Optimize bumpmapping mathematics

OpenGL_vertex: * bufferize a duplicate calcul * Factorize vertexes
minetest · Jan 15, 2015 · 148fffb0f23fa437c67639ff3cc69177fb71d76a · 148fffb
1 parent bd0d786
commit 148fffb0f23fa437c67639ff3cc69177fb71d76a
diff --git a/client/shaders/nodes_shader/opengl_fragment.glsl b/client/shaders/nodes_shader/opengl_fragment.glsl
@@ -87,7 +87,12 @@ vec4 base = texture2D(baseTexture, uv).rgba;
 		vec3 E = normalize(eyeVec);
 		float specular = pow(clamp(dot(reflect(L, bump.xyz), E), 0.0, 1.0),0.5); 
 		float diffuse = dot(E,bump.xyz);		
-		color = 0.05*base.rgb + diffuse*base.rgb + 0.2*specular*base.rgb;
+		/* Mathematic optimization
+		* Original: color = 0.05*base.rgb + diffuse*base.rgb + 0.2*specular*base.rgb;
+		* This optimization save 2 multiplications (orig: 4 multiplications + 3 additions
+		* end: 2 multiplications + 3 additions)
+		*/
+		color = (0.05 + diffuse + 0.2 * specular) * base.rgb
 	} else {
 		color = base.rgb;
 	}

diff --git a/client/shaders/nodes_shader/opengl_vertex.glsl b/client/shaders/nodes_shader/opengl_vertex.glsl
@@ -35,22 +35,39 @@ void main(void)
 #if (MATERIAL_TYPE == TILE_MATERIAL_LIQUID_TRANSPARENT || MATERIAL_TYPE == TILE_MATERIAL_LIQUID_OPAQUE) && ENABLE_WAVING_WATER
 	vec4 pos = gl_Vertex;
 	pos.y -= 2.0;
-	pos.y -= sin (pos.z/WATER_WAVE_LENGTH + animationTimer * WATER_WAVE_SPEED * WATER_WAVE_LENGTH) * WATER_WAVE_HEIGHT
-		+ sin ((pos.z/WATER_WAVE_LENGTH + animationTimer * WATER_WAVE_SPEED * WATER_WAVE_LENGTH) / 7.0) * WATER_WAVE_HEIGHT;
+
+	float posYbuf = (pos.z / WATER_WAVE_LENGTH + animationTimer * WATER_WAVE_SPEED * WATER_WAVE_LENGTH);
+
+	pos.y -= sin(posYbuf) * WATER_WAVE_HEIGHT + sin(posYbuf / 7.0) * WATER_WAVE_HEIGHT;
 	gl_Position = mWorldViewProj * pos;
 #elif MATERIAL_TYPE == TILE_MATERIAL_WAVING_LEAVES && ENABLE_WAVING_LEAVES
 	vec4 pos = gl_Vertex;
 	vec4 pos2 = mWorld * gl_Vertex;
-	pos.x += (smoothTriangleWave(animationTimer*10.0 + pos2.x * 0.01 + pos2.z * 0.01) * 2.0 - 1.0) * 0.4;
-	pos.y += (smoothTriangleWave(animationTimer*15.0 + pos2.x * -0.01 + pos2.z * -0.01) * 2.0 - 1.0) * 0.2;
-	pos.z += (smoothTriangleWave(animationTimer*10.0 + pos2.x * -0.01 + pos2.z * -0.01) * 2.0 - 1.0) * 0.4;
+
+	/*
+	 * Mathematic optimization: pos2.x * A + pos2.z * A (2 multiplications + 1 addition)
+	 * replaced with: (pos2.x + pos2.z) * A (1 addition + 1 multiplication)
+	 * And bufferize calcul to a float
+	 */
+	float pos2XpZ = pos2.x + pos2.z;
+
+	pos.x += (smoothTriangleWave(animationTimer*10.0 + pos2XpZ * 0.01) * 2.0 - 1.0) * 0.4;
+	pos.y += (smoothTriangleWave(animationTimer*15.0 + pos2XpZ * -0.01) * 2.0 - 1.0) * 0.2;
+	pos.z += (smoothTriangleWave(animationTimer*10.0 + pos2XpZ * -0.01) * 2.0 - 1.0) * 0.4;
 	gl_Position = mWorldViewProj * pos;
 #elif MATERIAL_TYPE == TILE_MATERIAL_WAVING_PLANTS && ENABLE_WAVING_PLANTS
 	vec4 pos = gl_Vertex;
 	vec4 pos2 = mWorld * gl_Vertex;
 	if (gl_TexCoord[0].y < 0.05) {
-		pos.x += (smoothTriangleWave(animationTimer * 20.0 + pos2.x * 0.1 + pos2.z * 0.1) * 2.0 - 1.0) * 0.8;
-		pos.y -= (smoothTriangleWave(animationTimer * 10.0 + pos2.x * -0.5 + pos2.z * -0.5) * 2.0 - 1.0) * 0.4;
+		/*
+		 * Mathematic optimization: pos2.x * A + pos2.z * A (2 multiplications + 1 addition)
+		 * replaced with: (pos2.x + pos2.z) * A (1 addition + 1 multiplication)
+		 * And bufferize calcul to a float
+		 */
+		float pos2XpZ = pos2.x + pos2.z;
+
+		pos.x += (smoothTriangleWave(animationTimer * 20.0 + pos2XpZ * 0.1) * 2.0 - 1.0) * 0.8;
+		pos.y -= (smoothTriangleWave(animationTimer * 10.0 + pos2XpZ * -0.5) * 2.0 - 1.0) * 0.4;
 	}
 	gl_Position = mWorldViewProj * pos;
 #else

