Added planes!

Change derived shape to only deal with local calculation they don't need anymore to deal with how they've been transformed.

README.md

@@ -3,4 +3,33 @@
 DoRayMe
 =======
 
-A Quick and dirty raytracer.
+A Quick and dirty raytracer.
+
+
+This raytracer is made following the book "[The Ray Tracer Challenge](https://pragprog.com/book/jbtracer/the-ray-tracer-challenge)" by Jamis Buck.
+
+It is writen in C++ with no STL and use [LodePNG](https://github.com/lvandeve/lodepng) to output PNG file.
+
+
+Examples outputs
+----------------
+
+From chapter 05:
+
+![Chapter 5 rendering test](output/ch5_test.png)
+
+From Chapter 06:
+
+![Chapter 6 rendering test](output/ch6_test.png)
+
+From Chapter 07:
+
+![Chapter 7 rendering test](output/ch7_test.png)
+
+From Chapter 08:
+
+![Chapter 8 rendering test](output/ch8_test.png)
+
+From Chapter 09:
+
+![Chapter 9 rendering test](output/ch9_test.png)

source/include/intersection.h

@@ -16,11 +16,13 @@ class Shape;
 
 struct Computation
 {
-    Computation(Shape *object, double t, Tuple point, Tuple eyev, Tuple normalv, bool inside) :
-          object(object), t(t), hitPoint(point), eyeVector(eyev), normalVector(normalv), inside(inside) { };
+    Computation(Shape *object, double t, Tuple point, Tuple eyev, Tuple normalv, Tuple overHitP, bool inside) :
+          object(object), t(t), hitPoint(point), eyeVector(eyev), normalVector(normalv), inside(inside), overHitPoint(overHitP) { };
+
     Shape *object;
     double t;
     Tuple hitPoint;
+    Tuple overHitPoint;
     Tuple eyeVector;
     Tuple normalVector;
 

source/include/material.h

@@ -25,7 +25,7 @@ public:
 public:
     Material() : colour(Colour(1, 1, 1)), ambient(0.1), diffuse(0.9), specular(0.9), shininess(200) {};
 
-    Colour lighting(Light light, Tuple point, Tuple eyeVector, Tuple normalVector);
+    Colour lighting(Light light, Tuple point, Tuple eyeVector, Tuple normalVector, bool inShadow = false);
 
     bool operator==(const Material &b) const { return double_equal(this->ambient,   b.ambient) &&
                                                       double_equal(this->diffuse,   b.diffuse) &&

source/include/math_helper.h

@@ -13,6 +13,7 @@
 #include <math.h>
 
 void set_equal_precision(double v);
+double getEpsilon();
 bool double_equal(double a, double b);
 
 double deg_to_rad(double deg);

source/include/plane.h

@@ -0,0 +1,22 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Plane header
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#ifndef DORAYME_PLANE_H
+#define DORAYME_PLANE_H
+
+class Plane : public Shape
+{
+private:
+    Intersect localIntersect(Ray r);
+    Tuple localNormalAt(Tuple point);
+
+public:
+    Plane() : Shape(SHAPE_PLANE) { };
+};
+
+#endif //DORAYME_PLANE_H

source/include/shape.h

@@ -21,6 +21,7 @@ enum ShapeType
 {
     SHAPE_NONE,
     SHAPE_SPHERE,
+    SHAPE_PLANE,
 };
 
 /* Base class for all object that can be presented in the world */
@@ -29,6 +30,10 @@ class Shape
 private:
     ShapeType type;
 
+private:
+    virtual Intersect localIntersect(Ray r) = 0;
+    virtual Tuple localNormalAt(Tuple point) = 0;
+
 public:
     Matrix transformMatrix;
     Matrix inverseTransform;
@@ -37,8 +42,8 @@ public:
 public:
     Shape(ShapeType = SHAPE_NONE);
 
