CCShake

CCShake.cpp

// Code by Francois Guibert
// Contact: www.frozax.com - http://twitter.com/frozax - www.facebook.com/frozax


#include "CCShake.h"
#include "cocos2d.h"
USING_NS_CC;

// not really useful, but I like clean default constructors
CCShake::CCShake() : m_strength_x(0), m_strength_y(0), m_initial_x(0), m_initial_y(0)
{
}

CCShake* CCShake::create( float d, float strength )
{
    // call other construction method with twice the same strength
    return createWithStrength( d, strength, strength );
}

CCShake* CCShake::createWithStrength(float duration, float strength_x, float strength_y)
{
    CCShake *pRet = new CCShake();
    
    if (pRet && pRet->initWithDuration(duration, strength_x, strength_y))
    {
        pRet->autorelease();
    }
    else
    {
        CC_SAFE_DELETE(pRet);
    }
    
    
    return pRet;
}

bool CCShake::initWithDuration(float duration, float strength_x, float strength_y)
{
    if (CCActionInterval::initWithDuration(duration))
    {
        m_strength_x = strength_x;
        m_strength_y = strength_y;
        return true;
    }
    
    return false;
}

// Helper function. I included it here so that you can compile the whole file
// it returns a random value between min and max included
static float fgRangeRand( float min, float max )
{
    float rnd = ((float)rand()/(float)RAND_MAX);
    return rnd*(max-min)+min;
}

void CCShake::update(float dt)
{
    float randx = fgRangeRand( -m_strength_x, m_strength_x )*dt;
    float randy = fgRangeRand( -m_strength_y, m_strength_y )*dt;
    
    // move the target to a shaked position
    m_pTarget->setPosition( ccpAdd(ccp(m_initial_x, m_initial_y),ccp( randx, randy)));
}

void CCShake::startWithTarget(CCNode *pTarget)
{
    CCActionInterval::startWithTarget( pTarget );
    
    // save the initial position
    m_initial_x = pTarget->getPosition().x;
    m_initial_y = pTarget->getPosition().y;
}

void CCShake::stop(void)
{
    // Action is done, reset clip position
    this->getTarget()->setPosition( ccp( m_initial_x, m_initial_y ) );
    
    CCActionInterval::stop();
}

CCShake.h

#ifndef __SHAKE_H__
#define __SHAKE_H__

#include "CCActionInterval.h"


class CCShake : public cocos2d::CCActionInterval
{
    // Code by Francois Guibert
    // Contact: www.frozax.com - http://twitter.com/frozax - www.facebook.com/frozax
public:
    CCShake();
    
    // Create the action with a time and a strength (same in x and y)
    static CCShake* create(float d, float strength );
    // Create the action with a time and strengths (different in x and y)
    static CCShake* createWithStrength(float d, float strength_x, float strength_y );
    bool initWithDuration(float d, float strength_x, float strength_y );
    
protected:
    
    void startWithTarget(cocos2d::CCNode *pTarget);
    void update(float time);
    void stop(void);
    
    
    // Initial position of the shaked node
    float m_initial_x, m_initial_y;
    // Strength of the action
    float m_strength_x, m_strength_y;
};

#endif //__SHAKE_H__