如何在秋千中创建一个立方体？

Question

我正在尝试创建一个类,当由a调用时JPanel,创建一个多维数据集.我所看到的,是一种叫做a的东西ColorCube,需要某种" Universe",而且Canvas,虽然我没有发现这种方法与之兼容JPanel.

为了澄清,我不是在问如何创建自定义JComponent(确切),也不是在询问如何添加颜色或旋转它,只是如何创建一个类,当通过JPanel将多维数据集呈现到屏幕来调用时.

Answer 1

那么你真正需要的就是x, y, and size传递给Cube全班

• 获取这些参数并为第一个方块构建一个角点数组,并为第二个移动的方块构建角点.请参阅类中的方法getCubeOnePoints和getCubeTwoPoints方法Cube.

• 画出第一个方块.绘制第二个方块,并连接点阵列中的点.查看课程中的drawCube方法Cube.

• 创建Cube传递必要参数的类的实例,并绘制多维数据集.请参阅CubePanel构造函数和paintComponent方法

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class CubePanel extends JPanel{
    private static final int D_W = 400;
    private static final int D_H = 400;

    Cube cube;
    public CubePanel() {
        cube = new Cube(75, 75, 200, 50);
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        cube.drawCube(g);
    }

    @Override
    public Dimension getPreferredSize() {
        return new Dimension(D_W, D_H);
    }

    public class Cube {
        int x, y, size, shift;
        Point[] cubeOnePoints;
        Point[] cubeTwoPoints;
        public Cube(int x, int y, int size, int shift) {
            this.x = x;
            this.y = y;
            this.size = size;
            this.shift = shift;
            cubeOnePoints = getCubeOnePoints();
            cubeTwoPoints = getCubeTwoPoints();
        }

        private Point[] getCubeOnePoints() {
            Point[] points = new Point[4];
            points[0] = new Point(x, y);
            points[1] = new Point(x + size, y);
            points[2] = new Point(x + size, y + size);
            points[3] = new Point(x, y + size);
            return points;
        }

        private Point[] getCubeTwoPoints() {
            int newX = x + shift;
            int newY = y + shift;
            Point[] points = new Point[4];
            points[0] = new Point(newX, newY);
            points[1] = new Point(newX + size, newY);
            points[2] = new Point(newX + size, newY + size);
            points[3] = new Point(newX, newY + size);
            return points;
        }

        public void drawCube(Graphics g) {
            g.drawRect(x, y, size, size);
            g.drawRect(x + shift, y + shift, size, size);
            // draw connecting lines
            for (int i = 0; i < 4; i++) {
                g.drawLine(cubeOnePoints[i].x, cubeOnePoints[i].y, 
                        cubeTwoPoints[i].x, cubeTwoPoints[i].y);
            }
        }
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JFrame frame = new JFrame();
                frame.add(new CubePanel());
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }
}

UPDATE

"如果我想在3D中可以绕过立方体怎么办？"

只要创建方法转移所有的xS或yS和调用它,然后重新绘制.该方法可能看起来像

    public void shiftLeft() {
        x -= SHIFT_INC;
        for (Point p : cubeOnePoints) {
            p.x -= SHIFT_INC;
        }
        for (Point p : cubeTwoPoints) {
            p.x -= SHIFT_INC;
        }
    }

在下面的示例中,我只是在密钥的密钥绑定中调用它←.

    im.put(KeyStroke.getKeyStroke("LEFT"), "shiftLeft");
    getActionMap().put("shiftLeft", new AbstractAction(){
        public void actionPerformed(ActionEvent e) {
            cube.shiftLeft();
            repaint();
        }
    });

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.InputMap;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
import javax.swing.SwingUtilities;

public class CubePanel extends JPanel{
    private static final int D_W = 400;
    private static final int D_H = 300;

    Cube cube;
    public CubePanel() {
        cube = new Cube(75, 75, 50, 15);
        InputMap im = getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
        im.put(KeyStroke.getKeyStroke("RIGHT"), "shiftRight");
        getActionMap().put("shiftRight", new AbstractAction(){
            public void actionPerformed(ActionEvent e) {
                cube.shiftRight();
                repaint();
            }
        });
        im.put(KeyStroke.getKeyStroke("LEFT"), "shiftLeft");
        getActionMap().put("shiftLeft", new AbstractAction(){
            public void actionPerformed(ActionEvent e) {
                cube.shiftLeft();
                repaint();
            }
        });
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        cube.drawCube(g);
    }

    @Override
    public Dimension getPreferredSize() {
        return new Dimension(D_W, D_H);
    }

    public class Cube {
        private static final int SHIFT_INC = 5;
        int x, y, size, shift;
        Point[] cubeOnePoints;
        Point[] cubeTwoPoints;
        public Cube(int x, int y, int size, int shift) {
            this.x = x;
            this.y = y;
            this.size = size;
            this.shift = shift;
            cubeOnePoints = getCubeOnePoints();
            cubeTwoPoints = getCubeTwoPoints();
        }

        private Point[] getCubeOnePoints() {
            Point[] points = new Point[4];
            points[0] = new Point(x, y);
            points[1] = new Point(x + size, y);
            points[2] = new Point(x + size, y + size);
            points[3] = new Point(x, y + size);
            return points;
        }

        private Point[] getCubeTwoPoints() {
            int newX = x + shift;
            int newY = y + shift;
            Point[] points = new Point[4];
            points[0] = new Point(newX, newY);
            points[1] = new Point(newX + size, newY);
            points[2] = new Point(newX + size, newY + size);
            points[3] = new Point(newX, newY + size);
            return points;
        }

        public void shiftLeft() {
            x -= SHIFT_INC;
            for (Point p : cubeOnePoints) {
                p.x -= SHIFT_INC;
            }
            for (Point p : cubeTwoPoints) {
                p.x -= SHIFT_INC;
            }
        }

        public void shiftRight() {
            x += SHIFT_INC;
            for (Point p : cubeOnePoints) {
                p.x += SHIFT_INC;
            }
            for (Point p : cubeTwoPoints) {
                p.x += SHIFT_INC;
            }
        }

        public void drawCube(Graphics g) {
            g.drawRect(x, y, size, size);
            g.drawRect(x + shift, y + shift, size, size);
            // draw connecting lines
            for (int i = 0; i < 4; i++) {
                g.drawLine(cubeOnePoints[i].x, cubeOnePoints[i].y, 
                        cubeTwoPoints[i].x, cubeTwoPoints[i].y);
            }
        }
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JFrame frame = new JFrame();
                frame.add(new CubePanel());
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }
}