static bool
ParseAngle(const TCHAR *&src, Angle &angle)
{
// 41.234234N
TCHAR *endptr;
// Parse numerical value
double value = _tcstod(src, &endptr);
if (endptr == src)
return false;
src = endptr;
angle = Angle::Degrees(value);
// Skip until next whitespace and look for NSEW signs
bool found = false;
while (*src != _T(' ') && *src != _T('\0')) {
if (!found) {
if (*src == _T('N') || *src == _T('n') ||
*src == _T('E') || *src == _T('e')) {
found = true;
} else if (*src == _T('S') || *src == _T('s') ||
*src == _T('W') || *src == _T('w')) {
found = true;
angle.Flip();
}
}
src++;
}
return found;
}
Angle
SunEphemeris::GetHourAngle(Angle lat, Angle declin)
{
Angle dfo = Angle::Degrees(SUN_DIAMETER / 2 + AIR_REFRACTION);
// Correction: different sign at southern hemisphere
if (negative(lat.Degrees()))
dfo.Flip();
fixed fo = (declin + dfo).tan() * lat.tan();
return Angle::asin(fo) + Angle::QuarterCircle();
}
static bool
ReadLongitude(NMEAInputLine &line, Angle &value_r)
{
Angle value;
if (!ReadPositiveAngle(line, value))
return false;
if (line.read_first_char() == 'W')
value.Flip();
value_r = value;
return true;
}
static bool
ReadLongitude(NMEAInputLine &line, Angle &value_r)
{
Angle value;
if (!ReadGeoAngle(line, value))
return false;
char ch = line.ReadOneChar();
if (ch == 'W')
value.Flip();
else if (ch != 'E')
return false;
value_r = value;
return true;
}