Performance optimization for deciding when the directional shadow gets rendered.

data/shader/phong.fsh

@@ -47,6 +47,7 @@ uniform bool movingTexture;
 uniform vec2 movement;
 uniform vec2 movingTextureOffset;
 uniform float time;
+uniform bool sampleDirectionalShadowSwitch;
 
 vec2 poissonDisk[16] = vec2[](
    vec2( -0.94201624, -0.39906216 ),
@@ -171,10 +172,9 @@ void main()
 
     // direction lighting
     float sunAngle = -1.0;
-    if(length(directionalLightVector)>0.0f) {
+    if(sampleDirectionalShadowSwitch) {
         vec3 directionalVector = normalize(directionalLightVector);
         sunAngle = dot(vec3(0.0, 1.0, 0.0), directionalVector);
-        if ( sunAngle > 0.0) {
         float directionalVisibility = 1.0f;
         float directionalIntensity = sunIntensity(sunAngle);
         if (distanceToBorder(shadowCoord1.xy) <= 0.5 && distanceToBorder(shadowCoord1.xy) > 0.2) {
@@ -205,7 +205,6 @@ void main()
         (length(cameraVector+directionalVector)*length(normalize(vNormal)))),shininess), 0.0, 1.0)
         *specularFactor*directionalIntensity*sunColor(sunAngle)*directionalVisibility;
     }
-    }
 
     // point lights
     float visibility = 1.0;

game/graphics.cc

@@ -30,6 +30,7 @@ Graphics::Graphics(glm::uvec2 windowSize, float nearPlane,
     renderFlames = true;
     renderWorld = true;
     renderDebug = false;
+    directionalShadowSwitch = false;
 }
 
 Graphics::Graphics() {
@@ -196,6 +197,7 @@ void Graphics::init(Level* level) {
     lightingShader->setUniform("fogColorRise", level->getFogColourRise());
     lightingShader->setUniform("fogColorNight", level->getFogColourNight());
     lightingShader->setUniform("ambientColor", level->getAmbientLight());
+    lightingShader->setUniform("sampleDirectionalShadowSwitch", false);
     if(level->getDirectionalLight()) {
         lightingShader->setUniform("directionalLightVector",
             level->getDirectionalLight()->getPosition());
@@ -361,18 +363,22 @@ void Graphics::render(double time)
                 }
             }
 
-            // render depth textures for sun
-            depthShader->use();
             glViewport(0, 0, windowSize.x, windowSize.y);
 
-            
+            // render depth textures for sun
             float sunAngle = glm::dot(glm::vec3(0.0f, 1.0f, 0.0f), glm::normalize(level->getDirectionalLight()->getPosition()));
             glm::vec3 sunVector = (level->getCameraCenter()->getPosition() + level->getDirectionalLight()->getPosition());
 
+            if (sunAngle > 0.0f) {
+                if (!directionalShadowSwitch) {
+                    lightingShader->use();
+                    lightingShader->setUniform("sampleDirectionalShadowSwitch", true);
+                    directionalShadowSwitch = true;
+                }
+                depthShader->use();
                 for (unsigned int i = 0; i<framebuffer_directional.size(); i++) {
                     framebuffer_directional.at(i)->bind();
                     glClear(GL_DEPTH_BUFFER_BIT);
-                if (sunAngle > 0.0f) {
                         float projection_size = 0.0f;
                         switch(i) {
                             case 0:
@@ -393,6 +399,11 @@ void Graphics::render(double time)
                         }
                 }
             }
+            else if (directionalShadowSwitch) {
+                lightingShader->use();
+                lightingShader->setUniform("sampleDirectionalShadowSwitch", false);
+                directionalShadowSwitch = false;
+            }
         }
         
         // lighting render pass

game/graphics.hh

@@ -84,6 +84,7 @@ class Graphics {
         bool renderFlames;
         bool renderDebug;
         bool renderWorld;
+        bool directionalShadowSwitch;
         DebugDraw debugDrawer;
         SharedArrayBuffer debug_ab;
         SharedVertexArrayObject debug_vao;