[FEAT] Add all test intersections

raytracing/src/intersection.cpp

@@ -29,6 +29,7 @@
 /* ------------------------------------------------------------------------- */
 
 #include "intersection.h"
+#include "common.h"
 
 using namespace Raytracer;
 
@@ -54,6 +55,14 @@ Intersection::Intersection(Intersection &an_intersection) :
 
 /* ------------------------------------------------------------------------- */
 
+Intersection::Intersection(const Intersection &an_intersection) :
+    m_distance_t(an_intersection.m_distance_t),
+    m_object(an_intersection.m_object)
+{
+}
+
+/* ------------------------------------------------------------------------- */
+
 const Intersection &Intersection::operator=(const Intersection &an_intersection)
 {
     if (this == &an_intersection)
@@ -69,7 +78,56 @@ const Intersection &Intersection::operator=(const Intersection &an_intersection)
 
 /* ------------------------------------------------------------------------- */
 
-double Intersection::distance_t(void)
+bool Intersection::operator==(const Intersection &an_other) const
+{
+    return (double_equal(m_distance_t, an_other.m_distance_t) && (m_object == an_other.m_object));
+}
+
+/* ------------------------------------------------------------------------- */
+
+bool Intersection::operator<(const Intersection &an_other) const
+{
+    return m_distance_t < an_other.m_distance_t;
+}
+
+/* ------------------------------------------------------------------------- */
+
+bool Intersection::operator>(const Intersection &an_other) const
+{
+    return m_distance_t > an_other.m_distance_t;
+}
+
+/* ------------------------------------------------------------------------- */
+
+bool Intersection::operator>(double a_distance) const
+{
+    return m_distance_t > a_distance;
+}
+
+/* ------------------------------------------------------------------------- */
+
+bool Intersection::operator>=(double a_distance) const
+{
+    return m_distance_t >= a_distance;
+}
+
+/* ------------------------------------------------------------------------- */
+
+bool Intersection::operator<(double a_distance) const
+{
+    return m_distance_t < a_distance;
+}
+
+/* ------------------------------------------------------------------------- */
+
+bool Intersection::operator<=(double a_distance) const
+{
+    return m_distance_t <= a_distance;
+}
+
+/* ------------------------------------------------------------------------- */
+
+double Intersection::distance_t(void) const
 {
     return m_distance_t;
 }

raytracing/src/intersection.h

@@ -40,10 +40,19 @@ namespace Raytracer
         Intersection(void);
         Intersection(double a_distance_t, Object an_object);
         Intersection(Intersection &an_intersection);
+        Intersection(const Intersection &an_intersection);
 
         const Intersection &operator=(const Intersection &an_intersection);
+        bool operator==(const Intersection &an_intersection) const;
+        bool operator<(const Intersection &an_other) const;
+        bool operator>(const Intersection &an_other) const;
 
-        double distance_t(void);
+        bool operator>(double a_distance) const;
+        bool operator>=(double a_distance) const;
+        bool operator<(double a_distance) const;
+        bool operator<=(double a_distance) const;
+
+        double distance_t(void) const;
         Object &object(void);
 
     private:

raytracing/src/intersections.cpp

@@ -34,42 +34,31 @@ using namespace Raytracer;
 
 /* ------------------------------------------------------------------------- */
 
-Intersections::Intersections(void) : m_count(0)
+Intersections::Intersections(void)
 {
 }
 
 /* ------------------------------------------------------------------------- */
 
-Intersections::Intersections(const Intersection &an_intersection1, const Intersection &an_intersection2)
+Intersections::Intersections(const std::initializer_list<Intersection> a_list)
 {
-    m_array[0] = an_intersection1;
-    m_array[1] = an_intersection2;
-    m_count    = 2;
-}
 
-/* ------------------------------------------------------------------------- */
-
-Intersections::Intersections(Intersection &an_intersection1, Intersection &an_intersection2)
-{
-    m_array[0] = an_intersection1;
-    m_array[1] = an_intersection2;
-    m_count    = 2;
+    m_data.reserve(a_list.size());
+    m_data.assign(a_list.begin(), a_list.end());
 }
 
