Java: 使用 drawArc 绘制圆形螺旋

Question

我正在做一个 java 编程练习，我们必须使用 drawArc 方法绘制一个圆形螺旋，这样结果看起来类似于：

我已经为此工作了一段时间，这是我目前所拥有的：

import java.awt.Graphics;
import javax.swing.JPanel;
import javax.swing.JFrame;

public class CircSpiral extends JPanel {
   public void paintComponent(Graphics g) {
      int x = 100;
      int y = 120;
      int width = 40;
      int height = 60;
      int startAngle = 20;
      int arcAngle = 80;
      for (int i = 0; i < 5; i++) {
         g.drawArc(x, y, width, height, startAngle, arcAngle);
         g.drawArc(x + 10, y + 10, width, height, startAngle + 10, arcAngle);
         x = x + 5;
         y = y + 5;
         startAngle = startAngle - 10;
         arcAngle = arcAngle + 10;
      }
   }

   public static void main(String[] args) {
      CircSpiral panel = new CircSpiral();
      JFrame application = new JFrame();
      application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      application.add(panel);
      application.setSize(300, 300);
      application.setVisible(true);
   }
}

我的代码给出了这个结果：

我知道问题出在我对 drawArc 方法的参数上，因为数字不正确，但我不知道如何让数字以循环方式运行。任何帮助表示赞赏。谢谢！

Answer 1

以下代码将输出此图像：

import java.awt.Graphics;
import javax.swing.JPanel;
import javax.swing.JFrame;

public class CircSpiral extends JPanel {
    public void paintComponent(Graphics g) {
        int centerX = getWidth() / 2;
        int centerY = getHeight() / 2;

        int numIterations = 5;

        int arcWidth = 10;
        int arcGrowDelta = 30;

        for (int i = 0; i < numIterations; i++) {
            g.drawArc(centerX - arcWidth, centerY - arcWidth, 2 * arcWidth, 2 * arcWidth, 0, 180);
            arcWidth += arcGrowDelta;
            g.drawArc(centerX - arcWidth, centerY - arcWidth, 2 * arcWidth - arcGrowDelta, 2 * arcWidth, 180, 180);
        }
    }

    public static void main(String[] args) {
        CircSpiral panel = new CircSpiral();
        JFrame application = new JFrame();
        application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        application.add(panel);
        application.setSize(300, 300);
        application.setVisible(true);
    }
}

思路很简单，画一个圆的上半部分就可以了，像这样：

然后将圆弧大小增加一个常数因子并绘制圆的下半部分，但要使该圆的终点与上圆匹配，为此，只需从底部衬底 arcGrowDelta圆圈宽度：

并重复。

Answer 2

如果这是我的项目，是的，我会在循环中绘制弧线，但在循环内，我会尝试使弧线的边界框更大但仍以同一位置为中心。为此，我将 x 和 y 递减一些 small 常数，比如 DELTA（我将其设置为 == 1），并将宽度和高度递增 2 * DELTA。我也会让我的 arcAngle 保持不变，而是像这样在循环中改变我的 startAngle：startAngle = startAngle - arcAngle;.

例如，这个：

import java.awt.Dimension;
import java.awt.Graphics;

import javax.swing.JPanel;
import javax.swing.JFrame;

@SuppressWarnings("serial")
public class CircSpiral extends JPanel {
   private static final int DELTA = 1;
   private static final int ARC_ANGLE = 20;
   private static final int PREF_W = 300;
   private static final int PREF_H = PREF_W;
   private static final int LOOP_MAX = 400;

   public void paintComponent(Graphics g) {
      int x = PREF_W / 2;
      int y = PREF_H / 2;
      int width = 1;
      int height = 1;
      int startAngle = 0;
      int arcAngle = ARC_ANGLE;
      for (int i = 0; i < LOOP_MAX; i++) {
         g.drawArc(x, y, width, height, startAngle, arcAngle);
         x = x - DELTA;
         y = y - DELTA;
         width += 2 * DELTA;
         height += 2 * DELTA;
         startAngle = startAngle - arcAngle;
      }
   }

   @Override
   public Dimension getPreferredSize() {
      if (isPreferredSizeSet()) {
         return super.getPreferredSize();
      }
      return new Dimension(PREF_W, PREF_H);
   }

   public static void main(String[] args) {
      CircSpiral panel = new CircSpiral();
      JFrame application = new JFrame();
      application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      application.add(panel);
      application.pack();
      application.setLocationRelativeTo(null);
      application.setVisible(true);
   }
}

