[FEAT] Tuple: add operator + and -

src/tuple.cpp

@@ -44,9 +44,9 @@ Tuple::Tuple(float a_x, float a_y, float a_z, float a_w) : m_x(a_x), m_y(a_y), m
 
 /* ------------------------------------------------------------------------- */
 
-bool Tuple::operator==(const Tuple &a_copy) const
+bool Tuple::operator==(const Tuple &an_other) const
 {
-    if (float_equal(m_x, a_copy.m_x) && float_equal(m_y, a_copy.m_y) && float_equal(m_z, a_copy.m_z) && float_equal(m_w, a_copy.m_w))
+    if (float_equal(m_x, an_other.m_x) && float_equal(m_y, an_other.m_y) && float_equal(m_z, an_other.m_z) && float_equal(m_w, an_other.m_w))
     {
         return true;
     }
@@ -56,6 +56,30 @@ bool Tuple::operator==(const Tuple &a_copy) 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;
+}
+
+/* ------------------------------------------------------------------------- */
+
+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;
+}
+
+/* ------------------------------------------------------------------------- */
+
 Tuple Tuple::Point(float an_x, float an_y, float an_z)
 {
     return Tuple(an_x, an_y, an_z, kRaytracerTuplePoint);

src/tuple.h

@@ -40,7 +40,9 @@ namespace Raytracer
     public:
         Tuple(float an_x, float an_y, float an_z, float an_w);
 
-        bool operator==(const Tuple &) const;
+        bool operator==(const Tuple &an_other) const;
+        Tuple &operator+(const Tuple &an_other);
+        Tuple &operator-(const Tuple &an_other);
 
         static Tuple Point(float an_x, float an_y, float an_z);
         static Tuple Vector(float an_x, float an_y, float an_z);

tests/chapitre01_tuples.cpp

@@ -69,7 +69,7 @@ TEST_CASE("Point() creates tuples with w=1", "[Tuple][Point]")
 {
   Tuple p = Tuple::Point(4, -4, 3);
 
-  REQUIRE(p == Tuple(4, -4, 3, kRaytracerTuplePoint));
+  REQUIRE(p == Tuple(4, -4, 3, 1));
 }
 
 /* ------------------------------------------------------------------------- */
@@ -78,5 +78,45 @@ TEST_CASE("Vector() creates tuples with w=0", "[Tuple][Vector]")
 {
   Tuple v = Tuple::Vector(4, -4, 3);
 
-  REQUIRE(v == Tuple(4, -4, 3, kRaytracerTupleVector));
+  REQUIRE(v == Tuple(4, -4, 3, 0));
+}
+
+/* ------------------------------------------------------------------------- */
+
+TEST_CASE("Adding two tuples", "[Tuple][Operations]")
+{
+  Tuple a1(3, -2, 5, 1);
+  Tuple a2(-2, 3, 1, 0);
+
+  REQUIRE((a1 + a2) == Tuple(1, 1, 6, 1));
+}
+
+/* ------------------------------------------------------------------------- */
+
+TEST_CASE("Subtracting two points", "[Tuple][Operations]")
+{
+  Tuple p1 = Tuple::Point(3, 2, 1);
+  Tuple p2 = Tuple::Point(5, 6, 7);
+
+  REQUIRE((p1 - p2) == Tuple::Vector(-2, -4, -6));
+}
+
+/* ------------------------------------------------------------------------- */
+
+TEST_CASE("Subtracting a vector from a point", "[Tuple][Operations]")
+{
+  Tuple p = Tuple::Point(3, 2, 1);
+  Tuple v= Tuple::Vector(5, 6, 7);
+
+  REQUIRE((p - v) == Tuple::Point(-2, -4, -6));
+}
+
+/* ------------------------------------------------------------------------- */
+
+TEST_CASE("Subtracting two vectors", "[Tuple][Operations]")
+{
+  Tuple v1 = Tuple::Vector(3, 2, 1);
+  Tuple v2 = Tuple::Vector(5, 6, 7);
+
+  REQUIRE((v1 - v2) == Tuple::Vector(-2, -4, -6));
 }