diff options
Diffstat (limited to 'src/projections/mbtfpq.cpp')
| -rw-r--r-- | src/projections/mbtfpq.cpp | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/src/projections/mbtfpq.cpp b/src/projections/mbtfpq.cpp index 9a419790..5c7f8ca6 100644 --- a/src/projections/mbtfpq.cpp +++ b/src/projections/mbtfpq.cpp @@ -20,14 +20,13 @@ PROJ_HEAD(mbtfpq, "McBryde-Thomas Flat-Polar Quartic") "\n\tCyl, Sph"; static PJ_XY mbtfpq_s_forward (PJ_LP lp, PJ *P) { /* Spheroidal, forward */ PJ_XY xy = {0.0,0.0}; - double th1, c; - int i; (void) P; - c = C * sin(lp.phi); - for (i = NITER; i; --i) { - lp.phi -= th1 = (sin(.5*lp.phi) + sin(lp.phi) - c) / - (.5*cos(.5*lp.phi) + cos(lp.phi)); + const double c = C * sin(lp.phi); + for (int i = NITER; i; --i) { + const double th1 = (sin(.5*lp.phi) + sin(lp.phi) - c) / + (.5*cos(.5*lp.phi) + cos(lp.phi)); + lp.phi -= th1; if (fabs(th1) < EPS) break; } xy.x = FXC * lp.lam * (1.0 + 2. * cos(lp.phi)/cos(0.5 * lp.phi)); @@ -46,10 +45,18 @@ static PJ_LP mbtfpq_s_inverse (PJ_XY xy, PJ *P) { /* Spheroidal, inver proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION); return lp; } - else if (lp.phi < 0.) { t = -1.; lp.phi = -M_PI; } - else { t = 1.; lp.phi = M_PI; } - } else - lp.phi = 2. * asin(t = lp.phi); + else if (lp.phi < 0.) { + t = -1.; + lp.phi = -M_PI; + } + else { + t = 1.; + lp.phi = M_PI; + } + } else { + t = lp.phi; + lp.phi = 2. * asin(lp.phi); + } lp.lam = RXC * xy.x / (1. + 2. * cos(lp.phi)/cos(0.5 * lp.phi)); lp.phi = RC * (t + sin(lp.phi)); if (fabs(lp.phi) > 1.) |