我想知道判断Shape对象是否与另一个形状相交的最佳方法。 目前，只要涉及到Shape与Rectangle相交或反过来，我的游戏就已经解决了碰撞检测问题。我遇到的问题是Shape类中的intersects()方法只能使用Rectangle或Point作为参数，而不能使用另一个Shape。有没有一种有效的方法来测试两个Shape对象是否有任何重叠？
我尝试的一种方法是使用for循环生成一组点区域，以测试它们是否在形状内，然后构建一个Point对象数组发送到另一个形状进行测试，但这会由于所有不必要的比较而显著降低我的帧率。
我搜索了很多，但在这里没有找到类似的东西。如果这是一个重复问题，请提前谅解。
虽然没有经过测试，但为什么不试一试呢：
import java.awt.geom.Area;
...
public static boolean testIntersection(Shape shapeA, Shape shapeB) {
Area areaA = new Area(shapeA);
areaA.intersect(new Area(shapeB));
return !areaA.isEmpty();
}
Area实现了Shape接口，但添加了一些有用的方法
你也可以使用形状本身的边界来进行比较：
public boolean collidesWith(Shape other) {
return shape.getBounds2D().intersects(other.getBounds2D());
}
这看起来更加舒适。
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Polygon;
import java.awt.geom.Area;
import javax.swing.JFrame;
public class Test {
private JFrame frame;
private Polygon polygon1;
private Polygon polygon2;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
Test window = new Test();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public Test() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
frame = new JFrame(){
private static final long serialVersionUID = 1L;
@Override
public void paint(Graphics g){
super.paint(g);
doDrawing(g);
}
};
frame.setBounds(100, 100, 450, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
int nShape1 = 4;
int xPoly1[] = {30,50,50,30};
int yPoly1[] = {30,30,50,50};
polygon1 = new Polygon(xPoly1,yPoly1,nShape1);
int nShape2 = 4;
int xPoly2[] = {35,55,55,35};
int yPoly2[] = {50,50,70,70};
// uncomment next line to rise second polygon vertically by one pixel
//yPoly2[] = {49,49,69,69};
polygon2 = new Polygon(xPoly2,yPoly2,nShape2);
}
public synchronized void doDrawing(Graphics g){
g.setColor(new Color(255,0,0));
// if you draw the polygon, collision on the exact outline won't be detected.
// uncomment draw or fill command to see what I mean.
g.drawPolygon(polygon1);
g.fillPolygon(polygon1);
g.setColor(new Color(0,0,255));
// if you draw the polygon, collision on the exact outline won't be detected.
// uncomment draw or fill command to see what I mean.
g.drawPolygon(polygon2);
g.fillPolygon(polygon2);
Area area = new Area(polygon1);
area.intersect(new Area(polygon2));
if(!area.isEmpty()){
System.out.println("intersects: yes");
}
else{
System.out.println("intersects: no");
}
}
}
if( myShape.getBounds().intersects(otherShape.getBounds()) ){
Area a = new Area(myShape);
a.intersect(new Area(otherShape));
if(!a.isEmpty()){
// do something
}
}