#include "library.h"

double f(double x)
{ return cos(x*x*x/1000000.0)/(x+1.0)*10000.0+250.0; }

double g(double x)
{ return sin(x*x/10000.0)/(x+1.0)*10000.0+250.0; }

// plot the graph of y=func(x) with x ranging from xmin to xmax.
// if the range of x (xmax - xmin) is very small, we could just
// draw a straight line and nobody would know the difference.
// Otherwise divide and conquer: find the middle x value then
// draw the two halves, one where x ranges from the minimum to
// the middle, and one where x ranges from the middle to the
// maximum.

void plot(double func(double x),
          double xmin, double xmax, double fineness)
{ if (xmax-xmin < fineness)
  { const double ymin = func(xmin), ymax = func(xmax);
    move_to(xmin, ymin);
    draw_to(xmax, ymax); }
  else
  { const double xmid = (xmin+xmax)/2;
    plot(func, xmid, xmax, fineness);
    plot(func, xmin, xmid, fineness); } }

void main()
{ make_window(500, 500);
  set_pen_width(2);
  set_pen_color(color::red);
  plot(f, 0.0, 500.0, 0.01);
  set_pen_color(color::blue);
  plot(g, 0.0, 500.0, 0.01); }