readstars.cpp

// readstars.cpp
//
// Copyright (C) 2001, Chris Laurel <claurel@shatters.net>
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.

#include <cmath>
#include <iostream>

#define MAX_STARS 120000

#define PI 3.1415926535898

#include "stellarclass.h"
#include "star.h"


int main(int argc, char *argv[])
{
    Star *stars = new Star[MAX_STARS];
    int nStars = 0;
    float brightest = 100000;

    while (nStars < MAX_STARS) {
        uint32_t catNo = 0;
        float RA = 0, dec = 0, parallax = 0;
        int16_t appMag;
        uint16_t stellarClass;

        cin.read((void *) &catNo, sizeof catNo);
        cin.read((void *) &RA, sizeof RA);
        cin.read((void *) &dec, sizeof dec);
        cin.read((void *) &parallax, sizeof parallax);
        cin.read((void *) &appMag, sizeof appMag);
        cin.read((void *) &stellarClass, sizeof stellarClass);
        if (!cin.good())
            break;

        Star *star = &stars[nStars];

        // Compute distance based on parallax
        double distance = 3.26 / (parallax > 0.0 ? parallax / 1000.0 : 1e-6);

        // Convert from RA, dec spherical to cartesian coordinates
        double theta = RA / 24.0 * PI * 2;
        double phi = (1.0 - dec / 90.0) * PI / 2;
        double x = cos(theta) * sin(phi) * distance;
        double y = cos(phi) * distance;
        double z = sin(theta) * sin(phi) * distance;
        star->setPosition((float) x, (float) y, (float) z);

        // Use apparent magnitude and distance to determine the absolute
        // magnitude of the star.
        star->setAbsoluteMagnitude((float) (appMag / 256.0 + 5 -
                                            5 * log10(distance / 3.26)));

        StellarClass sc((StellarClass::StarType) (stellarClass >> 12),
                        (StellarClass::SpectralClass)(stellarClass >> 8 & 0xf),
                        (unsigned int) (stellarClass >> 4 & 0xf),
                        (StellarClass::LuminosityClass) (stellarClass & 0xf));
        star->setStellarClass(sc);

        star->setCatalogNumber(catNo);

        if (parallax > 0.0 && star->getAbsoluteMagnitude() < brightest)
        {
            brightest = star->getAbsoluteMagnitude();
            cout << brightest << ' ' << sc << '\n';
        }

        nStars++;
    }

    cout << nStars << '\n';
    cout << sizeof(StellarClass) << '\n';
    cout << sizeof(stars[0]) << '\n';
}