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| author | Even Rouault <even.rouault@spatialys.com> | 2018-12-19 12:25:33 +0100 |
|---|---|---|
| committer | Even Rouault <even.rouault@spatialys.com> | 2018-12-26 10:08:54 +0100 |
| commit | e6de172371ea203f6393d745641d66c82b5b13e2 (patch) | |
| tree | 791fa07f431a2d1db6f6e813ab984db982587278 /src/projections/PJ_mbtfpq.cpp | |
| parent | ce8075076b4e4ffebd32afaba419e1d9ab27cd03 (diff) | |
| download | PROJ-e6de172371ea203f6393d745641d66c82b5b13e2.tar.gz PROJ-e6de172371ea203f6393d745641d66c82b5b13e2.zip | |
cpp conversion: move source files in apps/ iso19111/ conversions/ projections/ transformations/ tests/ subdirectories
Diffstat (limited to 'src/projections/PJ_mbtfpq.cpp')
| -rw-r--r-- | src/projections/PJ_mbtfpq.cpp | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/src/projections/PJ_mbtfpq.cpp b/src/projections/PJ_mbtfpq.cpp new file mode 100644 index 00000000..b7c0eb16 --- /dev/null +++ b/src/projections/PJ_mbtfpq.cpp @@ -0,0 +1,74 @@ +#define PJ_LIB__ + +#include <math.h> + +#include "proj.h" +#include "projects.h" + +PROJ_HEAD(mbtfpq, "McBryde-Thomas Flat-Polar Quartic") "\n\tCyl, Sph"; + +#define NITER 20 +#define EPS 1e-7 +#define ONETOL 1.000001 +#define C 1.70710678118654752440 +#define RC 0.58578643762690495119 +#define FYC 1.87475828462269495505 +#define RYC 0.53340209679417701685 +#define FXC 0.31245971410378249250 +#define RXC 3.20041258076506210122 + + +static XY s_forward (LP lp, PJ *P) { /* Spheroidal, forward */ + XY xy = {0.0,0.0}; + double th1, c; + int i; + (void) P; + + c = C * sin(lp.phi); + for (i = NITER; i; --i) { + lp.phi -= th1 = (sin(.5*lp.phi) + sin(lp.phi) - c) / + (.5*cos(.5*lp.phi) + cos(lp.phi)); + if (fabs(th1) < EPS) break; + } + xy.x = FXC * lp.lam * (1.0 + 2. * cos(lp.phi)/cos(0.5 * lp.phi)); + xy.y = FYC * sin(0.5 * lp.phi); + return xy; +} + + +static LP s_inverse (XY xy, PJ *P) { /* Spheroidal, inverse */ + LP lp = {0.0,0.0}; + double t; + + lp.phi = RYC * xy.y; + if (fabs(lp.phi) > 1.) { + if (fabs(lp.phi) > ONETOL) { + proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION); + return lp; + } + else if (lp.phi < 0.) { t = -1.; lp.phi = -M_PI; } + else { t = 1.; lp.phi = M_PI; } + } else + lp.phi = 2. * asin(t = lp.phi); + lp.lam = RXC * xy.x / (1. + 2. * cos(lp.phi)/cos(0.5 * lp.phi)); + lp.phi = RC * (t + sin(lp.phi)); + if (fabs(lp.phi) > 1.) + if (fabs(lp.phi) > ONETOL) { + proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION); + return lp; + } + else lp.phi = lp.phi < 0. ? -M_HALFPI : M_HALFPI; + else + lp.phi = asin(lp.phi); + return lp; +} + + +PJ *PROJECTION(mbtfpq) { + + P->es = 0.; + P->inv = s_inverse; + P->fwd = s_forward; + + return P; +} |