 /* ------------------------------------------------------------------------- */
 
 Intersections::Intersections(Intersections &an_other)
 {
-    m_array[0] = an_other.m_array[0];
-    m_array[1] = an_other.m_array[1];
-    m_count    = an_other.m_count;
+    std::copy(an_other.m_data.begin(), an_other.m_data.end(), m_data.begin());
 }
 
 /* ------------------------------------------------------------------------- */
 
 Intersection &Intersections::operator[](uint8_t an_index)
 {
-    return m_array[an_index];
+    return m_data[an_index];
 }
 
 /* ------------------------------------------------------------------------- */
@@ -81,21 +70,16 @@ const Intersections &Intersections::operator=(const Intersections &an_other)
         return *this;
     }
 
-    m_array[0] = an_other.m_array[0];
-    m_array[1] = an_other.m_array[1];
-    m_count    = an_other.m_count;
+    std::copy(an_other.m_data.begin(), an_other.m_data.end(), m_data.begin());
 
     return *this;
 }
 
 /* ------------------------------------------------------------------------- */
 
-bool Intersections::set(Intersection an_intersection1, Intersection an_intersection2)
+bool Intersections::add(const Intersection &an_intersection)
 {
-    m_array[0] = an_intersection1;
-    m_array[1] = an_intersection2;
-    m_count    = 2;
-
+    m_data.push_back(an_intersection);
     return true;
 }
 
@@ -103,5 +87,28 @@ bool Intersections::set(Intersection an_intersection1, Intersection an_intersect
 
 uint8_t Intersections::count(void) const
 {
-    return m_count;
+    return m_data.size();
+}
+
+/* ------------------------------------------------------------------------- */
+
+Intersection Intersections::hit(void)
+{
+    if (m_data.size() == 0)
+    {
+        return {};
+    }
+    auto the_it = std::min_element(m_data.begin(), m_data.end(),
+                                   [](const Intersection &a, const Intersection &b)
+                                   {
+                                       // Use < comparison for strict positivity check
+                                       return a.distance_t() < b.distance_t() && a.distance_t() > 0;
+                                   });
+
+    if (the_it == m_data.end() || the_it->distance_t() <= 0)
+    {
+        return {};
+    }
+
+    return *the_it;
 }

raytracing/src/intersections.h

@@ -29,6 +29,8 @@
 /* ------------------------------------------------------------------------- */
 
 #include <cstdint>
+#include <initializer_list>
+#include <vector>
 
 #include "intersection.h"
 
@@ -40,20 +42,20 @@ namespace Raytracer
     {
     public:
         Intersections(void);
-        Intersections(const Intersection &an_intersection1, const Intersection &an_intersection2);
-        Intersections(Intersection &an_intersection1, Intersection &an_intersection2);
+        Intersections(const std::initializer_list<Intersection> a_list);
         Intersections(Intersections &an_intersections);
 
         Intersection &operator[](uint8_t an_index);
         const Intersections &operator=(const Intersections &an_other);
 
-        bool set(Intersection an_intersection1, Intersection an_intersection2);
+        bool add(const Intersection &an_intersection);
 
         uint8_t count(void) const;
 
+        Intersection hit(void);
+
     private:
-        uint8_t m_count;
-        Intersection m_array[2];
+        std::vector<Intersection> m_data;
     };
 }; // namespace Raytracer
 

raytracing/src/object.cpp

@@ -34,11 +34,13 @@ using namespace Raytracer;
 
 /* ------------------------------------------------------------------------- */
 
+#define kNothing 0
+
 uint32_t Object::s_current_index = 0;
 
 /* ------------------------------------------------------------------------- */
 
-Object::Object(void) : m_id(s_current_index++)
+Object::Object(void) : m_id(kNothing)
 {
 }
 
@@ -50,6 +52,12 @@ Object::Object(Object &a_copy) : m_id(a_copy.m_id)
 
