/// <summary>
/// Reloads the specified asset.
/// </summary>
/// <typeparam name="T">The Type of asset to reload</typeparam>
/// <param name="assetName">Name of the asset to load</param>
/// <returns>The new reference to the reloaded asset</returns>
public T Reload <T>(string assetName)
{
if (loadedAssets.ContainsKey(assetName))
{
AssetTracker oldAssetTracker = loadedAssets[assetName];
// Remove tracker so Load<T>() will create a new one
loadedAssets.Remove(assetName);
loadedAssetNames.Remove(assetName);
// Load it again
T asset = Load <T>(assetName);
// Invoke AssetChanged event
oldAssetTracker.OnAssetChanged(asset);
// Destroy previous tracker
DisposeAssetTracker(oldAssetTracker, true);
return(asset);
}
else
{
return(Load <T>(assetName));
}
}
/// <summary>
/// Constructor for convenience
/// </summary>
internal LoadAsyncParams(Type type, string name, AssetLoaded loadedMethod)
{
AssetType = type;
ItemLoadedMethods.Add(loadedMethod);
Tracker = new AssetTracker();
Tracker.AssetName = name;
Tracker.RefCount = 1;
Tracker.Status = AssetStatus.Loading;
}
/// <summary>
/// Force an asset to be disposed. Optionally releases child assets
/// </summary>
/// <param name="assetName">Name of asset to unload</param>
/// <param name="releaseChildren">Release child assets</param>
public void Unload(string assetName, bool releaseChildren)
{
if (assetName != null && loadedAssets.ContainsKey(assetName))
{
AssetTracker tracker = loadedAssets[assetName];
// Fire changed event
tracker.OnAssetChanged(null);
// Destroy disposables
DisposeAssetTracker(tracker, releaseChildren);
// Remove from dictionary
loadedAssets.Remove(assetName);
loadedAssetNames.Remove(assetName);
}
}
/// <summary>
/// Release asset. Decrements the reference count and
/// removes child assets when the count is zero
/// </summary>
/// <param name="assetName">Asset to release</param>
public void Release(string assetName)
{
if (assetName != null && loadedAssets.ContainsKey(assetName))
{
AssetTracker tracker = loadedAssets[assetName];
tracker.RefCount--;
if (tracker.RefCount == 0)
{
tracker.OnAssetChanged(null);
DisposeAssetTracker(tracker, true);
// Remove from dictionary
loadedAssets.Remove(assetName);
loadedAssetNames.Remove(assetName);
}
}
}
/// <summary>
/// Destroy IDisposables that were tracked by this asset but do not
/// exist as assets in their own right. This will also dispose the
/// unmanaged internals like vertex and index buffers
/// </summary>
/// <param name="tracker">AssetTracker to dispose</param>
/// <param name="releaseChildren">If true, child assets will be released</param>
private void DisposeAssetTracker(AssetTracker tracker, bool releaseChildren)
{
// Invoke asset changed event.
tracker.OnAssetChanged(null);
// Mark tracker as disposed
tracker.Status = AssetStatus.Disposed;
// Destroy tracked disposables
foreach (IDisposable disposable in tracker.Disposables)
{
disposable.Dispose();
}
// Dispose the actual asset, if possible
if (tracker.Asset is IDisposable)
{
((IDisposable)tracker.Asset).Dispose();
}
// Handle child assets
foreach (string childAsset in tracker.RefersTo)
{
if (loadedAssets.ContainsKey(childAsset))
{
// Maintain child reference list
loadedAssets[childAsset].ReferredToBy.Remove(tracker.AssetName);
// release child assets if requested
if (releaseChildren)
{
Release(childAsset);
}
}
}
}
/// <summary>
/// Asyncronously loads the specified asset
/// </summary>
/// <typeparam name="T">Generic type parameter</typeparam>
/// <param name="assetName">Name of asset to laod</param>
/// <param name="itemLoadedMethod">Method to call once load is completed</param>
/// <returns>AssetTracker of asset to be loaded. Allows
/// users to poll the asset status if desired</returns>
public AssetTracker LoadAsync <T>(string assetName, AssetLoaded itemLoadedMethod)
{
AssetTracker tracker = null;
// Check if asset is already loaded
if (loadedAssets.ContainsKey(assetName))
{
tracker = loadedAssets[assetName];
// Increment reference count
tracker.RefCount++;
// Call the specified item loaded method
if (itemLoadedMethod != null)
{
itemLoadedMethod(tracker.Asset);
}
}
else
{
if (loadThread == null)
{
// First time LoadAsync has been called so
// initialise thread, reset event and queue
loadThread = new Thread(new ThreadStart(LoadingThreadWorker));
loadThread.Name = "File Loading Worker";
loadItemsQueue = new Queue <LoadAsyncParams>();
loadResetEvent = new AutoResetEvent(false);
//reset the request flag to close the thread
mCloseRequested = false;
// Start thread. It will wait once queue is empty
loadThread.Start();
}
// Create the async argument structure and enqueue it for async load.
