added ambient_occlusion global scene option to parser and vim keywords; added ambient_occlusion scene file

git-svn-id: svn://anubis/fart/trunk@263 7f9b0f55-74a9-4bce-be96-3c2cd072584d

main/Scene-load.cc

@@ -202,6 +202,10 @@ void Scene::processOptions(refptr<Node> node)
         {
             setAmbientLight(Color((*it)->getVector()));
         }
+        else if ( typeid(**it) == typeid(AmbientOcclusionNode) )
+        {
+            m_ambient_occlusion_level = (*it)->getInteger();
+        }
     }
 }
 

main/Scene.cc

@@ -30,6 +30,7 @@ Scene::Scene(const map<string, const char *> & options,
     m_ambient_light = Color(0.2, 0.2, 0.2);
     m_max_depth = 10;
     m_exposure = 1.0f;
+    m_ambient_occlusion_level = 0;
     m_transforms.push(Transform());
 
     load(filename);
@@ -215,8 +216,12 @@ Color Scene::computePhong(const refptr<Material> material,
                           const Vector & surfacePoint,
                           const Vector & surfaceNormal)
 {
-    Color result = m_ambient_light * material->getAmbientColor()
-        * calculateAmbientOcclusion(Ray(surfacePoint, surfaceNormal).shift(1e-7));
+    Color result = m_ambient_light * material->getAmbientColor();
+    if (m_ambient_occlusion_level > 0)
+    {
+        result *= calculateAmbientOcclusion(
+                Ray(surfacePoint, surfaceNormal).shift(1e-7));
+    }
 
     Vector viewDirection = -viewRay.getDirection();
     double shininess = material->getShininess();
@@ -327,7 +332,8 @@ Color Scene::calculateLightContribution(const Ray & toLight,
 Color Scene::calculateAmbientOcclusion(const Ray & surfaceNormal)
 {
     Color result(1, 1, 1);
-    const int nISteps = 30, nJSteps = 15;
+    const int nISteps = m_ambient_occlusion_level * 6;
+    const int nJSteps = nISteps / 2;
     int nRays = 0;
     Vector perpX = surfaceNormal.getDirection().getPerpendicular().normalize();
     Vector perpY = (surfaceNormal.getDirection() * perpX).normalize();

main/Scene.h

@@ -37,6 +37,7 @@ class Scene
         int getWidth() { return m_width; }
         int getHeight() { return m_height; }
         int getMultisampleLevel() { return m_multisample_level; }
+        int getAmbientOcclusionLevel() { return m_ambient_occlusion_level; }
         double getVFOV() { return m_vfov; }
 
     protected:
@@ -79,6 +80,7 @@ class Scene
         Color m_ambient_light;
         int m_max_depth;
         double m_exposure;
+        int m_ambient_occlusion_level;
 
         /* private data */
         std::vector< refptr<Shape> > m_shapes;

main/fart.cc

@@ -187,6 +187,7 @@ int main(int argc, char * argv[])
         cout << "    Width: " << width << endl;
         cout << "    Height: " << height << endl;
         cout << "    Multisample Level: " << scene.getMultisampleLevel() << endl;
+        cout << "    Ambient Occlusion Level: " << scene.getAmbientOcclusionLevel() << endl;
         cout << "    Vertical Field of View: " << scene.getVFOV() << endl;
         cout << "----------------------------------------" << endl;
     }