options.cpp

#include <iostream>

#include <unistd.h>

#include "decl.hpp"
#include "options.hpp"

namespace rematrix {
namespace {

vec3 parse_color(string_view s)
{
    const runtime_error err { "invalid color" };

    if (s.size() != 7 || s[0] != '#') {
        throw err;
    }

    size_t n { 0 };

    // XXX: allows "#+12345" or "#-12345"
    const auto color { stoul(string(s.substr(1)), &n, 16) };

    if (n != 6 || color > 0xFFFFFF) {
        throw err;
    }

    return {
        ((color >> 16) & 0xFF) / 255.0f,
        ((color >> 8) & 0xFF) / 255.0f,
        (color & 0xFF) / 255.0f
    };
}

} // namespace

options parse_options(int argc, char* argv[])
{
    using std::cerr;
    using std::endl;

    options ans;

    int opt { -1 };
    while ((opt = getopt(argc, argv, "c:f:l:m:owr:")) != -1) {
        switch (opt) {
        case 'c':
            ans.char_color = parse_color(optarg);
            break;
        case 'f':
            ans.feeder_color = parse_color(optarg);
            break;
        case 'l':
            ans.clear_color = parse_color(optarg);
            break;
        case 'm': {
            const string_view s { optarg };
            if (s == "bin" || s == "binary") {
                ans.mode = options::binary;
            } else if (s == "dna") {
                ans.mode = options::dna;
            } else if (s == "dec" || s == "decimal") {
                ans.mode = options::decimal;
            } else if (s == "hex" || s == "hexadecimal") {
                ans.mode = options::hexadecimal;
            } else if (s == "matrix") {
                ans.mode = options::matrix;
            } else {
                throw runtime_error("invalid mode");
            }
        } break;
        case 'o':
            ans.enable_fog = !ans.enable_fog;
            break;
        case 'w':
            ans.enable_waves = !ans.enable_waves;
            break;
        case 'r':
            ans.frame_rate = stoul(optarg, nullptr);
            if (ans.frame_rate > 30) {
                throw runtime_error("invalid frame rate");
            }
            break;
        default:
            cerr << "Usage: " << argv[0]
                 << " [-c char_color]"
                 << " [-f feeder_color]"
                 << " [-l clear_color]"
                 << " [-m binary|dna|decimal|hexadecimal|matrix]"
                 << " [-o]"
                 << " [-w]"
                 << " [-r frame-rate]"
                 << endl;
            exit(EXIT_FAILURE);
            break;
        }
    }

    return ans;
}

} // namespace rematrix