Add transformation to objects.

tests/ray_test.cpp

@@ -7,6 +7,8 @@
  *
  */
 #include <ray.h>
+#include <transformation.h>
+#include <object.h>
 #include <gtest/gtest.h>
 
 
@@ -29,4 +31,34 @@ TEST(RayTest, Computing_a_point_from_a_distance)
     ASSERT_EQ(r.position(1), Point(3, 3, 4));
     ASSERT_EQ(r.position(-1), Point(1, 3, 4));
     ASSERT_EQ(r.position(2.5), Point(4.5, 3, 4));
+}
+
+TEST(RayTest, Translating_a_ray)
+{
+    Ray r = Ray(Point(1, 2, 3), Vector(0, 1, 0));
+
+    Matrix m = translation(3, 4, 5);
+    Object o = Object();
+
+    o.setTransform(m);
+
+    Ray r2 = o.transform(r);
+
+    ASSERT_EQ(r2.origin, Point(4, 6, 8));
+    ASSERT_EQ(r2.direction, Vector(0, 1, 0));
+}
+
+TEST(RayTest, Scaling_a_ray)
+{
+    Ray r = Ray(Point(1, 2, 3), Vector(0, 1, 0));
+
+    Matrix m = scaling(2, 3, 4);
+    Object o = Object();
+
+    o.setTransform(m);
+
+    Ray r2 = o.transform(r);
+
+    ASSERT_EQ(r2.origin, Point(2, 6, 12));
+    ASSERT_EQ(r2.direction, Vector(0, 3, 0));
 }