void geod_lineinit_int(geod_geodesic g, double lat1, double lon1, double azi1, double salp1, double calp1, GEOD caps)
{
a = g.a;
f = g.f;
b = g.b;
c2 = g.c2;
f1 = g.f1;
// If caps is 0 assume the standard direct calculation
this.caps = (caps != 0 ? caps : GEOD.DISTANCE_IN | GEOD.LONGITUDE) |
GEOD.LATITUDE | GEOD.AZIMUTH | GEOD.LONG_UNROLL; // always allow latitude and azimuth and unrolling of longitude
this.lat1 = LatFix(lat1);
this.lon1 = lon1;
this.azi1 = azi1;
this.salp1 = salp1;
this.calp1 = calp1;
double cbet1, sbet1;
sincosdx(AngRound(lat1), out sbet1, out cbet1); sbet1 *= f1;
// Ensure cbet1 = +epsilon at poles
norm2(ref sbet1, ref cbet1); cbet1 = maxx(tiny, cbet1);
dn1 = Math.Sqrt(1 + g.ep2 * sq(sbet1));
// Evaluate alp0 from sin(alp1) * cos(bet1) = sin(alp0),
salp0 = salp1 * cbet1; // alp0 in [0, pi/2 - |bet1|]
// Alt: calp0 = hypot(sbet1, calp1 * cbet1). The following
// is slightly better (consider the case salp1 = 0).
calp0 = hypotx(calp1, salp1 * sbet1);
// Evaluate sig with tan(bet1) = tan(sig1) * cos(alp1).
// sig = 0 is nearest northward crossing of equator.
// With bet1 = 0, alp1 = pi/2, we have sig1 = 0 (equatorial line).
// With bet1 = pi/2, alp1 = -pi, sig1 = pi/2
// With bet1 = -pi/2, alp1 = 0 , sig1 = -pi/2
// Evaluate omg1 with tan(omg1) = sin(alp0) * tan(sig1).
// With alp0 in (0, pi/2], quadrants for sig and omg coincide.
// No atan2(0,0) ambiguity at poles since cbet1 = +epsilon.
// With alp0 = 0, omg1 = 0 for alp1 = 0, omg1 = pi for alp1 = pi.
ssig1 = sbet1; somg1 = salp0 * sbet1;
csig1 = comg1 = sbet1 != 0 || calp1 != 0 ? cbet1 * calp1 : 1;
norm2(ref ssig1, ref csig1); // sig1 in (-pi, pi]
// norm2(somg1, comg1); -- don't need to normalize!
k2 = sq(calp0) * g.ep2;
double eps = k2 / (2 * (1 + Math.Sqrt(1 + k2)) + k2);
if ((this.caps & GEOD.CAP_C1) != 0)
{
double s, c;
A1m1 = geod_geodesic.A1m1f(eps);
geod_geodesic.C1f(eps, C1a);
B11 = SinCosSeries(true, ssig1, csig1, C1a, nC1);
s = Math.Sin(B11); c = Math.Cos(B11);
// tau1=sig1+B11
stau1 = ssig1 * c + csig1 * s;
ctau1 = csig1 * c - ssig1 * s;
// Not necessary because C1pa reverts C1a
// B11=-SinCosSeries(TRUE, stau1, ctau1, C1pa, nC1p);
}
if ((this.caps & GEOD.CAP_C1p) != 0)
geod_geodesic.C1pf(eps, C1pa);
if ((this.caps & GEOD.CAP_C2) != 0)
{
A2m1 = geod_geodesic.A2m1f(eps);
geod_geodesic.C2f(eps, C2a);
B21 = SinCosSeries(true, ssig1, csig1, C2a, nC2);
}
if ((this.caps & GEOD.CAP_C3) != 0)
{
g.C3f(eps, C3a);
A3c = -f * salp0 * g.A3f(eps);
B31 = SinCosSeries(true, ssig1, csig1, C3a, nC3 - 1);
}
if ((this.caps & GEOD.CAP_C4) != 0)
{
g.C4f(eps, C4a);
// Multiplier=a^2*e^2*cos(alpha0)*sin(alpha0)
A4 = sq(a) * calp0 * salp0 * g.e2;
B41 = SinCosSeries(false, ssig1, csig1, C4a, nC4);
}
a13 = s13 = double.NaN;
}
public override PJ Init()
{
g=new geod_geodesic(a, es/(1+Math.Sqrt(one_es)));
phi0=Proj.pj_param_r(ctx, parameters, "lat_0");
if(Math.Abs(Math.Abs(phi0)-Proj.HALFPI)<EPS10)
{
mode=phi0<0.0?aeqd_mode.S_POLE:aeqd_mode.N_POLE;
sinph0=phi0<0.0?-1.0:1.0;
cosph0=0.0;
}
else if(Math.Abs(phi0)<EPS10)
{
mode=aeqd_mode.EQUIT;
sinph0=0.0;
cosph0=1.0;
}
else
{
mode=aeqd_mode.OBLIQ;
sinph0=Math.Sin(phi0);
cosph0=Math.Cos(phi0);
}
if(es==0)
{
inv=s_inverse;
fwd=s_forward;
}
else
{
en=Proj.pj_enfn(es);
if(en==null) return null;
if(Proj.pj_param_b(ctx, parameters, "guam"))
{
M1=Proj.pj_mlfn(phi0, sinph0, cosph0, en);
