Class Buddhabrot

java.lang.Object
  Fractal
      Buddhabrot

public class Buddhabrot
extends Fractal

This class supports the 2011-2012 ICS3U Final Exam. As an alternative fractal algorithm to the Mandelbrot class, this class similarly extends Fractal. No palette object is required as the grayscale colors are determined from the recorded data itself.

Author:

Chris Darcy

Field Summary

Fields inherited from class Fractal

bailout, bottomBound, centreX, centreY, delta, dimension, domain, filename, invert, iteration, iterations, leftBound, MAX_ITERATE, palette, paletteName, point, range, rightBound, TARGET, topBound, xCenter, xMax, xMin, yCenter, yMax, yMin

Constructor Summary

Buddhabrot(java.lang.String xC, java.lang.String yC, java.lang.String delta, java.lang.String bailout, java.lang.String samples, java.lang.String filename)
The Buddhabrot constructor accepts parameters similar to the Mandelbrot class constructor.

Method Summary

protected void	draw(java.awt.Graphics g) This method overrides Fractal's draw method to render the Buddhabrot image.
protected void	findMaxHitCount() This method is called by iterateSamples after the iterate method has entirely populated the 2D hitCounts array.
protected boolean	iterate(ComplexNumber c, boolean recordIt) Called by iterateSamples for each c.
protected void	iterateSamples() This method runs through a loop from 0 to samples.

Methods inherited from class Fractal

getDimension, getFilename, getMaxIterations, isPartOfSet, iteration, mapColumnToReal, mapImaginaryToRow, mapRealToColumn, mapRowToImaginary, setDimension, setEscapeTime, zoom

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Buddhabrot

public Buddhabrot(java.lang.String xC,
                  java.lang.String yC,
                  java.lang.String delta,
                  java.lang.String bailout,
                  java.lang.String samples,
                  java.lang.String filename)

The Buddhabrot constructor accepts parameters similar to the Mandelbrot class constructor. Since a palette object is not required, simply pass null to the Fractal constructor in its place. The number of c values to randomly generate (samples) can be saved and used locally as it is not required by the Fractal superclass.

Parameters:

xC - the real value of the center

yC - the imaginary value of the center

delta - the half width of the region of the Argand Plane centered at xC+yCi

bailout - the maximum allowed exposure before concluding the c value did not escape

samples - the number of random c values to test

filename - the name of the file for the purpose of saving the image

Method Detail

draw

protected void draw(java.awt.Graphics g)

This method overrides Fractal's draw method to render the Buddhabrot image. The method first calls the iterateSamples method to populate the 2D array hitCounts for those c that escaped the Mandelbrot Set. After which the maximum hit count is determined and used as a denominator for all entries in hitCount to achieve a float value between 0.0f and 1.0f. This value is used an the red, green, and blue values in the Color(float,float,float) constructor and the pixel is drawn.

Overrides:

draw in class Fractal

Parameters:

g - the Graphic2D reference to the bufferedImage passed to it by Plot's getImage method

iterateSamples

protected void iterateSamples()

This method runs through a loop from 0 to samples. With each iteration a random c value within the region of the Argand Plane is constructed and passed to the iterate method to determine if it escaped the Set, given the bailout limit. Only if it did escape does the same c value get passed to the iterate method a second time, this time each z in its orbit is recorded in the 2D hitCounts array (provided the corresponding row and column are within the bounds of the array).

iterate

protected boolean iterate(ComplexNumber c,
                          boolean recordIt)

Called by iterateSamples for each c. Each c is given a a maximum number of iterations (bailout) to determine if the orbit escaped the Mandelbrot Set (|z|>2.0) if it escapes the method returns a value true; false otherwise. If the drawIt parameter is true, the 2D hitCounts array is incremented for each z in the orbit. This requires that the Fractal methods

        protected int mapRealToColumn(double x)
        protected int mapImaginaryToRow(double y)
 

be called to determine the pixel location corresponding to z.

Parameters:

c - the ComplexNumber to sampled

recordIt - whether or not hits are to be record in the hitCounts array

findMaxHitCount

protected void findMaxHitCount()

This method is called by iterateSamples after the iterate method has entirely populated the 2D hitCounts array. This method traverses the entire hitCounts array to determine the maximum hit count, setting the instance field maxHitCount to this value.