Rewrite sequence linting / missing file handling.

- Distinguish between missing sequences and missing sprites
- Lint default sequences as well as maps
- Improved performance
- Correctly handle null images

OpenRA.Game/Graphics/SequenceProvider.cs

@@ -41,7 +41,6 @@ namespace OpenRA.Graphics
 
 	public interface ISpriteSequenceLoader
 	{
-		Action<string> OnMissingSpriteError { get; set; }
 		IReadOnlyDictionary<string, ISpriteSequence> ParseSequences(ModData modData, TileSet tileSet, SpriteCache cache, MiniYamlNode node);
 	}
 
@@ -79,6 +78,8 @@ namespace OpenRA.Graphics
 			return seq;
 		}
 
+		public IEnumerable<string> Images { get { return sequences.Value.Keys; } }
+
 		public bool HasSequence(string unitName)
 		{
 			return sequences.Value.ContainsKey(unitName);
@@ -104,10 +105,11 @@ namespace OpenRA.Graphics
 		{
 			var nodes = MiniYaml.Load(fileSystem, modData.Manifest.Sequences, additionalSequences);
 			var items = new Dictionary<string, UnitSequences>();
-			foreach (var n in nodes)
+			foreach (var node in nodes)
 			{
-				// Work around the loop closure issue in older versions of C#
+				// Nodes starting with ^ are inheritable but never loaded directly
-				var node = n;
+				if (node.Key.StartsWith(ActorInfo.AbstractActorPrefix, StringComparison.Ordinal))
+					continue;
 
 				var key = node.Value.ToLines(node.Key).JoinWith("|");
 

OpenRA.Game/ModData.cs

@@ -79,7 +79,6 @@ namespace OpenRA
 				throw new InvalidOperationException("Unable to find a sequence loader for type '{0}'.".F(sequenceFormat.Type));
 
 			SpriteSequenceLoader = (ISpriteSequenceLoader)sequenceCtor.Invoke(new[] { this });
-			SpriteSequenceLoader.OnMissingSpriteError = s => Log.Write("debug", s);
 
 			var modelFormat = Manifest.Get<ModelSequenceFormat>();
 			var modelLoader = ObjectCreator.FindType(modelFormat.Type + "Loader");

OpenRA.Game/Traits/LintAttributes.cs

@@ -31,12 +31,13 @@ namespace OpenRA.Traits
 	{
 		public readonly string ImageReference; // The field name in the same trait info that contains the image name.
 		public readonly bool Prefix;
-		public readonly bool ActorNameFallback;
+		public readonly bool AllowNullImage;
-		public SequenceReferenceAttribute(string imageReference = null, bool prefix = false, bool actorNameFallback = false)
+
+		public SequenceReferenceAttribute(string imageReference = null, bool prefix = false, bool allowNullImage = false)
 		{
 			ImageReference = imageReference;
 			Prefix = prefix;
-			ActorNameFallback = actorNameFallback;
+			AllowNullImage = allowNullImage;
 		}
 	}
 

OpenRA.Mods.Cnc/Traits/SupportPowers/ChronoshiftPower.cs

@@ -37,7 +37,7 @@ namespace OpenRA.Mods.Cnc.Traits
 
 		public readonly string FootprintImage = "overlay";
 
-		[SequenceReference("FootprintImage", true)]
+		[SequenceReference("FootprintImage", prefix: true)]
 		public readonly string ValidFootprintSequence = "target-valid";
 
 		[SequenceReference("FootprintImage")]

OpenRA.Mods.Common/Graphics/DefaultSpriteSequence.cs

@@ -40,7 +40,6 @@ namespace OpenRA.Mods.Common.Graphics
 
 	public class DefaultSpriteSequenceLoader : ISpriteSequenceLoader
 	{
-		public Action<string> OnMissingSpriteError { get; set; }
 		public DefaultSpriteSequenceLoader(ModData modData) { }
 
 		public virtual ISpriteSequence CreateSequence(ModData modData, TileSet tileSet, SpriteCache cache, string sequence, string animation, MiniYaml info)
@@ -80,8 +79,9 @@ namespace OpenRA.Mods.Common.Graphics
 					}
 					catch (FileNotFoundException ex)
 					{
-						// Eat the FileNotFound exceptions from missing sprites
+						// Defer exception until something tries to access the sequence
-						OnMissingSpriteError(ex.Message);
+						// This allows the asset installer and OpenRA.Utility to load the game without having the actor assets
+						sequences.Add(kvp.Key, new FileNotFoundSequence(ex));
 					}
 				}
 			}
@@ -90,6 +90,34 @@ namespace OpenRA.Mods.Common.Graphics
 		}
 	}
 