diff --git a/client/shaders/water_surface_shader/opengl_fragment.glsl b/client/shaders/water_surface_shader/opengl_fragment.glsl
@@ -87,7 +87,12 @@ vec4 base = texture2D(baseTexture, uv).rgba;
 		vec3 E = normalize(eyeVec);
 		float specular = pow(clamp(dot(reflect(L, bump.xyz), E), 0.0, 1.0),0.5); 
 		float diffuse = dot(E,bump.xyz);		
-		color = 0.05*base.rgb + diffuse*base.rgb + 0.2*specular*base.rgb;
+		/* Mathematic optimization
+		* Original: color = 0.05*base.rgb + diffuse*base.rgb + 0.2*specular*base.rgb;
+		* This optimization save 2 multiplications (orig: 4 multiplications + 3 additions
+		* end: 2 multiplications + 3 additions)
+		*/
+		color = (0.05 + diffuse + 0.2 * specular) * base.rgb
 	} else {
 		color = base.rgb;
 	}

diff --git a/client/shaders/water_surface_shader/opengl_vertex.glsl b/client/shaders/water_surface_shader/opengl_vertex.glsl
@@ -31,26 +31,40 @@ float smoothTriangleWave( float x ) {
 void main(void)
 {
 	gl_TexCoord[0] = gl_MultiTexCoord0;
-	
+
 #if (MATERIAL_TYPE == TILE_MATERIAL_LIQUID_TRANSPARENT || MATERIAL_TYPE == TILE_MATERIAL_LIQUID_OPAQUE) && ENABLE_WAVING_WATER
 	vec4 pos = gl_Vertex;
 	pos.y -= 2.0;
-	pos.y -= sin (pos.z/WATER_WAVE_LENGTH + animationTimer * WATER_WAVE_SPEED * WATER_WAVE_LENGTH) * WATER_WAVE_HEIGHT
-		+ sin ((pos.z/WATER_WAVE_LENGTH + animationTimer * WATER_WAVE_SPEED * WATER_WAVE_LENGTH) / 7.0) * WATER_WAVE_HEIGHT;
+
+	float posYbuf = (pos.z / WATER_WAVE_LENGTH + animationTimer * WATER_WAVE_SPEED * WATER_WAVE_LENGTH);
+
+	pos.y -= sin(posYbuf) * WATER_WAVE_HEIGHT + sin(posYbuf / 7.0) * WATER_WAVE_HEIGHT;
 	gl_Position = mWorldViewProj * pos;
 #elif MATERIAL_TYPE == TILE_MATERIAL_WAVING_LEAVES && ENABLE_WAVING_LEAVES
 	vec4 pos = gl_Vertex;
 	vec4 pos2 = mWorld * gl_Vertex;
-	pos.x += (smoothTriangleWave(animationTimer*10.0 + pos2.x * 0.01 + pos2.z * 0.01) * 2.0 - 1.0) * 0.4;
-	pos.y += (smoothTriangleWave(animationTimer*15.0 + pos2.x * -0.01 + pos2.z * -0.01) * 2.0 - 1.0) * 0.2;
