renderer: add the EXP_CLAMP bit to normalize the expression value

illwieckz · illwieckz · commit 0b284f58a397 · 2025-08-01T11:56:38.000+02:00
diff --git a/src/engine/renderer/tr_local.h b/src/engine/renderer/tr_local.h
@@ -863,6 +863,7 @@ enum class ssaoMode {
 enum
 {
 	EXP_NONE,
+	EXP_CLAMP = BIT( 0 ),
 	EXP_SRGB = BIT( 1 ),
 };
 
diff --git a/src/engine/renderer/tr_shade.cpp b/src/engine/renderer/tr_shade.cpp
@@ -1778,7 +1778,7 @@ void Tess_ComputeColor( shaderStage_t *pStage )
 
 		case colorGen_t::CGEN_CUSTOM_RGB:
 			{
-				rgb = Math::Clamp( RB_EvalExpression( &pStage->rgbExp, 1.0 ), 0.0f, 1.0f );
+				rgb = RB_EvalExpression( &pStage->rgbExp, 1.0 );
 
 				tess.svars.color = Color::White * rgb;
 				break;
@@ -1788,18 +1788,15 @@ void Tess_ComputeColor( shaderStage_t *pStage )
 			{
 				if ( backEnd.currentEntity )
 				{
-					red =
-					  Math::Clamp( RB_EvalExpression( &pStage->redExp, backEnd.currentEntity->e.shaderRGBA.Red() * ( 1.0 / 255.0 ) ), 0.0f, 1.0f );
-					green =
-					  Math::Clamp( RB_EvalExpression( &pStage->greenExp, backEnd.currentEntity->e.shaderRGBA.Green() * ( 1.0 / 255.0 ) ), 0.0f, 1.0f );
-					blue =
-					  Math::Clamp( RB_EvalExpression( &pStage->blueExp, backEnd.currentEntity->e.shaderRGBA.Blue() * ( 1.0 / 255.0 ) ), 0.0f, 1.0f );
+					red = RB_EvalExpression( &pStage->redExp, backEnd.currentEntity->e.shaderRGBA.Red() * ( 1.0 / 255.0 ) );
+					green = RB_EvalExpression( &pStage->greenExp, backEnd.currentEntity->e.shaderRGBA.Green() * ( 1.0 / 255.0 ) );
+					blue = RB_EvalExpression( &pStage->blueExp, backEnd.currentEntity->e.shaderRGBA.Blue() * ( 1.0 / 255.0 ) );
 				}
 				else
 				{
-					red = Math::Clamp( RB_EvalExpression( &pStage->redExp, 1.0 ), 0.0f, 1.0f );
-					green = Math::Clamp( RB_EvalExpression( &pStage->greenExp, 1.0 ), 0.0f, 1.0f );
-					blue = Math::Clamp( RB_EvalExpression( &pStage->blueExp, 1.0 ), 0.0f, 1.0f );
+					red = RB_EvalExpression( &pStage->redExp, 1.0 );
+					green = RB_EvalExpression( &pStage->greenExp, 1.0 );
+					blue = RB_EvalExpression( &pStage->blueExp, 1.0 );
 				}
 
 				tess.svars.color.SetRed( red );
@@ -1878,7 +1875,7 @@ void Tess_ComputeColor( shaderStage_t *pStage )
 
 		case alphaGen_t::AGEN_CUSTOM:
 			{
-				alpha = Math::Clamp( RB_EvalExpression( &pStage->alphaExp, 1.0 ), 0.0f, 1.0f );
+				alpha = RB_EvalExpression( &pStage->alphaExp, 1.0 );
 
 				tess.svars.color.SetAlpha( alpha );
 				break;
diff --git a/src/engine/renderer/tr_shade_calc.cpp b/src/engine/renderer/tr_shade_calc.cpp
@@ -441,9 +441,13 @@ float RB_EvalExpression( const expression_t *exp, float defaultValue )
 
 	float value = EvalExpression( exp, defaultValue );
 
