围绕字符旋转图像（JAVA）

是的，我知道你可以使用AffineTransformation，但是我希望我的剑形图像能够360度旋转，而不是一次旋转。 基本上我想要一个类似于Terraria的轮换系统。 我知道如何获得字符的x和y，所以问题是：我如何使它围绕我定义的点旋转？ 我的代码是这样设置的

f.addMouseListener(new MouseAdapter(){ public void mouseClicked(MouseEvent e){ swordSwinging=true; } }); 

…

 if(swordSwinging){ //swinging code goes here } repaint(); 

Answer 1

你的意思是…

（请注意，红线是指示中心angular度的引导线，您不需要它;））

花哨的， getSwordHandlePoint东西在getSwordHandlePoint方法中，它计算沿着向量应该放置句柄的点…

 public class TestSword { public static void main(String[] args) { new TestSword(); } public TestSword() { EventQueue.invokeLater(new Runnable() { @Override public void run() { try { UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); } catch (ClassNotFoundException ex) { } catch (InstantiationException ex) { } catch (IllegalAccessException ex) { } catch (UnsupportedLookAndFeelException ex) { } JFrame frame = new JFrame("Test"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setLayout(new BorderLayout()); frame.add(new SwordPane()); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } }); } public class SwordPane extends JPanel { private BufferedImage character; private BufferedImage sword; private double angle = 0; public SwordPane() { try { character = ImageIO.read(new File("character.png")); sword = ImageIO.read(new File("Sword.png")); } catch (IOException exp) { exp.printStackTrace(); } Timer timer = new Timer(100, new ActionListener() { @Override public void actionPerformed(ActionEvent e) { angle += 10; if (angle > 360) { angle -= 360; } repaint(); } }); timer.setRepeats(true); timer.setCoalesce(true); timer.start(); } @Override public Dimension getPreferredSize() { int width = character.getHeight() + sword.getWidth(); int height = character.getHeight() + sword.getWidth(); return new Dimension(width * 2, height * 2); } protected Point getSwordHandlePoint() { int radius = 272; // This is the height of the character... int x = Math.round(getWidth() / 2); int y = Math.round(getHeight() / 2); double rads = Math.toRadians(angle - 180); // Make 0 point out to the right... // If you add sword.getWidth, you might be able to change the above... int fullLength = Math.round((radius / 2f)) - sword.getWidth(); // Calculate the outter point of the line int xPosy = Math.round((float) (x + Math.cos(rads) * fullLength)); int yPosy = Math.round((float) (y - Math.sin(rads) * fullLength)); return new Point(xPosy, yPosy); } @Override protected void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2d = (Graphics2D) g.create(); int x = (getWidth() - character.getWidth()) / 2; int y = (getHeight() - character.getHeight()) / 2; g2d.drawImage(character, x, y, this); x = getWidth() / 2; y = getHeight() / 2; Point p = getSwordHandlePoint(); g2d.setColor(Color.RED); g2d.drawLine(x, y, px, py); AffineTransform at = AffineTransform.getTranslateInstance(px, py); at.rotate(Math.toRadians(-angle)); g2d.setTransform(at); g2d.drawImage(sword, 0, 0, this); g2d.dispose(); } } } 

现在，我的触发是无望的，没有那么绝望。 我从网上“借用”algorithm，并根据自己的需要调整。

Answer 2

Graphics2D类有一个方法g2.rotate(...) ，调用一个for loop ，一次调用一次旋转，然后调用g2.drawImage(...) ，在循环中，每个改变（如果它在paintComponent()方法中，并且循环在外部 – 在for循环中调用repaint() ）。