/// <summary>
/// Initializes the transform using the parameters from the specified coordinate system information
/// </summary>
/// <param name="projInfo">A ProjectionInfo class contains all the standard and custom parameters needed to initialize this transform</param>
protected override void OnInit(ProjectionInfo projInfo)
{
Y0 = projInfo.IsSouth ? 10000000 : 0;
projInfo.FalseNorthing = Y0;
X0 = 500000;
projInfo.FalseEasting = X0;
int zone;
if (projInfo.Zone != null)
{
zone = projInfo.Zone.Value;
if (zone <= 0 || zone > 60)
{
throw new ProjectionException(35);
}
zone--;
}
else
{
zone = (int)Math.Floor((Proj.Adjlon(Lam0) + Math.PI) * 30 / Math.PI);
if (zone < 0)
{
zone = 0;
}
if (zone >= 60)
{
zone = 59;
}
}
Lam0 = (zone + .5) * Math.PI / 30.00 - Math.PI;
projInfo.Lam0 = Lam0;
K0 = 0.9996;
Phi0 = 0;
base.OnInit(projInfo);
}
/// <summary>
/// Initializes the transform using the parameters from the specified coordinate system information
/// </summary>
/// <param name="projInfo">A ProjectionInfo class contains all the standard and custom parameters needed to initialize this transform</param>
protected override void OnInit(ProjectionInfo projInfo)
{
double pp;
/* get control point locations */
double phi1 = projInfo.Phi1;
double lam1 = projInfo.Lam1;
double phi2 = projInfo.Phi2;
double lam2 = projInfo.Lam2;
if (phi1 == phi2 && lam1 == lam2)
{
throw new ProjectionException(-25);
}
Lam0 = Proj.Adjlon(0.5 * (lam1 + lam2));
_dlam2 = Proj.Adjlon(lam2 - lam1);
_cp1 = Math.Cos(phi1);
_cp2 = Math.Cos(phi2);
_sp1 = Math.Sin(phi1);
_sp2 = Math.Sin(phi2);
_cs = _cp1 * _sp2;
_sc = _sp1 * _cp2;
_ccs = _cp1 * _cp2 * Math.Sin(_dlam2);
_z02 = Proj.Aacos(_sp1 * _sp2 + _cp1 * _cp2 * Math.Cos(_dlam2));
_hz0 = .5 * _z02;
double a12 = Math.Atan2(_cp2 * Math.Sin(_dlam2),
_cp1 * _sp2 - _sp1 * _cp2 * Math.Cos(_dlam2));
_ca = Math.Cos(pp = Proj.Aasin(_cp1 * Math.Sin(a12)));
_sa = Math.Sin(pp);
_lp = Proj.Adjlon(Math.Atan2(_cp1 * Math.Cos(a12), _sp1) - _hz0);
_dlam2 *= .5;
_lamc = HALF_PI - Math.Atan2(Math.Sin(a12) * _sp1, Math.Cos(a12)) - _dlam2;
_thz0 = Math.Tan(_hz0);
_rhshz0 = .5 / Math.Sin(_hz0);
_r2Z0 = 0.5 / _z02;
_z02 *= _z02;
}
/// <inheritdoc />
protected override void OnForward(double[] lp, double[] xy, int startIndex, int numPoints)
{
bool bAlphaIs90 = Math.Abs(Math.Abs(_alpha) - HALF_PI) <= EPS10;
double _lamcMinusLam0 = Proj.Adjlon(_lamc - Lam0);
for (int i = startIndex; i < startIndex + numPoints; i++)
{
int phi = i * 2 + PHI;
int lam = i * 2 + LAMBDA;
int x = i * 2 + X;
int y = i * 2 + Y;
double ul, us;
double vl = Math.Sin(_bl * lp[lam]);
if (Math.Abs(Math.Abs(lp[phi]) - Math.PI / 2) <= EPS10)
{
ul = lp[phi] < 0 ? -_singam : _singam;
us = _al * lp[phi] / _bl;
}
else
{
double q = _el / (_ellips ? Math.Pow(Proj.Tsfn(lp[phi], Math.Sin(lp[phi]), E), _bl) : Tsfn0(lp[phi]));
double s = .5 * (q - 1 / q);
ul = 2.0 * (s * _singam - vl * _cosgam) / (q + 1.0 / q);
double con = Math.Cos(_bl * lp[lam]);
if (Math.Abs(con) >= TOLERANCE)
{
us = _al * Math.Atan((s * _cosgam + vl * _singam) / con) / _bl;
// if (con < 0) us += Math.PI * _al / _bl; taken care of below...
