#include "library.h"

const int screen_size = 600;
const double function_max = 60.0;

const double pi = acos(-1.0);

double f1(double x, double y)
{ const double w = x/3, z = y/3;
  const double a = sqrt(w*w+z*z);
  const double b = sin(a)/pi;
  const double c = sqrt((w-5)*(w-5)+(z-2)*(z-2));
  const double d = cos(c)/pi;
  return 9.86*b*d; }

void screen_pos_to_function(int scrx, int scry, double & x, double & y)
{ x = (scrx-screen_size/2.0)/(screen_size/2.0)*function_max;
  y = (screen_size/2.0-scry)/(screen_size/2.0)*function_max; }

void function_to_screen_pos(double x, double y, int & scrx, int & scry)
{ scrx = (int)(x/function_max*(screen_size/2)+screen_size/2);
  scry = screen_size/2-(int)(y/function_max*(screen_size/2)); }

void draw_cross(int x, int y)
{ move_to(x-10, y-10);
  draw_to(x+10, y+10);
  move_to(x-10, y+10);
  draw_to(x+10, y-10); }

void main()
{ make_window(screen_size, screen_size);
  while (true)
  { wait_for_mouse_click();
    int scrx = get_click_x(), scry = get_click_y();
    cout << "(" << scrx << ", " << scry << ") -> ";
    double x, y;
    screen_pos_to_function(scrx, scry, x, y);
    cout << x << ", " << y << " -> ";
    int nx, ny;
    function_to_screen_pos(x, y, nx, ny);
    cout << "(" << nx << ", " << ny << ")\n";
    draw_cross(nx, ny); } }














/*
  double minz=f1(0, 0);
  double maxz=minz;
  for (int scrx=0; scrx<screen_size; scrx+=1)
  { for (int scry=0; scry<screen_size; scry+=1)
    { double x, y;
      screen_pos_to_function(scrx, scry, x, y);
      double z = f1(x, y);
      if (z>maxz) maxz=z;
      if (z<minz) minz=z;
      if (z>0)
        set_pixel_color(scrx, scry, make_color(z, 0, 0));
      else
        set_pixel_color(scrx, scry, make_color(0, 0, -z)); } }
  cout << "min = " << minz << "\n";
  cout << "max = " << maxz << "\n"; }
*/