#! /usr/bin/python -t
# _*_ coding: iso-8859-1 _*_
# Last edited on 2010-06-15 18:04:35 by stolfi

MODULE_NAME = "jspnm"
MODULE_DESC = "Read and write PGM/PPM images"
MODULE_VERS = "1.0"

MODULE_COPYRIGHT = "Copyright © 2010 State University of Campinas"

MODULE_INFO = \
  "A library module to read and write PNM/PPM/PBM images.\n" \
  "\n" \
  "  Bla bla.\n"

import sys
import copy
from math import sqrt

def quantize(fval) :
  # Converts a float sample in {[0 _ 1]} to an int in {0..255}
  if (fval <= 0) :
    val = 0
  elif (fval >= 1) :
    val = 255
  else : 
    val = 1 + math.floor(fval*254);
    if (val > 254) :
      val = 254
  return val
  # ----------------------------------------------------------------------

def write_ppm_image(name, pic, nx, ny) :
  wr = open(name, "w")
  wr.write("P3\n")
  wr.write("%d %d %d\n" % (nx, ny, 255))
  for iy in range(ny) :
    for ix in range(nx) :
      pix = pic[iy][ix]
      if ((pix == None) or (len(pix) != 3)) :
        sys.stderr.write("bogus color value in pixel (%d,%d) = %s\n" % (ix,iy,pix));
      for ic in range(3) :
        val = quantize(pix[ic])
        wr.write(" %d" % val )
      if (ix % 10 == 0) :
        wr.write("\n")
    wr.write("\n")
  wr.close()
  # ----------------------------------------------------------------------

def write_pgm_image(name, pic, nx, ny) :
  wr = open(name, "w")
  wr.write("P2\n")
  wr.write("%d %d %d\n" % (nx, ny, 255))
  for iy in range(ny) :
    for ix in range(nx) :
      val = quantize(pic[iy][ix])
      wr.write(" %d" % val )
      if (ix % 30 == 0) :
        wr.write("\n")
    wr.write("\n")
  wr.close()
  # ----------------------------------------------------------------------

# ----------------------------------------------------------------------