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Welcome to the FractalQT wiki!

Articles

• https://www.ted.com/talks/benoit_mandelbrot_fractals_and_the_art_of_roughness/transcript#t-951199
• https://awesomeopensource.com/project/crapp/geomandel

Sample codes

• http://marvinproject.sourceforge.net/en/plugins/iteratedFunctionSystem.html
• http://rosettacode.org/wiki/Mandelbrot_set

The Fractal Flame Algorithm, pdf, 2008

• https://flam3.com/flame_draves.pdf

Example code sets

Julia set java code

import java.awt.Graphics;

public class c13_julia extends java.applet.Applet {
  static final int left = 20;
  static final int w = 300;
  static final int s = w/3;
  static final int orig = left + w/2;
  static final double xc = -1;
  static final double yc = 0.1;

  public void paint(Graphics g)
  {
    LineTo lt = new LineTo(g);
    lt.drawLine(left, left+w/2, left+w, left+w/2);
    lt.drawLine(left+w/2, left, left+w/2, left+w);
    double xn = 0.25;
    double yn = 0;
    for (int i = 0; i < 5000; i++) {
      double a = xn - xc;
      double b = yn - yc;
      if (a == 0) {
        xn = Math.sqrt(Math.abs(b)/2);
        if (xn > 0) {
          yn = b/(2*xn);
        } else {
          yn = 0;
        }
      } else if (a > 0) {
        xn = Math.sqrt((Math.sqrt(a*a + b*b) + a)/2);
        yn = b / (2 * xn);
      } else {
        yn = Math.sqrt((Math.sqrt(a*a + b*b) - a)/2);
        xn = b / (2 * yn);
      }
      if (i == 0) {
        xn += 0.5;
      }
      if (Math.random() >= 0.5) {
        xn = -xn;
        yn = -yn;
      }
      lt.setPixel((int)(xn*s + orig), (int)(-yn*s + orig));
    }
  }
}

koch curve java code

import java.awt.*;
import java.awt.event.*;

public class c03_koch extends java.applet.Applet {
  double r = 0.29;
  int n = 5;
  Graph graph;
  Controls controls;

  class Graph extends Canvas {
    public void paint(Graphics g)
    {
      koch(g, 1, 30, 190, 30+300, 190);
    }

    private void koch(Graphics g, int level, double x1, double y1, double x2, double y2)
    {
      if (level < n) {
        double nx = (2*x1+x2)/3;
        double ny = (2*y1+y2)/3;
        koch(g, level+1, x1, y1, nx, ny);
        double ox = nx;
        double oy = ny;
        nx = (x1+x2)/2 - r*(y1-y2);
        ny = (y1+y2)/2 + r*(x1-x2);
        koch(g, level+1, ox, oy, nx, ny);
        ox = nx; oy = ny;
        nx = (x1+2*x2)/3;
        ny = (y1+2*y2)/3;
        koch(g, level+1, ox, oy, nx, ny);
        koch(g, level+1, nx, ny, x2, y2);
      } else {
        g.drawLine((int)x1, (int)y1, (int)x2, (int)y2);
      }
    }
  }

  class Controls extends Container {
    private TextField tr;
    private TextField tn;
    private Button redraw;

    public Controls()
    {
      setLayout(new FlowLayout());
      add(new Label("r =", Label.RIGHT));
      add(tr = new TextField(""+r, 6));
      add(new Label("n =", Label.RIGHT));
      add(tn = new TextField(""+n, 6));
      add(redraw = new Button("Redraw"));
      redraw.addActionListener(
        new ActionListener() {
          public void actionPerformed(ActionEvent e) {
            try {
              r = Double.valueOf(tr.getText()).doubleValue();
              n = Integer.parseInt(tn.getText());
            } catch (NumberFormatException nfx) {
            }
            c03_koch.this.graph.repaint();
          }
        }
      );
    }
  }

  public void init()
  {
    setLayout(new BorderLayout());
    add(controls = new Controls(), BorderLayout.SOUTH);
    add(graph = new Graph(), BorderLayout.CENTER);
  }
}