cocos3 图片按照椭圆运动
#pragma once #include "cocos2d.h" USING_NS_CC; typedef struct _EclipseConfig { //中心点坐标 CCPoint centerPosition; //椭圆a长,三角斜边 float aLength; //椭圆c长,三角底边 float cLength; } EclipseConfig; class Eclipse:public ActionInterval { public: bool initWithDuration(float duration, const EclipseConfig& deltaPosition); virtual void update(float time); virtual Eclipse* clone() const override; virtual Eclipse* reverse(void) const override; public: static Eclipse *actionWithDuration(float t, const EclipseConfig& c); protected: EclipseConfig m_sConfig; Point m_startPosition; Point s_startPosition; };
#include "Eclipse.h" static inline float tuoyuanXat( float a, float bx, float c,float t )//返回X坐标 { //参数方程 return -a*cos(2*3.1415926*t)+a; } static inline float tuoyuanYat( float a, float by, float c, float t )//返回Y坐标 { float b = sqrt(powf(a, 2) - powf(c, 2));//因为之前定义的参数是焦距c而不是短半轴b,所以需要计算出b //参数方程 return b*sin(2*3.1415926*t); } // //TuoyuanBy // Eclipse* Eclipse::actionWithDuration(float t, const EclipseConfig& c)//利用之前定义的椭圆的三个参数初始化椭圆 { Eclipse *pTuoyuanBy = new Eclipse(); pTuoyuanBy->initWithDuration(t, c); pTuoyuanBy->autorelease(); return pTuoyuanBy; } bool Eclipse::initWithDuration(float t, const EclipseConfig& c) { if (CCActionInterval::initWithDuration(t)) { m_sConfig = c; return true; } return false; } void Eclipse::update(float time) { if (_target) { CCPoint s_startPosition =m_sConfig.centerPosition;//中心点坐标 float a = m_sConfig.aLength; float bx = m_sConfig.centerPosition.x; float by = m_sConfig.centerPosition.y; float c = m_sConfig.cLength; float x = tuoyuanXat(a, bx, c, time);//调用之前的坐标计算函数来计算出坐标值 float y = tuoyuanYat(a, by, c, time); _target->setPosition(ccpAdd(s_startPosition, ccp(x-a, y)));//由于我们画计算出的椭圆你做值是以原点为中心的,所以需要加上我们设定的中心点坐标 } } Eclipse* Eclipse::clone() const { auto a = new Eclipse(); a->initWithDuration(_duration, m_sConfig); a->autorelease(); return a; } Eclipse* Eclipse::reverse() const { auto a = new Eclipse(); a->initWithDuration(_duration, m_sConfig); a->autorelease(); return a; }