圆和矩形是否相交

//圆和矩形是否相交
public static bool IsCircleRectIntersect(Vector2 a, Vector2 b, Vector2 c, float r)
{
    var o = (b - a) * 2; //矩形中心点
    //将矩形中心点作为原点建立坐标系
    a -= o;
    b -= o;
    c -= o;

    //将圆转换到第一象限
    c.x = Mathf.Abs(c.x);
    c.y = Mathf.Abs(c.y);

    //圆心到矩形的最短距离
    var bc = c - b;
    bc.x = Mathf.Max(bc.x, 0);
    bc.y = Mathf.Max(bc.y, 0);

    //最短距离<=r, 则和矩形相交
    return bc.sqrMagnitude <= r * r;
}