矩形绕(x,y)旋转

叁歲伎倆 2024-02-18 20:52 75阅读 0赞

import javax.swing.\*;  
import java.awt.\*;  
import java.util.Vector;  
import java.util.logging.Logger;  
  
  
public class Panel extends JPanel implements Runnable  
\{  
int angle=0;  
final int STEP=5;  
final int INTERVAL=100;  
  
  
public Panel()  
\{  
\}  
  
  
@Override  
public void run()  
\{  
while (true)  
\{  
try  
\{  
Thread.sleep(INTERVAL);  
\}  
catch (Exception e)  
\{  
e.printStackTrace();  
\}  
  
  
this.repaint();  
  
  
\}  
\}  
  
  
public void paint(Graphics g)  
\{  
super.paint(g);  
g.fillRect(0, 0, 400, 300);  
  
  
int r=20;  
  
  
Vector<Point> points=new Vector<>();  
points.add(new Point(-r,-r));  
points.add(new Point(r,-r));  
points.add(new Point(r,-2\*r));  
points.add(new Point(-r,-2\*r));  
  
  
Point center=new Point(100,100);  
  
  
this.drawTankAngle(points, center, g, angle);  
  
  
angle+=STEP;  
\}  
  
  
private double getAngleByPoint(float x, float y)  
\{  
return y>0 ? Math.acos( x / Math.sqrt(x \* x + y \* y)) : 2 \* Math.PI - Math.acos(x / Math.sqrt(x \* x + y \* y));  
\}  
  
  
public void drawTankAngle(Vector<Point> points, Point center, Graphics g, int angle)  
\{  
int iCenterX = (int)center.getX();  
int iCenterY = (int)center.getY();  
  
  
int\[\] xPoints = new int\[points.size()\];  
int\[\] yPoints = new int\[points.size()\];  
  
  
for(int i = 0; i < points.size(); i++)  
\{  
xPoints\[i\] = (int)(points.get(i).getX());  
yPoints\[i\] = (int)(points.get(i).getY());  
float x = xPoints\[i\];  
float y = yPoints\[i\];  
double d = getAngleByPoint(x, y) + angle / 360.0f \* 2 \* Math.PI;  
xPoints\[i\] = (int)(Math.abs(Math.sqrt(x \* x + y \* y)) \* Math.cos(d)) + iCenterX;  
yPoints\[i\] = (int)(Math.abs(Math.sqrt(x \* x + y \* y)) \* Math.sin(d)) + iCenterY;  
\}  
  
  
g.setColor(Color.yellow);  
g.drawString("0", iCenterX, iCenterY);  
  
  
g.drawPolygon(xPoints, yPoints, xPoints.length);  
\}  
\}

![70][]

![70 1][]

[70]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/29/a455207b9925498b91047d22d8849b49.png
[70 1]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/29/e994ca5c707d4f5893a845e06c418750.png