From 764afab8acb1ac86654e3def4db63599ede4817e Mon Sep 17 00:00:00 2001
From: Eryn Wells <eryn@erynwells.me>
Date: Mon, 16 Sep 2013 16:34:48 -0700
Subject: [PATCH] Camera stuff -- empty implementations of compute_primary_ray

---
 src/SConscript |  1 +
 src/camera.c   | 38 --------------------------------------
 src/camera.cc  | 39 +++++++++++++++++++++++++++++++++++++++
 src/camera.h   | 43 ++++++++++++++++++++++++++++---------------
 4 files changed, 68 insertions(+), 53 deletions(-)
 delete mode 100644 src/camera.c
 create mode 100644 src/camera.cc

diff --git a/src/SConscript b/src/SConscript
index 0305912..adc0480 100644
--- a/src/SConscript
+++ b/src/SConscript
@@ -6,6 +6,7 @@ Import('env')
 
 files = Split("""
     basics.cc
+    camera.cc
     light.cc
     material.cc
     object.cc
diff --git a/src/camera.c b/src/camera.c
deleted file mode 100644
index 2a454ef..0000000
--- a/src/camera.c
+++ /dev/null
@@ -1,38 +0,0 @@
-/* camera.c
- *
- * Camera definitions.
- *
- * Eryn Wells <eryn@erynwells.me>
- */
-
-#include <stdlib.h>
-#include "camera.h"
-
-
-Camera *
-camera_init()
-{
-    Camera *new_camera = malloc(sizeof(Camera));
-    if (new_camera == NULL) {
-        return NULL;
-    }
-
-    // Set some useful defaults.
-    new_camera->projection = CameraProjectionOrthographic;
-    new_camera->location = vector_init(0, 0, 0);
-    // The default image plane is a rectangle from (-1, 1) to (1, -1).
-    new_camera->image_plane = rect_init(-1, 1, 2, 2);
-
-    return new_camera;
-}
-
-
-void
-camera_destroy(Camera *camera)
-{
-    if (camera == NULL) {
-        return;
-    }
-
-    free(camera);
-}
diff --git a/src/camera.cc b/src/camera.cc
new file mode 100644
index 0000000..52873b0
--- /dev/null
+++ b/src/camera.cc
@@ -0,0 +1,39 @@
+/* camera.h
+ *
+ * The Camera is the eye into the scene. It defines several parameters and a single compute_primary_ray method
+ * that generates rays with which the ray tracer draws the scene.
+ *
+ * Eryn Wells <eryn@erynwells.me>
+ */
+
+#include "camera.h"
+
+
+#pragma mark - Generic Camera
+
+Camera::Camera()
+    : height(Vector3::Y),
+      width(4.0 / 3.0 * Vector3::X),
+      direction(Vector3::Z)
+{ }
+
+
+Camera::~Camera()
+{ }
+
+#pragma mark - Orthographic Camera
+
+/*
+ * OrthographicCamera::compute_primary_ray --
+ *
+ * Compute a primary ray given an (x,y) coordinate pair. The orthographic camera projects rays parallel to the viewing
+ * direction through the (x,y) coordinate given. Thus, the size of the orthographic camera should be set to the size of
+ * the view into the scene.
+ */
+Ray
+OrthographicCamera::compute_primary_ray(const int &x,
+                                        const int &y)
+    const
+{
+    return 0;
+}
diff --git a/src/camera.h b/src/camera.h
index 0fd6f32..82ec091 100644
--- a/src/camera.h
+++ b/src/camera.h
@@ -1,31 +1,44 @@
 /* camera.h
  *
- * Camera type and related functions.
+ * The Camera is the eye into the scene. It defines several parameters and a single compute_primary_ray method
+ * that generates rays with which the ray tracer draws the scene.
  *
  * Eryn Wells <eryn@erynwells.me>
  */
 
-#ifndef __CAMERA_H
-#define __CAMERA_H
+#ifndef __CAMERA_H__
+#define __CAMERA_H__
 
 #include "basics.h"
+#include "object.h"
 
 
-typedef enum {
-    CameraProjectionOrthographic = 1,
-} CameraProjection;
-
-
-typedef struct _Camera
+class Camera
+    : public Object
 {
-    CameraProjection projection;
-    Vector3 location;
-    Rect image_plane;
-} Camera;
+public:
+    Camera();
+    ~Camera();
+
+    virtual Ray compute_primary_ray(const int &x, const int &y) const = 0;
+
+private:
+    // Size of the image plane.
+    Vector3 height, width;
+
+    // Direction. A unit vector defining where the camera is pointed.
+    Vector3 direction;
+
+    // Horizontal viewing angle.
+    float angle;
+};
 
 
-Camera *camera_init();
-void camera_destroy(Camera *camera);
+class OrthographicCamera
+{
+public:
+    Ray compute_primary_ray(const int &x, const int &y) const;
+};
 
 
 #endif