diff options
Diffstat (limited to 'src/PJ_mbtfpp.c')
| -rw-r--r-- | src/PJ_mbtfpp.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/src/PJ_mbtfpp.c b/src/PJ_mbtfpp.c new file mode 100644 index 00000000..d2f8f18b --- /dev/null +++ b/src/PJ_mbtfpp.c @@ -0,0 +1,35 @@ +#ifndef lint +static const char SCCSID[]="@(#)PJ_mbtfpp.c 4.1 94/02/15 GIE REL"; +#endif +#define PJ_LIB__ +#include <projects.h> +PROJ_HEAD(mbtfpp, "McBride-Thomas Flat-Polar Parabolic") "\n\tCyl., Sph."; +#define CS .95257934441568037152 +#define FXC .92582009977255146156 +#define FYC 3.40168025708304504493 +#define C23 .66666666666666666666 +#define C13 .33333333333333333333 +#define ONEEPS 1.0000001 +FORWARD(s_forward); /* spheroid */ + lp.phi = asin(CS * sin(lp.phi)); + xy.x = FXC * lp.lam * (2. * cos(C23 * lp.phi) - 1.); + xy.y = FYC * sin(C13 * lp.phi); + return (xy); +} +INVERSE(s_inverse); /* spheroid */ + lp.phi = xy.y / FYC; + if (fabs(lp.phi) >= 1.) { + if (fabs(lp.phi) > ONEEPS) I_ERROR + else lp.phi = (lp.phi < 0.) ? -HALFPI : HALFPI; + } else + lp.phi = asin(lp.phi); + lp.lam = xy.x / ( FXC * (2. * cos(C23 * (lp.phi *= 3.)) - 1.) ); + if (fabs(lp.phi = sin(lp.phi) / CS) >= 1.) { + if (fabs(lp.phi) > ONEEPS) I_ERROR + else lp.phi = (lp.phi < 0.) ? -HALFPI : HALFPI; + } else + lp.phi = asin(lp.phi); + return (lp); +} +FREEUP; if (P) pj_dalloc(P); } +ENTRY0(mbtfpp) P->es = 0.; P->inv = s_inverse; P->fwd = s_forward; ENDENTRY(P) |