat( "Bloom attenuation" , &bloomAttenuation_ , .001f , 0. , 1 );
+	ImGui::DragFloat( "Strength" , &bloomStrength_ , .001f , 0. , 10 );
+	ImGui::DragFloat( "Attenuation" , &bloomAttenuation_ , .001f , 0. , 1 );
+
+	ImGui::Text( "Vignette" );
+	ImGui::DragFloat( "Shape mult." , &vignette_[ 0 ] , .01f , 0.5 , 20 );
+	ImGui::DragFloat( "Shape power" , &vignette_[ 1 ] , .01f , .5 , 50 );
+	ImGui::DragFloat( "Aspect ratio" , &vignette_[ 2 ] , .001f , 0 , 1 );
+	ImGui::DragFloat( "Shape reverse" , &vignette_[ 3 ] , .001f , .2 , 5 );
+	ImGui::DragFloat( "Apply base" , &vignette_[ 4 ] , .001f , 0 , 1 );
+	ImGui::DragFloat( "Apply max" , &vignette_[ 5 ] , .001f , 0 , 1 );
 }
 

combine.hh

@@ -24,5 +24,7 @@ struct T_CombinePass
 
 	float bloomStrength_;
 	float bloomAttenuation_;
+
+	float vignette_[ 6 ];
 };
 

shaders/combine.f.glsl

@@ -5,22 +5,54 @@
 layout( location = 0 ) uniform sampler2D u_MainInput;
 layout( location = 1 ) uniform sampler2D u_BlurInput;
 layout( location = 2 ) uniform vec2 u_OutputSize;
-layout( location = 3 ) uniform vec2 u_Parameters;
+layout( location = 3 ) uniform vec2 u_Bloom;
 
-layout( location = 0 ) out vec3 color;
+// Vignette parameters
+// 1.x = shape multiplier
+// 1.y = shape power
+// 1.z = aspect ratio
+// 1.w = reverse power multiplier
+// 2.x = apply base
+// 2.y = apply max
+layout( location = 4 ) uniform vec4 u_Vignette1;
+layout( location = 5 ) uniform vec2 u_Vignette2;
+
+#define uVigShapeMul (u_Vignette1.x)
+#define uVigShapePow (u_Vignette1.y)
+#define uVigAspect (u_Vignette1.z)
+#define uVigShapeReverse (u_Vignette1.w)
+#define uVigApplyBase (u_Vignette2.x)
+#define uVigApplyMax (u_Vignette2.y)
+
+
+layout( location = 0 ) out vec3 o_Color;
 
 void main( void )
 {
-	vec2 tmp = gl_FragCoord.xy / u_OutputSize;
+	vec2 pos = gl_FragCoord.xy / u_OutputSize;
-	float f = u_Parameters.x;
+	float f = u_Bloom.x;
-	color = textureLod( u_MainInput , tmp , 0 ).rgb;
+	o_Color = textureLod( u_MainInput , pos , 0 ).rgb;
+
+	// Bloom
 	vec3 bloom = vec3( 0 );
 	for ( int i = 0 ; i < 6 ; i ++ ) {
-		bloom += f * textureLod( u_BlurInput , tmp , i ).rgb;
+		bloom += f * textureLod( u_BlurInput , pos , i ).rgb;
-		f = pow( f , u_Parameters.y + 1 );
+		f = pow( f , u_Bloom.y + 1 );
 	}
-	color = color + bloom / 2.2;
+	o_Color = o_Color + bloom / 2.2;
 
-	color = color / ( color + 1. );
+	// Vignette
-	color = pow( color , vec3( 1.0 / 2.2 ) );
+	vec2 vShape = pow( abs( pos * 2 - 1 ) * uVigShapeMul ,
+		vec2( uVigShapePow ) );
+	float vignette = 1 - pow(
+		2 * ( uVigAspect * vShape.x + ( 1 - uVigAspect) * vShape.y ) ,
+		1 / ( uVigShapePow * uVigShapeReverse ) );
+	o_Color *= uVigApplyBase + smoothstep(
+		uVigApplyBase , uVigApplyBase + uVigApplyMax , vignette );
+
+	// Reinhart
+	o_Color = o_Color / ( o_Color + 1. );
+
+	// Gamma
+	o_Color = pow( o_Color , vec3( 1.0 / 2.2 ) );
 }