private double GetAltitudeFromLatLng(double lat, double lng, bool meters)
{
Vector3d testPoint = Coordinates.GeoTo3dDouble(lat, lng);
Vector2d uv = DistanceCalc.GetUVFromInnerPoint(TopLeft, TopRight, BottomLeft, BottomRight, testPoint);
// Get 4 samples and interpolate
double uud = Math.Max(0, Math.Min(16, (uv.X * 16)));
double vvd = Math.Max(0, Math.Min(16, (uv.Y * 16)));
int uu = Math.Max(0, Math.Min(15, (int)(uv.X * 16)));
int vv = Math.Max(0, Math.Min(15, (int)(uv.Y * 16)));
double ha = uud - uu;
double va = vvd - vv;
if (demArray != null)
{
// 4 nearest neighbors
double ul = demArray[uu + 17 * vv];
double ur = demArray[(uu + 1) + 17 * vv];
double ll = demArray[uu + 17 * (vv + 1)];
double lr = demArray[(uu + 1) + 17 * (vv + 1)];
double top = ul * (1 - ha) + ha * ur;
double bottom = ll * (1 - ha) + ha * lr;
double val = top * (1 - va) + va * bottom;
return(val / (meters ? 1 : DemScaleFactor));
}
return(demAverage / (meters ? 1 : DemScaleFactor));
}
public override double GetSurfacePointAltitude(double lat, double lng, bool meters)
{
if (Level < lastDeepestLevel)
{
//interate children
for (int ii = 0; ii < 4; ii++)
{
Tile child = children[ii];
if (child != null)
{
if (child.IsPointInTile(lat, lng))
{
double retVal = child.GetSurfacePointAltitude(lat, lng, meters);
if (retVal != 0)
{
return(retVal);
}
else
{
break;
}
}
}
}
}
TileTargetLevel = Level;
TileTargetX = tileX;
TileTargetY = tileY;
Vector3d testPoint = Coordinates.GeoTo3dDouble(-lat, lng);
testPoint = Vector3d.SubtractVectors(new Vector3d(), testPoint);
Vector2d uv = DistanceCalc.GetUVFromInnerPoint(TopLeft.Copy(), TopRight.Copy(), BottomLeft.Copy(), BottomRight.Copy(), testPoint.Copy());
//Document.Title = "u:" + uv.X + ", v:" + uv.Y;
//uv.X = 1 - uv.X;
//uv.Y = 1 - uv.Y;
// Get 4 samples and interpolate
double uud = Math.Max(0, Math.Min(16, (uv.X * 16)));
double vvd = Math.Max(0, Math.Min(16, (uv.Y * 16)));
int uu = Math.Max(0, Math.Min(15, (int)(uv.X * 16)));
int vv = Math.Max(0, Math.Min(15, (int)(uv.Y * 16)));
double ha = uud - uu;
double va = vvd - vv;
if (demArray != null)
{
// 4 nearest neighbors
double ul = demArray[uu + 17 * vv];
double ur = demArray[(uu + 1) + 17 * vv];
double ll = demArray[uu + 17 * (vv + 1)];
double lr = demArray[(uu + 1) + 17 * (vv + 1)];
double top = ul * (1 - ha) + ha * ur;
double bottom = ll * (1 - ha) + ha * lr;
double val = top * (1 - va) + va * bottom;
return(val / DemScaleFactor);
}
return(demAverage / DemScaleFactor);
}