-    virtual Intersect intersect(Ray r);
-    virtual Tuple normalAt(Tuple point);
+    Intersect intersect(Ray r);
+    Tuple normalAt(Tuple point);
 
     void setTransform(Matrix transform);
     void setMaterial(Material material) { this->material = material; };

source/include/sphere.h

@@ -15,11 +15,13 @@
 
 class Sphere : public Shape
 {
+private:
+    Intersect localIntersect(Ray r);
+    Tuple localNormalAt(Tuple point);
+
 public:
     Sphere() : Shape(SHAPE_SPHERE) { };
     /* All sphere are at (0, 0, 0) and radius 1 in the object space */
-    virtual Intersect intersect(Ray r);
-    virtual Tuple normalAt(Tuple point);
 };
 
 #endif /* DORAYME_SPHERE_H */

source/include/testshape.h

@@ -0,0 +1,28 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Test shape header
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#ifndef DORAYME_TESTSHAPE_H
+#define DORAYME_TESTSHAPE_H
+
+#include <shape.h>
+#include <ray.h>
+#include <tuple.h>
+
+class TestShape : public Shape
+{
+private:
+    Intersect localIntersect(Ray r);
+    Tuple localNormalAt(Tuple point);
+
+public:
+    Ray localRay;
+
+    TestShape();
+};
+
+#endif //DORAYME_TESTSHAPE_H

source/include/world.h

@@ -43,6 +43,7 @@ public:
 
     Tuple shadeHit(Computation comps);;
     Tuple colourAt(Ray r);
+    bool isShadowed(Tuple point);
 
     Intersect intersect(Ray r);
 

source/intersection.cpp

@@ -22,11 +22,13 @@ Computation Intersection::prepareComputation(Ray r)
         normalV = -normalV;
     }
 
+    Tuple overHitP = hitP + normalV * getEpsilon();
 
     return Computation(this->object,
                        this->t,
                        hitP,
                        eyeV,
                        normalV,
+                       overHitP,
                        inside);
 }

source/math_helper.cpp

@@ -18,6 +18,11 @@ void set_equal_precision(double v)
     current_precision = v;
 }
 
+double getEpsilon()
+{
+    return current_precision;
+}
+
 bool double_equal(double a, double b)
 {
     return fabs(a - b) < current_precision;

source/shapes/material.cpp

@@ -10,7 +10,7 @@
 #include <material.h>
 #include <colour.h>
 
-Colour Material::lighting(Light light, Tuple point, Tuple eyeVector, Tuple normalVector)
+Colour Material::lighting(Light light, Tuple point, Tuple eyeVector, Tuple normalVector, bool inShadow)
 {
     Tuple lightVector = (light.position - point).normalise();
     Tuple reflectVector = Tuple(0, 0, 0, 0);
@@ -25,31 +25,33 @@ Colour Material::lighting(Light light, Tuple point, Tuple eyeVector, Tuple norma
 
     ambientColour = effectiveColour * this->ambient;
 
-    lightDotNormal = lightVector.dot(normalVector);
-
-    if (lightDotNormal < 0)
+    if (!inShadow)
     {
-        diffuseColour = Colour(0, 0, 0);
-        specularColour = Colour(0, 0, 0);
-    }
-    else
-    {
-        diffuseColour = effectiveColour * this->diffuse * lightDotNormal;
-        reflectVector = -lightVector.reflect(normalVector);
+        lightDotNormal = lightVector.dot(normalVector);
 
-        reflectDotEye = reflectVector.dot(eyeVector);
-
-        if (reflectDotEye < 0)
+        if (lightDotNormal < 0)
         {
+            diffuseColour = Colour(0, 0, 0);
             specularColour = Colour(0, 0, 0);
         }
         else
         {
-            double factor = pow(reflectDotEye, this->shininess);
-            specularColour = light.intensity * this->specular * factor;
+            diffuseColour = effectiveColour * this->diffuse * lightDotNormal;
+            reflectVector = -lightVector.reflect(normalVector);
+
+            reflectDotEye = reflectVector.dot(eyeVector);
+
+            if (reflectDotEye < 0)
+            {
+                specularColour = Colour(0, 0, 0);
+            }
+            else
+            {
+                double factor = pow(reflectDotEye, this->shininess);
+                specularColour = light.intensity * this->specular * factor;
+            }
         }
     }
-
     finalColour = ambientColour + diffuseColour + specularColour;
 
