Refactor storing of ray-casted distances.

The ray-casting is done when camera_update() is called, and distances
are stored in the Camera struct.

camera.h

@@ -3,14 +3,24 @@
 
 #include <SFML/Graphics.hpp>
 
+typedef struct
+{
+	float direction;
+	float distance;
+} CameraRay;
+
 typedef struct
 {
 	sf::Vector2f pos;
 	float direction;
 	unsigned int resolution;
 	float fov;
+
+	CameraRay* rays;
 } Camera;
 
+int camera_init(Camera* camera, sf::Vector2f pos, float direction, unsigned int resolution, float fov);
 void camera_update(Camera* camera, float t);
+void camera_destroy(Camera* camera);
 
 #endif