-	if ( exp->bits & EXP_SRGB )
+	if ( exp->bits & EXP_CLAMP )
 	{
 		value = Math::Clamp( value, 0.0f, 1.0f );
+	}
+
+	if ( exp->bits & EXP_SRGB )
+	{
 		value = tr.convertFloatFromSRGB( value );
 	}
 
diff --git a/src/engine/renderer/tr_shader.cpp b/src/engine/renderer/tr_shader.cpp
@@ -2739,25 +2739,25 @@ static bool ParseStage( shaderStage_t *stage, const char **text )
 		else if ( !Q_stricmp( token, "rgb" ) )
 		{
 			stage->rgbGen = colorGen_t::CGEN_CUSTOM_RGB;
-			ParseExpression( text, &stage->rgbExp, EXP_SRGB );
+			ParseExpression( text, &stage->rgbExp, EXP_CLAMP | EXP_SRGB );
 		}
 		// red <arithmetic expression>
 		else if ( !Q_stricmp( token, "red" ) )
 		{
 			stage->rgbGen = colorGen_t::CGEN_CUSTOM_RGBs;
-			ParseExpression( text, &stage->redExp, EXP_SRGB );
+			ParseExpression( text, &stage->redExp, EXP_CLAMP | EXP_SRGB );
 		}
 		// green <arithmetic expression>
 		else if ( !Q_stricmp( token, "green" ) )
 		{
 			stage->rgbGen = colorGen_t::CGEN_CUSTOM_RGBs;
-			ParseExpression( text, &stage->greenExp, EXP_SRGB );
+			ParseExpression( text, &stage->greenExp, EXP_CLAMP | EXP_SRGB );
 		}
 		// blue <arithmetic expression>
 		else if ( !Q_stricmp( token, "blue" ) )
 		{
 			stage->rgbGen = colorGen_t::CGEN_CUSTOM_RGBs;
-			ParseExpression( text, &stage->blueExp, EXP_SRGB );
+			ParseExpression( text, &stage->blueExp, EXP_CLAMP | EXP_SRGB );
 		}
 		// colored
 		else if ( !Q_stricmp( token, "colored" ) )
@@ -2859,17 +2859,17 @@ static bool ParseStage( shaderStage_t *stage, const char **text )
 		else if ( !Q_stricmp( token, "alpha" ) )
 		{
 			stage->alphaGen = alphaGen_t::AGEN_CUSTOM;
-			ParseExpression( text, &stage->alphaExp );
+			ParseExpression( text, &stage->alphaExp, EXP_CLAMP );
 		}
 		// color <exp>, <exp>, <exp>, <exp>
 		else if ( !Q_stricmp( token, "color" ) )
 		{
 			stage->rgbGen = colorGen_t::CGEN_CUSTOM_RGBs;
 			stage->alphaGen = alphaGen_t::AGEN_CUSTOM;
-			ParseExpression( text, &stage->redExp, EXP_SRGB );
-			ParseExpression( text, &stage->greenExp, EXP_SRGB );
-			ParseExpression( text, &stage->blueExp, EXP_SRGB );
-			ParseExpression( text, &stage->alphaExp );
+			ParseExpression( text, &stage->redExp, EXP_CLAMP | EXP_SRGB );
+			ParseExpression( text, &stage->greenExp, EXP_CLAMP | EXP_SRGB );
+			ParseExpression( text, &stage->blueExp, EXP_CLAMP | EXP_SRGB );
+			ParseExpression( text, &stage->alphaExp, EXP_CLAMP );
 		}
 		// tcGen <function>
 		else if ( !Q_stricmp( token, "texGen" ) || !Q_stricmp( token, "tcGen" ) )

