move SheetBuilder singleton onto ModData

OpenRA.Game/Graphics/SheetBuilder.cs

@@ -14,12 +14,6 @@ namespace OpenRA.Graphics
 {
 	public class SheetBuilder
 	{
-		public static SheetBuilder SharedInstance;
-		internal static void Initialize()
-		{
-			SharedInstance = new SheetBuilder(TextureChannel.Red);
-		}
-
 		internal SheetBuilder(TextureChannel ch)
 		{
 			current = null;

OpenRA.Game/Graphics/SpriteSheetBuilder.cs

@@ -27,7 +27,7 @@ namespace OpenRA.Graphics
 		static Sprite[] LoadSprites(string filename)
 		{
 			var shp = new ShpReader(FileSystem.OpenWithExts(filename, exts));
-			return shp.Select(a => SheetBuilder.SharedInstance.Add(a.Image, shp.Size)).ToArray();
+			return shp.Select(a => Game.modData.SheetBuilder.Add(a.Image, shp.Size)).ToArray();
 		}
 
 		public static Sprite[] LoadAllSprites(string filename) { return sprites[filename]; }

OpenRA.Game/Graphics/TerrainRenderer.cs

@@ -33,7 +33,7 @@ namespace OpenRA.Graphics
 			Size tileSize = new Size( Game.CellSize, Game.CellSize );
 
 			var tileMapping = new Cache<TileReference<ushort,byte>, Sprite>(
-				x => SheetBuilder.SharedInstance.Add(world.TileSet.GetBytes(x), tileSize));
+				x => Game.modData.SheetBuilder.Add(world.TileSet.GetBytes(x), tileSize));
 
 			Vertex[] vertices = new Vertex[4 * map.Height * map.Width];
 			ushort[] indices = new ushort[6 * map.Height * map.Width];