/* Parsing and handling gamma arguments. */
/* Last edited on 2016-04-12 13:22:12 by stolfilocal */

#ifndef dsm_gamma_H
#define dsm_gamma_H

#define _GNU_SOURCE
#include <stdio.h>

#include <bool.h>
#include <argparser.h>
          
#define dsm_gamma_MIN 0.10
#define dsm_gamma_MAX 10.0
  /* Min and max allowed values of the {gamma} parameter. */
  
double dsm_gamma_pick_parameter(const char *p_name, double p_given, double p_file, double p_default, bool_t verbose);
  /* Chooses the gamma or bias to be used for decoding an input file.
    The result is the client-given value {p_given} if not {NAN},
    else the value {p_file} specified implicitly or implicitly in the 
    input file if not {NAN}, else the default value {p_default}.
    Prints the choice if verbose, using the string {p_name} as the 
    parameter's name.  */

/* COMMAND LINE PARSING */

double dsm_gamma_arg_parse(argparser_t *pp, const char *keyword);
  /* Looks for a command line argument equal to {keyword} and parses the next
    argument as gamma argument, according to the string {dsm_gamma_arg_INFO} below.
    Otherwise returns {NAN}. */

#define dsm_gamma_arg_INFO \
  "This argument specifies the nonlinearity" \
  " exponent (\"gamma\") of the pixel encoding used in the" \
  " images. It is used to convert" \
  " the integer sample values in the files to" \
  " fractional intensity values in memory, and vice-versa.  This argument is optional for input images in PNG, PGM, or PPM" \
  " format, in which case, if given, it overrides the gamma specified" \
  " in the file.   This argument is mandatory for the JPEG image format."

#endif