[FEAT] add dot and cross

raytracing/src/tuple.cpp

@@ -70,6 +70,18 @@ bool Tuple::operator==(const Tuple &an_other) const
 
 /* ------------------------------------------------------------------------- */
 
+const Tuple &Tuple::operator=(const Tuple &an_other)
+{
+    m_x = an_other.m_x;
+    m_y = an_other.m_y;
+    m_z = an_other.m_z;
+    m_w = an_other.m_w;
+
+    return *this;
+}
+
+/* ------------------------------------------------------------------------- */
+
 const Tuple &Tuple::operator+(const Tuple &an_other)
 {
     m_x += an_other.m_x;
@@ -206,6 +218,27 @@ Tuple Tuple::normalize(void)
 
 /* ------------------------------------------------------------------------- */
 
+double Tuple::dot(const Tuple &a_tuple)
+{
+    return m_x * a_tuple.m_x +
+           m_y * a_tuple.m_y +
+           m_z * a_tuple.m_z +
+           m_w * a_tuple.m_w;
+}
+
+/* ------------------------------------------------------------------------- */
+
+Tuple Tuple::cross(const Tuple &a_tuple)
+{
+    return Vector(
+        m_y * a_tuple.m_z - m_z * a_tuple.m_y,
+        m_z * a_tuple.m_x - m_x * a_tuple.m_z,
+        m_x * a_tuple.m_y - m_y * a_tuple.m_x
+    );
+}
+
+/* ------------------------------------------------------------------------- */
+
 bool Tuple::double_equal(double a, double b) const
 {
     if ((std::abs((a) - (b)) < kEpsilon))

raytracing/src/tuple.h

@@ -43,6 +43,7 @@ namespace Raytracer
         Tuple(double an_x, double an_y, double an_z, double an_w);
 
         bool operator==(const Tuple &an_other) const;
+        const Tuple &operator=(const Tuple &an_other);
         const Tuple &operator+(const Tuple &an_other);
         const Tuple &operator-(const Tuple &an_other);
         const Tuple &operator-(void);
@@ -64,14 +65,16 @@ namespace Raytracer
         double magnitude(void) const;
         Tuple normalize(void);
 
-    protected:
+        double dot(const Tuple &a_tuple);
+        Tuple cross(const Tuple &a_tuple);
+
+    private:
+        bool double_equal(double a, double b) const;
+
         double m_x;
         double m_y;
         double m_z;
         double m_w;
-
-    private:
-        bool double_equal(double a, double b) const;
     };
 
 };

tests/chapitre01_tuples.cpp

@@ -64,6 +64,18 @@ TEST_CASE("a tuple with w=0 is a vector", "[Tuple]")
 
 /* ------------------------------------------------------------------------- */
 
+TEST_CASE("Tuple could be copy", "[Tuple]")
+{
+  Tuple p = Tuple::Point(4, -4, 3);
+  Tuple n;
+
+  n = p;
+
+  REQUIRE(n == p);
+}
+
+/* ------------------------------------------------------------------------- */
+
 TEST_CASE("Point() creates tuples with w=1", "[Tuple][Point]")
 {
   Tuple p = Tuple::Point(4, -4, 3);
@@ -231,3 +243,24 @@ TEST_CASE("The magnitude of a normalized vector", "[Tuple][Normalize]")
 
   REQUIRE(norm.magnitude() == 1);
 }
+
+/* ------------------------------------------------------------------------- */
+
+TEST_CASE("The dot product of two tuples", "[Tuple][Dot]")
+{
+  Tuple a = Tuple::Vector(1, 2, 3);
+  Tuple b = Tuple::Vector(2, 3, 4);
+
+  REQUIRE(a.dot(b) == 20);
+}
+
+/* ------------------------------------------------------------------------- */
+
+TEST_CASE("The cross product of two vector", "[Tuple][Cross]")
+{
+  Tuple a = Tuple::Vector(1, 2, 3);
+  Tuple b = Tuple::Vector(2, 3, 4);
+
+  REQUIRE(a.cross(b) == Tuple::Vector(-1, 2, -1));
+  REQUIRE(b.cross(a) == Tuple::Vector(1, -2, 1));
+}