Set world framebuffer size based on minimum zoom.

This avoids reallocating buffers each time the player changes zoom level.

OpenRA.Game/Graphics/Viewport.cs

@@ -250,6 +250,9 @@ namespace OpenRA.Graphics
 			else
 				Zoom = Zoom.Clamp(minZoom, maxZoom);
 
+			var maxSize = (1f / (unlockMinZoom ? unlockedMinZoom : minZoom) * new float2(Game.Renderer.NativeResolution));
+			Game.Renderer.SetMaximumViewportSize(new Size((int)maxSize.X, (int)maxSize.Y));
+
 			foreach (var t in worldRenderer.World.WorldActor.TraitsImplementing<INotifyViewportZoomExtentsChanged>())
 				t.ViewportZoomExtentsChanged(minZoom, maxZoom);
 		}

OpenRA.Game/Renderer.cs

@@ -50,8 +50,11 @@ namespace OpenRA
 		Sprite screenSprite;
 
 		IFrameBuffer worldBuffer;
+		Sheet worldSheet;
 		Sprite worldSprite;
 
+		public Size WorldFrameBufferSize => worldSheet.Size;
+
 		SheetBuilder fontSheetBuilder;
 		readonly IPlatform platform;
 
@@ -59,7 +62,6 @@ namespace OpenRA
 
 		Size lastBufferSize = new Size(-1, -1);
 
-		Size lastWorldBufferSize = new Size(-1, -1);
 		Rectangle lastWorldViewport = Rectangle.Empty;
 		ITexture currentPaletteTexture;
 		IBatchRenderer currentBatchRenderer;
@@ -178,14 +180,9 @@ namespace OpenRA
 			}
 		}
 
-		public void BeginWorld(Rectangle worldViewport)
+		public void SetMaximumViewportSize(Size size)
 		{
-			if (renderType != RenderType.None)
-				throw new InvalidOperationException($"BeginWorld called with renderType = {renderType}, expected RenderType.None.");
-
-			BeginFrame();
-
-			var worldBufferSize = worldViewport.Size.NextPowerOf2();
+			var worldBufferSize = size.NextPowerOf2();
 			if (worldSprite == null || worldSprite.Sheet.Size != worldBufferSize)
 			{
 				worldBuffer?.Dispose();
@@ -195,24 +192,36 @@ namespace OpenRA
 
 				// Pixel art scaling mode is a customized bilinear sampling
 				worldBuffer.Texture.ScaleFilter = TextureScaleFilter.Linear;
+				worldSheet = new Sheet(SheetType.BGRA, worldBuffer.Texture);
+
+				// Invalidate cached state to force a shader update
+				lastWorldViewport = Rectangle.Empty;
+				worldSprite = null;
 			}
+		}
+
+		public void BeginWorld(Rectangle worldViewport)
+		{
+			if (renderType != RenderType.None)
+				throw new InvalidOperationException($"BeginWorld called with renderType = {renderType}, expected RenderType.None.");
+
+			BeginFrame();
+
+			if (worldSheet == null)
+				throw new InvalidOperationException($"BeginWorld called before SetMaximumViewportSize has been set.");
 
 			if (worldSprite == null || worldViewport.Size != worldSprite.Bounds.Size)
-			{
-				var worldSheet = new Sheet(SheetType.BGRA, worldBuffer.Texture);
 				worldSprite = new Sprite(worldSheet, new Rectangle(int2.Zero, worldViewport.Size), TextureChannel.RGBA);
-			}
 
 			worldBuffer.Bind();
 
-			if (worldBufferSize != lastWorldBufferSize || lastWorldViewport != worldViewport)
+			if (lastWorldViewport != worldViewport)
 			{
-				var depthScale = worldBufferSize.Height / (worldBufferSize.Height + depthMargin);
-				WorldSpriteRenderer.SetViewportParams(worldBufferSize, depthScale, depthScale / 2, worldViewport.Location);
-				WorldModelRenderer.SetViewportParams(worldBufferSize, worldViewport.Location);
+				var depthScale = worldSheet.Size.Height / (worldSheet.Size.Height + depthMargin);
+				WorldSpriteRenderer.SetViewportParams(worldSheet.Size, depthScale, depthScale / 2, worldViewport.Location);
+				WorldModelRenderer.SetViewportParams(worldSheet.Size, worldViewport.Location);
 
 				lastWorldViewport = worldViewport;
-				lastWorldBufferSize = worldBufferSize;
 			}
 
 			renderType = RenderType.World;

OpenRA.Mods.Common/Widgets/Logic/PerfDebugLogic.cs

@@ -10,6 +10,7 @@
 #endregion
 
 using System.Diagnostics;
+using OpenRA.Graphics;
 using OpenRA.Support;
 using OpenRA.Widgets;
 
@@ -18,7 +19,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 	public class PerfDebugLogic : ChromeLogic
 	{
 		[ObjectCreator.UseCtor]
-		public PerfDebugLogic(Widget widget)
+		public PerfDebugLogic(Widget widget, WorldRenderer worldRenderer)
 		{
 			var perfGraph = widget.Get("GRAPH_BG");
 			perfGraph.IsVisible = () => Game.Settings.Debug.PerfGraph;
@@ -40,7 +41,13 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 					fpsReferenceFrame = Game.RenderFrame;
 				}
 
-				return $"FPS: {fps}\nTick {Game.LocalTick} @ {PerfHistory.Items["tick_time"].Average(Game.Settings.Debug.Samples):F1} ms\nRender {Game.RenderFrame} @ {PerfHistory.Items["render"].Average(Game.Settings.Debug.Samples):F1} ms\nBatches: {PerfHistory.Items["batches"].LastValue}";
+				var wfbSize = Game.Renderer.WorldFrameBufferSize;
+				var viewportSize = worldRenderer.Viewport.Rectangle.Size;
+				return $"FPS: {fps}\nTick {Game.LocalTick} @ {PerfHistory.Items["tick_time"].Average(Game.Settings.Debug.Samples):F1} ms\n" +
+					$"Render {Game.RenderFrame} @ {PerfHistory.Items["render"].Average(Game.Settings.Debug.Samples):F1} ms\n" +
+					$"Batches: {PerfHistory.Items["batches"].LastValue}\n" +
+					$"Viewport Size: {viewportSize.Width} x {viewportSize.Height}\n" +
+					$"WFB Size: {wfbSize.Width} x {wfbSize.Height}";
 			};
 		}
 	}

mods/cnc/chrome/ingame.yaml

@@ -53,7 +53,7 @@ Container@PERF_WIDGETS:
 	Children:
 		Label@PERF_TEXT:
 			X: WINDOW_RIGHT - 200
-			Y: WINDOW_BOTTOM - 70
+			Y: WINDOW_BOTTOM - 90
 			Width: 170
 			Height: 40
 			Contrast: true