[FEAT] Finish the Chapter 05 with the render of a sphere shadow.

Doc.md

@@ -0,0 +1,6 @@
+## Le Livre est ici:
+
+https://lire.amazon.fr/?asin=B07Q84TQ91&ref_=kwl_kr_iv_rec_1
+
+
+https://github.com/sraaphorst/raytracer-cpp/blob/b57794ce9f4ed80d782711adb9131f3e3097d4b0/CMakeLists.txt

README.md

@@ -1,10 +1,22 @@
+# Ray Tracer Challenge in C++
 
+**Current status:** In progress
 
 [![Build Status](https://drone.nadal-fr.com/api/badges/raytracing/raytracing_challenge/status.svg)](https://drone.nadal-fr.com/raytracing/raytracing_challenge)
 
-## Le Livre est ici:
+## Presentation
 
-https://lire.amazon.fr/?asin=B07Q84TQ91&ref_=kwl_kr_iv_rec_1
+Implementation of the book **The Ray Tracer Challenge** by Jamis Buck.
+
+This Git repository contains my C++ implementation of the Ray Tracer Challenge.
+
+![book](data/the_raytracing_challenge.png)
 
 
-https://github.com/sraaphorst/raytracer-cpp/blob/b57794ce9f4ed80d782711adb9131f3e3097d4b0/CMakeLists.txt
+### Useful links:
+
+Ray Tracing: The Next Week book: http://raytracerchallenge.com/
+
+# Output
+### Chapter 05
+![chapter_05](data/chapter_05.png)

apps/CMakeLists.txt

@@ -5,7 +5,6 @@ project(main)
 set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
-add_executable(raytracer main.cpp)
-# We need hello.h and the hello library
-target_link_libraries(raytracer
-    PRIVATE raytracing)
+add_executable(chapter_05 chapter_05.cpp)
+
+target_link_libraries(chapter_05 PRIVATE raytracing)

apps/chapter_05.cpp

@@ -0,0 +1,91 @@
+/*!
+ * chapter_05.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: 14/02/2024
+ *
+ */
+
+// 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);
+    Color the_color = Color(1, 0, 0); // Red
+    Sphere the_shape;
+    Tuple the_ray_origin = Tuple::Point(0, 0, -5);
+
+    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())
+            {
+                the_canvas.write_pixel(x, y, the_color);
+            }
+        }
+    }
+
+    the_canvas.save_to_file("chapter05.ppm");
+
+    return 0;
+}
+
+/* ------------------------------------------------------------------------- */
+
+int main(void)
+{
+    printf("Chapter 05 example.\n");
+    return shadow_sphere(kImageSize, kWallSize, kWallZ);
+}

apps/main.cpp

@@ -1,40 +0,0 @@
-/*!
- * main.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: 30/01/2024
- *
- */
-
-// 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 <raytracing.h>
-#include <cstdio>
-
-/* ------------------------------------------------------------------------- */
-
-int main(void)
-{
-    printf("Later Here we will have main function\n");
-
-    return 0;
-}

raytracing/include/raytracing.h

@@ -25,6 +25,7 @@
 
 #pragma once
 
+#include "canvas.h"
 #include "color.h"
 #include "common.h"
 #include "intersection.h"

raytracing/src/canvas.cpp

@@ -28,6 +28,9 @@
 
 /* ------------------------------------------------------------------------- */
 
+#include <fcntl.h>
+#include <unistd.h>
+
 #include "canvas.h"
 #include "common.h"
 
@@ -91,7 +94,7 @@ std::string Canvas::to_ppm(void)
 
     // Header
     the_result = "P3\n";
-    the_result += std::to_string(m_width) + " " + std::to_string(m_height) + "\n";
+    the_result += std::to_string(m_width) + " " + std::to_string(m_height) + '\n';
     the_result += "255\n";
 
     for (int j = 0; j < m_height; j++)
@@ -122,7 +125,7 @@ bool Canvas::add_color_component(std::string &a_str_value, uint32_t &a_col_numbe
 
     if ((the_color_value.length() + 1 + a_col_number) >= 70)
     {
-        a_str_value += "\n";
+        a_str_value += '\n';
         a_col_number = 0;
     }
 
@@ -137,3 +140,28 @@ bool Canvas::add_color_component(std::string &a_str_value, uint32_t &a_col_numbe
 
     return true;
 }
+
+/* ------------------------------------------------------------------------- */
+
+bool Canvas::save_to_file(const std::string &a_filename)
+{
+    std::string the_data;
+
+    int the_fd = open(a_filename.c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0644);
+    if (the_fd == -1)
+    {
+        return false;
+    }
+
+    the_data = to_ppm();
+
+    size_t the_written = write(the_fd, the_data.data(), the_data.size());
+    if (the_written != the_data.size())
+    {
+        close(the_fd);
+        return false;
+    }
+
+    close(the_fd);
+    return true;
+}

raytracing/src/canvas.h

@@ -52,6 +52,7 @@ namespace Raytracer
         bool write_pixel(uint16_t a_pos_x, uint16_t a_pos_y, const Color &a_color);
 
         std::string to_ppm(void);
+        bool save_to_file(const std::string &a_filename);
 
     private:
         bool add_color_component(std::string &a_str_value, uint32_t &a_col_number, uint8_t a_color);

raytracing/src/intersection.cpp

@@ -43,7 +43,7 @@ Intersection::Intersection(void) : m_is_nothing(true), m_distance_t(0.0), m_obje
 /* ------------------------------------------------------------------------- */
 
 Intersection::Intersection(double a_distance_t, const Object &an_object) :
-    m_is_nothing(true),
+    m_is_nothing(false),
     m_distance_t(a_distance_t),
     m_object(an_object)
 {
@@ -152,3 +152,10 @@ bool Intersection::is_nothing(void)
 {
     return m_is_nothing;
 }
+
+/* ------------------------------------------------------------------------- */
+
+bool Intersection::is_defined(void)
+{
+    return !m_is_nothing;
+}

raytracing/src/intersection.h

@@ -57,6 +57,7 @@ namespace Raytracer
         double distance_t(void) const;
         const Object &object(void) const;
         bool is_nothing(void);
+        bool is_defined(void);
 
     private:
         bool m_is_nothing;

tests/05_rays.cpp

@@ -459,6 +459,10 @@ SCENARIO("The hit is always the lowest nonnegative intersection", "[features/int
                                 {
                                     REQUIRE(i == i4);
                                 }
+                                AND_THEN("i is defined")
+                                {
+                                    REQUIRE(i.is_defined());
+                                }
                             }
                         }
                     }