diff options
Diffstat (limited to 'src/projections/mbt_fps.cpp')
| -rw-r--r-- | src/projections/mbt_fps.cpp | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/src/projections/mbt_fps.cpp b/src/projections/mbt_fps.cpp index 9ce2aa36..85051dc7 100644 --- a/src/projections/mbt_fps.cpp +++ b/src/projections/mbt_fps.cpp @@ -18,19 +18,18 @@ PROJ_HEAD(mbt_fps, "McBryde-Thomas Flat-Pole Sine (No. 2)") "\n\tCyl, Sph"; static PJ_XY mbt_fps_s_forward (PJ_LP lp, PJ *P) { /* Spheroidal, forward */ PJ_XY xy = {0.0,0.0}; - double k, V, t; - int i; (void) P; - k = C3 * sin(lp.phi); - for (i = MAX_ITER; i ; --i) { - t = lp.phi / C2; - lp.phi -= V = (C1 * sin(t) + sin(lp.phi) - k) / - (C1_2 * cos(t) + cos(lp.phi)); + const double k = C3 * sin(lp.phi); + for (int i = MAX_ITER; i ; --i) { + const double t = lp.phi / C2; + const double V = (C1 * sin(t) + sin(lp.phi) - k) / + (C1_2 * cos(t) + cos(lp.phi)); + lp.phi -= V; if (fabs(V) < LOOP_TOL) break; } - t = lp.phi / C2; + const double t = lp.phi / C2; xy.x = C_x * lp.lam * (1. + 3. * cos(lp.phi)/cos(t) ); xy.y = C_y * sin(t); return xy; @@ -39,9 +38,9 @@ static PJ_XY mbt_fps_s_forward (PJ_LP lp, PJ *P) { /* Spheroidal, forw static PJ_LP mbt_fps_s_inverse (PJ_XY xy, PJ *P) { /* Spheroidal, inverse */ PJ_LP lp = {0.0,0.0}; - double t; - lp.phi = C2 * (t = aasin(P->ctx,xy.y / C_y)); + const double t = aasin(P->ctx,xy.y / C_y); + lp.phi = C2 * t; lp.lam = xy.x / (C_x * (1. + 3. * cos(lp.phi)/cos(t))); lp.phi = aasin(P->ctx,(C1 * sin(t) + sin(lp.phi)) / C3); return (lp); |