# include <cstdlib>
# include <iostream>
# include <iomanip>
# include <ctime>

using namespace std;

# include "triangle_grid.hpp"

//****************************************************************************80

void timestamp ( )

//****************************************************************************80
//
//  Purpose:
//
//    TIMESTAMP prints the current YMDHMS date as a time stamp.
//
//  Example:
//
//    31 May 2001 09:45:54 AM
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license. 
//
//  Modified:
//
//    08 July 2009
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    None
//
{
# define TIME_SIZE 40

  static char time_buffer[TIME_SIZE];
  const struct std::tm *tm_ptr;
  size_t len;
  std::time_t now;

  now = std::time ( NULL );
  tm_ptr = std::localtime ( &now );

  len = std::strftime ( time_buffer, TIME_SIZE, "%d %B %Y %I:%M:%S %p", tm_ptr );

  std::cout << time_buffer << "\n";

  return;
# undef TIME_SIZE
}
//****************************************************************************80

double *triangle_grid ( int n, double t[] )

//****************************************************************************80
//
//  Purpose:
//
//    TRIANGLE_GRID computes points on a triangular grid.
//
//  Discussion:
//
//    The grid is defined by specifying the coordinates of an enclosing
//    triangle T, and the number of subintervals each side of the triangle
//    should be divided into.
//
//    Choosing N = 10, for instance, breaks each side into 10 subintervals,
//    and produces a grid of ((10+1)*(10+2))/2 = 66 points.
//
//              X
//             9 X
//            8 9 X
//           7 8 9 X
//          6 7 8 9 X
//         5 6 7 8 9 X
//        4 5 6 7 8 9 X
//       3 4 5 6 7 8 9 X
//      2 3 4 5 6 7 8 9 X
//     1 2 3 4 5 6 7 8 9 X
//    0 1 2 3 4 5 6 7 8 9 X
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license.
//
//  Modified:
//
//    02 September 2010
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    Input, int N, the number of subintervals.
//
//    Input, double T[2*3], the coordinates of the points
//    defining the triangle.
//
//    Output, double *TRIANGLE_GRID[2*((N+1)*(N+2))/2], the coordinates
//    of the points in the triangle.
//
{
  int i;
  double ir;
  int j;
  double jr;
  int k;
  double kr;
  int l;
  int ng;
  double nr;
  int p;
  double *tg;

  ng = ( ( n + 1 ) * ( n + 2 ) ) / 2;
  tg = new double[2*ng];

  p = 0;
  nr = ( double ) ( n );

  for ( i = 0; i <= n; i++ )
  {
    ir = ( double ) ( i );
    for ( j = 0; j <= n - i; j++ )
    {
      jr = ( double ) ( j );
      k = n - i - j;
      kr = ( double ) ( k );
      for ( l = 0; l < 2; l++ )
      {
        tg[l+p*2] = ( ir * t[l+0*2] + jr * t[l+1*2] + kr * t[l+2*2] ) / nr;
      }
      p = p + 1;
    }
  }

  return tg;
}