Add Chapter 5 "putting it together" example.

A bit more clean (on the code side)

CMakeLists.txt

@@ -6,17 +6,6 @@ project(DoRayMe)
 
 set(CMAKE_CXX_STANDARD 11)
 
-
-#Add external projects that directly need to be builded
-ExternalProject_Add(googletest
-        SOURCE_DIR        "${CMAKE_CURRENT_SOURCE_DIR}/external/googletest"
-        BINARY_DIR        "${CMAKE_CURRENT_BINARY_DIR}/external/googletest"
-        CONFIGURE_COMMAND ""
-        BUILD_COMMAND     ""
-        INSTALL_COMMAND   ""
-        TEST_COMMAND      ""
-)
-
 # LodePNG don't make a .a or .so, so let's build a library here
 add_library(LodePNG STATIC)
 set(LODEPNG_INCLUDE_FOLDER ${CMAKE_CURRENT_SOURCE_DIR}/external/lodepng)
@@ -25,5 +14,11 @@ target_sources(LodePNG PRIVATE external/lodepng/lodepng.cpp external/lodepng/lod
 
 # Main app
 add_subdirectory(source)
-# Unit Tests
+
-add_subdirectory(tests)
+option(PACKAGE_TESTS "Build the tests" ON)
+if(PACKAGE_TESTS)
+    enable_testing()
+    include(GoogleTest)
+	 add_subdirectory("${PROJECT_SOURCE_DIR}/external/googletest" "external/googletest")
+    add_subdirectory(tests)
+endif()

source/CMakeLists.txt

@@ -3,8 +3,11 @@
 # First most is build as a library
 add_library(rayonnement STATIC)
 
-set(RAY_HEADERS include/tuples.h include/math_helper.h include/colour.h include/canvas.h include/matrix.h)
+set(RAY_HEADERS include/tuple.h include/math_helper.h include/colour.h include/canvas.h
-set(RAY_SOURCES tuples.cpp math_helper.cpp colour.cpp canvas.cpp matrix.cpp)
+        include/matrix.h include/transformation.h include/intersect.h include/intersection.h
+        include/object.h include/ray.h include/sphere.h)
+set(RAY_SOURCES tuple.cpp math_helper.cpp colour.cpp canvas.cpp matrix.cpp transformation.cpp intersect.cpp
+        objects/object.cpp objects/ray.cpp objects/sphere.cpp)
 
 target_include_directories(rayonnement PUBLIC include)
 target_sources(rayonnement PRIVATE ${RAY_HEADERS} ${RAY_SOURCES})

source/include/colour.h

@@ -9,7 +9,7 @@
 #ifndef DORAYME_COLOUR_H
 #define DORAYME_COLOUR_H
 
-#include <tuples.h>
+#include <tuple.h>
 
 class Colour : public Tuple
 {

source/include/intersect.h

@@ -0,0 +1,29 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Intersect header
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#ifndef DORAYME_INTERSECT_H
+#define DORAYME_INTERSECT_H
+
+#include <stdint.h>
+#include <intersection.h>
+
+class Intersect
+{
+private:
+    Intersection *list;
+    uint32_t num;
+    uint32_t allocated;
+public:
+    Intersect();
+    void add(Intersection i);
+    int count() { return this->num; };
+    Intersection operator[](const int p) { return this->list[p]; }
+    Intersection hit();
+};
+
+#endif //DORAYME_INTERSECT_H

source/include/intersection.h

@@ -0,0 +1,29 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Intersection header
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#ifndef DORAYME_INTERSECTION_H
+#define DORAYME_INTERSECTION_H
+
+#include <stdlib.h>
+
+class Object;
+
+class Intersection
+{
+public:
+    double t;
+    Object *object;
+
+public:
+    Intersection(double t, Object *object) : t(t), object(object) { };
+    bool nothing() { return (this->object == nullptr); };
+
+    bool operator==(const Intersection &b) const { return ((this->t == b.t) && (this->object == b.object)); };
+};
+
+#endif //DORAYME_INTERSECTION_H

source/include/math_helper.h

@@ -10,7 +10,11 @@
 #ifndef DORAYME_MATH_HELPER_H
 #define DORAYME_MATH_HELPER_H
 
+#include <math.h>
+
 void set_equal_precision(double v);
 bool double_equal(double a, double b);
 
