CUPinchInput.h

//
//  CUPinchInput.h
//  Cornell University Game Library (CUGL)
//
//  This class provides basic support for pinch gestures.  SDL blurs pinches,
//  rotations, and pans all into a single input event.  Therefore, you need to
//  set the sensitivity threshold to distinguish them.
//
//  This class is a singleton and should never be allocated directly.  It
//  should only be accessed via the Input dispatcher.
//
//  CUGL MIT License:
//      This software is provided 'as-is', without any express or implied
//      warranty.  In no event will the authors be held liable for any damages
//      arising from the use of this software.
//
//      Permission is granted to anyone to use this software for any purpose,
//      including commercial applications, and to alter it and redistribute it
//      freely, subject to the following restrictions:
//
//      1. The origin of this software must not be misrepresented; you must not
//      claim that you wrote the original software. If you use this software
//      in a product, an acknowledgment in the product documentation would be
//      appreciated but is not required.
//
//      2. Altered source versions must be plainly marked as such, and must not
//      be misrepresented as being the original software.
//
//      3. This notice may not be removed or altered from any source distribution.
//
//  Author: Walker White
//  Version: 12/20/16
//
#ifndef __CU_PINCH_INPUT_H__
#define __CU_PINCH_INPUT_H__
#include <cugl/input/CUInput.h>
#include <cugl/math/CUVec2.h>
 
namespace cugl {
 
#pragma mark -
#pragma mark PinchEvent
 
class PinchEvent {
public:
    Timestamp timestamp;
    Vec2 position;
    int fingers;
    float pinch;
    float delta;
    
    PinchEvent() : fingers(0), pinch(0.0f), delta(0.0f) {}
    
    PinchEvent(const Vec2& point, int down, float distance, const Timestamp& stamp) {
        position = point; fingers = down; pinch = distance; delta = pinch; timestamp = stamp;
    }
};
 
 
#pragma mark -
#pragma mark PinchInput
 
class PinchInput : public InputDevice {
public:
#pragma mark Listener
    
    typedef std::function<void(const PinchEvent& event, bool focus)> Listener;
 
protected:
    bool  _screen;
    bool  _active;
    float _threshold;
    PinchEvent _event;
    
    std::unordered_map<Uint32, Listener> _beginListeners;
    std::unordered_map<Uint32, Listener> _finishListeners;
    std::unordered_map<Uint32, Listener> _changeListeners;
 
 
#pragma mark Constructor
 
    PinchInput();
    
    virtual ~PinchInput() {}
    
    virtual void dispose() override;
   
#pragma mark Device Attributes
public:
    bool isTouchScreen() const { return _screen; }
 
    void setTouchScreen(bool flag);
    
    float getThreshold() const { return _threshold; }
    
    void setThreshold(float threshold);
    
    
#pragma mark Data Polling
 
    bool isActive() const { return _active; }
    
    float getDelta() const { return _active ? _event.delta : 0.0f; }
    
    float getPinch() const { return _active ? _event.pinch : 0.0f; }
    
    int getFingers() const { return _active ? _event.fingers : 0; }
    
    const Vec2& getPosition() const { return _active ? _event.position : Vec2::ZERO; }
    
    
#pragma mark Listeners
 
    virtual bool requestFocus(Uint32 key) override;
    
    bool isListener(Uint32 key) const;
    
    const Listener getBeginListener(Uint32 key) const;
    
    const Listener getEndListener(Uint32 key) const;
    
    const Listener getChangeListener(Uint32 key) const;
    
    bool addBeginListener(Uint32 key, Listener listener);
    
    bool addEndListener(Uint32 key, Listener listener);
    
    bool addChangeListener(Uint32 key, Listener listener);
    
    bool removeBeginListener(Uint32 key);
    
    bool removeEndListener(Uint32 key);
    
    bool removeChangeListener(Uint32 key);
 
    
protected:
#pragma mark Input Device
 
    virtual void clearState() override;
    
    virtual bool updateState(const SDL_Event& event, const Timestamp& stamp) override;
 
    virtual void queryEvents(std::vector<Uint32>& eventset) override;
    
    // Apparently friends are not inherited
    friend class Input;
};
    
}
#endif /* __CU_PINCH_INPUT_H__ */