Java Circle-Circle 碰撞检测

Question

这是圆类:

public class Circle {
    private double radius;

    private double x;
    private double y;
}

如何判断此类(圆圈)中的两个对象是否发生碰撞？

附言可以使用避免开平方的方法吗？

Answer 1

double xDif = x1 - x2;
double yDif = y1 - y2;
double distanceSquared = xDif * xDif + yDif * yDif;
boolean collision = distanceSquared < (radius1 + radius2) * (radius1 + radius2);