+double deg_to_rad(double deg);
+
 #endif //DORAYME_MATH_HELPER_H

source/include/matrix.h

@@ -9,7 +9,7 @@
 #ifndef DORAYME_MATRIX_H
 #define DORAYME_MATRIX_H
 
-#include <tuples.h>
+#include <tuple.h>
 
 class Matrix
 {
@@ -19,7 +19,7 @@ protected:
     int size;
 
 public:
-    Matrix(int size);
+    Matrix(int size = 4);
     Matrix(double values[], int size);
 
     double get(int x, int y) const { return this->data[this->size * x + y]; };

source/include/object.h

@@ -0,0 +1,35 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Object header
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#ifndef DORAYME_OBJECT_H
+#define DORAYME_OBJECT_H
+
+class Object;
+
+#include <ray.h>
+#include <tuple.h>
+#include <matrix.h>
+#include <intersect.h>
+
+/* Base class for all object that can be presented in the world */
+class Object
+{
+public:
+    Matrix transformMatrix;
+    Matrix inverseTransform;
+
+public:
+    Object();
+
+    virtual Intersect intersect(Ray r);
+    void setTransform(Matrix transform);
+    Ray transform(Ray r) {  return Ray(this->transformMatrix * r.origin, this->transformMatrix * r.direction); };
+    Ray invTransform(Ray r) {  return Ray(this->inverseTransform * r.origin, this->inverseTransform * r.direction); };
+};
+
+#endif //DORAYME_OBJECT_H

source/include/ray.h

@@ -0,0 +1,25 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Ray header
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#ifndef DORAYME_RAY_H
+#define DORAYME_RAY_H
+
+#include <tuple.h>
+
+class Ray
+{
+public:
+    Tuple direction;
+    Tuple origin;
+
+    Ray(Tuple origin, Tuple direction) : origin(origin), direction(direction) { };
+
+    Tuple position(double t) { return this->origin + this->direction * t; };
+};
+
+#endif //DORAYME_RAY_H

source/include/sphere.h

@@ -0,0 +1,23 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Sphere header
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#ifndef DORAYME_SPHERE_H
+#define DORAYME_SPHERE_H
+
+#include <object.h>
+#include <ray.h>
+#include <intersect.h>
+
+class Sphere : public Object
+{
+public:
+    /* All sphere are at (0, 0, 0) and radius 1 in the object space */
+    virtual Intersect intersect(Ray r);
+};
+
+#endif //DORAYME_SPHERE_H

source/include/transformation.h

@@ -0,0 +1,24 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Transformation header
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#ifndef DORAYME_TRANSFORMATION_H
+#define DORAYME_TRANSFORMATION_H
+
+#include <matrix.h>
+
+Matrix translation(double x, double y, double z);
+
+Matrix scaling(double x, double y, double z);
+
+Matrix rotation_x(double angle);
+Matrix rotation_y(double angle);
+Matrix rotation_z(double angle);
+
+Matrix shearing(double Xy, double Xx, double Yx, double Yz, double Zx, double Zy);
+
+#endif /* DORAYME_TRANSFORMATION_H */

source/include/tuple.h

@@ -6,8 +6,8 @@
  *  Copyright (c) 2020 986-Studio.
  *
  */
-#ifndef DORAYME_TUPLES_H
+#ifndef DORAYME_TUPLE_H
-#define DORAYME_TUPLES_H
+#define DORAYME_TUPLE_H
 
 #include <math_helper.h>
 
@@ -41,6 +41,8 @@ public:
     double magnitude();
     Tuple normalise();
     double dot(const Tuple &b);
+
+    Tuple cross(const Tuple &b) const;
 };
 
 class Point: public Tuple
@@ -53,7 +55,6 @@ class Vector: public Tuple
 {
 public:
     Vector(double x, double y, double z) : Tuple(x, y, z, 0.0) {};
-    Vector cross(const Vector &b) const;
 };
 