Original file line number	Diff line number	Diff line change
`@@ -863,6 +863,7 @@ enum class ssaoMode {`
`863`	`863`	`enum`
`864`	`864`	`{`
`865`	`865`	`EXP_NONE,`
	`866`	`+ EXP_CLAMP = BIT( 0 ),`
`866`	`867`	`EXP_SRGB = BIT( 1 ),`
`867`	`868`	`};`
`868`	`869`
Original file line number	Diff line number	Diff line change
`@@ -1778,7 +1778,7 @@ void Tess_ComputeColor( shaderStage_t *pStage )`
`1778`	`1778`
`1779`	`1779`	`case colorGen_t::CGEN_CUSTOM_RGB:`
`1780`	`1780`	`{`
`1781`		`- rgb = Math::Clamp( RB_EvalExpression( &pStage->rgbExp, 1.0 ), 0.0f, 1.0f );`
	`1781`	`+ rgb = RB_EvalExpression( &pStage->rgbExp, 1.0 );`
`1782`	`1782`
`1783`	`1783`	`tess.svars.color = Color::White * rgb;`
`1784`	`1784`	`break;`
`@@ -1788,18 +1788,15 @@ void Tess_ComputeColor( shaderStage_t *pStage )`
`1788`	`1788`	`{`
`1789`	`1789`	`if ( backEnd.currentEntity )`
`1790`	`1790`	`{`
`1791`		`- red =`
`1792`		`- Math::Clamp( RB_EvalExpression( &pStage->redExp, backEnd.currentEntity->e.shaderRGBA.Red() * ( 1.0 / 255.0 ) ), 0.0f, 1.0f );`
`1793`		`- green =`
`1794`		`- Math::Clamp( RB_EvalExpression( &pStage->greenExp, backEnd.currentEntity->e.shaderRGBA.Green() * ( 1.0 / 255.0 ) ), 0.0f, 1.0f );`
`1795`		`- blue =`
`1796`		`- Math::Clamp( RB_EvalExpression( &pStage->blueExp, backEnd.currentEntity->e.shaderRGBA.Blue() * ( 1.0 / 255.0 ) ), 0.0f, 1.0f );`
	`1791`	`+ red = RB_EvalExpression( &pStage->redExp, backEnd.currentEntity->e.shaderRGBA.Red() * ( 1.0 / 255.0 ) );`
	`1792`	`+ green = RB_EvalExpression( &pStage->greenExp, backEnd.currentEntity->e.shaderRGBA.Green() * ( 1.0 / 255.0 ) );`
	`1793`	`+ blue = RB_EvalExpression( &pStage->blueExp, backEnd.currentEntity->e.shaderRGBA.Blue() * ( 1.0 / 255.0 ) );`
`1797`	`1794`	`}`
`1798`	`1795`	`else`
`1799`	`1796`	`{`
`1800`		`- red = Math::Clamp( RB_EvalExpression( &pStage->redExp, 1.0 ), 0.0f, 1.0f );`
`1801`		`- green = Math::Clamp( RB_EvalExpression( &pStage->greenExp, 1.0 ), 0.0f, 1.0f );`
`1802`		`- blue = Math::Clamp( RB_EvalExpression( &pStage->blueExp, 1.0 ), 0.0f, 1.0f );`
	`1797`	`+ red = RB_EvalExpression( &pStage->redExp, 1.0 );`
	`1798`	`+ green = RB_EvalExpression( &pStage->greenExp, 1.0 );`
	`1799`	`+ blue = RB_EvalExpression( &pStage->blueExp, 1.0 );`
`1803`	`1800`	`}`
`1804`	`1801`
`1805`	`1802`	`tess.svars.color.SetRed( red );`
`@@ -1878,7 +1875,7 @@ void Tess_ComputeColor( shaderStage_t *pStage )`
`1878`	`1875`
`1879`	`1876`	`case alphaGen_t::AGEN_CUSTOM:`
`1880`	`1877`	`{`
`1881`		`- alpha = Math::Clamp( RB_EvalExpression( &pStage->alphaExp, 1.0 ), 0.0f, 1.0f );`
	`1878`	`+ alpha = RB_EvalExpression( &pStage->alphaExp, 1.0 );`
`1882`	`1879`
`1883`	`1880`	`tess.svars.color.SetAlpha( alpha );`
`1884`	`1881`	`break;`
Original file line number	Diff line number	Diff line change
`@@ -441,9 +441,13 @@ float RB_EvalExpression( const expression_t *exp, float defaultValue )`
`441`	`441`
`442`	`442`	`float value = EvalExpression( exp, defaultValue );`
`443`	`443`
`444`		`- if ( exp->bits & EXP_SRGB )`
	`444`	`+ if ( exp->bits & EXP_CLAMP )`
`445`	`445`	`{`