+	public class FileNotFoundSequence : ISpriteSequence
+	{
+		readonly FileNotFoundException exception;
+
+		public FileNotFoundSequence(FileNotFoundException exception)
+		{
+			this.exception = exception;
+		}
+
+		public string Filename { get { return exception.FileName; } }
+
+		string ISpriteSequence.Name { get { throw exception; } }
+		int ISpriteSequence.Start { get { throw exception; } }
+		int ISpriteSequence.Length { get { throw exception; } }
+		int ISpriteSequence.Stride { get { throw exception; } }
+		int ISpriteSequence.Facings { get { throw exception; } }
+		int ISpriteSequence.Tick { get { throw exception; } }
+		int ISpriteSequence.ZOffset { get { throw exception; } }
+		int ISpriteSequence.ShadowStart { get { throw exception; } }
+		int ISpriteSequence.ShadowZOffset { get { throw exception; } }
+		int[] ISpriteSequence.Frames { get { throw exception; } }
+		Rectangle ISpriteSequence.Bounds { get { throw exception; } }
+		bool ISpriteSequence.IgnoreWorldTint { get { throw exception; } }
+		Sprite ISpriteSequence.GetSprite(int frame) { throw exception; }
+		Sprite ISpriteSequence.GetSprite(int frame, WAngle facing) { throw exception; }
+		Sprite ISpriteSequence.GetShadow(int frame, WAngle facing) { throw exception; }
+	}
+
 	public class DefaultSpriteSequence : ISpriteSequence
 	{
 		static readonly WDist DefaultShadowSpriteZOffset = new WDist(-5);

OpenRA.Mods.Common/Lint/CheckSequences.cs

@@ -12,172 +12,136 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Reflection;
+using OpenRA.Graphics;
 using OpenRA.Mods.Common.Traits.Render;
 using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Lint
 {
-	class CheckSequences : ILintMapPass
+	class CheckSequences : ILintRulesPass
 	{
-		Action<string> emitError;
+		void ILintRulesPass.Run(Action<string> emitError, Action<string> emitWarning, ModData modData, Ruleset rules)
-
-		List<MiniYamlNode> sequenceDefinitions;
-
-		public void Run(Action<string> emitError, Action<string> emitWarning, ModData modData, Map map)
 		{
-			if (map.SequenceDefinitions == null)
+			// Custom maps define rules.Sequences, default mod rules leave it null.
-				return;
+			if (rules.Sequences == null)
+			{
+				foreach (var kv in modData.DefaultSequences)
+				{
+					Console.WriteLine("Testing default sequences for {0}", kv.Key);
+					Run(emitError, emitWarning, rules, kv.Value);
+				}
+			}
+			else if (!modData.DefaultSequences.Values.Contains(rules.Sequences))
+				Run(emitError, emitWarning, rules, rules.Sequences);
+		}
 
-			this.emitError = emitError;
+		void Run(Action<string> emitError, Action<string> emitWarning, Ruleset rules, SequenceProvider sequences)
-
+		{
-			sequenceDefinitions = MiniYaml.Load(map, modData.Manifest.Sequences, map.SequenceDefinitions);
-
-			var rules = map.Rules;
 			var factions = rules.Actors["world"].TraitInfos<FactionInfo>().Select(f => f.InternalName).ToArray();
-			var sequenceProviders = new[] { rules.Sequences };
-
 			foreach (var actorInfo in rules.Actors)
 			{
-				foreach (var renderInfo in actorInfo.Value.TraitInfos<RenderSpritesInfo>())
+				// Actors may have 0 or 1 RenderSprites traits
+				var renderInfo = actorInfo.Value.TraitInfoOrDefault<RenderSpritesInfo>();
+				if (renderInfo == null)
+					continue;
+
+				var images = new HashSet<string>()
 				{
-					foreach (var faction in factions)
+					renderInfo.GetImage(actorInfo.Value, sequences, null).ToLowerInvariant()
-					{
+				};
-						foreach (var sequenceProvider in sequenceProviders)
+
-						{
+				// Some actors define faction-specific artwork
-							var image = renderInfo.GetImage(actorInfo.Value, sequenceProvider, faction);
+				foreach (var faction in factions)
-							if (sequenceDefinitions.All(s => s.Key != image.ToLowerInvariant()))
+					images.Add(renderInfo.GetImage(actorInfo.Value, sequences, faction).ToLowerInvariant());
-								emitError("Sprite image {0} from actor {1} using faction {2} has no sequence definition."
-									.F(image, actorInfo.Value.Name, faction));
-						}
-					}
-				}
 