}
else
{
us = _al * _bl * lp[lam];
}
}
if (Math.Abs(Math.Abs(ul) - 1.0) <= EPS10)
{
xy[x] = double.NaN;
xy[y] = double.NaN;
continue;
//ProjectionException(20);
}
double vs = .5 * _al * Math.Log((1 - ul) / (1 + ul)) / _bl;
if (bAlphaIs90)
{
if (Math.Abs(_lamcMinusLam0 - lp[lam]) < EPS10)
{
us = 0;
}
else if (_lamcMinusLam0 - lp[lam] < 0) // from OGP guidance note 7 term: "SIGN(lamc-lam)"
{
us -= -_u0;
}
else
{
us -= _u0;
}
}
else
{
us -= _u0;
}
xy[x] = vs * _cosrot + us * _sinrot;
xy[y] = us * _cosrot - vs * _sinrot;
}
}
/// <summary>
/// Initializes the transform using the parameters from the specified coordinate system information
/// </summary>
/// <param name="projInfo">A ProjectionInfo class contains all the standard and custom parameters needed to initialize this transform</param>
protected override void OnInit(ProjectionInfo projInfo)
{
double con;
double f;
double d;
double toRadians = projInfo.GeographicInfo.Unit.Radians;
_rot = !projInfo.no_rot.HasValue || projInfo.no_rot.Value == 0;
bool azi = projInfo.alpha.HasValue;
if (azi)
{
if (projInfo.lonc.HasValue)
{
_lamc = projInfo.lonc.Value * toRadians;
}
if (projInfo.alpha.HasValue)
{
_alpha = projInfo.alpha.Value * toRadians;
}
if (Math.Abs(_alpha) < TOLERANCE ||
Math.Abs(Math.Abs(Phi0) - HALF_PI) <= TOLERANCE ||
Math.Abs(Math.Abs(_alpha) - HALF_PI) <= TOLERANCE)
{
throw new ProjectionException(32);
}
}
else
{
_lam1 = projInfo.Lam1;
_phi1 = projInfo.Phi1;
_lam2 = projInfo.Lam2;
_phi2 = projInfo.Phi2;
if (Math.Abs(_phi1 - _phi2) <= TOLERANCE ||
(con = Math.Abs(_phi1)) <= TOLERANCE ||
Math.Abs(con - HALF_PI) <= TOLERANCE ||
Math.Abs(Math.Abs(Phi0) - HALF_PI) <= TOLERANCE ||
Math.Abs(Math.Abs(_phi2) - HALF_PI) <= TOLERANCE)
{
throw new ProjectionException(33);
}
}
_ellips = Es > 0;
double com = _ellips ? Math.Sqrt(OneEs) : 1;
if (Math.Abs(Phi0) > EPS10)
{
double sinph0 = Math.Sin(Phi0);
double cosph0 = Math.Cos(Phi0);
if (_ellips)
{
con = 1 - Es * sinph0 * sinph0;
_bl = cosph0 * cosph0;
_bl = Math.Sqrt(1 + Es * _bl * _bl / OneEs);
_al = _bl * K0 * com / con;
d = _bl * com / (cosph0 * Math.Sqrt(con));
}
else
{
_bl = 1;
_al = K0;
d = 1 / cosph0;
}
if ((f = d * d - 1) <= 0)
{
f = 0;
}
else
{
f = Math.Sqrt(f);
if (Phi0 < 0)
{
f = -f;
}
}
_el = f += d;
if (_ellips)
{
_el *= Math.Pow(Proj.Tsfn(Phi0, sinph0, E), _bl);
}
else
{
_el *= Tsfn0(Phi0);
}
}
else
{
_bl = 1 / com;
_al = K0;
_el = d = f = 1;
}
if (azi)
{
_gamma = Math.Asin(Math.Sin(_alpha) / d);
Lam0 = _lamc - Math.Asin((.5 * (f - 1 / f)) * Math.Tan(_gamma)) / _bl;
projInfo.Lam0 = Lam0;
}
else
{
double h;
double l;
if (_ellips)
{
h = Math.Pow(Proj.Tsfn(_phi1, Math.Sin(_phi1), E), _bl);
l = Math.Pow(Proj.Tsfn(_phi2, Math.Sin(_phi2), E), _bl);
}
else
{
h = Tsfn0(_phi1);
l = Tsfn0(_phi2);
}
f = _el / h;
double p = (l - h) / (l + h);
double j = _el * _el;
j = (j - l * h) / (j + l * h);
if ((con = _lam1 - _lam2) < -Math.PI)
{
_lam2 -= Math.PI * 2;
}
else if (con > Math.PI)
{
_lam2 += Math.PI * 2;
}
Lam0 = Proj.Adjlon(.5 * (_lam1 + _lam2) - Math.Atan(j * Math.Tan(.5 * _bl * (_lam1 - _lam2)) / p) / _bl);
projInfo.Lam0 = Lam0;
_gamma = Math.Atan(2 * Math.Sin(_bl * Proj.Adjlon(_lam1 - Lam0)) / (f - 1 / f));
_alpha = Math.Asin(d * Math.Sin(_gamma));
}
_singam = Math.Sin(_gamma);
_cosgam = Math.Cos(_gamma);
if (projInfo.rot_conv.HasValue)
{
f = _alpha;
}
else
{
f = _gamma;
}
_sinrot = Math.Sin(f);
_cosrot = Math.Cos(f);
if (projInfo.no_uoff.HasValue)
{
_u0 = Math.Abs(_al * Math.Atan(Math.Sqrt(d * d - 1) / _cosrot) / _bl);
}
else
{
_u0 = 0;
}
if (Phi0 < 0)
{
_u0 = -_u0;
}
}