     return Colour(finalColour.x, finalColour.y, finalColour.z);

source/shapes/plane.cpp

@@ -0,0 +1,36 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Plane implementation
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#include <tuple.h>
+#include <ray.h>
+#include <shape.h>
+#include <plane.h>
+#include <math_helper.h>
+
+Intersect Plane::localIntersect(Ray r)
+{
+    double t;
+    Intersect ret = Intersect();
+
+    if (fabs(r.direction.y) < getEpsilon())
+    {
+        /* With a direction == 0, the ray can't intersect the plane */
+        return ret;
+    }
+
+    t = -r.origin.y / r.direction.y;
+
+    ret.add(Intersection(t, this));
+
+    return ret;
+}
+
+Tuple Plane::localNormalAt(Tuple point)
+{
+    return Vector(0, 1, 0);
+}

source/shapes/shape.cpp

@@ -22,12 +22,21 @@ Shape::Shape(ShapeType type)
 
 Intersect Shape::intersect(Ray r)
 {
-    return Intersect();
+    return this->localIntersect(this->invTransform(r));
 };
 
 Tuple Shape::normalAt(Tuple point)
 {
-    return Vector(0, 0, 0);
+    Tuple local_point = this->inverseTransform * point;
+
+    Tuple local_normal = this->localNormalAt(local_point);
+
+    Tuple world_normal = this->inverseTransform.transpose() * local_normal;
+
+    /* W may get wrong, so hack it. This is perfectly normal as we are using a 4x4 matrix instead of a 3x3 */
+    world_normal.w = 0;
+
+    return world_normal.normalise();
 }
 
 void Shape::setTransform(Matrix transform)

source/shapes/sphere.cpp

@@ -13,17 +13,15 @@
 #include <tuple.h>
 #include <intersect.h>
 
-Intersect Sphere::intersect(Ray r)
+Intersect Sphere::localIntersect(Ray r)
 {
     Intersect ret;
     double a, b, c, discriminant;
 
-    Ray transRay = this->invTransform(r);
+    Tuple sphere_to_ray = r.origin - Point(0, 0, 0);
 
-    Tuple sphere_to_ray = transRay.origin - Point(0, 0, 0);
-
-    a = transRay.direction.dot(transRay.direction);
-    b = 2 * transRay.direction.dot(sphere_to_ray);
+    a = r.direction.dot(r.direction);
+    b = 2 * r.direction.dot(sphere_to_ray);
     c = sphere_to_ray.dot(sphere_to_ray) - 1;
 
     discriminant = b * b - 4 * a * c;
@@ -37,14 +35,7 @@ Intersect Sphere::intersect(Ray r)
     return ret;
 }
 
-Tuple Sphere::normalAt(Tuple point)
+Tuple Sphere::localNormalAt(Tuple point)
 {
-    Tuple object_point = this->inverseTransform * point;
-    Tuple object_normal = (object_point - Point(0, 0, 0)).normalise();
-    Tuple world_normal = this->inverseTransform.transpose() * object_normal;
-
-    /* W may get wrong, so hack it. This is perfectly normal as we are using a 4x4 matrix instead of a 3x3 */
-    world_normal.w = 0;
-
-    return world_normal.normalise();
+    return (point - Point(0, 0, 0)).normalise();
 }

source/shapes/testshape.cpp

@@ -0,0 +1,25 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Test shape implementation
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#include <shape.h>
+#include <testshape.h>
+
+TestShape::TestShape() : localRay(Point(0, 0, 0), Vector(0, 0, 0))
+{
+}
+
+Intersect TestShape::localIntersect(Ray r)
+{
+    this->localRay = r;
+    return Intersect();
+}
+
+Tuple TestShape::localNormalAt(Tuple point)
+{
+     return Vector(point.x, point.y, point.z);
+}

source/world.cpp

@@ -94,7 +94,12 @@ Intersect World::intersect(Ray r)
 
 Tuple World::shadeHit(Computation comps)
 {
-    return comps.object->material.lighting(*this->lightList[0], comps.hitPoint, comps.eyeVector, comps.normalVector);
+    /* TODO: Add support for more than one light */
+
+    bool isThereAnObstacle = this->isShadowed(comps.overHitPoint);
+
+    return comps.object->material.lighting(*this->lightList[0], comps.overHitPoint, comps.eyeVector,
+            comps.normalVector, isThereAnObstacle);
 }
 