 				foreach (var traitInfo in actorInfo.Value.TraitInfos<TraitInfo>())
 				{
+					// Remove the "Info" suffix
+					var traitName = traitInfo.GetType().Name;
+					traitName = traitName.Remove(traitName.Length - 4);
+
 					var fields = traitInfo.GetType().GetFields();
 					foreach (var field in fields)
 					{
-						if (field.HasAttribute<SequenceReferenceAttribute>())
+						var sequenceReference = field.GetCustomAttributes<SequenceReferenceAttribute>(true).FirstOrDefault();
+						if (sequenceReference == null)
+							continue;
+
+						// Some sequences may specify their own Image override
+						IEnumerable<string> sequenceImages = images;
+						if (!string.IsNullOrEmpty(sequenceReference.ImageReference))
 						{
-							var sequences = LintExts.GetFieldValues(traitInfo, field, emitError);
+							var imageField = fields.First(f => f.Name == sequenceReference.ImageReference);
-							foreach (var sequence in sequences)
+							var imageOverride = (string)imageField.GetValue(traitInfo);
+							if (string.IsNullOrEmpty(imageOverride))
 							{
-								if (string.IsNullOrEmpty(sequence))
+								if (!sequenceReference.AllowNullImage)
-									continue;
+									emitError("Actor type `{0}` trait `{1}` must define a value for `{2}`".F(actorInfo.Value.Name, traitName, sequenceReference.ImageReference));
-
+								continue;
-								var renderInfo = actorInfo.Value.TraitInfos<RenderSpritesInfo>().FirstOrDefault();
-								if (renderInfo == null)
-									continue;
-
-								foreach (var faction in factions)
-								{
-									var sequenceReference = field.GetCustomAttributes<SequenceReferenceAttribute>(true).FirstOrDefault();
-									if (sequenceReference != null && !string.IsNullOrEmpty(sequenceReference.ImageReference))
-									{
-										var imageField = fields.FirstOrDefault(f => f.Name == sequenceReference.ImageReference);
-										if (imageField != null)
-										{
-											foreach (var imageOverride in LintExts.GetFieldValues(traitInfo, imageField, emitError))
-											{
-												if (string.IsNullOrEmpty(imageOverride))
-												{
-													if (!sequenceReference.ActorNameFallback)
-													{
-														emitWarning("Custom sprite image of actor {0} is null and there is no fallback.".F(actorInfo.Value.Name));
-														continue;
-													}
-
-													foreach (var sequenceProvider in sequenceProviders)
-													{
-														var image = renderInfo.GetImage(actorInfo.Value, sequenceProvider, faction);
-														CheckDefinitions(image, sequenceReference, actorInfo, sequence, faction, field, traitInfo);
-													}
-
-													continue;
-												}
-
-												if (sequenceDefinitions.All(s => s.Key != imageOverride.ToLowerInvariant()))
-													emitError("Custom sprite image {0} from actor {1} has no sequence definition.".F(imageOverride, actorInfo.Value.Name));
-												else
-													CheckDefinitions(imageOverride, sequenceReference, actorInfo, sequence, faction, field, traitInfo);
-											}
-										}
-									}
-									else
-									{
-										foreach (var sequenceProvider in sequenceProviders)
-										{
-											var image = renderInfo.GetImage(actorInfo.Value, sequenceProvider, faction);
-											CheckDefinitions(image, sequenceReference, actorInfo, sequence, faction, field, traitInfo);
-										}
-									}
-								}
 							}
+
+							sequenceImages = new[] { imageOverride.ToLowerInvariant() };
 						}
-					}
-				}
 