lock (loadItemsQueue)
{
// first check if this item is already enqueued
Queue <LoadAsyncParams> .Enumerator enumer = loadItemsQueue.GetEnumerator();
while (enumer.MoveNext())
{
if (enumer.Current.Tracker.AssetName == assetName)
{
// Register the itemLoaded method
enumer.Current.ItemLoadedMethods.Add(itemLoadedMethod);
tracker = enumer.Current.Tracker;
tracker.RefCount++;
break;
}
}
// Item not already queued for loading
if (tracker == null)
{
LoadAsyncParams args = new LoadAsyncParams(typeof(T), assetName, itemLoadedMethod);
tracker = args.Tracker;
loadItemsQueue.Enqueue(args);
}
}
// Tell loading thread to stop waiting
loadResetEvent.Set();
}
// Return tracker. Allows async caller to poll loaded status
return(tracker);
}
/// <summary>
/// Return the specified asset. Read it from disk if not available
/// </summary>
/// <typeparam name="T">The Type of asset to load</typeparam>
/// <param name="assetName">Name of the asset to load</param>
/// <param name="tracker">An AssetTracker to use when loading this asset. May be null</param>
/// <param name="forceReadAsset">if set to <c>true</c> [force read asset].</param>
/// <returns>
/// A reference to the loaded asset
/// </returns>
public T LoadToTracker <T>(string assetName, AssetTracker tracker, bool forceReadAsset)
{
// Return asset if currently loaded
if (!forceReadAsset && loadedAssets.ContainsKey(assetName))
{
// Get asset tracker
AssetTracker trackerExisting = loadedAssets[assetName];
// Get asset as correct type
T asset = (T)trackerExisting.Asset;
// Increment tracker's reference count after the cast as the cast will
// throw an exception if the incorrect generic type parameter is given
trackerExisting.RefCount++;
// Maintain the reference lists to show that this asset was loaded by
// the asset on the top of the stack
if (loadingAssetsStack.Count > 0)
{
loadingAssetsStack.Peek().RefersTo.Add(assetName);
trackerExisting.ReferredToBy.Add(loadingAssetsStack.Peek().AssetName);
}
return(asset);
}
// Need to load the asset. Create an AssetTracker to track it
// unless we have been passed an existing AssetTracker
if (tracker == null)
{
// Initialise tracker
tracker = new AssetTracker();
tracker.RefCount = 1;
tracker.AssetName = assetName;
}
// Stack count will be zero if called by user.
// Otherwise, Load<T> was called internally by ReadAsset<T>
if (loadingAssetsStack.Count > 0)
{
// Maintain the reference lists
// The asset on the top of the stack refers to this asset
loadingAssetsStack.Peek().RefersTo.Add(assetName);
// This asset was loaded by the asset on the top of the stack
tracker.ReferredToBy.Add(loadingAssetsStack.Peek().AssetName);
}
// Put current asset tracker on top of the stack
// for next call to Load<T>
loadingAssetsStack.Push(tracker);
try
{
// Preparation complete. Now finally read the asset from disk.
// This is where the internal magic happens.
#if WINDOWS
string fileName;
if (UseSourceAssets && TrySearchForValidAssetSource <T>(assetName, out fileName))
{
tracker.Asset = SourceAssetLoaders[typeof(T)].loadAssetDelegate(fileName);
}
else
#endif
tracker.Asset = ReadAsset <T>(assetName, tracker.TrackDisposableAsset);
// Ensure the list of disposables doesn't refer to the
// actual asset, or to any assets in the loadedAssets Dictionary.
// Best to do this now to avoid multiple disposing later
tracker.Disposables.RemoveAll(delegate(IDisposable d)
{
string tmp = "";
return(tracker.Asset == d || SearchForAsset(d, out tmp));
});
}
finally
{
// Asset has been loaded so the top tracker is not needed on the stack
loadingAssetsStack.Pop();
}
// Store the asset and it's disposables list
if (forceReadAsset)
{
untrackedAssets.Add(tracker);
}
else
{
loadedAssets.Add(assetName, tracker);
loadedAssetNames.Add(assetName);
}
// Mark tracker as ready to use
tracker.Status = AssetStatus.Active;
// Return loaded asset
return((T)tracker.Asset);
}
