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| author | Kristian Evers <kristianevers@gmail.com> | 2018-12-26 10:53:01 +0100 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2018-12-26 10:53:01 +0100 |
| commit | 81ec8c0b58d66333fccd3703dab62a11132a0331 (patch) | |
| tree | 41b4675d169f849516649700ab4f50d4cffa4c02 /src/projections/collg.cpp | |
| parent | 355d681ed88019e97742344bd642c2fd97e700a1 (diff) | |
| parent | 80dad6ef2bed4a83008db06986dc168918d48476 (diff) | |
| download | PROJ-81ec8c0b58d66333fccd3703dab62a11132a0331.tar.gz PROJ-81ec8c0b58d66333fccd3703dab62a11132a0331.zip | |
Merge pull request #1203 from rouault/cpp_conversion
Conversion of most C files to C++
Diffstat (limited to 'src/projections/collg.cpp')
| -rw-r--r-- | src/projections/collg.cpp | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/src/projections/collg.cpp b/src/projections/collg.cpp new file mode 100644 index 00000000..7904de29 --- /dev/null +++ b/src/projections/collg.cpp @@ -0,0 +1,53 @@ +#define PJ_LIB__ + +#include <math.h> + +#include "proj.h" +#include "projects.h" + +PROJ_HEAD(collg, "Collignon") "\n\tPCyl, Sph"; +#define FXC 1.12837916709551257390 +#define FYC 1.77245385090551602729 +#define ONEEPS 1.0000001 + + +static XY s_forward (LP lp, PJ *P) { /* Spheroidal, forward */ + XY xy = {0.0,0.0}; + (void) P; + if ((xy.y = 1. - sin(lp.phi)) <= 0.) + xy.y = 0.; + else + xy.y = sqrt(xy.y); + xy.x = FXC * lp.lam * xy.y; + xy.y = FYC * (1. - xy.y); + return (xy); +} + + +static LP s_inverse (XY xy, PJ *P) { /* Spheroidal, inverse */ + LP lp = {0.0,0.0}; + lp.phi = xy.y / FYC - 1.; + if (fabs(lp.phi = 1. - lp.phi * lp.phi) < 1.) + lp.phi = asin(lp.phi); + else if (fabs(lp.phi) > ONEEPS) { + proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION); + return lp; + } else { + lp.phi = lp.phi < 0. ? -M_HALFPI : M_HALFPI; + } + + if ((lp.lam = 1. - sin(lp.phi)) <= 0.) + lp.lam = 0.; + else + lp.lam = xy.x / (FXC * sqrt(lp.lam)); + return (lp); +} + + +PJ *PROJECTION(collg) { + P->es = 0.0; + P->inv = s_inverse; + P->fwd = s_forward; + + return P; +} |