-				foreach (var weaponInfo in rules.Weapons)
+						foreach (var sequence in LintExts.GetFieldValues(traitInfo, field, emitError))
-				{
-					var projectileInfo = weaponInfo.Value.Projectile;
-					if (projectileInfo == null)
-						continue;
-
-					var fields = projectileInfo.GetType().GetFields();
-					foreach (var field in fields)
-					{
-						if (field.HasAttribute<SequenceReferenceAttribute>())
 						{
-							var sequences = LintExts.GetFieldValues(projectileInfo, field, emitError);
+							if (string.IsNullOrEmpty(sequence))
-							foreach (var sequence in sequences)
+								continue;
-							{
-								if (string.IsNullOrEmpty(sequence))
-									continue;
 
-								var sequenceReference = field.GetCustomAttributes<SequenceReferenceAttribute>(true).FirstOrDefault();
+							foreach (var i in sequenceImages)
-								if (sequenceReference != null && !string.IsNullOrEmpty(sequenceReference.ImageReference))
+							{
+								if (sequenceReference.Prefix)
 								{
-									var imageField = fields.FirstOrDefault(f => f.Name == sequenceReference.ImageReference);
+									// TODO: Remove prefixed sequence references and instead use explicit lists of lintable references
-									if (imageField != null)
+									if (!sequences.Sequences(i).Any(s => s.StartsWith(sequence)))
-									{
+										emitWarning("Actor type `{0}` trait `{1}` field `{2}` defines a prefix `{3}` that does not match any sequences on image `{4}`.".F(actorInfo.Value.Name, traitName, field.Name, sequence, i));
-										foreach (var imageOverride in LintExts.GetFieldValues(projectileInfo, imageField, emitError))
-										{
-											if (!string.IsNullOrEmpty(imageOverride))
-											{
-												var definitions = sequenceDefinitions.FirstOrDefault(n => n.Key == imageOverride.ToLowerInvariant());
-												if (definitions == null)
-													emitError("Can't find sequence definition for projectile image {0} at weapon {1}.".F(imageOverride, weaponInfo.Key));
-												else if (!definitions.Value.Nodes.Any(n => n.Key == sequence))
-													emitError("Projectile sprite image {0} from weapon {1} does not define sequence {2} from field {3} of {4}"
-														.F(imageOverride, weaponInfo.Key, sequence, field.Name, projectileInfo));
-											}
-										}
-									}
 								}
+								else if (!sequences.HasSequence(i, sequence))
+									emitError("Actor type `{0}` trait `{1}` field `{2}` references an undefined sequence `{3}` on image `{4}`.".F(actorInfo.Value.Name, traitName, field.Name, sequence, i));
 							}
 						}
 					}
 				}
 			}
-		}
 
-		void CheckDefinitions(string image, SequenceReferenceAttribute sequenceReference,
+			foreach (var weaponInfo in rules.Weapons)
-			KeyValuePair<string, ActorInfo> actorInfo, string sequence, string faction, FieldInfo field, TraitInfo traitInfo)
-		{
-			var definitions = sequenceDefinitions.FirstOrDefault(n => n.Key == image.ToLowerInvariant());
-			if (definitions != null)
 			{
-				if (sequenceReference != null && sequenceReference.Prefix)
+				var projectileInfo = weaponInfo.Value.Projectile;
+				if (projectileInfo == null)
+					continue;
+
+				var fields = projectileInfo.GetType().GetFields();
+				foreach (var field in fields)
 				{
-					if (!definitions.Value.Nodes.Any(n => n.Key.StartsWith(sequence)))
+					var sequenceReference = field.GetCustomAttributes<SequenceReferenceAttribute>(true).FirstOrDefault();
-						emitError("Sprite image {0} from actor {1} of faction {2} does not define sequence prefix {3} from field {4} of {5}"
+					if (sequenceReference == null)
-							.F(image, actorInfo.Value.Name, faction, sequence, field.Name, traitInfo));
+						continue;
-				}
+
-				else if (definitions.Value.Nodes.All(n => n.Key != sequence))
+					// All weapon sequences must specify their corresponding image
-				{
+					var image = ((string)fields.First(f => f.Name == sequenceReference.ImageReference).GetValue(projectileInfo));
-					emitError("Sprite image {0} from actor {1} of faction {2} does not define sequence {3} from field {4} of {5}"
+					if (string.IsNullOrEmpty(image))
-						.F(image, actorInfo.Value.Name, faction, sequence, field.Name, traitInfo));
+					{
+						if (!sequenceReference.AllowNullImage)
+							emitError("Weapon type `{0}` projectile field `{1}` must define a value".F(weaponInfo.Key, sequenceReference.ImageReference));
+
+						continue;
+					}
+
+					image = image.ToLowerInvariant();
+					foreach (var sequence in LintExts.GetFieldValues(projectileInfo, field, emitError))
+					{
+						if (string.IsNullOrEmpty(sequence))
+							continue;
+
+						if (sequenceReference.Prefix)
+						{
+							// TODO: Remove prefixed sequence references and instead use explicit lists of lintable references
+							if (!sequences.Sequences(image).Any(s => s.StartsWith(sequence)))
+								emitWarning("Weapon type `{0}` projectile field `{1}` defines a prefix `{2}` that does not match any sequences on image `{3}`.".F(weaponInfo.Key, field.Name, sequence, image));
+						}
+						else if (!sequences.HasSequence(image, sequence))
+							emitError("Weapon type `{0}` projectile field `{1}` references an undefined sequence `{2}` on image `{3}`.".F(weaponInfo.Key, field.Name, sequence, image));
+					}
 				}
 			}
 		}

