【Cocos2d-x】新手自学(八)自定义路径,随心所欲移动精灵(2.0.1版本)

class HelloWorld : public cocos2d::CCLayer
{
public:
virtual bool init();

// there's no 'id' in cpp, so we recommand to return the exactly class pointer
static cocos2d::CCScene* scene();
void draw();

// implement the "static node()" method manually
LAYER_CREATE_FUNC(HelloWorld);
private:
cocos2d::CCPointArray *m_pArray;
};

bool HelloWorld::init()
{
bool bRet = false;
do
{
CC_BREAK_IF(! CCLayer::init());
CCSize s = CCDirector::sharedDirector()->getWinSize();

//以下是蓝色方块
CCSprite* blue = CCSprite::create("blue.png");
CC_BREAK_IF(!blue);
blue->setPosition(ccp(50,50));
this->addChild(blue);

//创建一个点数组..
CCPointArray * array = CCPointArray::create(20);

//添加控制点...依次添加就可以
array->addControlPoint(ccp(0, 0));
array->addControlPoint(ccp(s.width/2-30, 0));
array->addControlPoint(ccp(s.width/2-30, s.height-80));
array->addControlPoint(ccp(0, s.height-80));
array->addControlPoint(ccp(0, 0));

//create(参数1：持续时间, 参数二:点数组,参数3:张力,可以理解为惯性,数值越大,惯性越大)
CCCardinalSplineBy *action = CCCardinalSplineBy::create(6, array, 7);
CCActionInterval *reverse = action->reverse();//创建一个相反动作

//创建一个序列动作..
CCFiniteTimeAction *seq = CCSequence::create(action, reverse, NULL);
blue->runAction(seq);

//以下是红色方块
CCSprite *red = CCSprite::create("red.png");
CC_BREAK_IF(!red);
red->setPosition(ccp(s.width/2, 50));
this->addChild(red);

CCCardinalSplineBy *action2 = CCCardinalSplineBy::create(3,array,1);
CCActionInterval *reverse2 = action2->reverse();

CCFiniteTimeAction *seq2 = CCSequence::create(action2,reverse2,NULL);
red->runAction(seq2);

m_pArray = array;//把点数组中的内容赋值给成员变量,用于绘制路径
array->retain();//使内容保持

bRet = true;
} while (0);

return bRet;
}

//重载绘制函数,用于绘制移动路径
void HelloWorld::draw()
{
// move to 50,50 since the "by" path will start at 50,50
kmGLPushMatrix();//这个的意思不是很懂,猜测是打开绘制
kmGLTranslatef(50, 50, 0);//设置位置,（x，y，z）
ccDrawCardinalSpline(m_pArray, 7, 100);//根据点与张力来画线（参数1：点数组，参数2：张力值，参数三：精度,指的是线段的精细程度,越大分段越多,越精细）

kmGLPopMatrix();//停止绘制

CCSize s = CCDirector::sharedDirector()->getWinSize();

kmGLPushMatrix();
kmGLTranslatef(s.width/2, 50, 0);
ccDrawCardinalSpline(m_pArray, 1, 100);
kmGLPopMatrix();
}