/Proj4/PJ_aitoff.c
http://github.com/route-me/route-me · C · 82 lines · 42 code · 5 blank · 35 comment · 7 complexity · a92d6f64aef790b457624c681de9868f MD5 · raw file
- /******************************************************************************
- * $Id: PJ_aitoff.c,v 1.3 2002/12/14 19:32:27 warmerda Exp $
- *
- * Project: PROJ.4
- * Purpose: Implementation of the aitoff (Aitoff) and wintri (Winkel Tripel)
- * projections.
- * Author: Gerald Evenden
- *
- ******************************************************************************
- * Copyright (c) 1995, Gerald Evenden
- *
- * 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.
- ******************************************************************************
- *
- * $Log: PJ_aitoff.c,v $
- * Revision 1.3 2002/12/14 19:32:27 warmerda
- * updated header
- *
- */
- #define PROJ_PARMS__ \
- double cosphi1; \
- int mode;
- #define PJ_LIB__
- #include "projects.h"
- PJ_CVSID("$Id: PJ_aitoff.c,v 1.3 2002/12/14 19:32:27 warmerda Exp $");
- 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 = acos(cos(lp.phi) * cos(c = 0.5 * lp.lam)))) {/* basic Aitoff */
- xy.x = 2. * d * cos(lp.phi) * sin(c) * (xy.y = 1. / sin(d));
- xy.y *= d * sin(lp.phi);
- } 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) pj_dalloc(P); }
- static PJ *
- setup(PJ *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 (pj_param(P->params, "tlat_1").i)
- {
- if ((P->cosphi1 = cos(pj_param(P->params, "rlat_1").f)) == 0.)
- E_ERROR(-22)
- }
- else /* 50d28' or acos(2/pi) */
- P->cosphi1 = 0.636619772367581343;
- ENDENTRY(setup(P))