inv=e_guam_inv;
fwd=e_guam_fwd;
}
else
{
switch(mode)
{
case aeqd_mode.N_POLE:
Mp=Proj.pj_mlfn(Proj.HALFPI, 1.0, 0.0, en);
break;
case aeqd_mode.S_POLE:
Mp=Proj.pj_mlfn(-Proj.HALFPI, -1.0, 0.0, en);
break;
case aeqd_mode.EQUIT:
case aeqd_mode.OBLIQ:
inv=e_inverse;
fwd=e_forward;
N1=1.0/Math.Sqrt(1.0-es*sinph0*sinph0);
He=e/Math.Sqrt(one_es);
G=sinph0*He;
He*=cosph0;
break;
}
inv=e_inverse;
fwd=e_forward;
}
}
return this;
}
/// <summary>
/// Initialize a geod_geodesicline object in terms of the inverse geodesic problem.
/// </summary>
/// <param name="g">The <see cref="geod_geodesic"/> object specifying the ellipsoid.</param>
/// <param name="lat1">Latitude of point 1 (degrees).</param>
/// <param name="lon1">Longitude of point 1 (degrees).</param>
/// <param name="lat2">Latitude of point 2 (degrees).</param>
/// <param name="lon2">Longitude of point 2 (degrees).</param>
/// <param name="caps">Bitor'ed combination of <see cref="geod_mask"/> values. See remarks for more informations.</param>
/// <remarks>
/// <paramref name="caps"/> bitor'ed combination of geod_mask() values specifying
/// the capabilities the geod_geodesicline object should possess, i.e., which
/// quantities can be returned in calls to geod_position() and
/// geod_genposition().
///
/// This function sets point 3 of the geod_geodesicline to correspond to point
/// 2 of the direct geodesic problem. See geod_lineinit() for more
/// information.
/// </remarks>
public void geod_inverseline(geod_geodesic g, double lat1, double lon1, double lat2, double lon2, GEOD caps)
{
double salp1, calp1, dummy;
double a12 = g.geod_geninverse_int(lat1, lon1, lat2, lon2, out dummy, out salp1, out calp1, out dummy, out dummy, out dummy, out dummy, out dummy, out dummy);
double azi1 = atan2dx(salp1, calp1);
caps = caps != 0 ? caps : GEOD.DISTANCE_IN | GEOD.LONGITUDE;
// Ensure that a12 can be converted to a distance
if ((caps & (GEOD.OUT_ALL & GEOD.DISTANCE_IN)) != 0) caps |= GEOD.DISTANCE;
geod_lineinit_int(g, lat1, lon1, azi1, salp1, calp1, caps);
geod_setarc(a12);
}
/// <summary>
/// geod_gendirectline : Initialize a geod_geodesicline object in terms of the direct geodesic
/// problem specified in terms of either distance or arc length.
/// </summary>
/// <param name="g">The <see cref="geod_geodesic"/> object specifying the ellipsoid.</param>
/// <param name="lat1">Latitude of point 1 (degrees).</param>
/// <param name="lon1">Longitude of point 1 (degrees).</param>
/// <param name="azi1">Azimuth at point 1 (degrees).</param>
/// <param name="flags">Must be either <see cref="GEOD.NOFLAGS"/> or <see cref="GEOD.ARCMODE"/> to determining the meaning of the <paramref name="s12_a12"/>.</param>
/// <param name="s12_a12">if <paramref name="flags"/> = <see cref="GEOD.NOFLAGS"/>, this is the distance from point 1 to point 2 (meters);
/// if <paramref name="flags"/> = <see cref="GEOD.ARCMODE"/>, it is the arc length from point 1 to point 2 (degrees); it can be negative.</param>
/// <param name="caps">Bitor'ed combination of <see cref="geod_mask"/> values. See remarks for more informations.</param>
/// <remarks>
/// <paramref name="caps"/> bitor'ed combination of geod_mask() values specifying
/// the capabilities the geod_geodesicline object should possess, i.e., which
/// quantities can be returned in calls to geod_position() and
/// geod_genposition().
