text: /*************************************************************************/
  /*  spatial_velocity_tracker.h                                           */
  /*************************************************************************/
  /*                       This file is part of:                           */
  /*                           GODOT ENGINE                                */
  /*                      https://godotengine.org                          */
  /*************************************************************************/
  /* Copyright (c) 2007-2018 Juan Linietsky, Ariel Manzur.                 */
  /* Copyright (c) 2014-2018 Godot Engine contributors (cf. AUTHORS.md)    */
  /*                                                                       */
  /* Permission is hereby granted, free of charge, to any person obtaining */
  /* a copy of this software and associated documentation files (the       */
  /* "Software"), to deal in the Software without restriction, including   */
  /* without limitation the rights to use, copy, modify, merge, publish,   */
  /* distribute, sublicense, and/or sell copies of the Software, and to    */
  /* permit persons to whom the Software is furnished to do so, subject to */
  /* the following conditions:                                             */
  /*                                                                       */
  /* The above copyright notice and this permission notice shall be        */
  /* included in all copies or substantial portions of the Software.       */
  /*                                                                       */
  /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
  /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
  /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
  /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
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  /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
  /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
  /*************************************************************************/
  
  #ifndef SPATIAL_VELOCITY_TRACKER_H
  #define SPATIAL_VELOCITY_TRACKER_H
  
  #include "scene/3d/spatial.h"
  
  class SpatialVelocityTracker : public Reference {
  	GDCLASS(SpatialVelocityTracker, Reference)
  
  	struct PositionHistory {
  		uint64_t frame;
  		Vector3 position;
  	};
  
  	bool physics_step;
  	Vector<PositionHistory> position_history;
  	int position_history_len;
  
  protected:
  	static void _bind_methods();
  
  public:
  	void reset(const Vector3 &p_new_pos);
  	void set_track_physics_step(bool p_track_physics_step);
  	bool is_tracking_physics_step() const;
  	void update_position(const Vector3 &p_position);
  	Vector3 get_tracked_linear_velocity() const;
  
  	SpatialVelocityTracker();
  };
  
  #endif // SPATIAL_VELOCITY_TRACKER_H
  