-#endif /* DORAYME_TUPLES_H */
+#endif /*DORAYME_TUPLE_H*/

source/intersect.cpp

@@ -0,0 +1,54 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Intersect implementation
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#include <stdlib.h>
+#include <math_helper.h>
+#include <intersect.h>
+
+#include <float.h>
+
+#define MIN_ALLOC (2)
+
+Intersect::Intersect()
+{
+    this->allocated = MIN_ALLOC;
+    this->list = (Intersection *)calloc(sizeof(Object *), MIN_ALLOC);
+    this->num = 0;
+}
+
+void Intersect::add(Intersection i)
+{
+    if ((this->num + 1) < this->allocated)
+    {
+        this->allocated *= 2;
+        this->list = (Intersection *)realloc(this->list, sizeof(Object *) * this->allocated);
+    }
+    this->list[this->num++] = i;
+}
+
+Intersection Intersect::hit()
+{
+    int i;
+    double minHit = DBL_MAX;
+    uint32_t curHit = -1;
+    for(i = 0; i < this->num; i++)
+    {
+        if ((this->list[i].t >= 0) && (this->list[i].t < minHit))
+        {
+            curHit = i;
+            minHit = this->list[i].t;
+        }
+    }
+
+    if (curHit == -1)
+    {
+        return Intersection(0, nullptr);
+    }
+
+    return this->list[curHit];
+}

source/math_helper.cpp

@@ -22,3 +22,8 @@ bool double_equal(double a, double b)
 {
     return fabs(a - b) < current_precision;
 }
+
+double deg_to_rad(double deg)
+{
+   return deg * M_PI / 180.;
+}

source/matrix.cpp

@@ -9,7 +9,7 @@
 
 #include <stdio.h>
 #include <matrix.h>
-#include <tuples.h>
+#include <tuple.h>
 #include <math_helper.h>
 
 Matrix::Matrix(int width)

source/objects/object.cpp

@@ -0,0 +1,31 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Object implementation
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+
+#include <ray.h>
+#include <object.h>
+#include <matrix.h>
+#include <tuple.h>
+#include <intersect.h>
+
+Object::Object()
+{
+    this->transformMatrix = Matrix4().identity();
+    this->inverseTransform = this->transformMatrix.inverse();
+}
+
+Intersect Object::intersect(Ray r)
+{
+    return Intersect();
+};
+
+void Object::setTransform(Matrix transform)
+{
+    this->transformMatrix = transform;
+    this->inverseTransform = transform.inverse();
+}

source/objects/ray.cpp

@@ -0,0 +1,8 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Ray implementation
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */

source/objects/sphere.cpp

@@ -0,0 +1,38 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Sphere implementation
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#include <math.h>
+
+#include <sphere.h>
+#include <ray.h>
+#include <tuple.h>
+#include <intersect.h>
+
+Intersect Sphere::intersect(Ray r)
+{
+    Intersect ret;
+    double a, b, c, discriminant;
+
+    Ray transRay = this->invTransform(r);
+
+    Tuple sphere_to_ray = transRay.origin - Point(0, 0, 0);
+
+    a = transRay.direction.dot(transRay.direction);
+    b = 2 * transRay.direction.dot(sphere_to_ray);
+    c = sphere_to_ray.dot(sphere_to_ray) - 1;
+
+    discriminant = b * b - 4 * a * c;
+
+    if (discriminant >= 0)
+    {
+        ret.add(Intersection((-b - sqrt(discriminant)) / (2 * a), this));
+        ret.add(Intersection((-b + sqrt(discriminant)) / (2 * a), this));
+    }
+
+    return ret;
+}

