diff options
Diffstat (limited to 'src/projections/aitoff.cpp')
| -rw-r--r-- | src/projections/aitoff.cpp | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/src/projections/aitoff.cpp b/src/projections/aitoff.cpp index dadae12d..7920309c 100644 --- a/src/projections/aitoff.cpp +++ b/src/projections/aitoff.cpp @@ -67,7 +67,9 @@ static PJ_XY aitoff_s_forward (PJ_LP lp, PJ *P) { /* Spheroidal, forwa struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque); double c, d; - if((d = acos(cos(lp.phi) * cos(c = 0.5 * lp.lam))) != 0.0) {/* basic Aitoff */ + c = 0.5 * lp.lam; + d = acos(cos(lp.phi) * cos(c)); + if(d != 0.0) {/* basic Aitoff */ xy.x = 2. * d * cos(lp.phi) * sin(c) * (xy.y = 1. / sin(d)); xy.y *= d * sin(lp.phi); } else @@ -113,8 +115,10 @@ static PJ_LP aitoff_s_inverse (PJ_XY xy, PJ *P) { /* Spheroidal, inver do { iter = 0; do { - sl = sin(lp.lam * 0.5); cl = cos(lp.lam * 0.5); - sp = sin(lp.phi); cp = cos(lp.phi); + sl = sin(lp.lam * 0.5); + cl = cos(lp.lam * 0.5); + sp = sin(lp.phi); + cp = cos(lp.phi); D = cp * cl; C = 1. - D * D; const double denom = pow(C, 1.5); @@ -137,11 +141,14 @@ static PJ_LP aitoff_s_inverse (PJ_XY xy, PJ *P) { /* Spheroidal, inver f2p = 0.5 * (f2p + 1.); f2l *= 0.5; } - f1 -= xy.x; f2 -= xy.y; - dl = (f2 * f1p - f1 * f2p) / (dp = f1p * f2l - f2p * f1l); + f1 -= xy.x; + f2 -= xy.y; + dp = f1p * f2l - f2p * f1l; + dl = (f2 * f1p - f1 * f2p) / dp; dp = (f1 * f2l - f2 * f1l) / dp; dl = fmod(dl, M_PI); /* set to interval [-M_PI, M_PI] */ - lp.phi -= dp; lp.lam -= dl; + lp.phi -= dp; + lp.lam -= dl; } while ((fabs(dp) > EPSILON || fabs(dl) > EPSILON) && (iter++ < MAXITER)); if (lp.phi > M_PI_2) lp.phi -= 2.*(lp.phi-M_PI_2); /* correct if symmetrical solution for Aitoff */ if (lp.phi < -M_PI_2) lp.phi -= 2.*(lp.phi+M_PI_2); /* correct if symmetrical solution for Aitoff */ @@ -149,7 +156,8 @@ static PJ_LP aitoff_s_inverse (PJ_XY xy, PJ *P) { /* Spheroidal, inver /* calculate x,y coordinates with solution obtained */ if((D = acos(cos(lp.phi) * cos(C = 0.5 * lp.lam))) != 0.0) {/* Aitoff */ - x = 2. * D * cos(lp.phi) * sin(C) * (y = 1. / sin(D)); + y = 1. / sin(D); + x = 2. * D * cos(lp.phi) * sin(C) * y; y *= D * sin(lp.phi); } else x = y = 0.; |