diff options
Diffstat (limited to 'src/projections/vandg.cpp')
| -rw-r--r-- | src/projections/vandg.cpp | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/src/projections/vandg.cpp b/src/projections/vandg.cpp index 89620356..7d485aff 100644 --- a/src/projections/vandg.cpp +++ b/src/projections/vandg.cpp @@ -13,7 +13,7 @@ PROJ_HEAD(vandg, "van der Grinten (I)") "\n\tMisc Sph"; # define HPISQ 4.93480220054467930934 -static PJ_XY s_forward (PJ_LP lp, PJ *P) { /* Spheroidal, forward */ +static PJ_XY vandg_s_forward (PJ_LP lp, PJ *P) { /* Spheroidal, forward */ PJ_XY xy = {0.0,0.0}; double al, al2, g, g2, p2; @@ -58,7 +58,7 @@ static PJ_XY s_forward (PJ_LP lp, PJ *P) { /* Spheroidal, forward */ } -static PJ_LP s_inverse (PJ_XY xy, PJ *P) { /* Spheroidal, inverse */ +static PJ_LP vandg_s_inverse (PJ_XY xy, PJ *P) { /* Spheroidal, inverse */ PJ_LP lp = {0.0,0.0}; double t, c0, c1, c2, c3, al, r2, r, m, d, ay, x2, y2; @@ -80,7 +80,14 @@ static PJ_LP s_inverse (PJ_XY xy, PJ *P) { /* Spheroidal, inverse */ al = c1 / c3 - THIRD * c2 * c2; m = 2. * sqrt(-THIRD * al); d = C2_27 * c2 * c2 * c2 + (c0 * c0 - THIRD * c2 * c1) / c3; - if (((t = fabs(d = 3. * d / (al * m))) - TOL) <= 1.) { + const double al_mul_m = al * m; + if( al_mul_m == 0 ) { + proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION); + return proj_coord_error().lp; + } + d = 3. * d /al_mul_m; + t = fabs(d); + if ((t - TOL) <= 1.) { d = t > 1. ? (d > 0. ? 0. : M_PI) : acos(d); lp.phi = M_PI * (m * cos(d * THIRD + PI4_3) - THIRD * c2); if (xy.y < 0.) lp.phi = -lp.phi; @@ -98,8 +105,8 @@ static PJ_LP s_inverse (PJ_XY xy, PJ *P) { /* Spheroidal, inverse */ PJ *PROJECTION(vandg) { P->es = 0.; - P->inv = s_inverse; - P->fwd = s_forward; + P->inv = vandg_s_inverse; + P->fwd = vandg_s_forward; return P; } |