ColorMandelbrot.java

/*************************************************************************
 *  Compilation:  javac Mandelbrot.java
 *  Execution:    java Mandelbrot xmin ymin width height < colors.txt
 *  Dependencies: Picture.java StdIn.java
 *
 *  Plots the Mandelbrot set in color.
 *
 *  % java Mandelbrot -1.5 -1.0 2.0 2.0 < mandel.txt
 *
 *  % java Mandelbrot .10259 -.641 .0086 .0086 < mandel.txt
 *
 *************************************************************************/
import java.awt.Color;

public class ColorMandelbrot {

   // return number of iterations to check if c = a + ib is in the Mandelbrot set           
    public static int mand(Complex c, int ITERS) {
        Complex z = c;
        for (int t = 0; t < ITERS; t++) {
            if (z.abs() >= 2.0) return t;
            z = z.times(z).plus(c);
        }
        return ITERS - 1;
    }


    public static void main(String args[]) {
        double xmin   = Double.parseDouble(args[0]);      // min x coordinate
        double ymin   = Double.parseDouble(args[1]);      // min y coordinate
        double width  = Double.parseDouble(args[2]);      // width of plot
        double height = Double.parseDouble(args[3]);      // height of plot

        int WIDTH  = 250;
        int HEIGHT = 250;
        int ITERS  = 256;

        // read in color map
        Color[] colors = new Color[ITERS];
        for (int t = 0; t < ITERS; t++) {
            int r = StdIn.readInt();
            int g = StdIn.readInt();
            int b = StdIn.readInt();
            colors[t] = new Color(r, g, b);
        }

        Picture pic = new Picture(WIDTH, HEIGHT);

        for (int i = 0; i < WIDTH; i++) {
            for (int j = 0; j < HEIGHT; j++) {
                double a = xmin + i * width / WIDTH;
                double b = ymin + j * height / HEIGHT;
                Complex c = new Complex(a, b);
                int t = mand(c, ITERS);
                pic.setColor(i, j, colors[t]);
            }
            pic.show();
        }
        pic.save("temp.png");
    }

}