source/transformation.cpp

@@ -0,0 +1,84 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Transformation implementation
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#include <math.h>
+
+#include <transformation.h>
+
+Matrix translation(double x, double y, double z)
+{
+   Matrix ret = Matrix4().identity();
+   
+   ret.set(0, 3, x);
+   ret.set(1, 3, y);
+   ret.set(2, 3, z);
+   
+   return ret;
+}
+
+Matrix scaling(double x, double y, double z)
+{
+   Matrix ret = Matrix4();
+   
+   ret.set(0, 0, x);
+   ret.set(1, 1, y);
+   ret.set(2, 2, z);
+   ret.set(3, 3, 1);
+   
+   return ret;
+}
+
+Matrix rotation_x(double angle)
+{
+   Matrix ret = Matrix4().identity();
+   
+   ret.set(1, 1, cos(angle));
+   ret.set(1, 2, -sin(angle));
+   ret.set(2, 1, sin(angle));
+   ret.set(2, 2, cos(angle));
+   
+   return ret;
+}
+
+Matrix rotation_y(double angle)
+{
+   Matrix ret = Matrix4().identity();
+   
+   ret.set(0, 0, cos(angle));
+   ret.set(0, 2, sin(angle));
+   ret.set(2, 0, -sin(angle));
+   ret.set(2, 2, cos(angle));
+   
+   return ret;
+}
+
+Matrix rotation_z(double angle)
+{
+   Matrix ret = Matrix4().identity();
+   
+   ret.set(0, 0, cos(angle));
+   ret.set(0, 1, -sin(angle));
+   ret.set(1, 0, sin(angle));
+   ret.set(1, 1, cos(angle));
+   
+   return ret;
+}
+
+Matrix shearing(double Xy, double Xz, double Yx, double Yz, double Zx, double Zy)
+{
+    Matrix ret = Matrix4().identity();
+
+    ret.set(0, 1, Xy);
+    ret.set(0, 2, Xz);
+    ret.set(1, 0, Yx);
+    ret.set(1, 2, Yz);
+    ret.set(2, 0, Zx);
+    ret.set(2, 1, Zy);
+
+    return ret;
+}

source/tuple.cpp

@@ -6,7 +6,7 @@
  *  Copyright (c) 2020 986-Studio.
  *
  */
-#include <tuples.h>
+#include <tuple.h>
 
 #include <math.h>
 
@@ -27,9 +27,10 @@ double Tuple::dot(const Tuple &b)
     return this->x * b.x + this->y * b.y + this->z * b.z + this->w * b.w;
 }
 
-Vector Vector::cross(const Vector &b) const
+Tuple Tuple::cross(const Tuple &b) const
 {
-    return Vector(this->y * b.z - this->z * b.y,
+    return Tuple(this->y * b.z - this->z * b.y,
-                  this->z * b.x - this->x * b.z,
+                 this->z * b.x - this->x * b.z,
-                  this->x * b.y - this->y * b.x);
+                 this->x * b.y - this->y * b.x,
+                 0);
 }

tests/CMakeLists.txt

@@ -3,10 +3,22 @@ project(DoRayTested)
 set(THREADS_PREFER_PTHREAD_FLAG ON)
 find_package(Threads REQUIRED)
 
-set(TESTS_SRC tuples_test.cpp colour_test.cpp canvas_test.cpp matrix_test.cpp)
+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)
 
 add_executable(testMyRays)
 target_include_directories(testMyRays PUBLIC ${gtest_SOURCE_DIR}/include ${gtest_SOURCE_DIR})
 target_include_directories(testMyRays PUBLIC ../source/include)
 target_sources(testMyRays PRIVATE ${TESTS_SRC})
-target_link_libraries(testMyRays gtest gtest_main rayonnement Threads::Threads)
+target_link_libraries(testMyRays gtest gtest_main rayonnement Threads::Threads)
+
+gtest_discover_tests(testMyRays
+   WORKING_DIRECTORY ${PROJECT_DIR}
+   PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY "${PROJECT_DIR}"
+   )
+
+
+add_executable(ch5_test)
+target_include_directories(ch5_test PUBLIC ../source/include)
+target_sources(ch5_test PRIVATE ch5_test.cpp)
+target_link_libraries(ch5_test rayonnement)

tests/ch5_test.cpp

@@ -0,0 +1,46 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Render test for chapter 5 "Put it together".
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#include <ray.h>
+#include <sphere.h>
+#include <colour.h>
+#include <canvas.h>
+#include <transformation.h>
+
+int main()
+{
+    int x, y;
+    Canvas c = Canvas(100, 100);
+
+    Sphere s = Sphere();
+    Colour red = Colour(1, 0, 0);
+
+    Point cameraOrigin = Point(0, 0, -5);
+    double wallDistance = 10;
+    double wallSize = 7;
+    double pixelSize = wallSize / c.width;
+    for(y = 0; y < c.height; y++)
+    {
+        double worldY = (wallSize / 2) - pixelSize * y;
+        for(x = 0; x < c.width; x++)
+        {
+            double worldX = (wallSize / 2) - pixelSize * x;
+            Point position = Point(worldX, worldY, wallDistance);
+            Ray r = Ray(cameraOrigin, (position - cameraOrigin).normalise());
+            Intersect xs = s.intersect(r);
+
+            if (!xs.hit().nothing())
+            {
+                c.put_pixel(x, y, red);
+            }
+        }
+    }
+
+    c.SaveAsPNG("ch5_test.png");
+    return 0;
+}

