public virtual void ComputeViewMatrix()
{
double lat1 = _latitude.Degrees;
double lon1 = _longitude.Degrees;
EyeDiff.X = SMath.DegreesToRadians(_latitude.Degrees - lat1);
EyeDiff.Y = SMath.DegreesToRadians(_longitude.Degrees - lon1);
ReferenceCenter = SMath.SphericalToCartesianV3D(
_latitude.Degrees,
_longitude.Degrees,
WorldRadius);
if (World.Settings.Project == Projection.OrthoGraghics)
{
//lat1 = 0;
//lon1 = 0;
EyeDiff.X = 0;
EyeDiff.Y = 0;
}
Vector3d defaultPosition = SMath.SphericalToCartesianV3D(lat1, lon1, _worldRadius);
m_ViewMatrix = Matrix4d.LookAtRH(
defaultPosition,
Vector3d.Empty,
cameraUpVector);
//TODO JHJ 这是干什么的 有什么用
m_ViewMatrix *= Matrix4d.Translation(0, 0, _worldRadius);
m_ViewMatrix *= Matrix4d.RotationYawPitchRoll(-EyeDiff.Y, EyeDiff.X, 0);
m_ViewMatrix *= Matrix4d.Translation(0, 0, -_worldRadius);
m_ViewMatrix *= Matrix4d.RotationYawPitchRoll(
0,
-_tilt.Radians,
this._heading.Radians);
m_ViewMatrix *= Matrix4d.Translation(0, 0, (-this._distance));
if (World.Settings.Project == Projection.Perspective)
{
m_ViewMatrix *= Matrix4d.RotationZ(this._bank.Radians);
}
else
{
m_ViewMatrix *= Matrix4d.RotationZ(this._bank.Radians);
}
// Extract camera position
Matrix4d cam = Matrix4d.Invert(m_ViewMatrix);
_position = new Vector3d(cam[3, 0], cam[3, 1], cam[3, 2]);
}
public static Vector3d GetGeocentricPosition(System.DateTime utcDateTime)
{
if (World.Settings.SunSynchedWithTime)
{
// Sun synched with time and date
double JD = getJulianDay(utcDateTime);
double T = (JD - 2451545.0) / 36525; // number of Julian centuries since Jan 1, 2000, 12 UT
double k = Math.PI / 180.0;
double M = 357.52910 + 35999.05030 * T - 0.0001559 * T * T - 0.00000048 * T * T * T; // mean anomaly, degree
double L0 = 280.46645 + 36000.76983 * T + 0.0003032 * T * T; // mean longitude, degree
double DL = (1.914600 - 0.004817 * T - 0.000014 * T * T) * Math.Sin(k * M) + (0.019993 - 0.000101 * T) * Math.Sin(k * 2 * M) + 0.000290 * Math.Sin(k * 3 * M);
double L = L0 + DL; // true longitude, degree
L = L % 360;
// obliquity eps of ecliptic:
double eps = 23.0 + 26.0 / 60.0 + 21.448 / 3600.0 - (46.8150 * T + 0.00059 * T * T - 0.001813 * T * T * T) / 3600;
double X = Math.Cos(k * L);
double Y = Math.Cos(k * eps) * Math.Sin(k * L);
double Z = Math.Sin(k * eps) * Math.Sin(k * L);
double R = Math.Sqrt(1.0 - Z * Z);
double dec = (180 / Math.PI) * Math.Atan(Z / R); // in degrees
double RA = (24 / Math.PI) * Math.Atan(Y / (X + R)); // in hours
double theta0 = 280.46061837 + 360.98564736629 * (JD - 2451545.0) + 0.000387933 * T * T - T * T * T / 38710000.0; // Greenwich Sidereal Time
theta0 = theta0 % 360;
RA *= 15; // convert from hours to degrees
double tau = theta0 - RA;
Vector3d pos = SMath.SphericalToCartesianV3D(
-dec,
-(tau - 180), 1);
return(pos);
}
else
{
// Fixed sun heading and elevation
double worldRadius = 6378137; // Earth meter
Vector3 position = SMath.SphericalToCartesian(DrawArgs.Instance.WorldCamera.Latitude.Degrees, DrawArgs.Instance.WorldCamera.Longitude.Degrees, worldRadius);
return(GetGeocentricPosition(position, Angle.FromRadians(World.Settings.SunHeading), Angle.FromRadians(World.Settings.SunElevation), World.Settings.SunDistance));
}
}
public void Update(double south, double north, double west, double east, double radius1, double radius2)
{
double scale = radius2 / radius1;
SMath.SphericalToCartesianV3D(south, west, radius1, ref this.corners[0]);
this.corners[1] = this.corners[0];
this.corners[1].scale(scale);
SMath.SphericalToCartesianV3D(south, east, radius1, ref this.corners[2]);
this.corners[3] = this.corners[2];
this.corners[3].scale(scale);
SMath.SphericalToCartesianV3D(north, west, radius1, ref this.corners[4]);
this.corners[5] = this.corners[4];
this.corners[5].scale(scale);
SMath.SphericalToCartesianV3D(north, east, radius1, ref this.corners[6]);
this.corners[7] = this.corners[6];
this.corners[7].scale(scale);
ComputeBoundSphere();
}
