/Proj4/PJ_mbtfpp.c
C | 35 lines | 35 code | 0 blank | 0 comment | 5 complexity | 54510a69d33012bd36133f29024230ad MD5 | raw file
1#ifndef lint 2static const char SCCSID[]="@(#)PJ_mbtfpp.c 4.1 94/02/15 GIE REL"; 3#endif 4#define PJ_LIB__ 5#include "projects.h" 6PROJ_HEAD(mbtfpp, "McBride-Thomas Flat-Polar Parabolic") "\n\tCyl., Sph."; 7#define CS .95257934441568037152 8#define FXC .92582009977255146156 9#define FYC 3.40168025708304504493 10#define C23 .66666666666666666666 11#define C13 .33333333333333333333 12#define ONEEPS 1.0000001 13FORWARD(s_forward); /* spheroid */ 14 lp.phi = asin(CS * sin(lp.phi)); 15 xy.x = FXC * lp.lam * (2. * cos(C23 * lp.phi) - 1.); 16 xy.y = FYC * sin(C13 * lp.phi); 17 return (xy); 18} 19INVERSE(s_inverse); /* spheroid */ 20 lp.phi = xy.y / FYC; 21 if (fabs(lp.phi) >= 1.) { 22 if (fabs(lp.phi) > ONEEPS) I_ERROR 23 else lp.phi = (lp.phi < 0.) ? -HALFPI : HALFPI; 24 } else 25 lp.phi = asin(lp.phi); 26 lp.lam = xy.x / ( FXC * (2. * cos(C23 * (lp.phi *= 3.)) - 1.) ); 27 if (fabs(lp.phi = sin(lp.phi) / CS) >= 1.) { 28 if (fabs(lp.phi) > ONEEPS) I_ERROR 29 else lp.phi = (lp.phi < 0.) ? -HALFPI : HALFPI; 30 } else 31 lp.phi = asin(lp.phi); 32 return (lp); 33} 34FREEUP; if (P) pj_dalloc(P); } 35ENTRY0(mbtfpp) P->es = 0.; P->inv = s_inverse; P->fwd = s_forward; ENDENTRY(P)