Shape is now an abstract class and can't be instanciated.

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

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);
+}