Cyrus-Beck算法java代码
时间: 2023-11-10 12:14:20 浏览: 33
以下是Cyrus-Beck算法的Java代码实现:
```java
public class CyrusBeckAlgorithm {
private static final double epsilon = 1e-6;
public static List<Point2D> clip(List<Point2D> polygon, Point2D p1, Point2D p2) {
List<Point2D> result = new ArrayList<>();
int n = polygon.size();
for (int i = 0; i < n; i++) {
Point2D p = polygon.get(i);
Point2D q = polygon.get((i + 1) % n);
Point2D d = new Point2D(q.getX() - p.getX(), q.getY() - p.getY());
Point2D w = new Point2D(p1.getX() - p.getX(), p1.getY() - p.getY());
double numerator = d.getX() * w.getX() + d.getY() * w.getY();
double denominator = d.getX() * (p2.getX() - p1.getX()) + d.getY() * (p2.getY() - p1.getY());
if (Math.abs(denominator) > epsilon) {
double t = numerator / denominator;
if (t >= 0 && t <= 1) {
double x = p1.getX() + t * (p2.getX() - p1.getX());
double y = p1.getY() + t * (p2.getY() - p1.getY());
result.add(new Point2D(x, y));
}
} else if (Math.abs(numerator) <= epsilon) {
result.add(p);
}
}
return result;
}
}
```
其中,`clip`方法接受一个多边形顶点列表和一条线段的两个端点,返回线段与多边形的交点列表。该方法的实现基于Cyrus-Beck算法,对于多边形的每条边,计算线段与边的交点,如果交点满足线段的参数方程,则加入结果列表中。需要注意的是,当线段与边平行时,需要特判。