tests/intersect_test.cpp

@@ -0,0 +1,132 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Intersect unit tests
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#include <intersect.h>
+#include <sphere.h>
+#include <gtest/gtest.h>
+
+
+TEST(IntersectTest, Creating_an_intersect_and_do_some_check)
+{
+    Intersect i;
+
+    ASSERT_EQ(i.count(), 0);
+
+    i.add(Intersection(1.0, nullptr));
+    i.add(Intersection(4.2, nullptr));
+
+    ASSERT_EQ(i.count(), 2);
+
+    ASSERT_EQ(i[0].t, 1.0);
+    ASSERT_EQ(i[1].t, 4.2);
+}
+
+TEST(IntersectTest, An_intersection_encapsulate_t_and_object)
+{
+    Sphere s = Sphere();
+    Intersection i = Intersection(3.5, &s);
+
+    ASSERT_EQ(i.t, 3.5);
+    ASSERT_EQ(i.object, (Object *)&s);
+}
+
+TEST(IntersectTest, Aggregating_intersections)
+{
+    Sphere s = Sphere();
+    Intersection i1 = Intersection(1, &s);
+    Intersection i2 = Intersection(2, &s);
+
+    Intersect xs = Intersect();
+    xs.add(i1);
+    xs.add(i2);
+
+    ASSERT_EQ(xs.count(), 2);
+    ASSERT_EQ(xs[0].t, 1);
+    ASSERT_EQ(xs[1].t, 2);
+}
+
+TEST(IntersectTest, Intersect_sets_the_object_on_the_intersection)
+{
+    Ray r = Ray(Point(0, 0, -5), Vector(0, 0, 1));
+    Sphere s = Sphere();
+    Intersect xs = s.intersect(r);
+
+    ASSERT_EQ(xs.count(), 2);
+    ASSERT_EQ(xs[0].object, (Object *)&s);
+    ASSERT_EQ(xs[1].object, (Object *)&s);
+}
+
+TEST(IntersectTest, The_hit_when_all_intersection_have_positive_t)
+{
+    Sphere s = Sphere();
+    Intersect xs = Intersect();
+
+    Intersection i1 = Intersection(1, &s);
+    Intersection i2 = Intersection(2, &s);
+
+    xs.add(i1);
+    xs.add(i2);
+
+    Intersection i = xs.hit();
+
+    ASSERT_EQ(i, i1);
+}
+
+TEST(IntersectTest, The_hit_when_some_intersection_have_negative_t)
+{
+    Sphere s = Sphere();
+    Intersect xs = Intersect();
+
+    Intersection i1 = Intersection(-1, &s);
+    Intersection i2 = Intersection(2, &s);
+    Intersection i3 = Intersection(12, &s);
+
+    xs.add(i1);
+    xs.add(i2);
+    xs.add(i3);
+
+    Intersection i = xs.hit();
+
+    ASSERT_EQ(i, i2);
+}
+
+TEST(IntersectTest, The_hit_when_all_intersection_have_negative_t)
+{
+    Sphere s = Sphere();
+    Intersect xs = Intersect();
+
+    Intersection i1 = Intersection(-2, &s);
+    Intersection i2 = Intersection(-1, &s);
+
+    xs.add(i1);
+    xs.add(i2);
+
+    Intersection i = xs.hit();
+
+    ASSERT_TRUE(i.nothing());
+}
+
+TEST(IntersectTest, The_hit_is_always_the_lowest_nonnegative_intersection)
+{
+    Sphere s = Sphere();
+    Intersect xs = Intersect();
+
+    Intersection i1 = Intersection(5, &s);
+    Intersection i2 = Intersection(7, &s);
+    Intersection i3 = Intersection(-3, &s);
+    Intersection i4 = Intersection(2, &s);
+
+    xs.add(i1);
+    xs.add(i2);
+    xs.add(i3);
+    xs.add(i4);
+
+    Intersection i = xs.hit();
+
+    ASSERT_EQ(i, i4);
+}

