java 圆和多边形是否重叠
时间: 2024-06-12 18:07:48 浏览: 8
判断圆和多边形是否重叠可以采用以下方法:
1. 判断圆心是否在多边形内部。可以使用射线法或者奇偶性判定法。
2. 判断圆是否与多边形的边相交。可以使用向量叉积法。
3. 如果圆心不在多边形内部,也没有与多边形的边相交,那么圆和多边形不重叠。
以下是使用射线法判断圆和多边形是否重叠的示例代码:
```java
public boolean isOverlap(Circle circle, Polygon polygon) {
Point center = circle.getCenter();
int n = polygon.getPoints().size();
List<Point> points = polygon.getPoints();
boolean inside = false;
for (int i = 0, j = n - 1; i < n; j = i++) {
Point pi = points.get(i);
Point pj = points.get(j);
if (((pi.getY() <= center.getY() && center.getY() < pj.getY())
|| (pj.getY() <= center.getY() && center.getY() < pi.getY()))
&& (center.getX() < (pj.getX() - pi.getX()) * (center.getY() - pi.getY())
/ (pj.getY() - pi.getY()) + pi.getX())) {
inside = !inside;
}
}
if (inside) {
return true;
}
double r = circle.getRadius();
for (int i = 0, j = n - 1; i < n; j = i++) {
Point pi = points.get(i);
Point pj = points.get(j);
if (distanceToSegment(center, pi, pj) < r) {
return true;
}
}
return false;
}
private double distanceToSegment(Point p, Point s1, Point s2) {
double x = p.getX();
double y = p.getY();
double x1 = s1.getX();
double y1 = s1.getY();
double x2 = s2.getX();
double y2 = s2.getY();
double cross = (x2 - x1) * (x - x1) + (y2 - y1) * (y - y1);
if (cross <= 0) {
return Math.sqrt((x - x1) * (x - x1) + (y - y1) * (y - y1));
}
double d2 = (x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1);
if (cross >= d2) {
return Math.sqrt((x - x2) * (x - x2) + (y - y2) * (y - y2));
}
double r = cross / d2;
double px = x1 + (x2 - x1) * r;
double py = y1 + (y2 - y1) * r;
return Math.sqrt((x - px) * (x - px) + (y - py) * (y - py));
}
```
其中,`distanceToSegment`方法用于计算点到线段的距离。