extract orbital camera into separate file

include/camera.hpp

@@ -0,0 +1,41 @@
+#ifndef __CAMERA_HPP_
+#define __CAMERA_HPP_
+
+#include <raylib.h>
+#include <raymath.h>
+
+#include "config.hpp"
+
+class OrbitCamera3D {
+  friend class Renderer;
+
+private:
+  Camera camera;
+  Vector3 target;
+  float distance;
+  float angle_x;
+  float angle_y;
+  Vector2 last_mouse;
+  bool dragging;
+  bool panning;
+  bool target_lock;
+
+public:
+  OrbitCamera3D()
+      : camera({0}), target(Vector3Zero()), distance(CAMERA_DISTANCE),
+        angle_x(0.0), angle_y(0.0), last_mouse(Vector2Zero()), dragging(false),
+        panning(false), target_lock(true) {
+    camera.position = Vector3(0, 0, -1.0 * distance);
+    camera.target = target;
+    camera.up = Vector3(0, 1.0, 0);
+    camera.fovy = CAMERA_FOV;
+    camera.projection = CAMERA_PERSPECTIVE;
+  }
+
+  ~OrbitCamera3D() {}
+
+public:
+  auto Update(const Vector3 &current_target) -> void;
+};
+
+#endif