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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/putp2.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/putp2.cpp')
| -rw-r--r-- | src/projections/putp2.cpp | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/src/projections/putp2.cpp b/src/projections/putp2.cpp new file mode 100644 index 00000000..d7a847c8 --- /dev/null +++ b/src/projections/putp2.cpp @@ -0,0 +1,61 @@ +#define PJ_LIB__ + +#include <math.h> + +#include "projects.h" + +PROJ_HEAD(putp2, "Putnins P2") "\n\tPCyl, Sph"; + +#define C_x 1.89490 +#define C_y 1.71848 +#define C_p 0.6141848493043784 +#define EPS 1e-10 +#define NITER 10 +#define PI_DIV_3 1.0471975511965977 + + +static XY s_forward (LP lp, PJ *P) { /* Spheroidal, forward */ + XY xy = {0.0,0.0}; + double p, c, s, V; + int i; + (void) P; + + p = C_p * sin(lp.phi); + s = lp.phi * lp.phi; + lp.phi *= 0.615709 + s * ( 0.00909953 + s * 0.0046292 ); + for (i = NITER; i ; --i) { + c = cos(lp.phi); + s = sin(lp.phi); + lp.phi -= V = (lp.phi + s * (c - 1.) - p) / + (1. + c * (c - 1.) - s * s); + if (fabs(V) < EPS) + break; + } + if (!i) + lp.phi = lp.phi < 0 ? - PI_DIV_3 : PI_DIV_3; + xy.x = C_x * lp.lam * (cos(lp.phi) - 0.5); + xy.y = C_y * sin(lp.phi); + + return xy; +} + + +static LP s_inverse (XY xy, PJ *P) { /* Spheroidal, inverse */ + LP lp = {0.0,0.0}; + double c; + + lp.phi = aasin(P->ctx,xy.y / C_y); + lp.lam = xy.x / (C_x * ((c = cos(lp.phi)) - 0.5)); + lp.phi = aasin(P->ctx,(lp.phi + sin(lp.phi) * (c - 1.)) / C_p); + + return lp; +} + + +PJ *PROJECTION(putp2) { + P->es = 0.; + P->inv = s_inverse; + P->fwd = s_forward; + + return P; +} |
