Remove the dependency on getopt.h (#380)

#include <iostream>

#include <fstream>

#include <getopt.h> // For parsing command-line options

struct Options {

  std::string model;              // the .json file in isd or model state format

  Options(): sample_rate(0), subpixel_offset(0.0), height_above_datum(0.0) {}

};

// Parse the input options with getopt.

bool parseOptions(int argc, char **argv, Options & opt) {

  // Collect the parsed options in a map

  std::map<std::string, std::string> parsed_options;

  int digit_optind = 0;

  while (1) {

    int this_option_optind = optind ? optind : 1;

    std::string short_options = ""; // no short options

    int option_index = 0;

    static struct option long_options[] = {

      {"model",              required_argument, 0,  0},

      {"output-model-state", required_argument, 0,  0},

      {"sample-rate",        required_argument, 0,  0},

      {"subpixel-offset",    required_argument, 0,  0},

      {"height-above-datum", required_argument, 0,  0},

      {"help",               no_argument,       0,  0}

    };

void printUsage(std::string const& progName) {

  std::cout << "Usage: " << progName << " --model <model file> [other options]"

            << "\nSee the documentation for more information.\n";

}

    int c = getopt_long(argc, argv, short_options.c_str(), long_options, &option_index);

    if (c == -1) // done parsing all options

      break;

// Do some naive parsing. Every option is assumed to start with two

// dashes and have a string value.  The --help option is handled

// separately.

bool parseOptions(int argc, char **argv, Options & opt) {

    std::string opt_name = long_options[option_index].name;

    if (c == 0) {

      if (optarg) {

        // The option has a value

        parsed_options[opt_name] = optarg;

      } else {

        // The option has no value

        parsed_options[opt_name] = "";

      }

    } else {

      // Something went wrong in parsing. The parser will print a message. Just add to it.

      std::cout << "Cannot continue.\n";

  std::vector<std::string> params;

  for (int it = 1; it < argc; it++) {

    if (std::string(argv[it]) == std::string("--help")) {

      printUsage(argv[0]);

      return false;

    }

    params.push_back(argv[it]);

  }

  // Print unexpected input arguments

  if (optind < argc) {

    printf("Unexpected argument: ");

    while (optind < argc)

      printf("%s ", argv[optind++]);

    printf("\n");

  if (params.size() %2 != 0 || params.empty()) {

    std::cout << "Could not parse correctly the input arguments.\n";

    printUsage(argv[0]);

    return false;

  }

  // See if the user asked for help

  bool print_help_and_exit = (parsed_options.find("help") != parsed_options.end());

  // Collect the parsed options in a map

  std::map<std::string, std::string> parsed_options;

  int num = params.size() / 2;

  for (int it = 0; it < num; it++) {

    std::string opt = params[2*it + 0];

    std::string val = params[2*it + 1];

    if (opt.size() <= 2 || opt[0] != '-' || opt[1] != '-' || val.empty() || val[0] == '-' ) {

      std::cout << "Could not parse correctly the input arguments.\n";

      printUsage(argv[0]);

      return false;

    }

    opt = opt.substr(2); // wipe the dashes

    parsed_options[opt] = val;

  }

  // It is safe to access non-existent values from a map, the result

  // will be an empty string

  opt.model = parsed_options["model"];

  if (opt.model == "") 

    print_help_and_exit = true;

  if (opt.model == "") {

    std::cout << "The input model file is empty.\n";

    printUsage(argv[0]);

    return false;

  }

  // Enforce that the sample rate is an integer

  // Enforce that the sample rate is an integer. Later the user can add

  // a subpixel offset to each sampled pixel, if desired.

  double sample_rate_double = atof(parsed_options["sample-rate"].c_str());

  if (sample_rate_double != round(sample_rate_double)) {

    std::cout << "The value of --sample-rate must be an integer.\n";

    print_help_and_exit = true;

  }

  // Print the help and exit

  if (print_help_and_exit) {

    std::cout << "Usage: " << argv[0] << " --model <model file> [other options]"

              << "\nSee the documentation for more information.\n";

    printUsage(argv[0]);

    return false;

  }

  // Collect all other option values. If not set the values will default to 0.

  // Collect all other option values. If not set, the values will default to 0.

  opt.output_model_state = parsed_options["output-model-state"];

  opt.sample_rate        = sample_rate_double;

  opt.subpixel_offset    = atof(parsed_options["subpixel-offset"].c_str());