 Tuple World::colourAt(Ray r)
@@ -109,4 +114,23 @@ Tuple World::colourAt(Ray r)
     {
         return this->shadeHit(hit.prepareComputation(r));
     }
-}
+}
+
+bool World::isShadowed(Tuple point)
+{
+    /* TODO: Add support for more than one light */
+
+    Tuple v = this->lightList[0]->position - point;
+    double distance = v.magnitude();
+    Tuple direction = v.normalise();
+
+    Ray r = Ray(point, direction);
+    Intersection h = this->intersect(r).hit();
+
+    if (!h.nothing() && (h.t < distance))
+    {
+        return true;
+    }
+
+    return false;
+}

tests/CMakeLists.txt

@@ -4,7 +4,8 @@ set(THREADS_PREFER_PTHREAD_FLAG ON)
 find_package(Threads REQUIRED)
 
 set(TESTS_SRC 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)
+        intersect_test.cpp sphere_test.cpp light_test.cpp material_test.cpp world_test.cpp camera_test.cpp
+        shape_test.cpp plane_test.cpp)
 
 add_executable(testMyRays)
 target_include_directories(testMyRays PUBLIC ${gtest_SOURCE_DIR}/include ${gtest_SOURCE_DIR})
@@ -33,6 +34,12 @@ target_include_directories(ch6_test PUBLIC ../source/include)
 target_sources(ch7_test PRIVATE ch7_test.cpp)
 target_link_libraries(ch7_test rayonnement)
 
+add_executable(ch9_test)
+target_include_directories(ch6_test PUBLIC ../source/include)
+target_sources(ch9_test PRIVATE ch9_test.cpp)
+target_link_libraries(ch9_test rayonnement)
+
 add_test(NAME Chapter05_Test COMMAND $<TARGET_FILE:ch5_test>)
 add_test(NAME Chapter06_Test COMMAND $<TARGET_FILE:ch6_test>)
-add_test(NAME Chapter07_Test COMMAND $<TARGET_FILE:ch7_test>)
+add_test(NAME Chapter07_Test COMMAND $<TARGET_FILE:ch7_test>)
+add_test(NAME Chapter09_Test COMMAND $<TARGET_FILE:ch9_test>)

tests/canvas_test.cpp

@@ -50,4 +50,22 @@ TEST(CanvasTest, Save_a_PNG_file)
 
     ASSERT_TRUE(c.SaveAsPNG("Save_a_PNG_file.png"));
 
+}
+
+TEST(CanvasTest, Create_a_canvas_from_another_using_reference)
+{
+    Canvas c = Canvas(100, 100);
+
+    Canvas copy = Canvas(c);
+
+    ASSERT_EQ(c.width, copy.width);
+}
+
+TEST(CanvasTest, Create_a_canvas_from_another_using_pointer)
+{
+    Canvas c = Canvas(100, 100);
+
+    Canvas copy = Canvas(&c);
+
+    ASSERT_EQ(c.width, copy.width);
 }

tests/ch7_test.cpp

@@ -68,7 +68,7 @@ int main()
     w.addLight(&light);
 
     /* Set the camera */
-    Camera camera = Camera(1000, 500, M_PI / 3);
+    Camera camera = Camera(100, 50, M_PI / 3);
     camera.setTransform(viewTransform(Point(0, 1.5, -5),
                                       Point(0, 1, 0),
                                       Vector(0, 1, 0)));

