Introduce ISpriteSequence interface.

OpenRA.Game/Graphics/Animation.cs

@@ -16,7 +16,7 @@ namespace OpenRA.Graphics
 	public class Animation
 	{
 		readonly int defaultTick = 40; // 25 fps == 40 ms
-		public Sequence CurrentSequence { get; private set; }
+		public ISpriteSequence CurrentSequence { get; private set; }
 		public bool IsDecoration = false;
 		public Func<bool> Paused;
 
@@ -177,7 +177,7 @@ namespace OpenRA.Graphics
 			}
 		}
 
-		public Sequence GetSequence(string sequenceName)
+		public ISpriteSequence GetSequence(string sequenceName)
 		{
 			return sequenceProvider.GetSequence(name, sequenceName);
 		}

OpenRA.Game/Graphics/Sequence.cs

@@ -13,21 +13,39 @@ using System.Linq;
 
 namespace OpenRA.Graphics
 {
-	public class Sequence
+	public interface ISpriteSequence
+	{
+		string Name { get; }
+		int Start { get; }
+		int Length { get; }
+		int Stride { get; }
+		int Facings { get; }
+		int Tick { get; }
+		int ZOffset { get; }
+		int ShadowStart { get; }
+		int ShadowZOffset { get; }
+		int[] Frames { get; }
+
+		Sprite GetSprite(int frame);
+		Sprite GetSprite(int frame, int facing);
+		Sprite GetShadow(int frame, int facing);
+	}
+
+	public class Sequence : ISpriteSequence
 	{
 		readonly Sprite[] sprites;
 		readonly bool reverseFacings, transpose;
 
-		public readonly string Name;
+		public string Name { get; private set; }
-		public readonly int Start;
+		public int Start { get; private set; }
-		public readonly int Length;
+		public int Length { get; private set; }
-		public readonly int Stride;
+		public int Stride { get; private set; }
-		public readonly int Facings;
+		public int Facings { get; private set; }
-		public readonly int Tick;
+		public int Tick { get; private set; }
-		public readonly int ZOffset;
+		public int ZOffset { get; private set; }
-		public readonly int ShadowStart;
+		public int ShadowStart { get; private set; }
-		public readonly int ShadowZOffset;
+		public int ShadowZOffset { get; private set; }
-		public readonly int[] Frames;
+		public int[] Frames { get; private set; }
 
 		public Sequence(SpriteCache cache, string unit, string name, MiniYaml info)
 		{

OpenRA.Game/Graphics/SequenceProvider.cs

@@ -15,8 +15,8 @@ using System.Linq;
 
 namespace OpenRA.Graphics
 {
-	using Sequences = IReadOnlyDictionary<string, Lazy<IReadOnlyDictionary<string, Sequence>>>;
+	using Sequences = IReadOnlyDictionary<string, Lazy<IReadOnlyDictionary<string, ISpriteSequence>>>;
-	using UnitSequences = Lazy<IReadOnlyDictionary<string, Sequence>>;
+	using UnitSequences = Lazy<IReadOnlyDictionary<string, ISpriteSequence>>;
 
 	public class SequenceProvider
 	{
@@ -29,13 +29,13 @@ namespace OpenRA.Graphics
 			this.SpriteCache = cache.SpriteCache;
 		}
 
-		public Sequence GetSequence(string unitName, string sequenceName)
+		public ISpriteSequence GetSequence(string unitName, string sequenceName)
 		{
 			UnitSequences unitSeq;
 			if (!sequences.Value.TryGetValue(unitName, out unitSeq))
 				throw new InvalidOperationException("Unit `{0}` does not have any sequences defined.".F(unitName));
 
-			Sequence seq;
+			ISpriteSequence seq;
 			if (!unitSeq.Value.TryGetValue(sequenceName, out seq))
 				throw new InvalidOperationException("Unit `{0}` does not have a sequence named `{1}`".F(unitName, sequenceName));
 
@@ -125,9 +125,9 @@ namespace OpenRA.Graphics
 			return new ReadOnlyDictionary<string, UnitSequences>(items);
 		}
 
-		IReadOnlyDictionary<string, Sequence> CreateUnitSequences(MiniYamlNode node)
+		IReadOnlyDictionary<string, ISpriteSequence> CreateUnitSequences(MiniYamlNode node)
 		{
-			var unitSequences = new Dictionary<string, Sequence>();
+			var unitSequences = new Dictionary<string, ISpriteSequence>();
 
 			foreach (var kvp in node.Value.ToDictionary())
 			{
@@ -144,7 +144,7 @@ namespace OpenRA.Graphics
 				}
 			}
 
-			return new ReadOnlyDictionary<string, Sequence>(unitSequences);
+			return new ReadOnlyDictionary<string, ISpriteSequence>(unitSequences);
 		}
 
 		public void Dispose()

OpenRA.Mods.RA/Graphics/TeslaZapRenderable.cs

@@ -94,7 +94,7 @@ namespace OpenRA.Mods.RA.Graphics
 					yield return z;
 		}
 
-		static IEnumerable<IFinalizedRenderable> DrawZapWandering(WorldRenderer wr, float2 from, float2 to, Sequence s, string pal)
+		static IEnumerable<IFinalizedRenderable> DrawZapWandering(WorldRenderer wr, float2 from, float2 to, ISpriteSequence s, string pal)
 		{
 			var z = float2.Zero;	/* hack */
 			var dist = to - from;
@@ -121,7 +121,7 @@ namespace OpenRA.Mods.RA.Graphics
 			return renderables;
 		}
 
-		static IEnumerable<IFinalizedRenderable> DrawZap(WorldRenderer wr, float2 from, float2 to, Sequence s, out float2 p, string palette)
+		static IEnumerable<IFinalizedRenderable> DrawZap(WorldRenderer wr, float2 from, float2 to, ISpriteSequence s, out float2 p, string palette)
 		{
 			var dist = to - from;
 			var q = new float2(-dist.Y, dist.X);