tests/matrix_test.cpp

@@ -7,7 +7,7 @@
  *
  */
 #include <matrix.h>
-#include <tuples.h>
+#include <tuple.h>
 #include <math.h>
 #include <gtest/gtest.h>
 

tests/ray_test.cpp

@@ -0,0 +1,64 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Ray unit tests
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#include <ray.h>
+#include <transformation.h>
+#include <object.h>
+#include <gtest/gtest.h>
+
+
+TEST(RayTest, Creating_a_ray_and_querying_it)
+{
+    Point origin = Point(1, 2, 3);
+    Vector direction = Vector(4, 5, 6);
+
+    Ray r = Ray(origin, direction);
+
+    ASSERT_EQ(r.origin, origin);
+    ASSERT_EQ(r.direction, direction);
+}
+
+TEST(RayTest, Computing_a_point_from_a_distance)
+{
+    Ray r = Ray(Point(2, 3, 4), Vector(1, 0, 0));
+
+    ASSERT_EQ(r.position(0), Point(2, 3, 4));
+    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));
+}

tests/sphere_test.cpp

@@ -0,0 +1,108 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Sphere unit tests
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#include <ray.h>
+#include <sphere.h>
+#include <transformation.h>
+#include <gtest/gtest.h>
+
+
+TEST(SphereTest, A_ray_intersect_a_sphere_at_two_points)
+{
+    Ray r = Ray(Point(0, 0, -5), Vector(0, 0, 1));
+    Sphere s = Sphere();
+    Intersect xs = s.intersect(r);
+
+    ASSERT_EQ(xs.count(), 2);
+    ASSERT_EQ(xs[0].t, 4.0);
+    ASSERT_EQ(xs[1].t, 6.0);
+}
+
+TEST(SphereTest, A_ray_intersect_a_sphere_at_a_tangent)
+{
+    Ray r = Ray(Point(0, 1, -5), Vector(0, 0, 1));
+    Sphere s = Sphere();
+    Intersect xs = s.intersect(r);
+
+    ASSERT_EQ(xs.count(), 2);
+    ASSERT_EQ(xs[0].t, 5.0);
+    ASSERT_EQ(xs[1].t, 5.0);
+}
+
+TEST(SphereTest, A_ray_miss_a_sphere)
+{
+    Ray r = Ray(Point(0, 2, -5), Vector(0, 0, 1));
+    Sphere s = Sphere();
+    Intersect xs = s.intersect(r);
+
+    ASSERT_EQ(xs.count(), 0);
+}
+
+TEST(SphereTest, A_ray_originate_inside_a_sphere)
+{
+    Ray r = Ray(Point(0, 0, 0), Vector(0, 0, 1));
+    Sphere s = Sphere();
+    Intersect xs = s.intersect(r);
+
+    ASSERT_EQ(xs.count(), 2);
+    ASSERT_EQ(xs[0].t, -1.0);
+    ASSERT_EQ(xs[1].t, 1.0);
+}
+
+TEST(SphereTest, A_sphere_is_behind_a_ray)
+{
+    Ray r = Ray(Point(0, 0, 5), Vector(0, 0, 1));
+    Sphere s = Sphere();
+    Intersect xs = s.intersect(r);
+
+    ASSERT_EQ(xs.count(), 2);
+    ASSERT_EQ(xs[0].t, -6.0);
+    ASSERT_EQ(xs[1].t, -4.0);
+}
+
+TEST(SphereTest, A_sphere_default_transformation)
+{
+    Sphere s = Sphere();
+    ASSERT_EQ(s.transformMatrix, Matrix4().identity());
+}
+
+TEST(SphereTest, Changing_a_sphere_transformation)
+{
+    Sphere s = Sphere();
+    Matrix t = translation(2, 3, 4);
+
+    s.setTransform(t);
+
+    ASSERT_EQ(s.transformMatrix, t);
+}
+
+TEST(SphereTest, Intersecting_a_scaled_sphere_with_a_ray)
+{
+    Ray r = Ray(Point(0, 0, -5), Vector(0, 0, 1));
+    Sphere s = Sphere();
+
+    s.setTransform(scaling(2, 2, 2));
+
+    Intersect xs = s.intersect(r);
+
+    ASSERT_EQ(xs.count(), 2);
+    ASSERT_EQ(xs[0].t, 3.0);
+    ASSERT_EQ(xs[1].t, 7.0);
+}
+
+TEST(SphereTest, Intersecting_a_translated_sphere_with_a_ray)
+{
+    Ray r = Ray(Point(0, 0, -5), Vector(0, 0, 1));
+    Sphere s = Sphere();
+
+    s.setTransform(translation(5, 0, 0));
+
+    Intersect xs = s.intersect(r);
+
+    ASSERT_EQ(xs.count(), 0);
+}

