Triangles!!!

tests/triangle_test.cpp

@@ -0,0 +1,91 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Triangle unit tests
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#include <triangle.h>
+#include <math.h>
+#include <gtest/gtest.h>
+
+TEST(TriangleTest, Construcring_a_triangle)
+{
+    Point p1 = Point(0, 1, 0);
+    Point p2 = Point(-1, 0, 0);
+    Point p3 = Point(1, 0, 0);
+
+    Triangle t = Triangle(p1, p2, p3);
+
+    ASSERT_EQ(t.p1, p1);
+    ASSERT_EQ(t.p2, p2);
+    ASSERT_EQ(t.p3, p3);
+    ASSERT_EQ(t.e1, Vector(-1, -1, 0));
+    ASSERT_EQ(t.e2, Vector(1, -1, 0));
+    ASSERT_EQ(t.normal, Vector(0, 0, -1));
+}
+
+TEST(TriangleTest, Finding_the_normal_on_a_triangle)
+{
+    Triangle t = Triangle(Point(0, 1, 0), Point(-1, 0, 0), Point(1, 0, 0));
+
+    Tuple n1 = t.normalAt(Point(0, 0.5, 0));
+    Tuple n2 = t.normalAt(Point(-0.5, 0.75, 0));
+    Tuple n3 = t.normalAt(Point(0.5, 0.25, 0));
+
+    ASSERT_EQ(n1, t.normal);
+    ASSERT_EQ(n2, t.normal);
+    ASSERT_EQ(n3, t.normal);
+}
+
+TEST(TriangleTest, Intersecting_a_ray_parallel_to_the_triangle)
+{
+    Triangle t = Triangle(Point(0, 1, 0), Point(-1, 0, 0), Point(1, 0, 0));
+    Ray r = Ray(Point(0, -1, -2), Vector(0, 1, 0));
+
+    Intersect xs = t.intersect(r);
+
+    ASSERT_EQ(xs.count(), 0);
+}
+
+TEST(TriangleTest, A_ray_miss_the_p1_p3_edge)
+{
+    Triangle t = Triangle(Point(0, 1, 0), Point(-1, 0, 0), Point(1, 0, 0));
+    Ray r = Ray(Point(1, 1, -2), Vector(0, 0, 1));
+
+    Intersect xs = t.intersect(r);
+
+    ASSERT_EQ(xs.count(), 0);
+}
+
+TEST(TriangleTest, A_ray_miss_the_p1_p2_edge)
+{
+    Triangle t = Triangle(Point(0, 1, 0), Point(-1, 0, 0), Point(1, 0, 0));
+    Ray r = Ray(Point(-1, 1, -2), Vector(0, 0, 1));
+
+    Intersect xs = t.intersect(r);
+
+    ASSERT_EQ(xs.count(), 0);
+}
+
+TEST(TriangleTest, A_ray_miss_the_p2_p3_edge)
+{
+    Triangle t = Triangle(Point(0, 1, 0), Point(-1, 0, 0), Point(1, 0, 0));
+    Ray r = Ray(Point(0, -1, -2), Vector(0, 0, 1));
+
+    Intersect xs = t.intersect(r);
+
+    ASSERT_EQ(xs.count(), 0);
+}
+
+TEST(TriangleTest, A_ray_strikes_a_triangle)
+{
+    Triangle t = Triangle(Point(0, 1, 0), Point(-1, 0, 0), Point(1, 0, 0));
+    Ray r = Ray(Point(0, .5, -2), Vector(0, 0, 1));
+
+    Intersect xs = t.intersect(r);
+
+    ASSERT_EQ(xs.count(), 1);
+    EXPECT_EQ(xs[0].t, 2);
+}