圆的原理就不说,大家去百度,google一下,应该就知道了
我这里就是提供如果用程序获取画圆的轨迹路线上的点
struct YuanInfo { Point point; //圆上的点坐标 float fDu; //改点在圆上的切线角度 };
YuanInfo getPointByDu(Point point, float fR, float fAuToDu)
{
YunInfo info;
int r = fR;
int a = point.x;
int b = point.y + fR;
float fDushu = fAuToDu*M_PI/180.0;
float k = -1.0/std::tan(fDushu);
float fDu = std::atan(k)*180.0f/M_PI;
if(fAuToDu > 0 && fAuToDu <180.0f)
{
fDu = 180.0f + fDu;
}
float x = (a + r*std::cos(fDushu));
float y = (b + r*std::sin(fDushu));
info.point = Point(x,y);
info.fDu = fDu*M_PI/180.0f;
return info;
}cocos2d-x 之 如何画圆的轨迹路线,布布扣,bubuko.com
原文:http://blog.csdn.net/tian2kong/article/details/21229073