/* moonage.c - Don Yang (uguu.org)

   Ported from moonage.pl

   07/10/03
                                                                           */

#include<assert.h>
#include<stdio.h>
#include<math.h>
#include<time.h>

#define SYN    29.530588853
#define AGE1   23.686
#define W      48
#define H      32
#define PI     3.14159265358979323846264338327950288419716939937510

static double MoonAge(void)
{
   time_t t;
   struct tm *g;
   double d;
   int y;

   t = time(NULL);
   g = gmtime(&t);
   assert(g != NULL);
   y = g->tm_year - 100;
   d = (double)(g->tm_yday + y * 365.
     + (int)((y + 3) / 4) + (int)((y - 1) / 100) + (int)((y - 1) / 400))
     + (g->tm_hour + (g->tm_min + g->tm_sec / 60.) / 60.) / 24.;

   return fmod(d + AGE1, SYN);
}

static void Render(double phase)
{
   static const char dict1[65] =
      " `'\" `'\" `'\"+++\",;:8,(|7+888+<89.::8+|88.8)P+8>P.888,d8).8b(odb8";
   static const char dict2[65] =
      " `'\"-`'\" ''\"-'`\",:::,:::.:::.:::.:::,:::.:::,:::.:::,:::.:::.:::";
   static const int vx[6] = {1, 0, 1, 0, 1, 0};
   static const int vy[6] = {0, 0, 1, 1, 2, 2};
   static int grid[W * 2 + 2][H * 2 + 2];
   unsigned int i, x1, x2;
   double s, l, r;
   int x, y, g;

   for(y = -H; y <= H; y++)
   {
      s = W * sqrt(1 - (double)(y * y) / (H * H));
      if( phase < SYN / 2 )
      {
         l = s * (1 - 4 * (phase / SYN));
         r = s;
      }
      else
      {
         l = s * -1.0;
         r = s * (3 - 4 * (phase / SYN));
      }
      for(x = -W; x <= W; x++)
      {
         grid[x + W + 1][y + H + 1] =
            ((double)x >= l && (double)x <= r) ? 1 : 0;
      }
      for(x = 0; x < 256; x++)
      {
         if( grid[(int)(W * cos(x * PI / 128.0)) + W + 1]
                 [(int)(H * sin(x * PI / 128.0)) + H + 1] == 0 )
             grid[(int)(W * cos(x * PI / 128.0)) + W + 1]
                 [(int)(H * sin(x * PI / 128.0)) + H + 1] = 2;
      }
   }
   for(y = -H; y < H; y += 3)
   {
      for(x = -W; x < W; x += 2)
      {
         for(i = x1 = x2 = 0; i < 6; i++)
         {
            g = grid[x + vx[i] + W + 1][y + vy[i] + H + 1];
            if( g == 1 )   x1 += (1 << i);
            if( g == 2 )   x2 += (1 << i);
         }
         if( dict1[x1] == ' ' )
            (void)putchar((int)dict2[x2]);
         else
            (void)putchar(dict1[x1]);
      }
      (void)putchar('\n');
   }
}


int main(void)
{
   Render(MoonAge());
   return 0;
}