也说说CCCardinalSplineBy

惯例先上图。

环境：WIN32 + cocos2d-x2.1.4。

m_pPoints = CCPointArray::create(5);
		m_pPoints->retain();
		// 这里的坐标均为closeNormal为原点进行计算，即以closeNormal为参照点
		m_pPoints->addControlPoint(ccp(0, 0));
		m_pPoints->addControlPoint(ccp(s.width / 2 - 50, 0));
		m_pPoints->addControlPoint(ccp(s.width / 2 - 50, s.height - 100));
		m_pPoints->addControlPoint(ccp(0, s.height - 100));
		m_pPoints->addControlPoint(ccp(0, 0));

		CCSprite* closeNormal = CCSprite::create("CloseNormal.png");
		closeNormal->setPosition(ccp(s.width / 2, 50));
		this->addChild(closeNormal, 1);

		CCCardinalSplineBy* actionBy = CCCardinalSplineBy::create(3.0F, m_pPoints, 1);
		closeNormal->runAction(CCSequence::create(actionBy, actionBy->reverse(), NULL));

void HelloWorld::draw() {
	kmGLPushMatrix();
	// 设置颜色
	ccDrawColor4B(255, 0, 0, 255);
	// 设置矩形框坐标点
	kmGLTranslatef(240, 50, 0);
	ccDrawCardinalSpline(m_pPoints, 1, 100);
	kmGLPopMatrix();
}

总结：

CCCardinalSplineBy::create(float duration, cocos2d::CCPointArray *points, float tension)；中duration是时间间隔，points是控制点列表，tension是松紧程度。tension==1时，样条线是分段直线。tension<1向外松弛弯曲，tension>1向内缩紧弯曲。By动作是以当前坐标为新坐标原点。