-	pos.z += (smoothTriangleWave(animationTimer*10.0 + pos2.x * -0.01 + pos2.z * -0.01) * 2.0 - 1.0) * 0.4;
+	/*
+	 * Mathematic optimization: pos2.x * A + pos2.z * A (2 multiplications + 1 addition)
+	 * replaced with: (pos2.x + pos2.z) * A (1 addition + 1 multiplication)
+	 * And bufferize calcul to a float
+	 */
+	float pos2XpZ = pos2.x + pos2.z;
+	pos.x += (smoothTriangleWave(animationTimer*10.0 + pos2XpZ * 0.01) * 2.0 - 1.0) * 0.4;
+	pos.y += (smoothTriangleWave(animationTimer*15.0 + pos2XpZ * -0.01) * 2.0 - 1.0) * 0.2;
+	pos.z += (smoothTriangleWave(animationTimer*10.0 + pos2XpZ * -0.01) * 2.0 - 1.0) * 0.4;
 	gl_Position = mWorldViewProj * pos;
 #elif MATERIAL_TYPE == TILE_MATERIAL_WAVING_PLANTS && ENABLE_WAVING_PLANTS
 	vec4 pos = gl_Vertex;
 	vec4 pos2 = mWorld * gl_Vertex;
 	if (gl_TexCoord[0].y < 0.05) {
-		pos.x += (smoothTriangleWave(animationTimer * 20.0 + pos2.x * 0.1 + pos2.z * 0.1) * 2.0 - 1.0) * 0.8;
-		pos.y -= (smoothTriangleWave(animationTimer * 10.0 + pos2.x * -0.5 + pos2.z * -0.5) * 2.0 - 1.0) * 0.4;	
+		/*
+		 * Mathematic optimization: pos2.x * A + pos2.z * A (2 multiplications + 1 addition)
+		 * replaced with: (pos2.x + pos2.z) * A (1 addition + 1 multiplication)
+		 * And bufferize calcul to a float
+		 */
+		float pos2XpZ = pos2.x + pos2.z;
+		pos.x += (smoothTriangleWave(animationTimer * 20.0 + pos2XpZ * 0.1) * 2.0 - 1.0) * 0.8;
+		pos.y -= (smoothTriangleWave(animationTimer * 10.0 + pos2XpZ * -0.5) * 2.0 - 1.0) * 0.4;
 	}
 	gl_Position = mWorldViewProj * pos;
 #else
@@ -88,9 +102,9 @@ void main(void)
 		tangent  = normalize(gl_NormalMatrix * vec3(-1.0,  0.0,  0.0));
 		binormal = normalize(gl_NormalMatrix * vec3( 0.0, -1.0,  0.0));
 	}
-	mat3 tbnMatrix = mat3(	tangent.x, binormal.x, normal.x,
-							tangent.y, binormal.y, normal.y,
-							tangent.z, binormal.z, normal.z);
+	mat3 tbnMatrix = mat3(tangent.x, binormal.x, normal.x,
+			tangent.y, binormal.y, normal.y,
+			tangent.z, binormal.z, normal.z);
 
 	lightVec = sunPosition - worldPosition;
 	tsLightVec = lightVec * tbnMatrix;