[FEAT] Finish the Chapter 06

apps/CMakeLists.txt

@@ -6,5 +6,7 @@ set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 add_executable(chapter_05 chapter_05.cpp)
-
 target_link_libraries(chapter_05 PRIVATE raytracing gcov)
+
+add_executable(chapter_06 chapter_06.cpp)
+target_link_libraries(chapter_06 PRIVATE raytracing gcov)

apps/chapter_06.cpp

@@ -0,0 +1,97 @@
+/*!
+ * chapter_06.cpp
+ *
+ * Copyright (c) 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: 20/02/2024
+ *
+ */
+
+// This is an independent project of an individual developer. Dear PVS-Studio, please check it.
+// PVS-Studio Static Code Analyzer for C, C++, C#, and Java: http://www.viva64.com
+
+#include <cstdio>
+
+#include <raytracing.h>
+
+/* ------------------------------------------------------------------------- */
+
+#define kImageSize 100
+#define kWallSize  7.0
+#define kWallZ     10
+
+using namespace Raytracer;
+
+/* ------------------------------------------------------------------------- */
+
+int shadow_sphere(uint8_t a_canvas_pixels, double a_wall_size, uint8_t a_wall_z)
+{
+    Canvas the_canvas(a_canvas_pixels, a_canvas_pixels);
+    Sphere the_shape;
+    Tuple the_ray_origin = Tuple::Point(0, 0, -5);
+    PointLight the_light = PointLight(Tuple::Point(-10, 10, -10), Color(1, 1, 1));
+
+    the_shape.material().set_color(Color(1, 0.2, 1));
+
+    double the_pixel_size = a_wall_size / a_canvas_pixels;
+    double the_half       = a_wall_size / 2;
+    double the_world_x, the_world_y;
+
+    // For each row of pixels in the canvas
+    for (int y = 0; y < a_canvas_pixels - 1; y++)
+    {
+        // Compute the world y coordinate (top = +half, bottom = -half)
+        the_world_y = the_half - the_pixel_size * y;
+
+        // For each pixel in the row
+        for (int x = 0; x < a_canvas_pixels; x++)
+        {
+            // Compute the world x coordinate (left = -half, right = half)
+            the_world_x = -the_half + the_pixel_size * x;
+
+            // Describe the point on the wall that the ray will target
+            Tuple the_position = Tuple::Point(the_world_x, the_world_y, a_wall_z);
+            the_position -= the_ray_origin;
+            Ray the_ray(the_ray_origin, the_position.normalize());
+
+            auto the_xs       = the_shape.intersect(the_ray);
+            auto the_intersec = the_xs.hit();
+            if (the_intersec.is_defined())
+            {
+                Tuple the_point  = the_ray.position(the_intersec.distance_t());
+                Tuple the_normal = the_intersec.object().normal_at(the_point);
+                Tuple the_eye    = -the_ray.direction();
+                Color the_color  = the_intersec.object().material().lighting(the_light, the_point, the_eye, the_normal);
+                the_canvas.write_pixel(x, y, the_color);
+            }
+        }
+    }
+
+    the_canvas.save_to_file("chapter06.ppm");
+
+    return 0;
+}
+
+/* ------------------------------------------------------------------------- */
+
+int main(void)
+{
+    printf("Chapter 06 example.\n");
+    return shadow_sphere(kImageSize, kWallSize, kWallZ);
+}