GameObject.h

///
/// The base game object.
///

#ifndef __GAME_OBJECT_H__
#define __GAME_OBJECT_H__

#include "Box.h"                ///< Objects have a bounding box.
#include "Event.h"              ///< Objects can handle events.
#include "Object.h"             ///< Base object class.
#include "Position.h"           ///< Objects need a location.
#include "Sprite.h"             ///< Objects (often) have sprites.

enum Solidness {
  HARD,                         ///< Objects cause collision and impede
  SOFT,                         ///< Objects cause collision, don't impede
  SPECTRAL                      ///< Objects don't cause collision
};

class GameObject : public Object {

 private:
  int altitude;                 ///< -MAX to MAX supported (lower drawn first).
  Solidness solidness;          ///< Solidness state of object.

 protected:
  float x_velocity;             ///< Horizontal speed in spaces per game step.
  float x_velocity_countdown;   ///< Countdown to horizontal movement.
  float y_velocity;             ///< Veritical speed in spaces per game step.
  float y_velocity_countdown;   ///< Countdown to vertical movement.
  
 public:
  GameObject(int on_level = -1);
  virtual ~GameObject();

  bool isSolid();               ///< True if hard or soft, else False

  /// Set object solidness, with checks for consistency.  
  /// Return 0 if ok, else -1.
  int setSolidness(Solidness new_solid);

  /// Return object altitude.
  Solidness getSolidness();

  // Set visibility of object.  Objects not visible are not drawn.
  // Return 0 if ok, else -1.
  int setVisibility(bool visible);

  // Set persistence of object. Persistent objects are active across all
  // levels.  Return 0 if ok, else -1.
  int setPersistence(bool persistent);
  
  /// Set object altitude, with checks for consistency.  
  /// Return 0 if ok, else -1.
  int setAltitude(int new_altitude);

  /// Return object altitude.
  int getAltitude();

  void setXVelocity(float new_x_velocity);
  float getXVelocity();
  void setYVelocity(float new_y_velocity);
  float getYVelocity();

  /// Perform 1 step of velocity in horizontal direction.
  /// Return horizontal distance moved this step.
  int getXVelocityStep();

  /// Perform 1 step of velocity in vertical direction.
  /// Return vertical distance moved this step.
  int getYVelocityStep();
};
 
#endif // __GAME_OBJECT_H__