[WIP] Add ray and sphere basic

tests/05_rays.cpp

@@ -0,0 +1,121 @@
+/*!
+ * 05_rays.cpp
+ *
+ * Copyright (c) 2015-2024, NADAL Jean-Baptiste. All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ *
+ * @Author:  NADAL Jean-Baptiste
+ * @Date: 05/02/2024
+ *
+ */
+
+/*---------------------------------------------------------------------------*/
+
+#include <catch.hpp>
+
+#include "raytracing.h"
+
+using namespace Raytracer;
+
+/* ------------------------------------------------------------------------- */
+
+/* ------------------------------------------------------------------------- */
+
+TEST_CASE("[05][Rays] Creating and querying a ray", "[Rays]")
+{
+    Tuple origin = Tuple::Point(1, 2, 3);
+    Tuple direction = Tuple::Vector(4, 5, 6);
+    Ray r(origin, direction);
+
+    REQUIRE(r.origin() == origin);
+    REQUIRE(r.direction() == direction);
+}
+
+/* ------------------------------------------------------------------------- */
+
+TEST_CASE("[05][Rays] Computing a point from a distance", "[Rays]")
+{
+    Ray r(Tuple::Point(2, 3, 4), Tuple::Vector(1, 0, 0));
+
+    REQUIRE(r.position(0) == Tuple::Point(2, 3, 4));
+    REQUIRE(r.position(1) == Tuple::Point(3, 3, 4));
+    REQUIRE(r.position(-1) == Tuple::Point(1, 3, 4));
+    REQUIRE(r.position(2.5) == Tuple::Point(4.5, 3, 4));
+}
+
+/* ------------------------------------------------------------------------- */
+
+TEST_CASE("[05][Rays] a ray intersects a sphere at two points", "[Rays]")
+{
+    Ray r(Tuple::Point(0, 0, -5), Tuple::Vector(0, 0, 1));
+    Sphere s;
+    auto xs = r.intersect(s);
+
+    REQUIRE(xs.size() == 2);
+    REQUIRE(xs[0] == 4.0);
+    REQUIRE(xs[1] == 6.0);
+}
+
+/* ------------------------------------------------------------------------- */
+
+TEST_CASE("[05][Rays] a ray intersects a sphere at a tangent", "[Rays]")
+{
+    Ray r(Tuple::Point(0, 1, -5), Tuple::Vector(0, 0, 1));
+    Sphere s;
+    auto xs = r.intersect(s);
+
+    REQUIRE(xs.size() == 2);
+    REQUIRE(xs[0] == 5.0);
+    REQUIRE(xs[1] == 5.0);
+}
+
+/* ------------------------------------------------------------------------- */
+
+TEST_CASE("[05][Rays] a ray misses a sphere", "[Rays]")
+{
+    Ray r(Tuple::Point(0, 2, -5), Tuple::Vector(0, 0, 1));
+    Sphere s;
+    auto xs = r.intersect(s);
+
+    REQUIRE(xs.size() == 0);
+}
+
+/* ------------------------------------------------------------------------- */
+
+TEST_CASE("[05][Rays] a originates inside a sphere", "[Rays]")
+{
+    Ray r(Tuple::Point(0, 0, 0), Tuple::Vector(0, 0, 1));
+    Sphere s;
+    auto xs = r.intersect(s);
+
+    REQUIRE(xs.size() == 2);
+    REQUIRE(xs[0] == -1.0);
+    REQUIRE(xs[1] == 1.0);
+}
+
+/* ------------------------------------------------------------------------- */
+
+TEST_CASE("[05][Rays] a sphere is behind a ray", "[Rays]")
+{
+    Ray r(Tuple::Point(0, 0, 5), Tuple::Vector(0, 0, 1));
+    Sphere s;
+    auto xs = r.intersect(s);
+
+    REQUIRE(xs.size() == 2);
+    REQUIRE(xs[0] == -6.0);
+    REQUIRE(xs[1] == -4.0);
+}

tests/CMakeLists.txt

@@ -15,6 +15,7 @@ add_executable(main_test
     02_2_canvas.cpp
     03_matrix.cpp
     04_transformations.cpp
+    05_rays.cpp
 )
 
 include_directories("${CMAKE_SOURCE_DIR}/tests")