mandelbrot_using_olc_pixel_engine.cpp

#define OLC_PGE_APPLICATION
#include "olcPixelGameEngine.h"
#include <complex>

class Example : public olc::PixelGameEngine
{
  public:
    Example() { sAppName = "Mandelbrot"; }

  public:
    bool OnUserCreate() override
    {
        // Called once at the start, so create things here
        return true;
    }

    bool OnUserUpdate(float fElapsedTime) override
    {
        size_t num_iters = 50;
        double bound = 2.0;
        auto w = ScreenWidth();
        auto h = ScreenHeight();
        for (size_t x = 0; x < w; ++x)
        {
            for (size_t y = 0; y < h; ++y)
            {
                std::complex<double> c{-2.0 + 4.0 / w * x, -2.0 + 4.0 / h * y};
                std::complex<double> z0;
                for (size_t i = 0; i < num_iters; ++i)
                {
                    auto z1 = std::pow(z0, 2.0) + c;
                    z0 = z1;
                    if (std::abs(z1) > bound)
                    {
                        Draw(x, y, olc::Pixel(0, 0, 0));
                        break;
                    }
                    else
                    {
                        Draw(x, y, olc::Pixel(255, 255, 255));
                    }
                }
            }
        }
        return true;
    }
};

int main()
{
    Example demo;
    if (demo.Construct(256, 240, 4, 4))
        demo.Start();

    return 0;
}