/// <summary>
/// Constructor.
/// </summary>
/// <param name="tile">TerrainTile to be cached.</param>
public TerrainTileCacheEntry(TerrainTile tile)
{
m_terrainTile = tile;
}
/// <summary>
/// Builds a terrain array with specified boundaries
/// </summary>
/// <param name="north">North edge in decimal degrees.</param>
/// <param name="south">South edge in decimal degrees.</param>
/// <param name="west">West edge in decimal degrees.</param>
/// <param name="east">East edge in decimal degrees.</param>
/// <param name="samples"></param>
public override TerrainTile GetElevationArray(double north, double south, double west, double east,
int samples)
{
TerrainTile res = null;
if (m_higherResolutionSubsets != null)
{
// TODO: Support more than 1 level of higher resolution sets and allow user selections
foreach (TerrainAccessor higherResSub in m_higherResolutionSubsets)
{
if (!higherResSub.IsOn)
{
continue;
}
if (north <= higherResSub.North && south >= higherResSub.South &&
west >= higherResSub.West && east <= higherResSub.East)
{
res = higherResSub.GetElevationArray(north, south, west, east, samples);
return(res);
}
}
}
res = new TerrainTile(m_terrainTileService);
res.North = north;
res.South = south;
res.West = west;
res.East = east;
res.SamplesPerTile = samples;
res.IsInitialized = true;
res.IsValid = true;
double samplesPerDegree = (double)samples / (double)(north - south);
double latrange = Math.Abs(north - south);
double lonrange = Math.Abs(east - west);
TerrainTileCacheEntry ttce = null;
float[,] data = new float[samples, samples];
if (samplesPerDegree < World.Settings.MinSamplesPerDegree)
{
res.ElevationData = data;
return(res);
}
double scaleFactor = (double)1 / (samples - 1);
for (int x = 0; x < samples; x++)
{
for (int y = 0; y < samples; y++)
{
double curLat = north - scaleFactor * latrange * x;
double curLon = west + scaleFactor * lonrange * y;
// Wrap lat/lon to fit range 90/-90 and -180/180 (PM 2006-11-17)
if (curLat > 90)
{
curLat = 90 - (curLat - 90);
curLon += 180;
}
if (curLat < -90)
{
curLat = -90 - (curLat + 90);
curLon += 180;
}
if (curLon > 180)
{
curLon -= 360;
}
if (curLon < -180)
{
curLon += 360;
}
if (ttce == null ||
curLat < ttce.TerrainTile.South ||
curLat > ttce.TerrainTile.North ||
curLon < ttce.TerrainTile.West ||
curLon > ttce.TerrainTile.East)
{
TerrainTile tt = m_terrainTileService.GetTerrainTile(curLat, curLon, samplesPerDegree);
ttce = (TerrainTileCacheEntry)m_tileCache[tt.TerrainTileFilePath];
if (ttce == null)
{
ttce = new TerrainTileCacheEntry(tt);
AddToCache(ttce);
}
if (!ttce.TerrainTile.IsInitialized)
{
ttce.TerrainTile.Initialize();
}
ttce.LastAccess = DateTime.Now;
if (!tt.IsValid)
{
res.IsValid = false;
}
}
data[x, y] = ttce.TerrainTile.GetElevationAt(curLat, curLon);
}
}
res.ElevationData = data;
return(res);
}
