/*
** libproj -- library of cartographic projections
**
** Copyright (c) 2003, 2006   Gerald I. Evenden
*/
static const char
LIBPROJ_ID[] = "Id";
/*
** Permission is hereby granted, free of charge, to any person obtaining
** a copy of this software and associated documentation files (the
** "Software"), to deal in the Software without restriction, including
** without limitation the rights to use, copy, modify, merge, publish,
** distribute, sublicense, and/or sell copies of the Software, and to
** permit persons to whom the Software is furnished to do so, subject to
** the following conditions:
**
** The above copyright notice and this permission notice shall be
** included in all copies or substantial portions of the Software.
**
** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
** SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#define PROJ_PARMS__ \
  double  cosphi1; \
  int    mode;
#define PROJ_LIB__
#include  <lib_proj.h>
PROJ_HEAD(aitoff, "Aitoff") "\n\tMisc Sph";
PROJ_HEAD(wintri, "Winkel Tripel") "\n\tMisc Sph\n\tlat_1=";
FORWARD(s_forward); /* spheroid */
  double c, d;

  if ((d = proj_acos(cos(lp.phi) * cos(0.5 * lp.lam)))) { /* basic Aitoff */
    c = sin(lp.phi)/sin(d);
    xy.x = 2. * d * sqrt(fabs(1. - c * c));
    if (lp.lam < 0.)
      xy.x = -xy.x;
    xy.y = d * c;
  } else
    xy.x = xy.y = 0.;
  if (P->mode) { /* Winkel Tripel */
    xy.x = (xy.x + lp.lam * P->cosphi1) * 0.5;
    xy.y = (xy.y + lp.phi) * 0.5;
  }
  return (xy);
}
FREEUP; if (P) free(P); }
  static PROJ *
setup(PROJ *P) {
  P->inv = 0;
  P->fwd = s_forward;
  P->es = 0.;
  return P;
}
ENTRY0(aitoff)
  P->mode = 0;
ENDENTRY(setup(P))
ENTRY0(wintri)
  P->mode = 1;
  if (proj_param(P->params, "tlat_1").i) {
    if ((P->cosphi1 = cos(proj_param(P->params, "rlat_1").f)) <= 0.)
      E_ERROR(-22)
  } else /* 50d28' or acos(2/pi) */
    P->cosphi1 = 0.636619772367581343;
ENDENTRY(setup(P))
/*
** Log: proj_aitoff.c
** Revision 3.1  2006/01/11 01:38:18  gie
** Initial
**
*/