Working on groups

tests/CMakeLists.txt

@@ -5,7 +5,7 @@ find_package(Threads REQUIRED)
 
 set(TESTS_SRC math_test.cpp tuple_test.cpp colour_test.cpp canvas_test.cpp matrix_test.cpp transformation_test.cpp
         ray_test.cpp intersect_test.cpp sphere_test.cpp light_test.cpp material_test.cpp world_test.cpp camera_test.cpp
-        shape_test.cpp plane_test.cpp pattern_test.cpp cube_test.cpp cylinder_test.cpp cone_test.cpp)
+        shape_test.cpp plane_test.cpp pattern_test.cpp cube_test.cpp cylinder_test.cpp cone_test.cpp group_test.cpp)
 
 add_executable(testMyRays)
 target_include_directories(testMyRays PUBLIC ${gtest_SOURCE_DIR}/include ${gtest_SOURCE_DIR})

tests/group_test.cpp

@@ -0,0 +1,82 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Group unit tests
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#include <intersect.h>
+#include <intersection.h>
+#include <group.h>
+#include <testshape.h>
+#include <sphere.h>
+
+#include <transformation.h>
+#include <gtest/gtest.h>
+
+TEST(GroupTest, Creating_a_new_group)
+{
+    Group g = Group();
+
+    ASSERT_EQ(g.transformMatrix, Matrix4().identity());
+    ASSERT_TRUE(g.isEmpty());
+}
+
+TEST(GroupTest, Adding_a_child_to_a_group)
+{
+    Group g = Group();
+    TestShape s = TestShape();
+
+    g.addObject(&s);
+
+    ASSERT_FALSE(g.isEmpty());
+    ASSERT_EQ(s.parent, &g);
+    ASSERT_EQ(g[0], &s);
+}
+
+TEST(GroupTest, Intersecting_a_ray_with_an_empty_group)
+{
+    Group g = Group();
+    Ray r = Ray(Point(0, 0, 0), Vector(0, 0, 1));
+    Intersect xs = g.intersect(r);
+    ASSERT_EQ(xs.count(), 0);
+}
+
+TEST(GroupTest, Intersecting_a_ray_with_an_nonempty_group)
+{
+    Group g = Group();
+    Sphere s1 = Sphere();
+    Sphere s2 = Sphere();
+    Sphere s3 = Sphere();
+
+    s2.setTransform(translation(0, 0, -3));
+    s3.setTransform(translation(5, 0, 0));
+
+    g.addObject(&s1);
+    g.addObject(&s2);
+    g.addObject(&s3);
+
+    Ray r = Ray(Point(0, 0, -5), Vector(0, 0, 1));
+    Intersect xs = g.intersect(r);
+    ASSERT_EQ(xs.count(), 4);
+    EXPECT_EQ(xs[0].object, &s2);
+    EXPECT_EQ(xs[1].object, &s2);
+    EXPECT_EQ(xs[2].object, &s1);
+    EXPECT_EQ(xs[3].object, &s1);
+}
+
+TEST(GroupTest, Intersecting_a_transformer_group)
+{
+    Group g = Group();
+    Sphere s = Sphere();
+
+    g.setTransform(scaling(2, 2, 2));
+    s.setTransform(translation(5, 0, 0));
+
+    g.addObject(&s);
+
+    Ray r = Ray(Point(10, 0, -50), Vector(0, 0, 1));
+    Intersect xs = g.intersect(r);
+    ASSERT_EQ(xs.count(), 2);
+}

tests/shape_test.cpp

@@ -9,6 +9,8 @@
 #include <shape.h>
 #include <testshape.h>
 #include <matrix.h>
+#include <group.h>
+#include <sphere.h>
 #include <transformation.h>
 #include <gtest/gtest.h>
 
@@ -94,5 +96,49 @@ TEST(ShapeTest, Computing_the_normal_on_a_tranformed_shape)
 
     ASSERT_EQ(n, Vector(0, 0.97014, -0.24254));
 
+    set_equal_precision(FLT_EPSILON);
+}
+
+TEST(ShapeTest, A_shape_has_a_parent_attribute)
+{
+    TestShape s = TestShape();
+
+    ASSERT_EQ(s.parent, nullptr);
+}
+
+TEST(TestShape, Converting_a_point_from_world_to_object_space)
+{
+    Group g1 = Group();
+    g1.setTransform(rotationY(M_PI / 2));
+    Group g2 = Group();
+    g2.setTransform(scaling(2, 2, 2));
+    g1.addObject(&g2);
+    Sphere s = Sphere();
+    s.setTransform(translation(5, 0, 0));
+    g2.addObject(&s);
+
+    Tuple p = s.worldToObject(Point(-2, 0, -10));
+
+    ASSERT_EQ(p, Point(0, 0, -1));
+}
+
+TEST(TestShape, Converting_a_normal_form_object_to_world_space)
+{
+    Group g1 = Group();
+    g1.setTransform(rotationY(M_PI / 2));
+    Group g2 = Group();
+    g2.setTransform(scaling(1, 2, 3));
+    g1.addObject(&g2);
+    Sphere s = Sphere();
+    s.setTransform(translation(5, 0, 0));
+    g2.addObject(&s);
+
+    Tuple p = s.normalToWorld(Point(sqrt(3)/3, sqrt(3)/3, sqrt(3)/3));
+
+    /* Temporary lower the precision */
+    set_equal_precision(0.0001);
+
+    ASSERT_EQ(p, Point(0.2857, 0.4286, -0.8571));
+
     set_equal_precision(FLT_EPSILON);
 }