Rewrite sequence loading logic.

Multiple layers of Lazy<T>ness are replaced with
an explicit two-part loading scheme.

Sequences are parsed immediately, without the need
for the sprite assets, and tell the SpriteCache
which frames they need. Use-cases that want the
actual sprites can then tell the SpriteCache to
load the frames and the sequences to resolve the
sprites.

OpenRA.Mods.Common/UtilityCommands/CheckMissingSprites.cs

@@ -10,7 +10,7 @@
 #endregion
 
 using System;
-using OpenRA.Mods.Common.Graphics;
+using OpenRA.Graphics;
 using OpenRA.Mods.Common.Terrain;
 using OpenRA.Mods.Common.Traits;
 
@@ -38,29 +38,21 @@ namespace OpenRA.Mods.Common.UtilityCommands
 			// any tilesets from being checked further.
 			try
 			{
-				// DefaultSequences is a dictionary of tileset: SequenceProvider
-				// so we can also use this to key our tileset checks
-				foreach (var kv in modData.DefaultSequences)
+				foreach (var (tileset, terrainInfo) in modData.DefaultTerrainInfo)
 				{
 					try
 					{
-						Console.WriteLine("Tileset: " + kv.Key);
-						var terrainInfo = modData.DefaultTerrainInfo[kv.Key];
-
+						Console.WriteLine("Tileset: " + tileset);
 						if (terrainInfo is ITemplatedTerrainInfo templatedTerrainInfo)
-							foreach (var r in modData.DefaultRules.Actors[SystemActors.World].TraitInfos<ITiledTerrainRendererInfo>())
-								failed |= r.ValidateTileSprites(templatedTerrainInfo, Console.WriteLine);
+							foreach (var ttr in modData.DefaultRules.Actors[SystemActors.World].TraitInfos<ITiledTerrainRendererInfo>())
+								failed |= ttr.ValidateTileSprites(templatedTerrainInfo, Console.WriteLine);
 
-						foreach (var image in kv.Value.Images)
+						var sequences = new SequenceSet(modData.DefaultFileSystem, modData, tileset, null);
+						sequences.SpriteCache.LoadReservations(modData);
+						foreach (var (filename, location) in sequences.SpriteCache.MissingFiles)
 						{
-							foreach (var sequence in kv.Value.Sequences(image))
-							{
-								if (!(kv.Value.GetSequence(image, sequence) is FileNotFoundSequence s))
-									continue;
-
-								Console.WriteLine("\tSequence `{0}.{1}` references sprite `{2}` that does not exist.", image, sequence, s.Filename);
-								failed = true;
-							}
+							Console.WriteLine($"\t{location}: {filename} not found");
+							failed = true;
 						}
 					}
 					catch (YamlException e)

OpenRA.Mods.Common/UtilityCommands/CheckYaml.cs

@@ -67,7 +67,7 @@ namespace OpenRA.Mods.Common.UtilityCommands
 					{
 						Console.WriteLine($"Testing default sequences for {tileset}");
 
-						var sequences = new SequenceProvider(modData.DefaultFileSystem, modData, tileset, null);
+						var sequences = new SequenceSet(modData.DefaultFileSystem, modData, tileset, null);
 						CheckSequences(modData, modData.DefaultRules, sequences);
 					}
 
@@ -165,7 +165,7 @@ namespace OpenRA.Mods.Common.UtilityCommands
 			}
 		}
 
-		void CheckSequences(ModData modData, Ruleset rules, SequenceProvider sequences)
+		void CheckSequences(ModData modData, Ruleset rules, SequenceSet sequences)
 		{
 			foreach (var customSequencesPassType in modData.ObjectCreator.GetTypesImplementing<ILintSequencesPass>())
 			{

OpenRA.Mods.Common/UtilityCommands/DumpSequenceSheetsCommand.cs

@@ -34,8 +34,10 @@ namespace OpenRA.Mods.Common.UtilityCommands
 
 			var palette = new ImmutablePalette(args[1], new[] { 0 }, Array.Empty<int>());
 
-			SequenceProvider sequences;
-			if (!modData.DefaultSequences.TryGetValue(args[2], out sequences))
+			SequenceSet sequences;
+			if (modData.DefaultTerrainInfo.ContainsKey(args[2]))
+				sequences = new SequenceSet(modData.ModFiles, modData, args[2], null);
+			else
 			{
 				var mapPackage = new Folder(Platform.EngineDir).OpenPackage(args[2], modData.ModFiles);
 				if (mapPackage == null)
@@ -44,7 +46,7 @@ namespace OpenRA.Mods.Common.UtilityCommands
 				sequences = new Map(modData, mapPackage).Sequences;
 			}
 
-			sequences.Preload();
+			sequences.LoadSprites();
 
 			var count = 0;
 

OpenRA.Mods.Common/UtilityCommands/ExtractSpriteSequenceDocsCommand.cs

@@ -51,8 +51,7 @@ namespace OpenRA.Mods.Common.UtilityCommands
 			var relatedEnumTypes = new HashSet<Type>();
 
 			var sequenceTypesInfo = sequenceTypes
-				.Where(x => !x.ContainsGenericParameters && !x.IsAbstract
-					&& x.Name != nameof(FileNotFoundSequence)) // NOTE: This is the simplest way to exclude FileNotFoundSequence, which shouldn't be added.
+				.Where(x => !x.ContainsGenericParameters && !x.IsAbstract)
 				.Select(type => new
 				{
 					type.Namespace,

OpenRA.Mods.Common/UtilityCommands/LintInterfaces.cs

@@ -17,5 +17,5 @@ namespace OpenRA.Mods.Common.Lint
 	public interface ILintPass { void Run(Action<string> emitError, Action<string> emitWarning, ModData modData); }
 	public interface ILintMapPass { void Run(Action<string> emitError, Action<string> emitWarning, ModData modData, Map map); }
 	public interface ILintRulesPass { void Run(Action<string> emitError, Action<string> emitWarning, ModData modData, Ruleset rules); }
-	public interface ILintSequencesPass { void Run(Action<string> emitError, Action<string> emitWarning, ModData modData, Ruleset rules, SequenceProvider sequences); }
+	public interface ILintSequencesPass { void Run(Action<string> emitError, Action<string> emitWarning, ModData modData, Ruleset rules, SequenceSet sequences); }
 }