Start of async asset loading

- Refactored content manager and asset loaders
- Asset placeholder
- Error asset

GlitchyEngine/src/Content/Asset.bf

@@ -8,7 +8,7 @@ using System.IO;
 namespace GlitchyEngine.Content;
 
 [BonTarget]
-class Asset : RefCounter
+abstract class Asset : RefCounter
 {
 	internal AssetHandle _handle = .Invalid;
 
@@ -22,15 +22,12 @@ class Asset : RefCounter
 	public StringView Identifier
 	{
 		get => _identifier;
-		set
-		{
-			_contentManager?.UpdateAssetIdentifier(this, _identifier, value);
-
-			_identifier.Set(value);
-			// TODO: do we need to tell the content manager, that the name changed?
-		}
+		internal set => _identifier.Set(value);
 	}
 
+	/// If true the asset is completely loaded. If false it is only partially loaded (if at all).
+	public bool Complete { get; internal set; }
+
 	// TODO: do we need unmanaged assets? Probably not...
 	/// Gets the content manager that manages this asset; or null if this asset isn't managed.
 	public IContentManager ContentManager => _contentManager;

GlitchyEngine/src/Content/AssetHandle.bf

@@ -11,10 +11,10 @@ struct AssetHandle : IHashable
 	private UUID _uuid;
 
 	/// Defines an asset that is invalid.
-	public const AssetHandle Invalid = .(UUID(0xAAAA'AAAA'AAAA'AAAA));
+	public const AssetHandle Invalid = .(UUID(0));
 
-	public bool IsValid => this == .Invalid;
-	public bool IsInvalid => !IsValid;
+	public bool IsValid => this != .Invalid;
+	public bool IsInvalid => this == .Invalid;
 
 	/// Create a new random AssetHandle
 	public this()
@@ -49,8 +49,8 @@ struct AssetHandle<T> where T : Asset
 
 	public const Self Invalid = .();
 
-	public bool IsValid => this == .Invalid;
-	public bool IsInvalid => !IsValid;
+	public bool IsValid => this != .Invalid;
+	public bool IsInvalid => this == .Invalid;
 
 	public this(AssetHandle handle, IContentManager contentManager = null)
 	{

GlitchyEngine/src/Content/ContentManager.bf

@@ -57,19 +57,25 @@ namespace GlitchyEngine.Content
 		/// @param contentManager The content manager used to load the asset.
 		/// @returns The loaded asset.
 		Asset LoadAsset(Stream file, AssetLoaderConfig config, StringView assetIdentifier, StringView? subAsset, IContentManager contentManager);
+
+		/// Returns the placeholder asset.
+		Asset GetPlaceholderAsset(Type assetType);
+
+		/// Returns the error asset.
+		Asset GetErrorAsset(Type assetType);
 	}
 
 	static class Content
 	{
 		/// Loads the specified asset with the given contentManager or the current applications content manager.
-		public static AssetHandle LoadAsset(StringView assetIdentifier, IContentManager contentManager = null)
+		public static AssetHandle LoadAsset(StringView assetIdentifier, IContentManager contentManager = null, bool blocking = false)
 		{
 			var contentManager;
 
 			if (contentManager == null)
 				contentManager = Application.Get().ContentManager;
 
-			AssetHandle handle = contentManager.LoadAsset(assetIdentifier);
+			AssetHandle handle = contentManager.LoadAsset(assetIdentifier, blocking);
 
 			return handle;
 		}
@@ -111,7 +117,7 @@ namespace GlitchyEngine.Content
 	interface IContentManager
 	{
 		/// Loads the Asset with the given handle and returns the handle.
-		AssetHandle LoadAsset(StringView assetIdentifier);
+		AssetHandle LoadAsset(StringView assetIdentifier, bool blocking = false);
 
 		/// Returns the asset for the given handle or null, if it isn't loaded.
 		Asset GetAsset(AssetHandle handle)
@@ -128,10 +134,6 @@ namespace GlitchyEngine.Content
 		/// The content manager will no longer manage the asset.
 		void UnmanageAsset(AssetHandle asset);
 
-		// TODO: Maybe calling UnmanageAsset -> ManageAsset is enough....
-		/// Provides a method for the asset to tell its content manager that the identifer changed.
-		void UpdateAssetIdentifier(Asset asset, StringView oldIdentifier, StringView newIdentifier);
-
 		/// Returns a data stream for the given asset.
 		Stream GetStream(StringView assetIdentifier);
 
@@ -149,7 +151,7 @@ namespace GlitchyEngine.Content
 			Runtime.NotImplemented();
 		}
 
-		public AssetHandle LoadAsset(StringView assetIdentifier)
+		public AssetHandle LoadAsset(StringView assetIdentifier, bool blocking = false)
 		{
 			Runtime.NotImplemented();
 		}
@@ -169,11 +171,6 @@ namespace GlitchyEngine.Content
 			Runtime.NotImplemented();
 		}
 
-		public void UpdateAssetIdentifier(Asset asset, StringView oldIdentifier, StringView newIdentifier)
-		{
-			Runtime.NotImplemented();
-		}
-
 		public Stream GetStream(StringView assetIdentifier)
 		{
 			Runtime.NotImplemented();