Question

我有一个带有x和y轴的二维图形，我试图围绕一个轴旋转一个形状（一系列点）。此旋转需要包含缩放功能。

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.AffineTransform;
import java.awt.geom.Point2D;
import javax.swing.*;
import java.lang.reflect.Array;

public class test extends JPanel implements ActionListener {

    int[] p1x = {200, 200, 240, 240, 220, 220, 200};
    int[] p1y = {200, 260, 260, 240, 240, 200, 200};
    int[] p2x = {600, 600, 620, 620, 640, 640, 660, 660, 600};
    int[] p2y = {400, 420, 420, 460, 460, 420, 420, 400, 400};
    int[] p3x = {400, 400, 460, 460, 440, 440, 420, 420, 400};
    int[] p3y = {400, 460, 460, 400, 400, 440, 440, 400, 400};
    int delay = 1000;
    int dx = 0;
    int dy = 5;
    int steps = 121;
    Polygon t;
    Timer tim = new Timer(delay, this);

    public void actionPerformed(ActionEvent event) {
        for (int i = 0; i < Array.getLength(p2x); i++) {
            //p2x[i] = (int) (p2x[i]*Math.cos(Math.toRadians(1))- p2y[i]*Math.sin(Math.toRadians(1)));
            //p2y[i] = (int) (p2x[i]*Math.sin(Math.toRadians(1))+ p2y[i]*Math.cos(Math.toRadians(1)));;

            Point2D original = new Point2D.Double(p2x[i], p2y[i]);
            AffineTransform at = new AffineTransform();
            //at.setToRotation(.02, 250, 250);
            at.scale(1, -1);
            Point2D rotated = at.transform(original, null);
            p2x[i] = (int) rotated.getX();
            p2y[i] = (int) rotated.getY();
        }
        repaint();

        if (--steps == 0) {
            tim.stop();
        }
    }

    public void paintComponent(Graphics g) {
        super.paintComponent(g);

        this.setBackground(Color.white);

        g.drawLine(this.getWidth() / 2, 0, this.getWidth() / 2, this.getWidth());
        g.drawLine(0, this.getHeight() / 2, this.getHeight(), this.getHeight() / 2);

        Polygon t = new Polygon(p2x, p2y, 9);
        g.drawPolygon(t);

        Letters u = new Letters(p3x, p3y, 9);
        u.draw(g);

        Letters l = new Letters(p1x, p1y, 7);
        l.draw(g);
    }

    public static void main(String[] args) {

        JFrame frame = new JFrame("Drawing line and a moving polygon");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        test sl = new test();
        frame.getContentPane().add(sl);
        frame.setSize(700, 700);
        frame.setVisible(true);

        sl.tim.start();
    }
}

Answer 1

如果没有明确的问题，使用坐标数组的简单动画如下所示。通常，您可以转换图形上下文（g2d）或多边形Shape本身（p3）;这个例子显示了两者。调整窗口大小以查看每个窗口的效果。

请注意at中转换的最后指定的首次应用顺序。首先，将p3上的合适点转换为原点，然后缩放p3，然后将p3转换为面板的中心。应用于+ 10的{{1}}软糖因子是没有对称旋转点的人工制品。相对于原点定义多边形可能更容易，如example所示。

AffineTest

p3

围绕x轴垂直旋转形状

1 个答案: