/*
 * Copyright (c) 1993, 1999 Alexandre Wennmacher (wennmach@geo.Uni-Koeln.DE)
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 * This product includes software developed by Alexandre Wennmacher.
 * 4. The name of Alexandre Wennmacher may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY ALEXANDRE WENNMACHER AND CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL ALEXANDRE WENNMACHER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <math.h>
#include "Sphere.h"
#include "SphereDim.h"
#include "const.h"

int
GetSpherePoint(Sphere *pSphere, SPHERETYPE *pValue, double Theta, double Phi)
{
    int iLat, iLon;
    int i;
  
    while (Phi < 0.0) Phi += TWO_PI;
    while (Phi >= TWO_PI) Phi -= TWO_PI;
    iLat = rint(Theta/pSphere->DeltaLatitude);
    if (iLat < 0 || iLat > NINTERVALS) return(SOUTOFRANGE);
    if (iLat == NINTERVALS) {
        *pValue = *(pSphere->SphereBuffer + pSphere->LastPoint);
        return(SOK);
    }

    iLon = Phi/ *(pSphere->PointSeparation + iLat); 

    if (iLon < 0 || iLon > *(pSphere->PointsPerLatitude + iLat))
      return(SOUTOFRANGE);

/* Handle rounding errors */
    if (iLon == *(pSphere->PointsPerLatitude + iLat))
      iLon = *(pSphere->PointsPerLatitude + iLat) - 1;

    i = *(pSphere->FirstPointOfLatitude + iLat) + iLon;
    *pValue = *(pSphere->SphereBuffer + i);

    return(SOK);
}