/Proj4/PJ_rpoly.c

http://github.com/route-me/route-me · C · 38 lines · 37 code · 1 blank · 0 comment · 5 complexity · c398879e18ed273adab56b90c1d5883a MD5 · raw file 

    

  1. #ifndef lint
    2. 

  2. static const char SCCSID[]="@(#)PJ_rpoly.c	4.1	94/02/15	GIE	REL";
    3. 

  3. #endif
    4. 

  4. #define PROJ_PARMS__ \
    5. 

  5. 	double	phi1; \
    6. 

  6. 	double	fxa; \
    7. 

  7. 	double	fxb; \
    8. 

  8. 	int		mode;
    9. 

  9. #define EPS	1e-9
    10. 

  10. #define PJ_LIB__
    11. 

  11. #include	"projects.h"
    12. 

  12. PROJ_HEAD(rpoly, "Rectangular Polyconic")
    13. 

  13. 	"\n\tConic, Sph., no inv.\n\tlat_ts=";
    14. 

  14. FORWARD(s_forward); /* spheroid */
    15. 

  15. 	double fa;
    16. 

  16. 

  17. 	if (P->mode)
    18. 

  18. 		fa = tan(lp.lam * P->fxb) * P->fxa;
    19. 

  19. 	else
    20. 

  20. 		fa = 0.5 * lp.lam;
    21. 

  21. 	if (fabs(lp.phi) < EPS) {
    22. 

  22. 		xy.x = fa + fa;
    23. 

  23. 		xy.y = - P->phi0;
    24. 

  24. 	} else {
    25. 

  25. 		xy.y = 1. / tan(lp.phi);
    26. 

  26. 		xy.x = sin(fa = 2. * atan(fa * sin(lp.phi))) * xy.y;
    27. 

  27. 		xy.y = lp.phi - P->phi0 + (1. - cos(fa)) * xy.y;
    28. 

  28. 	}
    29. 

  29. 	return (xy);
    30. 

  30. }
    31. 

  31. FREEUP; if (P) pj_dalloc(P); }
    32. 

  32. ENTRY0(rpoly)
    33. 

  33. 	if ((P->mode = (P->phi1 = fabs(pj_param(P->params, "rlat_ts").f)) > EPS)) {
    34. 

  34. 		P->fxb = 0.5 * sin(P->phi1);
    35. 

  35. 		P->fxa = 0.5 / P->fxb;
    36. 

  36. 	}
    37. 

  37. 	P->es = 0.; P->fwd = s_forward;
    38. 

  38. ENDENTRY(P)
    39.