From 568e3f4c559281edc6a4d2af9284d1cac42b2990 Mon Sep 17 00:00:00 2001
From: Eryn Wells <eryn@erynwells.me>
Date: Tue, 10 Sep 2013 16:28:32 -0700
Subject: [PATCH] Update scene module for C++

---
 src/scene.cc | 126 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/scene.h  |  46 ++++++++++---------
 2 files changed, 151 insertions(+), 21 deletions(-)
 create mode 100644 src/scene.cc

diff --git a/src/scene.cc b/src/scene.cc
new file mode 100644
index 0000000..910599b
--- /dev/null
+++ b/src/scene.cc
@@ -0,0 +1,126 @@
+/* scene.c
+ *
+ * Definition of Scene-related functions.
+ *
+ * Eryn Wells <eryn@erynwells.me>
+ */
+
+#include <cmath>
+#include "basics.h"
+#include "object.h"
+#include "scene.h"
+
+
+Scene::Scene()
+    : height(640), width(480),
+      pixels(NULL)
+{ }
+
+
+Scene::~Scene()
+{
+    if (pixels != NULL) {
+        delete[] pixels;
+        _is_rendered = false;
+    }
+}
+
+
+bool
+Scene::is_rendered()
+    const
+{
+    return _is_rendered;
+}
+
+
+/*
+ * scene_load --
+ *
+ * Load scene objects into this Scene from the given file.
+ */
+void
+Scene::read(FILE *file)
+{ }
+
+
+/*
+ * scene_save --
+ *
+ * Write a rendered scene to the given file.
+ */
+void
+Scene::write(FILE *file)
+{ }
+
+
+/*
+ * Scene::render --
+ *
+ * Render the given Scene.
+ */
+void
+Scene::render()
+{
+    pixels = new Color[width * height];
+    if (pixels == NULL) {
+        // TODO: Print an error.
+        return;
+    }
+
+    Ray primary_ray;
+    Vector3 o, d;
+    for (int y = 0; y < height; y++) {
+        for (int x = 0; x < width; x++) {
+            // Assemble a ray and trace it.
+            o = Vector3(x, y, -1000);
+            d = Vector3(0, 0, 1);
+            d.normalize();
+            primary_ray = Ray(o, d);
+            pixels[y * width + x] = trace_ray(primary_ray, 0);
+        }
+    }
+
+    _is_rendered = true;
+}
+
+
+void
+Scene::add_shape(Shape *shape)
+{
+    shapes.push_back(shape);
+}
+
+
+Color
+Scene::trace_ray(const Ray &ray, const int depth)
+{
+    Color out_color = Color::Black;
+
+    // Find intersections of this ray with objects in the scene.
+    Shape *intersected_shape = NULL;
+    float *t = NULL;
+    float nearest_t = INFINITY;
+    int nints;
+    for (Shape *s : shapes) {
+        nints = s->does_intersect(ray, &t);
+        if (nints > 0) {
+            for (int i = 0; i < nints; i++) {
+                if (t[i] < nearest_t) {
+                    intersected_shape = s;
+                    nearest_t = t[i];
+                }
+            }
+            delete[] t;
+        }
+    }
+
+    // If there was no intersection, return black.
+    if (intersected_shape == NULL) {
+        return out_color;
+    }
+
+    // TODO: Lighting.
+
+    return Color::Red;
+}
diff --git a/src/scene.h b/src/scene.h
index 158a8ec..0d59fd4 100644
--- a/src/scene.h
+++ b/src/scene.h
@@ -1,6 +1,9 @@
 /* scene.h
  *
- * Definition of Scene type and related functions.
+ * Definition of the Scene class.
+ *
+ * Scenes are the top level object in charles. Scenes contain objects, lights, a camera,
+ * etc. and can be rendered to pixel data and written to a file.
  *
  * Eryn Wells <eryn@erynwells.me>
  */
@@ -8,32 +11,33 @@
 #ifndef __SCENE_H__
 #define __SCENE_H__
 
-#include <stdio.h>
+#include <list>
 
-#include "camera.h"
-#include "object.h"
+class Shape;
 
 
-typedef struct _ObjectList ObjectList;
-
-
-typedef struct _Scene
+class Scene
 {
-    int height, width;      /* Pixel dimensions. */
-    Camera *camera;
+public:
+    Scene();
+    ~Scene();
 
-    ObjectList *objects;
+    bool is_rendered() const;
 
-    int is_rendered;
+    void read(FILE *f);
+    void write(FILE *f);
+    void render();
+
+    void add_shape(Shape *obj);
+
+private:
+    Color trace_ray(const Ray &ray, const int depth);
+
+    int height, width;
+    std::list<Shape *> shapes;
+
+    bool _is_rendered;
     Color *pixels;
-} Scene;
-
-
-Scene *scene_init();
-void scene_destroy(Scene *scene);
-void scene_load(Scene *scene, FILE *scene_file);
-void scene_render(Scene *scene);
-void scene_add_object(Scene *scene, Object *object);
-
+};
 
 #endif