Mandelbrot Set Demo

Introduction

This application demonstrates advantages of parallel execution done using Java Parallel API.

About

This JavaFX application renders an image using Mandelbrot set (wikipedia link) for any particular range of complex values.

Given a complex number the algorithm calculates an integer value which is then mapped to a color. Real part of a complex value is mapped to horizontal axis of the screen. Imaginary part of a complex value is mapped to a vertical axis of the screen.

Navigation

• Drag the picture with left mouse button to explore fractal boundaries.
• Scroll the mouse wheel to zoom in and out.
• Press "1", "2" and "3" control panel buttons to navigate to a particular predefined areas of the fractal.
• Press "0" to return to fractal overview.
• Click "Compare" control panel button to run rendering in comparison mode.
  • In this case the application will re-render the whole picture using:
    1. Sequential execution
    2. Parallel execution
  • Supporting it with visual feedback and showing elapsed time both graphically and in written.
• Type "I" to print current position parameters to the output stream.
• Type "R" to re-render current image using parallel calculation mode.

Details

MandelbrotSetTask.call() method contains code which is equivalent to the following when running in parallel mode:

IntStream.range(0, height).parallel().forEach((int y) -> {
    for (int x = 0; x < width; x++) {
        // calculate (x, y) pixel color 
    }
});

Command line options

    java -jar MandelbrotSet.jar -min <minReal>,<minImaginary> -max <maxReal>,<maxImaginary> -windowSize <width>x<height>

• -min <minReal>,<minImaginary> specifies left top corner of the fractal complex number area
• -max <maxReal>,<maxImaginary> specifies right bottom corner of the fractal complex number area
• -windowSize <width>x<height> specifies initial window size in pixels

Here is an example produced by typing "I" inside the app:

Use the following parameters to get to the same position
-min -2.4807381162845332,-1.3061943784663503
-max 0.9781413692299719,1.2879652356695286
-windowSize 800.0x600.0;    

Source code

• MandelbrotSetTask.java - Mandelbrot Set calculation code
• Complex.java - utility class for Complex numbers operations
• Main.java - JavaFX UI source code
• ControlPane.css - JavaFX CSS file for control panel elements