OpenRA.Mods.Common/Projectiles/Bullet.cs

@@ -36,7 +36,7 @@ namespace OpenRA.Mods.Common.Projectiles
 		[Desc("Image to display.")]
 		public readonly string Image = null;
 
-		[SequenceReference("Image")]
+		[SequenceReference("Image", allowNullImage: true)]
 		[Desc("Loop a randomly chosen sequence of Image from this list while this projectile is moving.")]
 		public readonly string[] Sequences = { "idle" };
 
@@ -57,7 +57,7 @@ namespace OpenRA.Mods.Common.Projectiles
 		[Desc("Trail animation.")]
 		public readonly string TrailImage = null;
 
-		[SequenceReference("TrailImage")]
+		[SequenceReference("TrailImage", allowNullImage: true)]
 		[Desc("Loop a randomly chosen sequence of TrailImage from this list while this projectile is moving.")]
 		public readonly string[] TrailSequences = { "idle" };
 

OpenRA.Mods.Common/Projectiles/GravityBomb.cs

@@ -20,11 +20,11 @@ namespace OpenRA.Mods.Common.Projectiles
 	{
 		public readonly string Image = null;
 
-		[SequenceReference("Image")]
+		[SequenceReference("Image", allowNullImage: true)]
 		[Desc("Loop a randomly chosen sequence of Image from this list while falling.")]
 		public readonly string[] Sequences = { "idle" };
 
-		[SequenceReference("Image")]
+		[SequenceReference("Image", allowNullImage: true)]
 		[Desc("Sequence to play when launched. Skipped if null or empty.")]
 		public readonly string OpenSequence = null;
 

OpenRA.Mods.Common/Projectiles/LaserZap.cs

@@ -78,7 +78,7 @@ namespace OpenRA.Mods.Common.Projectiles
 		[Desc("Impact animation.")]
 		public readonly string HitAnim = null;
 
-		[SequenceReference("HitAnim")]
+		[SequenceReference("HitAnim", allowNullImage: true)]
 		[Desc("Sequence of impact animation to use.")]
 		public readonly string HitAnimSequence = "idle";
 
@@ -88,7 +88,7 @@ namespace OpenRA.Mods.Common.Projectiles
 		[Desc("Image containing launch effect sequence.")]
 		public readonly string LaunchEffectImage = null;
 
-		[SequenceReference("LaunchEffectImage")]
+		[SequenceReference("LaunchEffectImage", allowNullImage: true)]
 		[Desc("Launch effect sequence to play.")]
 		public readonly string LaunchEffectSequence = null;
 

OpenRA.Mods.Common/Projectiles/Missile.cs

@@ -26,7 +26,7 @@ namespace OpenRA.Mods.Common.Projectiles
 		[Desc("Name of the image containing the projectile sequence.")]
 		public readonly string Image = null;
 
-		[SequenceReference("Image")]
+		[SequenceReference("Image", allowNullImage: true)]
 		[Desc("Loop a randomly chosen sequence of Image from this list while this projectile is moving.")]
 		public readonly string[] Sequences = { "idle" };
 
@@ -109,7 +109,7 @@ namespace OpenRA.Mods.Common.Projectiles
 		[Desc("Image that contains the trail animation.")]
 		public readonly string TrailImage = null;
 
-		[SequenceReference("TrailImage")]
+		[SequenceReference("TrailImage", allowNullImage: true)]
 		[Desc("Loop a randomly chosen sequence of TrailImage from this list while this projectile is moving.")]
 		public readonly string[] TrailSequences = { "idle" };
 

