IActionObject.hpp

/******************************************************************************
 
  nomlib - C++11 cross-platform game engine
 
Copyright (c) 2013, 2014 Jeffrey Carpenter <i8degrees@gmail.com>
All rights reserved.
 
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
 
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   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.
 
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******************************************************************************/
#ifndef NOMLIB_ACTIONS_IACTION_OBJECT_HPP
#define NOMLIB_ACTIONS_IACTION_OBJECT_HPP
 
#include <functional>
#include <vector>
 
#include "nomlib/config.hpp"
#include "nomlib/system/Timer.hpp"
 
namespace nom {

class IActionObject
{
  public:
    typedef IActionObject self_type;

    typedef
    std::function<real32(real32, real32, real32, real32)>  timing_curve_func;

    enum FrameState
    {
      COMPLETED,
      PLAYING,
    };
 
    IActionObject();
 
    virtual ~IActionObject();

    const std::string& name() const;

    real32 duration() const;

    real32 speed() const;

    const IActionObject::timing_curve_func& timing_curve() const;

    void set_name(const std::string& action_id);

    virtual void set_speed(real32 speed);

    virtual void set_timing_curve(const IActionObject::timing_curve_func& mode);

    virtual std::unique_ptr<IActionObject> clone() const = 0;

    virtual IActionObject::FrameState next_frame(real32 delta_time) = 0;

    virtual IActionObject::FrameState prev_frame(real32 delta_time) = 0;

    virtual void pause(real32 delta_time) = 0;

    virtual void resume(real32 delta_time) = 0;

    virtual void rewind(real32 delta_time) = 0;

    virtual void release() = 0;
 
  protected:
    IActionObject::FrameState status() const;

    void set_duration(real32 seconds);

    void set_status(FrameState state);

    real32 elapsed_frames_ = 0.0f;

    Timer timer_;
 
  private:
    FrameState status_ = FrameState::PLAYING;
    std::string name_;
    real32 duration_ = 0.0f;
    real32 speed_ = 1.0f;
    timing_curve_func timing_curve_ = nullptr;
};

typedef std::vector<std::shared_ptr<IActionObject>> action_list;

template<typename ObjectType, typename... ObjectArgs>
std::shared_ptr<ObjectType> create_action(ObjectArgs&&... args)
{
  // IMPORTANT: We risk object slicing if we use std::make_shared here! The
  // problem occurs when the end-user tries to return the created action
  // pointer by value.
  return( std::shared_ptr<ObjectType>(
          new ObjectType( std::forward<ObjectArgs>(args) ... ) ) );
}

template<typename ObjectType>
std::shared_ptr<ObjectType>
create_action(const action_list& actions)
{
  // IMPORTANT: We risk object slicing if we use std::make_shared here! The
  // problem occurs when the end-user tries to return the created action
  // pointer by value.
  return( std::shared_ptr<ObjectType>( new ObjectType(actions) ) );
}
 
} // namespace nom
 
#endif // include guard defined