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| author | Even Rouault <even.rouault@spatialys.com> | 2018-12-19 13:00:37 +0100 |
|---|---|---|
| committer | Even Rouault <even.rouault@spatialys.com> | 2018-12-26 10:08:55 +0100 |
| commit | df574ae332d57f556fd56314883b3354cab1d0ff (patch) | |
| tree | 63a68d40d7ed7932d6329d9c7baa340bb6294f7f /src/projections/tobmerc.cpp | |
| parent | e6de172371ea203f6393d745641d66c82b5b13e2 (diff) | |
| download | PROJ-df574ae332d57f556fd56314883b3354cab1d0ff.tar.gz PROJ-df574ae332d57f556fd56314883b3354cab1d0ff.zip | |
cpp conversion: remove useless pj_, PJ_ and proj_ filename prefixes
Diffstat (limited to 'src/projections/tobmerc.cpp')
| -rw-r--r-- | src/projections/tobmerc.cpp | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/src/projections/tobmerc.cpp b/src/projections/tobmerc.cpp new file mode 100644 index 00000000..9c939f0b --- /dev/null +++ b/src/projections/tobmerc.cpp @@ -0,0 +1,51 @@ +#define PJ_LIB__ + +#include <float.h> +#include <math.h> + +#include "proj_internal.h" +#include "proj.h" +#include "proj_math.h" +#include "projects.h" + +PROJ_HEAD(tobmerc, "Tobler-Mercator") "\n\tCyl, Sph"; + +#define EPS10 1.e-10 +static double logtanpfpim1(double x) { /* log(tan(x/2 + M_FORTPI)) */ + if (fabs(x) <= DBL_EPSILON) { + /* tan(M_FORTPI + .5 * x) can be approximated by 1.0 + x */ + return log1p(x); + } + return log(tan(M_FORTPI + .5 * x)); +} + +static XY s_forward (LP lp, PJ *P) { /* Spheroidal, forward */ + XY xy = {0.0, 0.0}; + double cosphi; + + if (fabs(fabs(lp.phi) - M_HALFPI) <= EPS10) { + proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION); + return xy; + } + + cosphi = cos(lp.phi); + xy.x = P->k0 * lp.lam * cosphi * cosphi; + xy.y = P->k0 * logtanpfpim1(lp.phi); + return xy; +} + +static LP s_inverse (XY xy, PJ *P) { /* Spheroidal, inverse */ + LP lp = {0.0, 0.0}; + double cosphi; + + lp.phi = atan(sinh(xy.y / P->k0)); + cosphi = cos(lp.phi); + lp.lam = xy.x / P->k0 / (cosphi * cosphi); + return lp; +} + +PJ *PROJECTION(tobmerc) { + P->inv = s_inverse; + P->fwd = s_forward; + return P; +} |
