/// <summary>
/// Select terrain elevation blocks from the terrain database.
/// </summary>
/// <param name="area">
/// The <see cref="GeoTreeArea"/> that the returned items must intersect.
/// </param>
/// <returns>
/// It returns a <see cref="ICollection{ITerrainBlock}"/> that intersect <paramref name="area"/>.
/// </returns>
public static ICollection <ITerrainBlock> SelectElevationBlocks(GeoTreeArea area)
{
List <ITerrainBlock> blocks = new List <ITerrainBlock>();
foreach (ITerrainBlock block in _GeoElevationTree.Select(area))
{
blocks.Add(block);
}
return(blocks);
}
/// <summary>
///
/// </summary>
/// <param name="geoArea">
///
/// </param>
/// <param name="precision">
///
/// </param>
private void CreateElevationTextures(GeoTreeArea geoArea, Vertex2d precision)
{
foreach (Terrain.ITerrainBlock terrainBlock in Terrain.SelectElevationBlocks(geoArea))
{
ElevationTexture elevationTexture;
// COllect texture if not defined yet
if (_ElevationTextures.TryGetValue(terrainBlock.Id, out elevationTexture))
{
elevationTexture = new ElevationTexture(terrainBlock);
LinkResource(elevationTexture);
_ElevationTextures.Add(terrainBlock.Id, elevationTexture);
}
// Do not dispose texture
elevationTexture.UpdateTime = DateTime.UtcNow;
// Determine which LOD need to be present
uint lod = 0;
for (double lodPrecision = terrainBlock.TextelPrecision; precision.x > lodPrecision; lodPrecision /= 2.0, lod++)
{
;
}
// Mipmap already loaded?
if (_ElevationTexture.HasMipMapLevel(lod))
{
continue;
}
// Load mipmap
elevationTexture.Create(lod);
}
}