OpenRA.Mods.Common/Projectiles/Railgun.cs

@@ -87,7 +87,7 @@ namespace OpenRA.Mods.Common.Projectiles
 		public readonly string HitAnim = null;
 
 		[Desc("Sequence of impact animation to use.")]
-		[SequenceReference("HitAnim")]
+		[SequenceReference("HitAnim", allowNullImage: true)]
 		public readonly string HitAnimSequence = "idle";
 
 		[PaletteReference]

OpenRA.Mods.Common/Traits/Buildings/RallyPoint.cs

@@ -24,10 +24,10 @@ namespace OpenRA.Mods.Common.Traits
 		[Desc("Width (in pixels) of the rallypoint line.")]
 		public readonly int LineWidth = 1;
 
-		[SequenceReference("Image")]
+		[SequenceReference("Image", allowNullImage: true)]
 		public readonly string FlagSequence = "flag";
 
-		[SequenceReference("Image")]
+		[SequenceReference("Image", allowNullImage: true)]
 		public readonly string CirclesSequence = "circles";
 
 		[Desc("Cursor to display when rally point can be set.")]

OpenRA.Mods.Common/Traits/Crates/CrateAction.cs

@@ -23,7 +23,7 @@ namespace OpenRA.Mods.Common.Traits
 		[Desc("Image containing the crate effect animation sequence.")]
 		public readonly string Image = "crate-effects";
 
-		[SequenceReference("Image")]
+		[SequenceReference("Image", allowNullImage: true)]
 		[Desc("Animation sequence played when collected. Leave empty for no effect.")]
 		public readonly string Sequence = null;
 

OpenRA.Mods.Common/Traits/GainsExperience.cs

@@ -32,7 +32,7 @@ namespace OpenRA.Mods.Common.Traits
 		[Desc("Image for the level up sprite.")]
 		public readonly string LevelUpImage = null;
 
-		[SequenceReference("LevelUpImage")]
+		[SequenceReference("LevelUpImage", allowNullImage: true)]
 		[Desc("Sequence for the level up sprite. Needs to be present on LevelUpImage.")]
 		public readonly string LevelUpSequence = "levelup";
 

OpenRA.Mods.Common/Traits/Parachutable.cs

@@ -29,7 +29,7 @@ namespace OpenRA.Mods.Common.Traits
 		[Desc("Image where Ground/WaterCorpseSequence is looked up.")]
 		public readonly string Image = "explosion";
 
-		[SequenceReference("Image")]
+		[SequenceReference("Image", allowNullImage: true)]
 		public readonly string GroundCorpseSequence = null;
 
 		[PaletteReference]
@@ -37,7 +37,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		public readonly string GroundImpactSound = null;
 
-		[SequenceReference("Image")]
+		[SequenceReference("Image", allowNullImage: true)]
 		public readonly string WaterCorpseSequence = null;
 
 		[PaletteReference]

OpenRA.Mods.Common/Traits/Render/WithDecoration.cs

@@ -23,7 +23,7 @@ namespace OpenRA.Mods.Common.Traits.Render
 		public readonly string Image = null;
 
 		[FieldLoader.Require]
-		[SequenceReference("Image", false, true)]
+		[SequenceReference("Image", allowNullImage: true)]
 		[Desc("Sequence used for this decoration (can be animated).")]
 		public readonly string Sequence = null;
 

OpenRA.Mods.Common/Traits/Render/WithIdleOverlay.cs

@@ -23,11 +23,11 @@ namespace OpenRA.Mods.Common.Traits.Render
 		[Desc("Image used for this decoration. Defaults to the actor's type.")]
 		public readonly string Image = null;
 
-		[SequenceReference("Image", false, true)]
+		[SequenceReference("Image", allowNullImage: true)]
 		[Desc("Animation to play when the actor is created.")]
 		public readonly string StartSequence = null;
 
-		[SequenceReference("Image", false, true)]
+		[SequenceReference("Image", allowNullImage: true)]
 		[Desc("Sequence name to use")]
 		public readonly string Sequence = "idle-overlay";
 

OpenRA.Mods.Common/Traits/Render/WithParachute.cs

@@ -25,15 +25,15 @@ namespace OpenRA.Mods.Common.Traits.Render
 		[Desc("The image that contains the parachute sequences.")]
 		public readonly string Image = null;
 