`446`	`446`	`value = Math::Clamp( value, 0.0f, 1.0f );`
	`447`	`+ }`
	`448`	`+`
	`449`	`+ if ( exp->bits & EXP_SRGB )`
	`450`	`+ {`
`447`	`451`	`value = tr.convertFloatFromSRGB( value );`
`448`	`452`	`}`
`449`	`453`
Original file line number	Diff line number	Diff line change
`@@ -2739,25 +2739,25 @@ static bool ParseStage( shaderStage_t stage, const char *text )`
`2739`	`2739`	`else if ( !Q_stricmp( token, "rgb" ) )`
`2740`	`2740`	`{`
`2741`	`2741`	`stage->rgbGen = colorGen_t::CGEN_CUSTOM_RGB;`
`2742`		`- ParseExpression( text, &stage->rgbExp, EXP_SRGB );`
	`2742`	`+ ParseExpression( text, &stage->rgbExp, EXP_CLAMP \| EXP_SRGB );`
`2743`	`2743`	`}`
`2744`	`2744`	`// red <arithmetic expression>`
`2745`	`2745`	`else if ( !Q_stricmp( token, "red" ) )`
`2746`	`2746`	`{`
`2747`	`2747`	`stage->rgbGen = colorGen_t::CGEN_CUSTOM_RGBs;`
`2748`		`- ParseExpression( text, &stage->redExp, EXP_SRGB );`
	`2748`	`+ ParseExpression( text, &stage->redExp, EXP_CLAMP \| EXP_SRGB );`
`2749`	`2749`	`}`
`2750`	`2750`	`// green <arithmetic expression>`
`2751`	`2751`	`else if ( !Q_stricmp( token, "green" ) )`
`2752`	`2752`	`{`
`2753`	`2753`	`stage->rgbGen = colorGen_t::CGEN_CUSTOM_RGBs;`
`2754`		`- ParseExpression( text, &stage->greenExp, EXP_SRGB );`
	`2754`	`+ ParseExpression( text, &stage->greenExp, EXP_CLAMP \| EXP_SRGB );`
`2755`	`2755`	`}`
`2756`	`2756`	`// blue <arithmetic expression>`
`2757`	`2757`	`else if ( !Q_stricmp( token, "blue" ) )`
`2758`	`2758`	`{`
`2759`	`2759`	`stage->rgbGen = colorGen_t::CGEN_CUSTOM_RGBs;`
`2760`		`- ParseExpression( text, &stage->blueExp, EXP_SRGB );`
	`2760`	`+ ParseExpression( text, &stage->blueExp, EXP_CLAMP \| EXP_SRGB );`
`2761`	`2761`	`}`
`2762`	`2762`	`// colored`
`2763`	`2763`	`else if ( !Q_stricmp( token, "colored" ) )`
`@@ -2859,17 +2859,17 @@ static bool ParseStage( shaderStage_t stage, const char *text )`
`2859`	`2859`	`else if ( !Q_stricmp( token, "alpha" ) )`
`2860`	`2860`	`{`
`2861`	`2861`	`stage->alphaGen = alphaGen_t::AGEN_CUSTOM;`
`2862`		`- ParseExpression( text, &stage->alphaExp );`
	`2862`	`+ ParseExpression( text, &stage->alphaExp, EXP_CLAMP );`
`2863`	`2863`	`}`
`2864`	`2864`	`// color <exp>, <exp>, <exp>, <exp>`
`2865`	`2865`	`else if ( !Q_stricmp( token, "color" ) )`
`2866`	`2866`	`{`
`2867`	`2867`	`stage->rgbGen = colorGen_t::CGEN_CUSTOM_RGBs;`
`2868`	`2868`	`stage->alphaGen = alphaGen_t::AGEN_CUSTOM;`
`2869`		`- ParseExpression( text, &stage->redExp, EXP_SRGB );`
`2870`		`- ParseExpression( text, &stage->greenExp, EXP_SRGB );`
`2871`		`- ParseExpression( text, &stage->blueExp, EXP_SRGB );`
`2872`		`- ParseExpression( text, &stage->alphaExp );`
	`2869`	`+ ParseExpression( text, &stage->redExp, EXP_CLAMP \| EXP_SRGB );`
	`2870`	`+ ParseExpression( text, &stage->greenExp, EXP_CLAMP \| EXP_SRGB );`
	`2871`	`+ ParseExpression( text, &stage->blueExp, EXP_CLAMP \| EXP_SRGB );`
	`2872`	`+ ParseExpression( text, &stage->alphaExp, EXP_CLAMP );`
`2873`	`2873`	`}`
`2874`	`2874`	`// tcGen <function>`
`2875`	`2875`	`else if ( !Q_stricmp( token, "texGen" ) \|\| !Q_stricmp( token, "tcGen" ) )`