shadowmap_*.glsl: Using texture2DCompare in PointLights code.

@mkkellogg Do you mind double checking that I didn't do anything stupid?

I've removed adjustShadowValue1K. Instead of multiplying every sample by 1000 and adding the bias I'm now dividing dp and subtracting the bias. I'm also using texture2dCompare which uses step() internaly instead of the if condition. The result seems to be identical but, at least on my gpu (Intel HD Graphics 6000), it runs much faster.

src/renderers/shaders/ShaderChunk/shadowmap_fragment.glsl

@@ -25,15 +25,12 @@ vec3 shadowMask = vec3( 1.0 );
 			// the distance from the light to the world-space position of the fragment.
 			vec3 lightToPosition = vShadowCoord[ i ].xyz;
 
-	#if defined( SHADOWMAP_TYPE_PCF ) || defined( SHADOWMAP_TYPE_PCF_SOFT )
-
 			// bd3D = base direction 3D
 			vec3 bd3D = normalize( lightToPosition );
 			// dp = distance from light to fragment position
-			float dp = length( lightToPosition );
+			float dp = ( length( lightToPosition ) - shadowBias[ i ] ) / 1000.0;
 
-			// base measurement
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D, texelSizeY ) ), shadowBias[ i ], shadow );
+	#if defined( SHADOWMAP_TYPE_PCF ) || defined( SHADOWMAP_TYPE_PCF_SOFT )
 
 			// Dr = disk radius
 
@@ -44,42 +41,37 @@ vec3 shadowMask = vec3( 1.0 );
 	#endif
 
 			// os = offset scale
-			float os = Dr *  2.0 * texelSizeY;
+			float os = Dr * 2.0 * texelSizeY;
 
 			const vec3 Gsd = vec3( - 1, 0, 1 );
 
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.zzz * os, texelSizeY ) ), shadowBias[ i ], shadow );
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.zxz * os, texelSizeY ) ), shadowBias[ i ], shadow );
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.xxz * os, texelSizeY ) ), shadowBias[ i ], shadow );
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.xzz * os, texelSizeY ) ), shadowBias[ i ], shadow );
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.zzx * os, texelSizeY ) ), shadowBias[ i ], shadow );
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.zxx * os, texelSizeY ) ), shadowBias[ i ], shadow );
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.xxx * os, texelSizeY ) ), shadowBias[ i ], shadow );
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.xzx * os, texelSizeY ) ), shadowBias[ i ], shadow );
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.zzy * os, texelSizeY ) ), shadowBias[ i ], shadow );
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.zxy * os, texelSizeY ) ), shadowBias[ i ], shadow );
-
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.xxy * os, texelSizeY ) ), shadowBias[ i ], shadow );
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.xzy * os, texelSizeY ) ), shadowBias[ i ], shadow );
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.zyz * os, texelSizeY ) ), shadowBias[ i ], shadow );
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.xyz * os, texelSizeY ) ), shadowBias[ i ], shadow );
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.zyx * os, texelSizeY ) ), shadowBias[ i ], shadow );
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.xyx * os, texelSizeY ) ), shadowBias[ i ], shadow );
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.yzz * os, texelSizeY ) ), shadowBias[ i ], shadow );
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.yxz * os, texelSizeY ) ), shadowBias[ i ], shadow );
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.yxx * os, texelSizeY ) ), shadowBias[ i ], shadow );
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D + Gsd.yzx * os, texelSizeY ) ), shadowBias[ i ], shadow );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.zzz * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.zxz * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.xxz * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.xzz * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.zzx * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.zxx * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.xxx * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.xzx * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.zzy * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.zxy * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.xxy * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.xzy * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.zyz * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.xyz * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.zyx * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.xyx * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.yzz * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.yxz * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.yxx * os, texelSizeY ), dp );
+			shadow += texture2DCompare( shadowMap[ i ], cubeToUV( bd3D + Gsd.yzx * os, texelSizeY ), dp );
 
 			shadow *= realShadowDarkness * ( 1.0 / 21.0 );
 
-	#else // no percentage-closer filtering:
-
-			vec3 bd3D = normalize( lightToPosition );
-			float dp = length( lightToPosition );
-
-			adjustShadowValue1K( dp, texture2D( shadowMap[ i ], cubeToUV( bd3D, texelSizeY ) ), shadowBias[ i ], shadow );
+	#else // no percentage-closer filtering
 
-			shadow *= realShadowDarkness;
+			shadow = texture2DCompare( shadowMap[ i ], cubeToUV( bd3D, texelSizeY ), dp ) * realShadowDarkness;
 
 	#endif
 

src/renderers/shaders/ShaderChunk/shadowmap_pars_fragment.glsl

@@ -23,18 +23,6 @@
 
 	#ifdef POINT_LIGHT_SHADOWS
 
-		// adjustShadowValue1K() upacks the depth value stored in @textureData, adds @bias to it, and then
-		// comapres the result with @testDepth. If @testDepth is larger than or equal to that result, then
-		// @shadowValue is incremented by 1.0.
-
-		void adjustShadowValue1K( const float testDepth, const vec4 textureData, const float bias, inout float shadowValue ) {
-
-			const vec4 bitSh = vec4( 1.0 / ( 256.0 * 256.0 * 256.0 ), 1.0 / ( 256.0 * 256.0 ), 1.0 / 256.0, 1.0 );
-			if ( testDepth >= dot( textureData, bitSh ) * 1000.0 + bias )
-				shadowValue += 1.0;
-
-		}
-
 		// cubeToUV() maps a 3D direction vector suitable for cube texture mapping to a 2D
 		// vector suitable for 2D texture mapping. This code uses the following layout for the
 		// 2D texture: