public static IEnumerable fHtmToCenterPoint(SqlInt64 HtmID)
{
double x, y, z;
ArrayList point = new ArrayList();
HtmTrixel htm = new HtmTrixel();
char[] name = new char[HtmTrixel.eMaxNameSize];
double[] v0, v1, v2;
double norm;
v0 = new double[3];
v1 = new double[3];
v2 = new double[3];
if (htm.hid2name(name, (long)HtmID) > 1)
{
htm.name2Triangle(name, v0, v1, v2);
x = v0[0] + v1[0] + v2[0];
y = v0[1] + v1[1] + v2[1];
z = v0[2] + v1[2] + v2[2];
norm = x * x + y * y + z * z;
norm = Math.Sqrt(norm);
x /= norm;
y /= norm;
z /= norm;
point.Add(new Triple(x, y, z));
}
else { /* return empty */ }
return (IEnumerable)point;
}
public static IEnumerable fHtmToCornerPoints(SqlInt64 HtmID)
{
ArrayList point = new ArrayList();
HtmTrixel htm = new HtmTrixel();
char[] name = new char[HtmTrixel.eMaxNameSize];
double[] v0, v1, v2;
v0 = new double[3];
v1 = new double[3];
v2 = new double[3];
if (htm.hid2name(name, (long)HtmID) > 1)
{
htm.name2Triangle(name, v0, v1, v2);
point.Add(new Triple(v0[0], v0[1], v0[2]));
point.Add(new Triple(v1[0], v1[1], v1[2]));
point.Add(new Triple(v2[0], v2[1], v2[2]));
}
else { /* return empty */ }
return (IEnumerable)point;
}
public static SqlDouble fHtmIDToSquareArcmin(SqlInt64 hid)
{
HtmTrixel htm = new HtmTrixel();
double t1, t2, t3;
double area;
if (htm.getAngles((Int64)hid, out t1, out t2, out t3))
{
// Area in stearadians A = R^2[(t1 + t2 + t3 ) - Pi], but R=1.
area = (t1 + t2 + t3) - Cartesian.Pi;
area *= Cartesian.RTOD * Cartesian.RTOD; // to get square degrees;
area *= 3600.0; // square arc minutes
}
else
{
area = 0.0;
}
return (area);
}
public static SqlString fHtmToString(SqlInt64 HtmID)
{
HtmTrixel htm = new HtmTrixel();
char[] name = new char[HtmTrixel.eMaxNameSize];
int level = htm.hid2name(name, (long)HtmID);
if (level < 0)
{
return (new SqlString("Invalid HTM Identifier."));
}
else
{
return (new SqlString(new string(name, 0, level)));
}
}
public static long fHtmLatLon(double lat, double lon)
{
double x, y, z;
HtmTrixel ht = new HtmTrixel();
SpatialVector.radec2cartesian(lon, lat, out x, out y, out z);
return ht.cartesian2HID(x, y, z, level);
}
public static long fHtmEq(double ra, double dec)
{
double x, y, z;
HtmTrixel ht = new HtmTrixel();
SpatialVector.radec2cartesian(ra, dec, out x, out y, out z);
return ht.cartesian2HID(x, y, z, level);
}
public static long fHtmXyz(double x, double y, double z)
{ // avoid zero vectors by setting them to 1,0,0.
if (Cartesian.Epsilon2 > (x * x + y * y + z * z)) { x = 0; y = 0; z = 1; }
HtmTrixel ht = new HtmTrixel();
return ht.cartesian2HID(x, y, z, level);
}
private void init(){
_halfspaces = new ArrayList(); // will change
_corners = new ArrayList();
_sign = Halfspace.Sign.Zero;
_boundingCircle = new Halfspace();
_htm = new HtmTrixel();
}
private void clear(){
_halfspaces = null;
_corners = null;
_sign = Halfspace.Sign.Zero;
_boundingCircle = null;
_htm = new HtmTrixel();
}