tests/transformation_test.cpp

@@ -0,0 +1,191 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Transformations unit tests
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+#include <transformation.h>
+#include <tuple.h>
+#include <math.h>
+#include <gtest/gtest.h>
+
+TEST(TransformationTest, Multiplying_by_a_translation_matrix)
+{
+   Matrix transform = translation(5, -3, 2);
+   Point p = Point(-3, 4, 5);
+   
+   ASSERT_EQ(transform * p, Point(2, 1, 7));
+}
+
+TEST(TransformationTest, Multiplying_by_the_inverse_of_a_translation_matrix)
+{
+   Matrix transform = translation(5, -3, 2);
+   Matrix inv = transform.inverse();
+   
+   Point p = Point(-3, 4, 5);
+   
+   ASSERT_EQ(inv * p, Point(-8, 7, 3));
+}
+
+TEST(TransformationTest, Translation_does_not_affect_vectors)
+{
+   Matrix transform = translation(5, -3, 2);
+   
+   Vector v = Vector(-3, 4, 5);
+   
+   ASSERT_EQ(transform * v, Vector(-3, 4, 5));
+}
+
+TEST(TransformationTest, A_scaling_matrix_applied_to_a_point)
+{
+   Matrix transform = scaling(2, 3, 4);
+   
+   Point p = Point(-4, 6, 8);
+   
+   ASSERT_EQ(transform * p, Point(-8, 18, 32));
+}
+
+TEST(TransformationTest, A_scaling_matrix_applied_to_a_vector)
+{
+   Matrix transform = scaling(2, 3, 4);
+   
+   Vector v = Vector(-4, 6, 8);
+   
+   ASSERT_EQ(transform * v, Vector(-8, 18, 32));
+}
+
+TEST(TransformationTest, Multiplaying_by_the_inverse_of_a_scaling_matrix)
+{
+   Matrix transform = scaling(2, 3, 4);
+   Matrix inv = transform.inverse();
+   
+   Vector v = Vector(-4, 6, 8);
+   
+   ASSERT_EQ(inv * v, Vector(-2, 2, 2));
+}
+
+TEST(TransformationTest, Reflexion_is_scaling_by_a_negative_value)
+{
+   Matrix transform = scaling(-1, 1, 1);
+   
+   Point p = Point(2, 3, 4);
+   
+   ASSERT_EQ(transform * p, Point(-2, 3, 4));
+}
+
+TEST(TransformationTest, Rotating_a_point_around_the_X_axis)
+{
+   Point p = Point(0, 1, 0);
+   Matrix half_quarter = rotation_x(M_PI / 4.);
+   Matrix full_quarter = rotation_x(M_PI / 2.);
+   
+   ASSERT_EQ(half_quarter * p, Point(0, sqrt(2)/2, sqrt(2)/2));
+   ASSERT_EQ(full_quarter * p, Point(0, 0, 1));
+}
+
+TEST(TransformationTest, The_inverse_of_an_x_rotation_rotates_in_the_opposite_direction)
+{
+   Point p = Point(0, 1, 0);
+   Matrix half_quarter = rotation_x(M_PI / 4.);
+   Matrix inv = half_quarter.inverse();
+   
+   ASSERT_EQ(inv * p, Point(0, sqrt(2)/2, -sqrt(2)/2));
+}
+
+TEST(TransformationTest, Rotating_a_point_around_the_Y_axis)
+{
+   Point p = Point(0, 0, 1);
+   Matrix half_quarter = rotation_y(M_PI / 4.);
+   Matrix full_quarter = rotation_y(M_PI / 2.);
+   
