/**
* This method is used to set the projection x/y. The Set forces an attempted
* calculation of the corresponding latitude/longitude position. This may or
* may not be successful and a status is returned as such.
*
* @param x X coordinate of the projection in units that are the same as the
* radii in the label
*
* @param y Y coordinate of the projection in units that are the same as the
* radii in the label
*
* @return bool
*/
bool TransverseMercator::SetCoordinate(const double x, const double y) {
// Save the coordinate
SetXY(x,y);
// Declare & Initialize variables
double f,g,h,temp,con,phi,dphi,sinphi,cosphi,tanphi;
double c,cs,t,ts,n,rp,d,ds;
const double epsilon = 1.0e-10;
// Sphere Conversion
if (p_sph) {
f = exp(GetX() / (p_equatorialRadius * p_scalefactor));
g = 0.5 * (f - 1.0 / f);
temp = p_centerLatitude + GetY() / (p_equatorialRadius * p_scalefactor);
h = cos(temp);
con = sqrt((1.0 - h * h) / (1.0 + g * g));
if (con > 1.0) con = 1.0;
if (con < -1.0) con = -1.0;
p_latitude = asin(con);
if (temp < 0.0 ) p_latitude = -p_latitude;
p_longitude = p_centerLongitude;
if (g != 0.0 || h != 0.0) {
p_longitude = atan2(g,h) + p_centerLongitude;
}
}
// Ellipsoid Conversion
else if (!p_sph) {
con = (p_ml0 + GetY() / p_scalefactor) / p_equatorialRadius;
phi = con;
for (int i = 1; i < 7; i++) {
dphi = ((con + p_e1 * sin(2.0 * phi) - p_e2 * sin(4.0 * phi)
+ p_e3 * sin(6.0 * phi)) / p_e0) - phi;
phi += dphi;
if (fabs(dphi) <= epsilon) break;
}
// Didn't converge
if (fabs(dphi) > epsilon) {
p_good = false;
return p_good;
}
if (fabs(phi) >= Isis::HALFPI) {
if (GetY() >= 0.0) p_latitude = fabs(Isis::HALFPI);
if (GetY() < 0.0) p_latitude = - fabs(Isis::HALFPI);
p_longitude = p_centerLongitude;
}
else {
sinphi = sin(phi);
cosphi = cos(phi);
tanphi = tan(phi);
c = p_esp * cosphi * cosphi;
cs = c * c;
t = tanphi * tanphi;
ts = t * t;
con = 1.0 - p_eccsq * sinphi * sinphi;
n = p_equatorialRadius / sqrt(con);
rp = n * (1.0 - p_eccsq) / con;
d = GetX() / (n * p_scalefactor);
ds = d * d;
p_latitude = phi - (n * tanphi * ds / rp) * (0.5 - ds /
24.0 * (5.0 + 3.0 * t + 10.0 * c - 4.0 * cs - 9.0 *
p_esp - ds / 30.0 * (61.0 + 90.0 * t + 298.0 * c +
45.0 * ts - 252.0 * p_esp - 3.0 * cs)));
// Latitude cannot be greater than + or - halfpi radians (or 90 degrees)
if (fabs(p_latitude) > Isis::HALFPI) {
p_good = false;
return p_good;
}
p_longitude = p_centerLongitude + (d * (1.0 - ds / 6.0 *
(1.0 + 2.0 * t + c - ds / 20.0 * (5.0 - 2.0 * c +
28.0 * t - 3.0 * cs + 8.0 * p_esp + 24.0 * ts))) / cosphi);
}
}
// Convert to Degrees
p_latitude *= 180.0 / Isis::PI;
p_longitude *= 180.0 / Isis::PI;
// Cleanup the longitude
if (p_longitudeDirection == PositiveWest) p_longitude *= -1.0;
// These need to be done for circular type projections
p_longitude = To360Domain (p_longitude);
if (p_longitudeDomain == 180) p_longitude = To180Domain(p_longitude);
// Cleanup the latitude
if (IsPlanetocentric()) p_latitude = ToPlanetocentric(p_latitude);
p_good = true;
return p_good;
}
/**
* This method is used to set the projection x/y. The Set forces an attempted
* calculation of the corresponding latitude/longitude position. This may or
* may not be successful and a status is returned as such.
*
* @param x X coordinate of the projection in units that are the same as the
* radii in the label
*
* @param y Y coordinate of the projection in units that are the same as the
* radii in the label
*
* @return bool
*/
bool PointPerspective::SetCoordinate(const double x, const double y) {
// Save the coordinate
SetXY(x, y);
// Declare instance variables and calculate rho
double rho, rp, con, com, z, sinz, cosz;
const double epsilon = 1.0e-10;
rho = sqrt(GetX() * GetX() + GetY() * GetY());
rp = rho / m_equatorialRadius;
con = m_P - 1.0;
com = m_P + 1.0;
// Error calculating rho - should be less than equatorial radius
if (rp > (sqrt(con / com))) {
m_good = false;
return m_good;
}
// Calculate the latitude and longitude
m_longitude = m_centerLongitude;
if (fabs(rho) <= epsilon) {
m_latitude = m_centerLatitude;
}
else {
if (rp <= epsilon) {
sinz = 0.0;
}
else {
sinz = (m_P - sqrt(1.0 - rp * rp * com / con)) / (con / rp + rp / con);
}
z = asin(sinz);
sinz = sin(z);
cosz = cos(z);
con = cosz * m_sinph0 + GetY() * sinz * m_cosph0 / rho;
if (con > 1.0) con = 1.0;
if (con < -1.0) con = -1.0;
m_latitude = asin(con);
con = fabs(m_centerLatitude) - HALFPI;
if (fabs(con) <= epsilon) {
if (m_centerLatitude >= 0.0) {
m_longitude += atan2(GetX(), -GetY());
}
else {
m_longitude += atan2(-GetX(), GetY());
}
}
else {
con = cosz - m_sinph0 * sin(m_latitude);
if ((fabs(con) >= epsilon) || (fabs(GetX()) >= epsilon)) {
m_longitude += atan2(GetX() * sinz * m_cosph0, con * rho);
}
}
}
// Convert to degrees
m_latitude *= 180.0 / PI;
m_longitude *= 180.0 / PI;
// Cleanup the longitude
if (m_longitudeDirection == PositiveWest) m_longitude *= -1.0;
// These need to be done for circular type projections
m_longitude = To360Domain(m_longitude);
if (m_longitudeDomain == 180) m_longitude = To180Domain(m_longitude);
// Cleanup the latitude
if (IsPlanetocentric()) m_latitude = ToPlanetocentric(m_latitude);
m_good = true;
return m_good;
}