public static void GetLocation(float radius, ref Vector3 vertexCoordinate, out Orientation orientation)
{
orientation = new Orientation();
//Set up the base vertex
//Suppose the vertex(0,0) is (startLongitude, 0N): 0N is definitely true;
float startLongitude = -90;
//Calculate Latitude: + N; - S
orientation.latitude = MathHelper.RadiansToDegrees((float) Math.Asin(vertexCoordinate.Y/radius));
//Calculate Longitude: x + (30E,180E,150W); x- W; z + (0+30 ; z- 180
//x^2+z^2
float currentRadius =
(float) Math.Sqrt(vertexCoordinate.X*vertexCoordinate.X + vertexCoordinate.Z*vertexCoordinate.Z);
orientation.longitude = (vertexCoordinate.Z >= 0)
? (360 +
MathHelper.RadiansToDegrees(
(float) Math.Asin(vertexCoordinate.X/currentRadius)) + startLongitude)%
360
: 180 -
MathHelper.RadiansToDegrees(
(float) Math.Asin(vertexCoordinate.X/currentRadius)) + startLongitude;
}
bool LocationFromScreen(int x, int y, out Orientation orient)
{
Vector3 vectorOut;//=new Vector3();
orient = new Orientation();
var vectorIn = new Vector3(x, glControl1.Height - y, 0);
Glu.UnProject(vectorIn, _viewmodelMatrix, _projectionMatrix, _viewportMatrix, out vectorOut);
float radius = _earth.Radius;
double sum = radius * radius - vectorOut.X * vectorOut.X - vectorOut.Y * vectorOut.Y;
if (sum >= 0)
{
vectorOut.Z = (float)Math.Sqrt(sum);
Matrix4 earthVert = Matrix4.Invert(FloatToMatrix4(_earthViewMatrix));
Vector3 newVec = Vector3.Transform(vectorOut, earthVert);
Earth.GetLocation(radius, ref newVec, out orient);
_fonts.Text = orient + " " + vectorOut;
}
else
{
_fonts.Text = vectorIn + " " + "Out of the sphere";
return false;
}
//vectorOut.X = vectorOut.X / radius;
//vectorOut.Y = vectorOut.Y / radius;
//vectorOut.Z = vectorOut.Z / radius;
return true;
}
//Transform orientation in Earth to position to draw terrain
Vector3 GetTerrainPosition(Orientation orient)
{
Vector3 vec, winVec, winLocation;
Earth.GetPosition(_earth.Radius, ref orient, out vec);
Vector3 vec1 = Vector3.Transform(vec, FloatToMatrix4(_earthViewMatrix));// + " " + newVec.ToString()
Glu.Project(vec1, _viewmodelMatrix, _projectionMatrix, _viewportMatrix, out winVec);
winVec.Z = 0.99f; //Depth in projection view
Glu.UnProject(winVec, _viewmodelMatrix, _terrainProjectionMatrix, _viewportMatrix, out winLocation);
return winLocation;
}
/// <summary>
/// Get vertexPosition on the Earth
/// </summary>
/// <param name="radius"></param>
/// <param name="orientation"></param>
/// <param name="vertexCoordinate"></param>
public static void GetPosition(float radius, ref Orientation orientation, out Vector3 vertexCoordinate)
{
vertexCoordinate = new Vector3();
//Set up the base vertex
//Suppose the vertex(0,0) is (startLongitude, 0N): 0N is definitely true;
float startLongitude = -90;
float bigSin = (float) Math.Sin(MathHelper.DegreesToRadians(orientation.latitude));
vertexCoordinate.Y = bigSin*radius;
float currentRadius = radius*(float) Math.Sqrt(1 - bigSin*bigSin);
float theta = orientation.longitude - startLongitude;
float smallSin = (float) Math.Sin(MathHelper.DegreesToRadians(theta));
vertexCoordinate.X = smallSin*currentRadius;
vertexCoordinate.Z = -currentRadius*(float) Math.Sqrt(1 - smallSin*smallSin);
}
