/Proj4/PJ_tcea.c
http://github.com/route-me/route-me · C · 30 lines · 29 code · 1 blank · 0 comment · 1 complexity · 2ea3ed35277cc32c04a9aa90fc716bfa MD5 · raw file
- #ifndef lint
- static const char SCCSID[]="@(#)PJ_tcea.c 4.1 94/02/15 GIE REL";
- #endif
- #define PROJ_PARMS__ \
- double rk0;
- #define PJ_LIB__
- #include "projects.h"
- PROJ_HEAD(tcea, "Transverse Cylindrical Equal Area") "\n\tCyl, Sph";
- FORWARD(s_forward); /* spheroid */
- xy.x = P->rk0 * cos(lp.phi) * sin(lp.lam);
- xy.y = P->k0 * (atan2(tan(lp.phi), cos(lp.lam)) - P->phi0);
- return (xy);
- }
- INVERSE(s_inverse); /* spheroid */
- double t;
- xy.y = xy.y * P->rk0 + P->phi0;
- xy.x *= P->k0;
- t = sqrt(1. - xy.x * xy.x);
- lp.phi = asin(t * sin(xy.y));
- lp.lam = atan2(xy.x, t * cos(xy.y));
- return (lp);
- }
- FREEUP; if (P) pj_dalloc(P); }
- ENTRY0(tcea)
- P->rk0 = 1 / P->k0;
- P->inv = s_inverse;
- P->fwd = s_forward;
- P->es = 0.;
- ENDENTRY(P)