added operators +, - to Vector, added inverse transform instance variable to shapes/Shape, changed Sphere to use its inverse transform when calculating intersections and normals, removed simplistic lighting from main/Scene

git-svn-id: svn://anubis/fart/trunk@47 7f9b0f55-74a9-4bce-be96-3c2cd072584d

shapes/Shape.h

@@ -11,12 +11,18 @@ class Shape
 {
     public:
         virtual Solver::Result intersect(const Ray & ray) = 0;
-        void setTransform(const Transform & t) { m_transform = t; }
-        Transform & getTransform() { return m_transform; }
         virtual Vector getNormalAt(const Vector & pt) = 0;
 
+        void setTransform(Transform & t)
+        {
+            m_transform = t;
+            m_inverse = t.getInverse();
+        }
+        Transform & getTransform() { return m_transform; }
+
     protected:
         Transform m_transform;
+        Transform m_inverse;
 };
 
 #endif

shapes/Sphere.cc

@@ -13,14 +13,16 @@ Sphere::Sphere(double radius)
 
 Solver::Result Sphere::intersect(const Ray & ray)
 {
+    Ray ray_inv = m_inverse.transform_ray(ray);
+
     Solver::Result res;
     QuadraticSolver solver(1.0,
-                           2 * ( ray.getOrigin()[0] * ray.getDirection()[0]
-                               + ray.getOrigin()[1] * ray.getDirection()[1]
-                               + ray.getOrigin()[2] * ray.getDirection()[2] ),
-                             ray.getOrigin()[0] * ray.getOrigin()[0]
-                           + ray.getOrigin()[1] * ray.getOrigin()[1]
-                           + ray.getOrigin()[2] * ray.getOrigin()[2]
+                           2 * ( ray_inv.getOrigin()[0] * ray_inv.getDirection()[0]
+                               + ray_inv.getOrigin()[1] * ray_inv.getDirection()[1]
+                               + ray_inv.getOrigin()[2] * ray_inv.getDirection()[2] ),
+                             ray_inv.getOrigin()[0] * ray_inv.getOrigin()[0]
+                           + ray_inv.getOrigin()[1] * ray_inv.getOrigin()[1]
+                           + ray_inv.getOrigin()[2] * ray_inv.getOrigin()[2]
                            - m_radius2);
     Solver::Result quadSolutions = solver.solve();
     for (int i = 0; i < quadSolutions.numResults; i++)
@@ -35,6 +37,8 @@ Solver::Result Sphere::intersect(const Ray & ray)
 
 Vector Sphere::getNormalAt(const Vector & pt)
 {
-    Vector normal = pt;
+    Vector pt_inv = m_inverse.transform_point(pt);
+
+    Vector normal = pt_inv;
     return normal.normalize();
 }