//TODO: Improve rendering code to segment spherical coordinates
//which are too far apart to follow curvature
public Vector3[] BuildSegment(Angle startLatitude, Angle startLongitude, Angle endLatitude, Angle endLongitude, float heightAboveSurface)
{
//check how far the point being added is from the last point
Angle angularDistance = World.ApproxAngularDistance(
startLatitude,
startLongitude,
endLatitude,
endLongitude);
Vector3[] newPoints = null;
if (angularDistance.Degrees >= 2.0)
{
int samples = (int)(angularDistance.Radians * 30); // 1 point for every 2 degrees.
if (samples < 2)
{
samples = 2;
}
Angle lat, lon = Angle.Zero;
newPoints = new Vector3[samples];
for (int i = 0; i < samples; i++)
{
float t = (float)i / (samples - 1);
World.IntermediateGCPoint(t, startLatitude, startLongitude, endLatitude, endLongitude,
angularDistance, out lat, out lon);
newPoints[i] = MathEngine.SphericalToCartesian(lat, lon, this._parentWorld.EquatorialRadius + this.verticalExaggeration * heightAboveSurface);
}
}
return(newPoints);
}
/// <summary>
/// Adds a point to the end of the line.
/// </summary>
/// <param name="x">Lon</param>
/// <param name="y">Lat</param>
/// <param name="z">Alt (meters)</param>
public void AddPoint(double x, double y, double z)
{
Point3d point = new Point3d(x, y, z);
//TODO:Divide into subsegments if too far
if (this.m_points.Count > 0)
{
Angle startlon = Angle.FromDegrees(this.m_points.Last.Value.X);
Angle startlat = Angle.FromDegrees(this.m_points.Last.Value.Y);
double startalt = this.m_points.Last.Value.Z;
Angle endlon = Angle.FromDegrees(x);
Angle endlat = Angle.FromDegrees(y);
double endalt = z;
Angle dist = World.ApproxAngularDistance(startlat, startlon, endlat, endlon);
if (dist.Degrees > 0.25)
{
double stepSize = 0.25;
int samples = (int)(dist.Degrees / stepSize);
for (int i = 0; i < samples; i++)
{
Angle lat, lon = Angle.Zero;
float frac = (float)i / samples;
World.IntermediateGCPoint(frac, startlat, startlon, endlat, endlon,
dist, out lat, out lon);
double alt = startalt + frac * (endalt - startalt);
Point3d pointint = new Point3d(lon.Degrees, lat.Degrees, alt);
this.AddPoint(pointint);
}
this.AddPoint(point);
}
else
{
this.AddPoint(point);
}
}
else
{
this.AddPoint(point);
}
this.NeedsUpdate = true;
}
/// <summary>
/// Calculates the segments of the measure curve
/// </summary>
public void Calculate(World world, bool useTerrain)
{
Angle angularDistance = World.ApproxAngularDistance( startLatitude, startLongitude, endLatitude, endLongitude );
Linear = angularDistance.Radians * world.EquatorialRadius;
int samples = (int)(angularDistance.Radians*30); // 1 point for every 2 degrees.
if(samples<2)
samples = 2;
LinearTrackLine = new CustomVertex.PositionColored[samples];
for(int i=0;i<LinearTrackLine.Length;i++)
LinearTrackLine[i].Color = World.Settings.MeasureLineLinearColorXml;;
Angle lat,lon=Angle.Zero;
for(int i=0; i<samples; i++)
{
float t = (float)i / (samples-1);
World.IntermediateGCPoint(t, startLatitude, startLongitude, endLatitude, endLongitude,
angularDistance, out lat, out lon );
double elevation = 0;
if(useTerrain)
elevation = world.TerrainAccessor.GetElevationAt(lat.Degrees,lon.Degrees,1024);
Vector3 subSegmentXyz = MathEngine.SphericalToCartesian(lat, lon,
world.EquatorialRadius + elevation * World.Settings.VerticalExaggeration );
LinearTrackLine[i].X = subSegmentXyz.X;
LinearTrackLine[i].Y = subSegmentXyz.Y;
LinearTrackLine[i].Z = subSegmentXyz.Z;
}
WorldXyzMid = world.IntermediateGCPoint(0.5f, startLatitude, startLongitude, endLatitude, endLongitude,
angularDistance );
}
