随机生成形状

Question

我正在开发一个 Java 屏幕保护程序项目，到目前为止我已经完成了很多工作。我需要代码在随机位置生成随机颜色的随机形状。我相信我已经处理了所有随机方面，但现在我只需要使用计时器以 500 毫秒的间隔创建这些形状。我还需要创建一个计数器来计算 30 个形状，然后清除屏幕并重新开始。 （我为项目的其他部分添加了背景和 keylistener，但它们工作得很好，以防有人想知道他们为什么在那里）。

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Random;

public class ScreenSaver1 extends JPanel implements ActionListener {
    private JFrame frame = new JFrame("FullSize");
    private Rectangle rectangle;
    Timer t;
    int x1, y1;
    boolean full;

    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        int shape;
        shape = (int)(Math.random() * 4);
    }

    ScreenSaver1() {
        t = new Timer(500, this);
        t.setDelay(500);
        t.start();
        // Remove the title bar, min, max, close stuff
        frame.setUndecorated(true);
        // Add a Key Listener to the frame
        frame.addKeyListener(new KeyHandler());
        // Add this panel object to the frame
        frame.add(this);
        // Get the dimensions of the screen
        rectangle = GraphicsEnvironment.getLocalGraphicsEnvironment()
        .getDefaultScreenDevice().getDefaultConfiguration().getBounds();
        // Set the size of the frame to the size of the screen
        frame.setSize(rectangle.width, rectangle.height);
        frame.setVisible(true);
        // Remember that we are currently at full size
        full = true;
    }


// This method will run when any key is pressed in the window
class KeyHandler extends KeyAdapter {
    public void keyPressed(KeyEvent e) {
        // Terminate the program.
        if (e.getKeyChar() == 'x') {
            System.out.println("Exiting");
            System.exit(0);
        }
        else if (e.getKeyChar() == 'r') {
            System.out.println("Change background color");
            setBackground(new Color((int)(Math.random() * 256), (int)(Math.random() * 256), (int)(Math.random() * 256)));
            repaint();
        }
        else if (e.getKeyChar() == 'z') {
            System.out.println("Resizing");
            frame.setSize((int)rectangle.getWidth() / 2, (int)rectangle.getHeight());
        }
    }

}

private void makeLine(Graphics g) {
    int x = (int)(Math.random() * rectangle.getWidth());
    int y = (int)(Math.random() * rectangle.getHeight());
    int x1 = (int)(Math.random() * 100);
    int y1 = (int)(Math.random() * 100);
    g.setColor(new Color((int)(Math.random() * 256), (int)(Math.random() * 256), (int)(Math.random() * 256) ));
    g.drawLine(x, y, x1, y1);
}

private void makeRect(Graphics g) {
    int x = (int)(Math.random() * rectangle.getWidth());
    int y = (int)(Math.random() * rectangle.getHeight());
    int width = (int)(Math.random() * 100);
    int height = (int)(Math.random() * 100);
    g.setColor(new Color((int)(Math.random() * 256), (int)(Math.random() * 256), (int)(Math.random() * 256) ));
    g.drawRect(x, y, width, height);
}

private void makeOval(Graphics g) {
    int x = (int)(Math.random() * rectangle.getWidth());
    int y = (int)(Math.random() * rectangle.getHeight());
    int width = (int)(Math.random() * 100);
    int height = (int)(Math.random() * 100);
    g.setColor(new Color((int)(Math.random() * 256), (int)(Math.random() * 256), (int)(Math.random() * 256) ));
    g.drawOval(x, y, width, height);
}

private void makeRoundRect(Graphics g) {
    int x = (int)(Math.random() * rectangle.getWidth());
    int y = (int)(Math.random() * rectangle.getHeight());
    int width = (int)(Math.random() * 100);
    int height = (int)(Math.random() * 100);
    int arcWidth = (int)(Math.random() * width);
    int arcHeight = (int)(Math.random() * height);
    g.setColor(new Color((int)(Math.random() * 256), (int)(Math.random() * 256), (int)(Math.random() * 256) ));
    g.drawRoundRect(x, y, width, height, arcWidth, arcHeight);
}

public static void main(String[] args) {
        ScreenSaver1 obj = new ScreenSaver1();
    }
}

Answer 1

你不会喜欢我的，但我建议你稍微支持一下……

首先，Java 提供了一个非常好的基本Shape 接口，它定义了应该如何呈现“形状”（以及其他内容），因此我建议您从这个完全重新发明轮子开始。

接下来，您需要某种对象来包装Shape（具有位置和大小信息）和Color，例如...

public class RandomShape {

    private final Color color;
    private final Shape shape;

    public RandomShape(Color color, Shape shape) {
        this.color = color;
        this.shape = shape;
    }

    public Color getColor() {
        return color;
    }

    public Shape getShape() {
        return shape;
    }

    public void paint(Graphics2D g2d) {
        g2d.setColor(color);
        g2d.draw(shape);
        g2d.fill(shape);
    }

}

这甚至有自己绘画的能力。

接下来，我将创建一个List 来包含这些形状...

private List<RandomShape> shapes;

这不仅可以作为您的计数器，还可以让更新屏幕变得异常简单。当 shapes List 包含 30 个或更多项目时，您只需将其清除并重新绘制屏幕...

接下来，你需要一个javax.swing.Timer，用于触发更新...

这个计时器应该...

检查shapes列表是否需要清除...

随机生成Color...

int r = (int) (Math.random() * 255);
int g = (int) (Math.random() * 255);
int b = (int) (Math.random() * 255);
Color color = new Color(r, g, b);

随机生成形状的大小和位置...

int width = 10 + (int) (Math.random() * 40);
int height = 10 + (int) (Math.random() * 40);
int x = (int) (Math.random() * (getWidth() - width));
int y = (int) (Math.random() * (getHeight() - height));

随机生成底层基本形状...

Shape shape = null;
switch (whichShape) {
    case 0:
        shape = new Line2D.Double(x, y, x + width, y + height);
        break;
    case 1:
        shape = new Rectangle2D.Double(x, y, width, height);
        break;
    case 2:
        shape = new Ellipse2D.Double(x, y, width, height);
        break;
}

创建RandomShape，将其添加到列表中并重新绘制组件...

RandomShape randomShape = new RandomShape(color, shape);
shapes.add(randomShape);
repaint();

简单;)

现在，当您需要绘制组件时，您只需遍历形状列表...

@Override
protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    Graphics2D g2d = (Graphics2D) g.create();
    for (RandomShape shape : shapes) {
        shape.paint(g2d);
    }
    g2d.dispose();
}

看看How to use Swing Timers和Working with Geometry

Answer 2

查看Playing With Shapes，了解一种允许您将形状用作真实组件的方法。然后您只需将组件添加到面板中，您就不必担心自定义绘画。

Answer 3

您可以在不使用这样的循环的情况下绘制所有形状

private void paintAllShapes(Graphics g, int n) {
    if(n < shapes.size()) {
        shapes.get(n).paint((Graphics2D)g);
        paintAllShapes(g, n+1);
    }
}

protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    paintAllShapes(g, 0);
}