tests/ch9_test.cpp

@@ -0,0 +1,69 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Render test for chapter 5 "Put it together".
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#include <world.h>
+#include <light.h>
+#include <sphere.h>
+#include <plane.h>
+#include <material.h>
+#include <colour.h>
+#include <canvas.h>
+#include <camera.h>
+#include <transformation.h>
+
+int main()
+{
+    /* First we need to construct the world */
+    Plane floor = Plane();
+    floor.material.colour = Colour(1, 0.9, 0.9);
+    floor.material.specular = 0;
+
+    Sphere middle = Sphere();
+    middle.setTransform(translation(-0.5, 1, 0.5));
+    middle.material.colour = Colour(0.1, 1, 0.5);
+    middle.material.diffuse = 0.7;
+    middle.material.specular = 0.3;
+
+    Sphere right = Sphere();
+    right.setTransform(translation(1.5, 0.5, -0.5) * scaling(0.5, 0.5, 0.5));
+    right.material.colour = Colour(0.5, 1, 0.1);
+    right.material.diffuse = 0.7;
+    right.material.specular = 0.3;
+
+    Sphere left = Sphere();
+    left.setTransform(translation(-1.5, 0.33, -0.75) * scaling(0.33, 0.33, 0.33));
+    left.material.colour = Colour(1, 0.8, 0.1);
+    left.material.diffuse = 0.7;
+    left.material.specular = 0.3;
+
+    World w = World();
+
+    w.addObject(&floor);
+    w.addObject(&middle);
+    w.addObject(&left);
+    w.addObject(&right);
+
+    /* Add light */
+    Light light = Light(POINT_LIGHT, Point(-10, 10, -10), Colour(1, 1, 1));
+
+    w.addLight(&light);
+
+    /* Set the camera */
+    Camera camera = Camera(1000, 500, M_PI / 3);
+    camera.setTransform(viewTransform(Point(0, 1.5, -5),
+                                      Point(0, 1, 0),
+                                      Vector(0, 1, 0)));
+
+    /* Now render it */
+    Canvas image = camera.render(w);
+
+    image.SaveAsPNG("ch9_test.png");
+
+
+    return 0;
+}

tests/intersect_test.cpp

@@ -9,9 +9,9 @@
 #include <intersect.h>
 #include <intersection.h>
 #include <sphere.h>
+#include <transformation.h>
 #include <gtest/gtest.h>
 
-
 TEST(IntersectTest, Creating_an_intersect_and_do_some_check)
 {
     Intersect i;
@@ -173,4 +173,20 @@ TEST(IntersectTest, The_hit_when_an_intersection_occurs_on_the_inside)
     /* Normal vector would have been (0, 0, 1); but is inverted ! */
 
     ASSERT_EQ(comps.normalVector, Vector(0, 0, -1));
+}
+
+TEST(IntersectTest, The_hit_should_offset_the_point)
+{
+    Ray r = Ray(Point(0, 0, -5), Vector(0, 0, 1));
+    Sphere shape = Sphere();
+    shape.setTransform(translation(0, 0, 1));
+
+    Intersection i = Intersection(5, &shape);
+
+    Computation comps = i.prepareComputation(r);
+
+    /* Normal vector would have been (0, 0, 1); but is inverted ! */
+
+    ASSERT_LT(comps.overHitPoint.z, -getEpsilon() / 2);
+    ASSERT_GT(comps.hitPoint.z, comps.overHitPoint.z);
 }

tests/material_test.cpp

@@ -86,5 +86,17 @@ TEST(MaterialTest, Lighting_with_the_light_behind_the_surface)
 
     Colour result = m.lighting(light, position, eyev, normalv);
 
+    ASSERT_EQ(result, Colour(0.1, 0.1, 0.1));
+}
+
+TEST(MaterialTest, Lighting_with_the_surface_in_shadow)
+{
+    Vector eyev = Vector(0, 0, -1);
+    Vector normalv = Vector(0, 0, -1);
+    Light light = Light(POINT_LIGHT, Point(0, 0, -10), Colour(1, 1, 1));
+    bool inShadow = true;
+
+    Colour result = m.lighting(light, position, eyev, normalv, inShadow);
+
     ASSERT_EQ(result, Colour(0.1, 0.1, 0.1));
 }