 /* ------------------------------------------------------------------------- */
 
+Object::Object(const Object &a_copy) : m_id(a_copy.m_id)
+{
+}
+
+/* ------------------------------------------------------------------------- */
+
 const Object &Object::operator=(const Object &an_other)
 {
     if (this == &an_other)
@@ -68,3 +76,17 @@ bool Object::operator==(const Object &an_object) const
 {
     return m_id == an_object.m_id;
 }
+
+/* ------------------------------------------------------------------------- */
+
+bool Object::is_nothing(void)
+{
+    return (m_id == kNothing);
+}
+
+/* ------------------------------------------------------------------------- */
+
+void Object::inc_id(void)
+{
+    m_id = s_current_index++;
+}

raytracing/src/object.h

@@ -39,10 +39,16 @@ namespace Raytracer
     public:
         Object(void);
         Object(Object &a_copy);
+        Object(const Object &a_copy);
 
         const Object &operator=(const Object &an_other);
         bool operator==(const Object &an_object) const;
 
+        bool is_nothing(void);
+
+    protected:
+        void inc_id(void);
+
     private:
         uint32_t m_id;
         static uint32_t s_current_index;

raytracing/src/ray.cpp

@@ -78,10 +78,8 @@ Intersections Ray::intersect(Sphere a_sphere)
 
     if (discriminant >= 0)
     {
-        the_intersections.set(Intersection((-the_b - the_sqrt) / (2 * the_a), a_sphere),
-                              Intersection((-the_b + the_sqrt) / (2 * the_a), a_sphere)
-
-        );
+        the_intersections.add(Intersection((-the_b - the_sqrt) / (2 * the_a), a_sphere));
+        the_intersections.add(Intersection((-the_b + the_sqrt) / (2 * the_a), a_sphere));
     }
 
     return the_intersections;

raytracing/src/sphere.cpp

@@ -37,4 +37,5 @@ using namespace Raytracer;
 
 Sphere::Sphere(void)
 {
+    inc_id();
 }

tests/05_rays.cpp

@@ -150,7 +150,7 @@ TEST_CASE("[05][Rays] Aggregating intersections", "[Intersections]")
     Sphere s;
     Intersection i1(1, s);
     Intersection i2(2, s);
-    Intersections xs = Intersections(i1, i2);
+    Intersections xs = Intersections({i1, i2});
 
     REQUIRE(xs.count() == 2);
     REQUIRE(xs[0].distance_t() == 1);
@@ -169,3 +169,61 @@ TEST_CASE("[05][Rays] Intersect set the object on the intersection", "[Intersect
     REQUIRE(xs[0].object() == s);
     REQUIRE(xs[1].object() == s);
 }
+
+/* ------------------------------------------------------------------------- */
+
+TEST_CASE("[05][Rays] The hit, when all intersections have positive t", "[Intersections]")
+{
+    Sphere s;
+    Intersection i1(1, s);
+    Intersection i2(2, s);
+    Intersections xs = Intersections({i2, i1});
+
+    Intersection i = xs.hit();
+
+    REQUIRE(i == i1);
+}
+
+/* ------------------------------------------------------------------------- */
+
+TEST_CASE("[05][Rays] The hit, when some intersections have negative t", "[Intersections]")
+{
+    Sphere s;
+    Intersection i1(-1, s);
+    Intersection i2(1, s);
+    Intersections xs = Intersections({i2, i1});
+
+    Intersection i = xs.hit();
+
+    REQUIRE(i == i2);
+}
+
+/* ------------------------------------------------------------------------- */
+
+TEST_CASE("[05][Rays] The hit, when all intersections have negative t", "[Intersections]")
+{
+    Sphere s;
+    Intersection i1(-2, s);
+    Intersection i2(-1, s);
+    Intersections xs = Intersections({i1, i2});
+
+    Intersection i = xs.hit();
+
+    REQUIRE(i.object().is_nothing());
+}
+
+/* ------------------------------------------------------------------------- */
+
+TEST_CASE("[05][Rays] The hit is always the lowest nonnegative intersection", "[Intersections]")
+{
+    Sphere s;
+    Intersection i1(5, s);
+    Intersection i2(7, s);
+    Intersection i3(-3, s);
+    Intersection i4(2, s);
+    Intersections xs = Intersections({i1, i2, i3, i4});
+
+    Intersection i = xs.hit();
+
+    REQUIRE(i == i4);
+}