juliacalc.java

通过线程控制来打印出julia集

public class JuliaCalc {

	double MinRe;

	double MaxRe;

	double MinIm;

	double MaxIm;

	double Re_factor;

	double Im_factor;

	int divisor;

	Complex K;

	public JuliaCalc(int ImageWidth, int ImageHeight, Complex K) {

		MinRe = JuliaFrame.MinRe;
		MaxRe = JuliaFrame.MaxRe;
		MinIm = JuliaFrame.MinIm;
		MaxIm = JuliaFrame.MaxIm;
		Re_factor = (MaxRe - MinRe) / (ImageWidth - 1);
		Im_factor = (MaxIm - MinIm) / (ImageHeight - 1);
		divisor = JuliaFrame.NO_OF_ITERATIONS / JuliaFrame.NO_OF_COLOURS;
		this.K = K;
	}

	public DataPacket calculate(DataPacket p) {

		double c_re = MinRe + p.X * Re_factor;
		double c_im = MaxIm - p.Y * Im_factor;
		double Z_re = c_re;
		double Z_im = c_im;
		double k_re = K.Re();
		double k_im = K.Im();

		for (int n = 0; n < JuliaFrame.NO_OF_ITERATIONS; n++) {
			double Z_re2 = Z_re * Z_re, Z_im2 = Z_im * Z_im;
			if (Z_re2 + Z_im2 > 4) {
				p.col = Math.min(n / divisor, (JuliaFrame.NO_OF_COLOURS - 1));
				return (p);
			}
			Z_im = 2 * Z_re * Z_im + k_im;
			Z_re = Z_re2 - Z_im2 + k_re;
		}
		return (p);

	}

}