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| author | Frank Warmerdam <warmerdam@pobox.com> | 1999-03-18 16:34:52 +0000 |
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| committer | Frank Warmerdam <warmerdam@pobox.com> | 1999-03-18 16:34:52 +0000 |
| commit | 565a4bd035b9d4a83955808efef20f1d8dfa24cf (patch) | |
| tree | 75785fc897708023f1ccdaf40079afcbaaf0fd3a /src/PJ_merc.c | |
| download | PROJ-565a4bd035b9d4a83955808efef20f1d8dfa24cf.tar.gz PROJ-565a4bd035b9d4a83955808efef20f1d8dfa24cf.zip | |
New
git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk@776 4e78687f-474d-0410-85f9-8d5e500ac6b2
Diffstat (limited to 'src/PJ_merc.c')
| -rw-r--r-- | src/PJ_merc.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/src/PJ_merc.c b/src/PJ_merc.c new file mode 100644 index 00000000..63bc3341 --- /dev/null +++ b/src/PJ_merc.c @@ -0,0 +1,50 @@ +#ifndef lint +static const char SCCSID[]="@(#)PJ_merc.c 4.1 94/02/15 GIE REL"; +#endif +#define PJ_LIB__ +#include <projects.h> +PROJ_HEAD(merc, "Mercator") "\n\tCyl, Sph&Ell\n\tlat_ts="; +#define EPS10 1.e-10 +FORWARD(e_forward); /* ellipsoid */ + if (fabs(fabs(lp.phi) - HALFPI) <= EPS10) F_ERROR; + xy.x = P->k0 * lp.lam; + xy.y = - P->k0 * log(pj_tsfn(lp.phi, sin(lp.phi), P->e)); + return (xy); +} +FORWARD(s_forward); /* spheroid */ + if (fabs(fabs(lp.phi) - HALFPI) <= EPS10) F_ERROR; + xy.x = P->k0 * lp.lam; + xy.y = P->k0 * log(tan(FORTPI + .5 * lp.phi)); + return (xy); +} +INVERSE(e_inverse); /* ellipsoid */ + if ((lp.phi = pj_phi2(exp(- xy.y / P->k0), P->e)) == HUGE_VAL) I_ERROR; + lp.lam = xy.x / P->k0; + return (lp); +} +INVERSE(s_inverse); /* spheroid */ + lp.phi = HALFPI - 2. * atan(exp(-xy.y / P->k0)); + lp.lam = xy.x / P->k0; + return (lp); +} +FREEUP; if (P) pj_dalloc(P); } +ENTRY0(merc) + double phits; + int is_phits; + + if (is_phits = pj_param(P->params, "tlat_ts").i) { + phits = fabs(pj_param(P->params, "rlat_ts").f); + if (phits >= HALFPI) E_ERROR(-24); + } + if (P->es) { /* ellipsoid */ + if (is_phits) + P->k0 = pj_msfn(sin(phits), cos(phits), P->es); + P->inv = e_inverse; + P->fwd = e_forward; + } else { /* sphere */ + if (is_phits) + P->k0 = cos(phits); + P->inv = s_inverse; + P->fwd = s_forward; + } +ENDENTRY(P) |