diff options
Diffstat (limited to 'src/projections/sterea.cpp')
| -rw-r--r-- | src/projections/sterea.cpp | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/src/projections/sterea.cpp b/src/projections/sterea.cpp index b6ebc7b4..ca3bfd06 100644 --- a/src/projections/sterea.cpp +++ b/src/projections/sterea.cpp @@ -44,7 +44,7 @@ PROJ_HEAD(sterea, "Oblique Stereographic Alternative") "\n\tAzimuthal, Sph&Ell"; -static PJ_XY e_forward (PJ_LP lp, PJ *P) { /* Ellipsoidal, forward */ +static PJ_XY sterea_e_forward (PJ_LP lp, PJ *P) { /* Ellipsoidal, forward */ PJ_XY xy = {0.0,0.0}; struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque); double cosc, sinc, cosl, k; @@ -53,14 +53,19 @@ static PJ_XY e_forward (PJ_LP lp, PJ *P) { /* Ellipsoidal, forward */ sinc = sin(lp.phi); cosc = cos(lp.phi); cosl = cos(lp.lam); - k = P->k0 * Q->R2 / (1. + Q->sinc0 * sinc + Q->cosc0 * cosc * cosl); + const double denom = 1. + Q->sinc0 * sinc + Q->cosc0 * cosc * cosl; + if( denom == 0.0 ) { + proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION); + return proj_coord_error().xy; + } + k = P->k0 * Q->R2 / denom; xy.x = k * cosc * sin(lp.lam); xy.y = k * (Q->cosc0 * sinc - Q->sinc0 * cosc * cosl); return xy; } -static PJ_LP e_inverse (PJ_XY xy, PJ *P) { /* Ellipsoidal, inverse */ +static PJ_LP sterea_e_inverse (PJ_XY xy, PJ *P) { /* Ellipsoidal, inverse */ PJ_LP lp = {0.0,0.0}; struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque); double rho, c, sinc, cosc; @@ -109,8 +114,8 @@ PJ *PROJECTION(sterea) { Q->cosc0 = cos (Q->phic0); Q->R2 = 2. * R; - P->inv = e_inverse; - P->fwd = e_forward; + P->inv = sterea_e_inverse; + P->fwd = sterea_e_forward; P->destructor = destructor; return P; |