Lazily generate buffer in Sheet.

The managed byte buffer is created on demand, meaning a newly allocated sheet will not waste memory holding onto the buffer until some changes are actually required to be written. This avoids a newly allocated sheet wasting memory on buffers that do not differ from their backing texture.

OpenRA.Game/Graphics/Sheet.cs

@@ -25,14 +25,25 @@ namespace OpenRA.Graphics
 		byte[] data;
 
 		public readonly Size Size;
-		public byte[] Data { get { return data ?? texture.GetData(); } }
-		public bool Buffered { get { return data != null; } }
+		public byte[] Data
+		{
+			get
+			{
+				if (data != null)
+					return data;
+				if (texture == null)
+					data = new byte[4 * Size.Width * Size.Height];
+				else
+					data = texture.GetData();
+				releaseBufferOnCommit = false;
+				return data;
+			}
+		}
+		public bool Buffered { get { return data != null || texture == null; } }
 
-		public Sheet(Size size, bool buffered)
+		public Sheet(Size size)
 		{
 			Size = size;
-			if (buffered)
-				data = new byte[4 * Size.Width * Size.Height];
 		}
 
 		public Sheet(ITexture texture)
@@ -80,7 +91,7 @@ namespace OpenRA.Graphics
 				dirty = true;
 			}
 
-			if (Buffered)
+			if (data != null)
 			{
 				lock (textureLock)
 				{
@@ -141,20 +152,28 @@ namespace OpenRA.Graphics
 
 		public void CommitData()
 		{
-			if (!Buffered)
-				throw new InvalidOperationException(
-					"This sheet is unbuffered. You cannot call CommitData on an unbuffered sheet. " +
-					"If you need to completely replace the texture data you should set data into the texture directly. " +
-					"If you need to make only small changes to the texture data consider creating a buffered sheet instead.");
-
-			lock (textureLock)
-				dirty = true;
+			CommitData(false);
 		}
 
 		public void ReleaseBuffer()
+		{
+			CommitData(true);
+		}
+
+		void CommitData(bool releaseBuffer)
 		{
 			lock (textureLock)
-				releaseBufferOnCommit = true;
+			{
+				if (!Buffered)
+					throw new InvalidOperationException(
+						"This sheet is unbuffered. You cannot call CommitData on an unbuffered sheet. " +
+						"If you need to completely replace the texture data you should set data into the texture directly. " +
+						"If you need to make only small changes to the texture data consider creating a buffered sheet instead.");
+
+				dirty = true;
+				if (releaseBuffer)
+					releaseBufferOnCommit = true;
+			}
 		}
 	}
 }

OpenRA.Game/Graphics/SheetBuilder.cs

@@ -38,7 +38,7 @@ namespace OpenRA.Graphics
 
 		public static Sheet AllocateSheet()
 		{
-			return new Sheet(new Size(Renderer.SheetSize, Renderer.SheetSize), true);
+			return new Sheet(new Size(Renderer.SheetSize, Renderer.SheetSize));
 		}
 
 		public SheetBuilder(SheetType t)

OpenRA.Game/Graphics/Theater.cs

@@ -33,7 +33,7 @@ namespace OpenRA.Graphics
 					throw new SheetOverflowException("Terrain sheet overflow. Try increasing the tileset SheetSize parameter.");
 				allocated = true;
 
-				return new Sheet(new Size(tileset.SheetSize, tileset.SheetSize), true);
+				return new Sheet(new Size(tileset.SheetSize, tileset.SheetSize));
 			};
 
 			sheetBuilder = new SheetBuilder(SheetType.Indexed, allocate);

OpenRA.Game/Widgets/VqaPlayerWidget.cs

@@ -61,7 +61,7 @@ namespace OpenRA.Widgets
 
 			var size = Math.Max(video.Width, video.Height);
 			var textureSize = Exts.NextPowerOf2(size);
-			var videoSheet = new Sheet(new Size(textureSize, textureSize), false);
+			var videoSheet = new Sheet(new Size(textureSize, textureSize));
 
 			videoSheet.Texture.ScaleFilter = TextureScaleFilter.Linear;
 			videoSheet.Texture.SetData(video.FrameData);
@@ -89,7 +89,7 @@ namespace OpenRA.Widgets
 			for (var y = 0; y < scaledHeight; y += 2)
 				overlay[y, 0] = black;
 
-			var overlaySheet = new Sheet(new Size(1, Exts.NextPowerOf2(scaledHeight)), false);
+			var overlaySheet = new Sheet(new Size(1, Exts.NextPowerOf2(scaledHeight)));
 			overlaySheet.Texture.SetData(overlay);
 			overlaySprite = new Sprite(overlaySheet, new Rectangle(0, 0, 1, scaledHeight), TextureChannel.Alpha);
 		}

OpenRA.Mods.Common/Widgets/ColorMixerWidget.cs

@@ -51,7 +51,7 @@ namespace OpenRA.Mods.Common.Widgets
 			back = new byte[4*256*256];
 
 			var rect = new Rectangle((int)(255*SRange[0]), (int)(255*(1 - VRange[1])), (int)(255*(SRange[1] - SRange[0]))+1, (int)(255*(VRange[1] - VRange[0])) + 1);
-			var mixerSheet = new Sheet(new Size(256, 256), false);
+			var mixerSheet = new Sheet(new Size(256, 256));
 			mixerSheet.Texture.SetData(front, 256, 256);
 			mixerSprite = new Sprite(mixerSheet, rect, TextureChannel.Alpha);
 		}

OpenRA.Mods.Common/Widgets/HueSliderWidget.cs

@@ -28,7 +28,7 @@ namespace OpenRA.Mods.Common.Widgets
 
 			using (var hueBitmap = new Bitmap(256, 256))
 			{
-				var hueSheet = new Sheet(new Size(256, 256), false);
+				var hueSheet = new Sheet(new Size(256, 256));
 				hueSprite = new Sprite(hueSheet, new Rectangle(0, 0, 256, 1), TextureChannel.Alpha);
 
 				var bitmapData = hueBitmap.LockBits(hueBitmap.Bounds(),

OpenRA.Mods.Common/Widgets/RadarWidget.cs

@@ -73,14 +73,14 @@ namespace OpenRA.Mods.Common.Widgets
 			{
 				var r = new Rectangle(0, 0, width, height);
 				var s = new Size(terrainBitmap.Width, terrainBitmap.Height);
-				var terrainSheet = new Sheet(s, false);
+				var terrainSheet = new Sheet(s);
 				terrainSheet.Texture.SetData(terrainBitmap);
 				terrainSprite = new Sprite(terrainSheet, r, TextureChannel.Alpha);
 
 				// Data is set in Tick()
-				customTerrainSprite = new Sprite(new Sheet(s, false), r, TextureChannel.Alpha);
-				actorSprite = new Sprite(new Sheet(s, false), r, TextureChannel.Alpha);
-				shroudSprite = new Sprite(new Sheet(s, false), r, TextureChannel.Alpha);
+				customTerrainSprite = new Sprite(new Sheet(s), r, TextureChannel.Alpha);
+				actorSprite = new Sprite(new Sheet(s), r, TextureChannel.Alpha);
+				shroudSprite = new Sprite(new Sheet(s), r, TextureChannel.Alpha);
 			}
 		}