Java 用递归算法绘制分形

我写了下面的代码画一个分形树一样的照片。但我在第二个递归方法中遇到了问题。（用于中间分支长度控制）。我如何改进和纠正它

我的代码：

import java.awt.BasicStroke;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import javax.swing.JFrame;

public class FractalTree1 extends Canvas {

// fields for drawing
private final JFrame frame;
private final int WINDOW_WIDTH = 1280;
private final int WINDOW_HEIGHT = 720;

public FractalTree1() {
    frame = new JFrame("Fractal Tree");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(WINDOW_WIDTH, WINDOW_HEIGHT);
    frame.setLocationRelativeTo(null);
    frame.setResizable(true);
    Component add = frame.add(this);
    frame.setVisible(true);
}

public static void main(String[] args) {
    FractalTree1 ft = new FractalTree1();
    ft.setVisible(true);
    ft.setBackground(Color.black);
}

@Override
public void paint(Graphics g) {
    g.setColor(Color.green);
    drawFractalTree(g, WINDOW_WIDTH / 2, WINDOW_HEIGHT - 75, -90, 2, true);
}

public void drawFractalTree(Graphics g, int x1, int y1, double angle, int depth, boolean value) {
    if (depth == 0) {
    } else {
        int x2, y2;
        if (value) {
            x2 = x1 + (int) (Math.cos(Math.toRadians(angle)) * depth * 100.0);
            y2 = y1 + (int) (Math.sin(Math.toRadians(angle)) * depth * 100.0);
        } else {
            x2 = (int) ((x1 + (int) (Math.cos(Math.toRadians(angle)) * depth * 100.0)) * 0.3);
            y2 = (int) (y1 + (int) (Math.sin(Math.toRadians(angle)) * depth * 100.0) * 0.3);
        }

        Graphics2D g2d = (Graphics2D) g;
        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

        g2d.setStroke(new BasicStroke(0.5f * depth));
        g2d.drawLine(x1, y1, x2, y2);

        drawFractalTree(g, x2, y2, angle + 10, depth - 1, true);
        drawFractalTree(g, x2, y2, angle - 35, depth - 1, false);
        drawFractalTree(g, x2, y2, angle - 70, depth - 1, true);
    }
}

}

我的目标照片：

我更新了代码：

import java.awt.BasicStroke;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import javax.swing.JFrame;

public class FractalTree1 extends Canvas {

// fields for drawing
private final JFrame frame;
private final int WINDOW_WIDTH = 1280;
private final int WINDOW_HEIGHT = 720;

public FractalTree1() {
    frame = new JFrame("Fractal Tree");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(WINDOW_WIDTH, WINDOW_HEIGHT);
    frame.setLocationRelativeTo(null);
    frame.setResizable(true);
    Component add = frame.add(this);
    frame.setVisible(true);
}

public static void main(String[] args) {
    FractalTree1 ft = new FractalTree1();
    ft.setVisible(true);
    ft.setBackground(Color.black);
}

@Override
public void paint(Graphics g) {
    g.setColor(Color.green);
    drawFractalTree((Graphics2D) g, WINDOW_WIDTH / 2, WINDOW_HEIGHT - 75, -90, 3,100, 1.0);
}

public void drawFractalTree(Graphics2D g, int x1, int y1, double angle, int depth, double size, double factor) {
if (depth > 0) {
    int x2 = x1 + (int) (Math.cos(Math.toRadians(angle)) * depth * size * factor);
    int y2 = y1 + (int) (Math.sin(Math.toRadians(angle)) * depth * size * factor);

    g.setStroke(new BasicStroke(0.5f * depth));
    g.drawLine(x1, y1, x2, y2);

    drawFractalTree(g, x2, y2, angle + 10, depth - 1, size, 1.0);
    drawFractalTree(g, x2, y2, angle - 35, depth - 1, size, 0.3);
    drawFractalTree(g, x2, y2, angle - 70, depth - 1, size, 1.0);
} }}

我在此照片链接中显示我的新结果：

---

但是第二个分支的长度是工作的。我如何像我的第一张照片（目标链接）一样更正它

您的

else

案例中的计算是错误的：

• y2=…

  行中缺少一些参数
• 将因子

  0.3

  应用于分支的端点，而不是分支的长度

试试这个：

} else {
    x2 = x1 + (int) (Math.cos(Math.toRadians(angle)) * depth * 100.0 * 0.3);
    y2 = y1 + (int) (Math.sin(Math.toRadians(angle)) * depth * 100.0 * 0.3);
}

不过，这需要对不同的尺寸和角度参数进行微调

此外，您还可以通过提供更多的参数并将抗锯齿设置移出方法来简化您的方法：

public void drawFractalTree(Graphics2D g, int x1, int y1, double angle, int depth, double size, double factor) {
    if (depth > 0) {
        int x2 = x1 + (int) (Math.cos(Math.toRadians(angle)) * depth * size * factor);
        int y2 = y1 + (int) (Math.sin(Math.toRadians(angle)) * depth * size * factor);

        g.setStroke(new BasicStroke(0.5f * depth));
        g.drawLine(x1, y1, x2, y2);

        drawFractalTree(g, x2, y2, angle + 10, depth - 1, size, 1.0);
        drawFractalTree(g, x2, y2, angle - 35, depth - 1, size, 0.3);
        drawFractalTree(g, x2, y2, angle - 70, depth - 1, size, 1.0);
    }
}

---

@tobias_k我的代码结果是错误的：（是的，我也猜到了。怎么会是错误的？顺便说一句，您在

y2=

行中缺少了一对参数，但似乎还有更多…谢谢：）但我还有其他问题。如果你用depth=3或5画这段代码，你可以看到中间的分支是错误的。因为它的长度不正确（请看我的目标照片：），它看起来适合我。你确定你在参数中移动了因子，所以它只适用于长度吗？也许你应该发布一个屏幕显示它现在的样子。@tobais_k我更新了我的代码和我的问题。我还上传了新代码的结果。@masoodtav AsI说，你必须稍微调整角度、长度和因子。