/// <summary> Gets childrent for quadkey. </summary>
private IEnumerable <QuadKey> GetChildren(QuadKey quadKey)
{
// TODO can be optimized to avoid string allocations.
var quadKeyName = quadKey.ToString();
yield return(QuadKey.FromString(quadKeyName + "0"));
yield return(QuadKey.FromString(quadKeyName + "1"));
yield return(QuadKey.FromString(quadKeyName + "2"));
yield return(QuadKey.FromString(quadKeyName + "3"));
}
/// <summary> Builds quadkeys if necessary. Decision is based on visible quadkey and lod level. </summary>
private void BuildIfNecessary(Transform planet)
{
var lod = (int)_zoom;
var actualGameObject = GetActual(planet, Coordinate, lod);
if (actualGameObject == planet)
{
return;
}
var actualQuadKey = QuadKey.FromString(actualGameObject.name);
var actualName = actualGameObject.name;
var parent = planet;
var quadKeys = new List <QuadKey>();
// zoom in
int disposedTiles = 0;
if (actualQuadKey.LevelOfDetail < lod)
{
quadKeys.AddRange(GetChildren(actualQuadKey));
var oldParent = actualGameObject.transform.parent;
disposedTiles = SafeDestroy(actualQuadKey, actualName) ? 1 : 0;
parent = new GameObject(actualName).transform;
parent.transform.parent = oldParent;
}
// zoom out
else if (actualQuadKey.LevelOfDetail > lod)
{
string name = actualName.Substring(0, actualName.Length - 1);
var quadKey = QuadKey.FromString(name);
// destroy all siblings
foreach (var child in GetChildren(quadKey))
{
disposedTiles += SafeDestroy(child, child.ToString()) ? 1 : 0;
}
// destroy current as it might be just placeholder.
SafeDestroy(actualQuadKey, name);
parent = GetParent(planet, quadKey);
quadKeys.Add(quadKey);
}
UnloadAssets(disposedTiles);
BuildQuadKeys(parent, quadKeys);
}
/// <summary> Gets parent game object for given quadkey. Creates hierarchy if necessary. </summary>
private Transform GetParent(Transform planet, QuadKey quadKey)
{
// recursion end
if (quadKey.LevelOfDetail <= LodRange.Minimum)
{
return(planet);
}
string quadKeyName = quadKey.ToString();
string parentName = quadKeyName.Substring(0, quadKeyName.Length - 1);
var parent = GameObject.Find(parentName);
return(parent != null
? parent.transform
: GetParent(planet, QuadKey.FromString(parentName)));
}
/// <summary> Gets quadkey which should be downloaded from remote server. </summary>
/// <remarks> Sometimes, mapzen returns more precise shapes then we need. </remarks>
private QuadKey GetDownloadQuadKey(QuadKey quadKey)
{
if (!LodMapping.ContainsKey(quadKey.LevelOfDetail))
{
return(quadKey);
}
int targetLod = LodMapping[quadKey.LevelOfDetail];
var isParent = targetLod < quadKey.LevelOfDetail;
var lod = quadKey.LevelOfDetail;
var newQuadKey = quadKey;
while (lod != targetLod)
{
var str = newQuadKey.ToString();
newQuadKey = QuadKey.FromString(str.Substring(0, str.Length - 1));
lod += (isParent ? -1 : 1);
}
return(newQuadKey);
}