使用旋轉矩陣旋轉Java中的矩形

Question

我在JPanel擴展類上繪製了一個矩形（一個Polygon對象）。

然後我嘗試創建另一個Polygon對象，該對象應該是原始Polygon的90度旋轉。

我使用了旋轉矩陣。

由於某種原因，它不起作用。運行該程序只會顯示原始矩形。

怎麼了？謝謝

public class DrawingPanel extends JPanel{ 

    public void paintComponent(Graphics g){ 

     super.paintComponent(g); 
     Graphics2D g2d = (Graphics2D) g; 

     Point p1,p2,p3,p4; 
     p1 = new Point(50,50); 
     p2 = new Point(200,50); 
     p3 = new Point(200,100); 
     p4 = new Point(50,100); 

     int[] x = {(int) p1.getX(), (int) p2.getX(), (int)p3.getX(), (int) p4.getX()}; 
     int[] y = {(int) p1.getY(), (int) p2.getY(), (int)p3.getY(), (int) p4.getY()}; 

     Polygon poly = new Polygon(x, y, x.length); 
     g2d.draw(poly); 

     p1.setLocation(p1.getX() * Math.cos(Math.toRadians(90)) - p1.getY() * Math.sin(Math.toRadians(90)), 
       p1.getX() * Math.sin(Math.toRadians(90)) + p1.getY() * Math.cos(Math.toRadians(90))); 
     p2.setLocation(p2.getX() * Math.cos(Math.toRadians(90)) - p2.getY() * Math.sin(Math.toRadians(90)), 
       p2.getX() * Math.sin(Math.toRadians(90)) + p2.getY() * Math.cos(Math.toRadians(90))); 
     p3.setLocation(p3.getX() * Math.cos(Math.toRadians(90)) - p3.getY() * Math.sin(Math.toRadians(90)), 
       p3.getX() * Math.sin(Math.toRadians(90)) + p3.getY() * Math.cos(Math.toRadians(90))); 
     p4.setLocation(p4.getX() * Math.cos(Math.toRadians(90)) - p4.getY() * Math.sin(Math.toRadians(90)), 
       p4.getX() * Math.sin(Math.toRadians(90)) + p4.getY() * Math.cos(Math.toRadians(90))); 

     int[] x2 = {(int) p1.getX(), (int) p2.getX(), (int)p3.getX(), (int) p4.getX()}; 
     int[] y2 = {(int) p1.getY(), (int) p2.getY(), (int)p3.getY(), (int) p4.getY()}; 

     Polygon poly2 = new Polygon(x2, y2, x2.length); 
     g2d.draw(poly2); 

    } 

} 

Answer 1

我相信你把它旋轉離開屏幕，所以我不會畫。

您的代碼將它旋轉90周圍的左上角，導致被屏幕