diff options
| -rw-r--r-- | docs/source/operations/projections/webmerc.rst | 12 | ||||
| -rw-r--r-- | src/PJ_merc.c | 10 |
2 files changed, 10 insertions, 12 deletions
diff --git a/docs/source/operations/projections/webmerc.rst b/docs/source/operations/projections/webmerc.rst index 92da2d45..3a3d9a47 100644 --- a/docs/source/operations/projections/webmerc.rst +++ b/docs/source/operations/projections/webmerc.rst @@ -24,9 +24,9 @@ From `Wikipedia <https://en.wikipedia.org/wiki/Web_Mercator>`_: +---------------------+----------------------------------------------------------+ | **Classification** | Cylindrical (non conformant if used with ellipsoid) | +---------------------+----------------------------------------------------------+ -| **Available forms** | Forward and inverse, spherical projection | +| **Available forms** | Forward and inverse | +---------------------+----------------------------------------------------------+ -| **Defined area** | Global, but best used near the equator | +| **Defined area** | Global | +---------------------+----------------------------------------------------------+ | **Alias** | webmerc | +---------------------+----------------------------------------------------------+ @@ -49,9 +49,13 @@ Example:: Parameters ################################################################################ -.. note:: All parameters for the projection are optional. +.. note:: All parameters for the projection are optional, except the ellipsoid + definition, which is WGS84 for the typical use case of EPSG:3857. + In which case, the other parameters are set to their default 0 value. -.. include:: ../options/R.rst +.. include:: ../options/ellps.rst + +.. include:: ../options/lon_0.rst .. include:: ../options/x_0.rst diff --git a/src/PJ_merc.c b/src/PJ_merc.c index b75f9b11..46cd4b3d 100644 --- a/src/PJ_merc.c +++ b/src/PJ_merc.c @@ -9,7 +9,7 @@ #include "projects.h" PROJ_HEAD(merc, "Mercator") "\n\tCyl, Sph&Ell\n\tlat_ts="; -PROJ_HEAD(webmerc, "Web Mercator / Pseudo Mercator") "\n\tCyl, Sph\n\t"; +PROJ_HEAD(webmerc, "Web Mercator / Pseudo Mercator") "\n\tCyl, Ell\n\t"; #define EPS10 1.e-10 static double logtanpfpim1(double x) { /* log(tan(x/2 + M_FORTPI)) */ @@ -92,15 +92,9 @@ PJ *PROJECTION(merc) { PJ *PROJECTION(webmerc) { - /* Overriding k_0, lat_0 and lon_0 with fixed parameters */ + /* Overriding k_0 with fixed parameter */ P->k0 = 1.0; - P->phi0 = 0.0; - P->lam0 = 0.0; - P->b = P->a; - /* Clean up the ellipsoidal parameters to reflect the sphere */ - P->es = P->e = P->f = 0; - pj_calc_ellipsoid_params (P, P->a, 0); P->inv = s_inverse; P->fwd = s_forward; return P; |