#! /usr/bin/python3
#
def pgma_write ( file_name, comment, width, height, maxval, gray ):

#*****************************************************************************80
#
## PGMA_WRITE writes an ASCII PGM graphics file.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license. 
#
#  Modified:
#
#    13 May 2017
#
#  Author:
#
#    John Burkardt
#
#  Parameters:
#
#    Input, string FILE_NAME, the name of the file.
#
#    Input, string COMMENT, a comment, which may be empty ('');
#
#    Input, integer WIDTH, HEIGHT, the width and height of the graphics image.
#
#    Input, integer MAXVAL, the maximum allowed gray value.
#
#    Input, integer GRAY[WIDTH,HEIGHT], gray values between 0 and MAXVAL.
#
  file_type = 'P2'

  file_handle = open ( file_name, 'wt' )
  file_handle.write ( "%s\n" % ( file_type ) ) 
  file_handle.write ( "#%s\n" % ( comment ) ) 
  file_handle.write ( "%d %d\n" % ( width, height ) ) 
  file_handle.write ( "%d\n" % ( maxval ) )

  for i in range ( height ):
    for j in range ( width ):
      file_handle.write ( " %d" % ( gray[i,j] ) ) 
    file_handle.write ( "\n" )

  file_handle.close ( )

  return

def pgma_write_test ( ):

#*****************************************************************************80
#
## PGMA_WRITE_TEST tests PGMA_WRITE.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license. 
#
#  Modified:
#
#    13 May 2017
#
#  Author:
#
#    John Burkardt
#
  import numpy as np

  print ( '' )
  print ( 'PGMA_WRITE_TEST:' )
  print ( '  PGMA_WRITE writes an ASCII PGM graphics file.' )

  file_name = 'pgma_io_test.pgm'

  comment = 'Example ASCII PGM graphics file.'

  width = 24
  height = 7
  maxval = 255

  gray = np.array \
  ( [ \
    [ 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0], \
    [ 0,  64,  64,  64,  64,   0,   0, 128, 128, 128, 128,   0,   0, 192, 192, 192, 192,   0,   0, 255, 255, 255, 255,   0], \
    [ 0,  64,   0,   0,   0,   0,   0, 128,   0,   0,   0,   0,   0, 192,   0,   0,   0,   0,   0, 255,   0,   0, 255,   0], \
    [ 0,  64,  64,  64,   0,   0,   0, 128, 128, 128,   0,   0,   0, 192, 192, 192,   0,   0,   0, 255, 255, 255, 255,   0], \
    [ 0,  64,   0,   0,   0,   0,   0, 128,   0,   0,   0,   0,   0, 192,   0,   0,   0,   0,   0, 255,   0,   0,   0,   0], \
    [ 0,  64,   0,   0,   0,   0,   0, 128, 128, 128, 128,   0,   0, 192, 192, 192, 192,   0,   0, 255,   0,   0,   0,   0], \
    [ 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0]  \
  ] )

  pgma_write ( file_name, comment, width, height, maxval, gray )

  print ( '' )
  print ( '  Graphics data stored in file "%s".' % ( file_name ) )
#
#  Terminate.
#
  print ( '' )
  print ( 'PGMA_WRITE_TEST:' )
  print ( '  Normal end of execution.' )
  return

if ( __name__ == '__main__' ):
  pgma_write_test ( )