tests/plane_test.cpp

@@ -0,0 +1,71 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Plane unit tests
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+
+#include <ray.h>
+#include <shape.h>
+#include <plane.h>
+#include <material.h>
+#include <transformation.h>
+#include <gtest/gtest.h>
+
+TEST(PlaneTest, The_normal_of_a_plane_is_constant_everywhere)
+{
+    Plane p = Plane();
+    Tuple n1 = p.normalAt(Point(0, 0, 0));
+    Tuple n2 = p.normalAt(Point(10, 0, -10));
+    Tuple n3 = p.normalAt(Point(-5, 0, 0150));
+
+    ASSERT_EQ(n1, Vector(0, 1, 0));
+    ASSERT_EQ(n2, Vector(0, 1, 0));
+    ASSERT_EQ(n3, Vector(0, 1, 0));
+}
+
+TEST(PlaneTest, Intersect_with_a_ray_parallel_to_the_plane)
+{
+    Plane p = Plane();
+    Ray r = Ray(Point(0, 10, 0), Vector(0, 0, 1));
+
+    Intersect xs = p.intersect(r);
+
+    ASSERT_EQ(xs.count(), 0);
+}
+
+TEST(PlaneTest, Intersect_with_a_coplanar_ray)
+{
+    Plane p = Plane();
+    Ray r = Ray(Point(0, 0, 0), Vector(0, 0, 1));
+
+    Intersect xs = p.intersect(r);
+
+    ASSERT_EQ(xs.count(), 0);
+}
+
+TEST(PlaneTest, A_ray_intersecting_a_plane_from_above)
+{
+    Plane p = Plane();
+    Ray r = Ray(Point(0, 1, 0), Vector(0, -1, 0));
+
+    Intersect xs = p.intersect(r);
+
+    ASSERT_EQ(xs.count(), 1);
+    ASSERT_EQ(xs[0].t, 1);
+    ASSERT_EQ(xs[0].object, &p);
+}
+
+TEST(PlaneTest, A_ray_intersecting_a_plane_from_below)
+{
+    Plane p = Plane();
+    Ray r = Ray(Point(0, -1, 0), Vector(0, 1, 0));
+
+    Intersect xs = p.intersect(r);
+
+    ASSERT_EQ(xs.count(), 1);
+    ASSERT_EQ(xs[0].t, 1);
+    ASSERT_EQ(xs[0].object, &p);
+}

tests/ray_test.cpp

@@ -9,6 +9,7 @@
 #include <ray.h>
 #include <transformation.h>
 #include <shape.h>
+#include <testshape.h>
 #include <gtest/gtest.h>
 
 
@@ -38,7 +39,7 @@ TEST(RayTest, Translating_a_ray)
     Ray r = Ray(Point(1, 2, 3), Vector(0, 1, 0));
 
     Matrix m = translation(3, 4, 5);
-    Shape o = Shape();
+    TestShape o = TestShape();
 
     o.setTransform(m);
 
@@ -53,7 +54,7 @@ TEST(RayTest, Scaling_a_ray)
     Ray r = Ray(Point(1, 2, 3), Vector(0, 1, 0));
 
     Matrix m = scaling(2, 3, 4);
-    Shape o = Shape();
+    TestShape o = TestShape();
 
     o.setTransform(m);
 