-		[SequenceReference("Image")]
+		[SequenceReference("Image", allowNullImage: true)]
 		[Desc("Parachute opening sequence.")]
 		public readonly string OpeningSequence = null;
 
-		[SequenceReference("Image")]
+		[SequenceReference("Image", allowNullImage: true)]
 		[Desc("Parachute idle sequence.")]
 		public readonly string Sequence = null;
 
-		[SequenceReference("Image")]
+		[SequenceReference("Image", allowNullImage: true)]
 		[Desc("Parachute closing sequence. Defaults to opening sequence played backwards.")]
 		public readonly string ClosingSequence = null;
 
@@ -49,7 +49,7 @@ namespace OpenRA.Mods.Common.Traits.Render
 		[Desc("The image that contains the shadow sequence for the paradropped unit.")]
 		public readonly string ShadowImage = null;
 
-		[SequenceReference("ShadowImage")]
+		[SequenceReference("ShadowImage", allowNullImage: true)]
 		[Desc("Paradropped unit's shadow sequence.")]
 		public readonly string ShadowSequence = null;
 

OpenRA.Mods.Common/Traits/SupportPowers/NukePower.cs

@@ -55,7 +55,7 @@ namespace OpenRA.Mods.Common.Traits
 		[Desc("Trail animation.")]
 		public readonly string TrailImage = null;
 
-		[SequenceReference("TrailImage")]
+		[SequenceReference("TrailImage", allowNullImage: true)]
 		[Desc("Loop a randomly chosen sequence of TrailImage from this list while this projectile is moving.")]
 		public readonly string[] TrailSequences = { };
 

OpenRA.Mods.Common/UtilityCommands/CheckSequenceSprites.cs

@@ -10,12 +10,11 @@
 #endregion
 
 using System;
-using System.Linq;
+using OpenRA.Mods.Common.Graphics;
-using OpenRA.Graphics;
 
 namespace OpenRA.Mods.Common.UtilityCommands
 {
-	class CheckSquenceSprites : IUtilityCommand
+	class CheckSequenceSprites : IUtilityCommand
 	{
 		string IUtilityCommand.Name { get { return "--check-sequence-sprites"; } }
 
@@ -29,18 +28,22 @@ namespace OpenRA.Mods.Common.UtilityCommands
 		{
 			// HACK: The engine code assumes that Game.modData is set.
 			var modData = Game.ModData = utility.ModData;
-
 			var failed = false;
-			modData.SpriteSequenceLoader.OnMissingSpriteError = s => { Console.WriteLine("\t" + s); failed = true; };
+			foreach (var kv in modData.DefaultSequences)
-
-			foreach (var t in modData.Manifest.TileSets)
 			{
-				var ts = new TileSet(modData.DefaultFileSystem, t);
+				Console.WriteLine("Tileset: " + kv.Key);
-				Console.WriteLine("Tileset: " + ts.Name);
+				foreach (var image in kv.Value.Images)
-				var sc = new SpriteCache(modData.DefaultFileSystem, modData.SpriteLoaders);
+				{
-				var nodes = MiniYaml.Merge(modData.Manifest.Sequences.Select(s => MiniYaml.FromStream(modData.DefaultFileSystem.Open(s), s)));
+					foreach (var sequence in kv.Value.Sequences(image))
-				foreach (var n in nodes.Where(node => !node.Key.StartsWith(ActorInfo.AbstractActorPrefix, StringComparison.Ordinal)))
+					{
-					modData.SpriteSequenceLoader.ParseSequences(modData, ts, sc, n);
+						var s = kv.Value.GetSequence(image, sequence) as FileNotFoundSequence;
+						if (s != null)
+						{
+							Console.WriteLine("\tSequence `{0}.{1}` references sprite `{2}` that does not exist.", image, sequence, s.Filename);
+							failed = true;
+						}
+					}
+				}
 			}
 
 			if (failed)

OpenRA.Mods.Common/Warheads/CreateEffectWarhead.cs

@@ -20,7 +20,7 @@ namespace OpenRA.Mods.Common.Warheads
 {
 	public class CreateEffectWarhead : Warhead
 	{
-		[SequenceReference("Image")]
+		[SequenceReference("Image", allowNullImage: true)]
 		[Desc("List of explosion sequences that can be used.")]
 		public readonly string[] Explosions = new string[0];