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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/boggs.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/boggs.cpp')
| -rw-r--r-- | src/projections/boggs.cpp | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/src/projections/boggs.cpp b/src/projections/boggs.cpp new file mode 100644 index 00000000..119357c0 --- /dev/null +++ b/src/projections/boggs.cpp @@ -0,0 +1,43 @@ +#define PJ_LIB__ +#include <math.h> + +#include "projects.h" + +PROJ_HEAD(boggs, "Boggs Eumorphic") "\n\tPCyl, no inv, Sph"; +# define NITER 20 +# define EPS 1e-7 +# define FXC 2.00276 +# define FXC2 1.11072 +# define FYC 0.49931 + + +static XY s_forward (LP lp, PJ *P) { /* Spheroidal, forward */ + XY xy = {0.0,0.0}; + double theta, th1, c; + int i; + (void) P; + + theta = lp.phi; + if (fabs(fabs(lp.phi) - M_HALFPI) < EPS) + xy.x = 0.; + else { + c = sin(theta) * M_PI; + for (i = NITER; i; --i) { + theta -= th1 = (theta + sin(theta) - c) / + (1. + cos(theta)); + if (fabs(th1) < EPS) break; + } + theta *= 0.5; + xy.x = FXC * lp.lam / (1. / cos(lp.phi) + FXC2 / cos(theta)); + } + xy.y = FYC * (lp.phi + M_SQRT2 * sin(theta)); + return (xy); +} + + + +PJ *PROJECTION(boggs) { + P->es = 0.; + P->fwd = s_forward; + return P; +} |
