Complex Iteration Example

/* (Z^2 + ((RE(Z) + IM(Z)) / 2.1)) - 0.83
   Very Crude and Quick Example by Chris M. Thomasson for Sparky...
   :^D
__________________________________________________________________
*/


#include <iostream>
#include <EasyBMP.h>
#include <complex>


typedef std::complex<double> complex_t;


void iterate_point(BMP& bmp, complex_t c, unsigned int x, unsigned int y)
{
    complex_t z = c;
    complex_t d = z;
    double g = 500.0;
    unsigned int imax = 168;


    for (unsigned int i = 0; i < imax; ++i)
    {
        //(Z^2 + ((RE(Z) + IM(Z)) / 2.1)) - 0.83

        z = (z*z + ((z.real() + z.imag()) / 2.1)) - 0.83;

        double e = std::abs(z);

        //if (e > 10)
        if (z.real() / d.real() > g && z.imag() / d.imag() > g)
        {
            RGBApixel color;
            color.Alpha = 255;
            color.Red = std::abs(std::sin((z.real() * z.imag()) / 7) * 255);
            color.Green = (i * 3) % 256;
            color.Blue = std::abs(std::cos((z.real() * z.imag()) / 13) * 255);

            bmp.SetPixel(x, y, color);

            return;
        }

        d = z;
    }

    RGBApixel color;
    color.Alpha = 255;
    color.Red = 0;
    color.Green = 0;
    color.Blue = 255;

    bmp.SetPixel(x, y, color);
}


void iterate_plane(BMP& bmp, unsigned int width, unsigned height)
{
    double xmin = -1.7;
    double xmax = 1.3;
    double ymin = -1.3;
    double ymax = 1.7;

    double xstep = (xmax - xmin) / (width - 1.0);
    double ystep = (ymax - ymin) / (height - 1.0);

    for (unsigned int y = 0; y < height; ++y)
    {
        for (unsigned int x = 0; x < width; ++x)
        {
            complex_t c(xmin + x * xstep, ymin + y * ystep);

            iterate_point(bmp, c, x, y);
        }

        std::cout << "y = " << y << "\r";
    }

    std::cout << "\r\n";
}



int main()
{
    {
        BMP this_bmp;

        unsigned int bmp_width = 340;
        unsigned int bmp_height = 340;

        this_bmp.SetSize(bmp_width, bmp_height);
        this_bmp.SetBitDepth(24);

        iterate_plane(this_bmp, bmp_width, bmp_height);

        this_bmp.WriteToFile("C:\\Users\\Chris\\Desktop\\hello_fractal.bmp");
    }

    std::cout << "Done\r\n";
    std::cin.get();

    return 0;
}