#include "library.h"

double formula(const double x, const double y)
{ return sin(hypot(x, y)) * sin(pow(hypot(x - 5, y - 5), 0.8)); }

double scale_x(const double x)
{ return (x + 10) * 25; }

double scale_y(const double y)
{ return (10 - y) * 25; }

int scale_z(const double z)
{ return z * 127 + 128; }

void vary_x_for_given_y(const double x, const double last, const double y)
{ const double z = formula(x, y);
  const int red = scale_z(z);
  const int blue = 255 - red;
  set_pixel_color(scale_x(x), scale_y(y), make_color_int(red, 0, blue));
  if (x < last)
    vary_x_for_given_y(x + 0.025, last, y); }

void vary_y(const double y, const double last)
{ vary_x_for_given_y(-10, 10, y);
  if (y < last)
    vary_y(y + 0.025, last); }

void main()
{ make_window(500, 500);
  vary_y(-10, 10); }