/Proj4/PJ_bacon.c

http://github.com/route-me/route-me · C · 44 lines · 43 code · 1 blank · 0 comment · 6 complexity · 370e6e8a722f3740fefc666d9639419c MD5 · raw file 

    

  1. #ifndef lint
    2. 

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

  3. #endif
    4. 

  4. # define HLFPI2	2.46740110027233965467
    5. 

  5. # define EPS	1e-10
    6. 

  6. #define PROJ_PARMS__ \
    7. 

  7. 	int bacn; \
    8. 

  8. 	int ortl;
    9. 

  9. #define PJ_LIB__
    10. 

  10. #include	"projects.h"
    11. 

  11. PROJ_HEAD(apian, "Apian Globular I") "\n\tMisc Sph, no inv.";
    12. 

  12. PROJ_HEAD(ortel, "Ortelius Oval") "\n\tMisc Sph, no inv.";
    13. 

  13. PROJ_HEAD(bacon, "Bacon Globular") "\n\tMisc Sph, no inv.";
    14. 

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

  15. 	double ax, f;
    16. 

  16. 

  17. 	xy.y = P->bacn ? HALFPI * sin(lp.phi) : lp.phi;
    18. 

  18. 	if ((ax = fabs(lp.lam)) >= EPS) {
    19. 

  19. 		if (P->ortl && ax >= HALFPI)
    20. 

  20. 			xy.x = sqrt(HLFPI2 - lp.phi * lp.phi + EPS) + ax - HALFPI;
    21. 

  21. 		else {
    22. 

  22. 			f = 0.5 * (HLFPI2 / ax + ax);
    23. 

  23. 			xy.x = ax - f + sqrt(f * f - xy.y * xy.y);
    24. 

  24. 		}
    25. 

  25. 		if (lp.lam < 0.) xy.x = - xy.x;
    26. 

  26. 	} else
    27. 

  27. 		xy.x = 0.;
    28. 

  28. 	return (xy);
    29. 

  29. }
    30. 

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

  31. ENTRY0(bacon)
    32. 

  32. 	P->bacn = 1;
    33. 

  33. 	P->ortl = 0;
    34. 

  34. 	P->es = 0.; P->fwd = s_forward;
    35. 

  35. ENDENTRY(P)
    36. 

  36. ENTRY0(apian)
    37. 

  37. 	P->bacn = P->ortl = 0;
    38. 

  38. 	P->es = 0.; P->fwd = s_forward;
    39. 

  39. ENDENTRY(P)
    40. 

  40. ENTRY0(ortel)
    41. 

  41. 	P->bacn = 0;
    42. 

  42. 	P->ortl = 1;
    43. 

  43. 	P->es = 0.; P->fwd = s_forward;
    44. 

  44. ENDENTRY(P)
    45.