tests/shape_test.cpp

@@ -0,0 +1,98 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Shape unit tests
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#include <shape.h>
+#include <testshape.h>
+#include <matrix.h>
+#include <transformation.h>
+#include <gtest/gtest.h>
+
+TEST(ShapeTest, The_default_transformation)
+{
+    TestShape s = TestShape();
+    ASSERT_EQ(s.transformMatrix, Matrix4().identity());
+}
+
+TEST(ShapeTest, Assigning_a_transformation)
+{
+    TestShape s = TestShape();
+
+    s.setTransform(translation(2, 3, 4));
+
+    ASSERT_EQ(s.transformMatrix, translation(2, 3, 4));
+}
+
+TEST(ShapeTest, The_default_material)
+{
+    TestShape s = TestShape();
+
+    ASSERT_EQ(s.material, Material());
+}
+
+TEST(ShapeTest, Assigning_a_material)
+{
+    TestShape s = TestShape();
+    Material m = Material();
+    m.ambient = 1;
+
+    s.material = m;
+
+    ASSERT_EQ(s.material, m);
+}
+
+TEST(ShapeTest, Intersecting_a_scaled_shape_with_a_ray)
+{
+    Ray r = Ray(Point(0, 0, -5), Vector(0, 0, 1));
+    TestShape s = TestShape();
+
+    s.setTransform(scaling(2, 2, 2));
+    Intersect xs = s.intersect(r);
+
+    ASSERT_EQ(s.localRay.origin, Point(0, 0, -2.5));
+    ASSERT_EQ(s.localRay.direction, Vector(0, 0, 0.5));
+}
+
+TEST(ShapeTest, Intersecting_a_translated_shape_with_a_ray)
+{
+    Ray r = Ray(Point(0, 0, -5), Vector(0, 0, 1));
+    TestShape s = TestShape();
+
+    s.setTransform(translation(5, 0, 0));
+    Intersect xs = s.intersect(r);
+
+    ASSERT_EQ(s.localRay.origin, Point(-5, 0, -5));
+    ASSERT_EQ(s.localRay.direction, Vector(0, 0, 1));
+}
+
+TEST(ShapeTest, Computing_the_normal_on_a_translated_shape)
+{
+    TestShape s = TestShape();
+    s.setTransform(translation(0, 1, 0));
+    Tuple n = s.normalAt(Point(0, 1.70711, -0.70711));
+
+    /* Temporary lower the precision */
+    set_equal_precision(0.00001);
+
+    ASSERT_EQ(n, Vector(0, 0.70711, -0.70711));
+
+    set_equal_precision(FLT_EPSILON);
+}
+
+TEST(ShapeTest, Computing_the_normal_on_a_tranformed_shape)
+{
+    TestShape s = TestShape();
+    s.setTransform(scaling(1, 0.5, 1) * rotationZ(M_PI / 5));
+    Tuple n = s.normalAt(Point(0, sqrt(2)/2, -sqrt(2)/2));
+
+    /* Temporary lower the precision */
+    set_equal_precision(0.00001);
+
+    ASSERT_EQ(n, Vector(0, 0.97014, -0.24254));
+
+    set_equal_precision(FLT_EPSILON);
+}

tests/world_test.cpp

@@ -111,4 +111,60 @@ TEST(WorldTest, The_colour_with_an_intersection_behind_the_ray)
     Tuple c = w.colourAt(r);
 
     ASSERT_EQ(c, inner->material.colour);
-}
+}
+
+TEST(WorldTest, There_is_no_shadow_when_nothing_is_collinear_with_point_and_light)
+{
+    World w = DefaultWorld();
+    Tuple p = Point(0, 10, 0);
+
+    ASSERT_FALSE(w.isShadowed(p));
+}
+
+TEST(WorldTest, The_shadow_when_an_object_is_between_the_point_and_the_light)
+{
+    World w = DefaultWorld();
+    Tuple p = Point(10, -10, 10);
+
+    ASSERT_TRUE(w.isShadowed(p));
+}
+
+TEST(WorldTest, There_is_no_shadow_whne_an_object_is_behing_the_light)
+{
+    World w = DefaultWorld();
+    Tuple p = Point(-20, 20, -20);
+
+    ASSERT_FALSE(w.isShadowed(p));
+}
+
+TEST(WorldTest, There_is_no_shadow_when_an_object_is_behing_the_point)
+{
+    World w = DefaultWorld();
+    Tuple p = Point(-2, 2, -2);
+
+    ASSERT_FALSE(w.isShadowed(p));
+}
+
+TEST(WorldTest, Shade_hit_is_given_an_intersection_in_shadow)
+{
+    World w = World();
+
+    Light l = Light(POINT_LIGHT, Point(0, 0, -10), Colour(1, 1, 1));
+    w.addLight(&l);
+
+    Sphere s1 = Sphere();
+
+    w.addObject(&s1);
+
+    Sphere s2 = Sphere();
+    s2.setTransform(translation(0, 0, 10));
+
+    w.addObject(&s2);
+
+    Ray r = Ray(Point(0, 0, 5), Vector(0, 0, 1));
+    Intersection i = Intersection(4, &s2);
+    Computation comps = i.prepareComputation(r);
+    Tuple c = w.shadeHit(comps);
+
+    ASSERT_EQ(c, Colour(0.1, 0.1, 0.1));
+};