///
/// This function sets point 3 of the geod_geodesicline to correspond to point
/// 2 of the direct geodesic problem. See geod_lineinit() for more
/// information.
/// </remarks>
public geod_geodesicline(geod_geodesic g, double lat1, double lon1, double azi1, GEOD flags, double s12_a12, GEOD caps) : this(g, lat1, lon1, azi1, caps)
{
geod_gensetdistance(flags, s12_a12);
}
/// <summary>
/// geod_directline : Initialize a geod_geodesicline object in terms of the direct geodesic problem.
/// </summary>
/// <param name="g">The <see cref="geod_geodesic"/> object specifying the ellipsoid.</param>
/// <param name="lat1">Latitude of point 1 (degrees).</param>
/// <param name="lon1">Longitude of point 1 (degrees).</param>
/// <param name="azi1">Azimuth at point 1 (degrees).</param>
/// <param name="s12">Distance from point 1 to point 2 (meters); it can be negative.</param>
/// <param name="caps">Bitor'ed combination of <see cref="geod_mask"/> values. See remarks for more informations.</param>
/// <remarks>
/// <paramref name="caps"/> bitor'ed combination of geod_mask() values specifying
/// the capabilities the geod_geodesicline object should possess, i.e., which
/// quantities can be returned in calls to geod_position() and
/// geod_genposition().
///
/// This function sets point 3 of the geod_geodesicline to correspond to point
/// 2 of the direct geodesic problem. See geod_lineinit() for more
/// information.
/// </remarks>
public geod_geodesicline(geod_geodesic g, double lat1, double lon1, double azi1, double s12, GEOD caps) : this(g, lat1, lon1, azi1, GEOD.NOFLAGS, s12, caps)
{ }
/// <summary>
/// geod_lineinit : Initialize a geod_geodesicline object.
/// </summary>
/// <param name="g">The <see cref="geod_geodesic"/> object specifying the ellipsoid.</param>
/// <param name="lat1">Latitude of point 1 (degrees).</param>
/// <param name="lon1">Longitude of point 1 (degrees).</param>
/// <param name="azi1">Azimuth at point 1 (degrees).</param>
/// <param name="caps">Bitor'ed combination of <see cref="geod_mask"/> values. See remarks for more informations.</param>
/// <remarks>
/// <paramref name="caps"/> bitor'ed combination of geod_mask() values specifying
/// the capabilities the geod_geodesicline object should possess, i.e., which
/// quantities can be returned in calls to geod_position() and
/// geod_genposition().
///
/// <paramref name="lat1"/> should be in the range [-90deg, 90deg].
///
/// The geod_mask values are:
/// - caps|=GEOD_LATITUDE for the latitude lat2; this is added automatically,
/// - caps|=GEOD_LONGITUDE for the latitude lon2,
/// - caps|=GEOD_AZIMUTH for the latitude azi2; this is added automatically,
/// - caps|=GEOD_DISTANCE for the distance s12,
/// - caps|=GEOD_REDUCEDLENGTH for the reduced length m12,
/// - caps|=GEOD_GEODESICSCALE for the geodesic scales M12 and M21,
/// - caps|=GEOD_AREA for the area S12,
/// - caps|=GEOD_DISTANCE_IN permits the length of the
/// geodesic to be given in terms of s12; without this capability the
/// length can only be specified in terms of arc length.
///
/// A value of caps=0 is treated as GEOD.LATITUDE|GEOD.LONGITUDE|GEOD.AZIMUTH|GEOD.DISTANCE_IN
/// (to support the solution of the "standard" direct problem).
///
/// When initialized by this function, point 3 is undefined (s13 = a13 = NaN).
/// </remarks>
public geod_geodesicline(geod_geodesic g, double lat1, double lon1, double azi1, GEOD caps)
{
azi1 = AngNormalize(azi1);
double salp1, calp1;
// Guard against underflow in salp0
sincosdx(AngRound(azi1), out salp1, out calp1);
geod_lineinit_int(g, lat1, lon1, azi1, salp1, calp1, caps);
}
public void Ini()
{
GlobalGeodesic = new geod_geodesic(geod_a, geod_f);
}