会导致：

Answer 3

你的想法差不多是对的。我做了一些修改。您需要反转角度以绘制螺旋的另一侧并使用固定点 startAngle.

import java.awt.Graphics;
import javax.swing.JPanel;
import javax.swing.JFrame;

public class CircSpiral extends JPanel {

    public void paintComponent(Graphics g) {
        int x = getSize().width / 2 - 10;
        int y = getSize().height/ 2 - 10;
        int width = 20;
        int height = 20;
        int startAngle = 0;
        int arcAngle = 180;
        int depth = 10;
        for (int i = 0; i < 10; i++) {
            if (i % 2 == 0) {
                //   g.drawArc(x + 10, y + 10, width, height, startAngle + 10, -arcAngle);
                //  x = x - 5;
                y = y - depth;
                width = width + 2 * depth;
                height = height + 2 * depth;
                g.drawArc(x, y, width, height, startAngle, -arcAngle);
            } else {
                //  g.drawArc(x + 10, y + 10, width, height, startAngle + 10, arcAngle);
                x = x - 2 * depth;
                y = y - depth;
                width = width + 2 * depth;
                height = height + 2 * depth;
                g.drawArc(x, y, width, height, startAngle, arcAngle);
            }
        }
    }

    public static void main(String[] args) {
        CircSpiral panel = new CircSpiral();
        JFrame application = new JFrame();
        application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        application.add(panel);
        application.setSize(300, 300);
        application.setVisible(true);
    }
}

Answer 4

这是我的解决方案：

package mainpack;

import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;

import javax.swing.JPanel;

public class SpiralPanel extends JPanel {

    private static final long serialVersionUID = 1L;

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

        Graphics2D g2d = (Graphics2D)g;

        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                RenderingHints.VALUE_ANTIALIAS_ON);

        g2d.setRenderingHint(RenderingHints.KEY_RENDERING,
                RenderingHints.VALUE_RENDER_QUALITY);

        int width = 10;
        int height = 10;
        int startAngle = 0;
        int arcAngle = 180;
        int x = (getWidth() - width) / 2;
        int y = (getHeight() - height) / 2;

        int i = 0;
        int t = 0;

        while (i < 36) {

            g2d.drawArc(x + t, y, width, height, startAngle, arcAngle);

            if (i % 2 == 0) {
                t -= 10;
            }
            y -= 5;
            width += 10;
            height += 10;
            startAngle += 180;

            i++;
        }
    }
}

Answer 5

我是 java 的初学者，终于学会了如何创建螺旋线。

这是我的代码：

int lineLength = 20; //starting line length
int x = getWidth() / 2; //start drawing from center of JPanel
int y = getHeight() / 2; //start drawing from center of JPanel
for( int counter = 0; counter < 10; counter++ )
{
    g.drawArc( x, y, lineLength, lineLength, 0, 180 ); //draws top semicircle of equal width and height
    lineLength += 20; //increases arc diameter
    x -= 20; //moves x coordinate left

    g.drawArc( x, y - 10, lineLength, lineLength, 0, -180 ); //draws bottom semicircle; 'y - 10' joins the 2 semicircles
    lineLength += 20; //increases arc diameter
    y -= 20; //moves y coordinate up
}

Answer 6

如果您愿意让一些古老的三角函数来完成这项工作，您可以使用这个：

import java.awt. *;
import javax.swing. *;
import java.math.*;

public class Spiral extends JFrame {

public Spiral()
{
    // Set Window
    setTitle("Spirale");
    setSize(1500, 1500);
    setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    setVisible(true);
}

public void paint(Graphics g)
{
    super.paint(g);
    for(double i = 1; i < 50000; i++)
    {
        int locY = 600 - (int) (Math.cos((Math.PI*i)/1800)*i/50);
        int locX = 600 - (int) (Math.sin((Math.PI*i)/1800)*i/50);
        g.drawLine(locX, locY, locX, locY);
    }
}

public static void main(String[] args) {
    new Spiral();
}

}

Java: 使用 drawArc 绘制圆形螺旋

Java: Draw a circular spiral using drawArc

java

graphics

swing

draw