+   ASSERT_EQ(half_quarter * p, Point(sqrt(2)/2, 0, sqrt(2)/2));
+   ASSERT_EQ(full_quarter * p, Point(1, 0, 0));
+}
+
+TEST(TransformationTest, Rotating_a_point_around_the_Z_axis)
+{
+   Point p = Point(0, 1, 0);
+   Matrix half_quarter = rotation_z(M_PI / 4.);
+   Matrix full_quarter = rotation_z(M_PI / 2.);
+   
+   ASSERT_EQ(half_quarter * p, Point(-sqrt(2)/2, sqrt(2)/2, 0));
+   ASSERT_EQ(full_quarter * p, Point(-1, 0, 0));
+}
+
+TEST(TransformationTest, A_shearing_transformation_moves_x_in_proportion_to_y)
+{
+    Matrix transform = shearing(1, 0, 0, 0, 0, 0);
+    Point p = Point(2, 3, 4);
+
+    ASSERT_EQ(transform * p, Point(5, 3, 4));
+}
+
+TEST(TransformationTest, A_shearing_transformation_moves_x_in_proportion_to_z)
+{
+    Matrix transform = shearing(0, 1, 0, 0, 0, 0);
+    Point p = Point(2, 3, 4);
+
+    ASSERT_EQ(transform * p, Point(6, 3, 4));
+}
+
+TEST(TransformationTest, A_shearing_transformation_moves_y_in_proportion_to_x)
+{
+    Matrix transform = shearing(0, 0, 1, 0, 0, 0);
+    Point p = Point(2, 3, 4);
+
+    ASSERT_EQ(transform * p, Point(2, 5, 4));
+}
+
+TEST(TransformationTest, A_shearing_transformation_moves_y_in_proportion_to_z)
+{
+    Matrix transform = shearing(0,  0, 0, 1, 0, 0);
+    Point p = Point(2, 3, 4);
+
+    ASSERT_EQ(transform * p, Point(2, 7, 4));
+}
+
+TEST(TransformationTest, A_shearing_transformation_moves_z_in_proportion_to_x)
+{
+    Matrix transform = shearing(0, 0, 0, 0, 1, 0);
+    Point p = Point(2, 3, 4);
+
+    ASSERT_EQ(transform * p, Point(2, 3, 6));
+}
+
+TEST(TransformationTest, A_shearing_transformation_moves_z_in_proportion_to_y)
+{
+    Matrix transform = shearing(0, 0, 0, 0, 0, 1);
+    Point p = Point(2, 3, 4);
+
+    ASSERT_EQ(transform * p, Point(2, 3, 7));
+}
+
+TEST(TransformationTest, Individual_trnasformations_are_applied_in_sequence)
+{
+    Point p = Point(1, 0, 1);
+    Matrix A = rotation_x(M_PI / 2.);
+    Matrix B = scaling(5, 5, 5);
+    Matrix C = translation(10, 5, 7);
+
+    Tuple p2 = A * p;
+    ASSERT_EQ(p2, Point(1, -1, 0));
+
+    Tuple p3 = B * p2;
+    ASSERT_EQ(p3, Point(5, -5, 0));
+
+    Tuple p4 = C * p3;
+    ASSERT_EQ(p4, Point(15, 0, 7));
+}
+
+TEST(TransformationTest, Chained_transformation_must_be_applied_in_reverse_order)
+{
+    Point p = Point(1, 0, 1);
+    Matrix A = rotation_x(M_PI / 2.);
+    Matrix B = scaling(5, 5, 5);
+    Matrix C = translation(10, 5, 7);
+
+    Matrix T = C * B * A;
+    ASSERT_EQ(T * p, Point(15, 0, 7));
+}

tests/tuple_test.cpp

@@ -6,7 +6,7 @@
  *  Copyright (c) 2020 986-Studio.
  *
  */
-#include <tuples.h>
+#include <tuple.h>
 #include <math.h>
 #include <gtest/gtest.h>