Support nested scissor rectangles.

OpenRA.Game/Graphics/Renderer.cs

@@ -39,12 +39,14 @@ namespace OpenRA.Graphics
 		Queue<IVertexBuffer<Vertex>> tempBuffers = new Queue<IVertexBuffer<Vertex>>();
 
 		public Dictionary<string, SpriteFont> Fonts;
+		Stack<Rectangle> scissorState;
 
 		public Renderer()
 		{
 			TempBufferSize = Game.Settings.Graphics.BatchSize;
 			TempBufferCount = Game.Settings.Graphics.NumTempBuffers;
 			SheetSize = Game.Settings.Graphics.SheetSize;
+			scissorState = new Stack<Rectangle>();
 
 			WorldSpriteRenderer = new SpriteRenderer(this, device.CreateShader("shp"));
 			WorldRgbaSpriteRenderer = new SpriteRenderer(this, device.CreateShader("rgba"));
@@ -183,16 +185,30 @@ namespace OpenRA.Graphics
 			}
 		}
 
-		public void EnableScissor(int left, int top, int width, int height)
+		public void EnableScissor(Rectangle rect)
 		{
+			// Must remain inside the current scissor rect
+			if (scissorState.Any())
+				rect.Intersect(scissorState.Peek());
+
 			Flush();
-			Device.EnableScissor(left, top, width, height);
+			Device.EnableScissor(rect.Left, rect.Top, rect.Width, rect.Height);
+			scissorState.Push(rect);
 		}
 
 		public void DisableScissor()
 		{
+			scissorState.Pop();
 			Flush();
-			Device.DisableScissor();
+
+			// Restore previous scissor rect
+			if (scissorState.Any())
+			{
+				var rect = scissorState.Peek();
+				Device.EnableScissor(rect.Left, rect.Top, rect.Width, rect.Height);
+			}
+			else
+				Device.DisableScissor();
 		}
 
 		public void EnableDepthBuffer()

OpenRA.Game/Graphics/WorldRenderer.cs

@@ -115,7 +115,7 @@ namespace OpenRA.Graphics
 
 			var renderables = GenerateRenderables();
 			var bounds = Viewport.ScissorBounds;
-			Game.Renderer.EnableScissor(bounds.Left, bounds.Top, bounds.Width, bounds.Height);
+			Game.Renderer.EnableScissor(bounds);
 
 			terrainRenderer.Draw(this, Viewport);
 			Game.Renderer.Flush();

OpenRA.Game/Widgets/ChatDisplayWidget.cs

@@ -38,7 +38,7 @@ namespace OpenRA.Widgets
 			var chatpos = new int2(chatLogArea.X + 5, chatLogArea.Bottom - 5);
 
 			var font = Game.Renderer.Fonts["Regular"];
-			Game.Renderer.EnableScissor(chatLogArea.Left, chatLogArea.Top, chatLogArea.Width, chatLogArea.Height);
+			Game.Renderer.EnableScissor(chatLogArea);
 
 			foreach (var line in recentLines.AsEnumerable().Reverse())
 			{

OpenRA.Game/Widgets/HotkeyEntryWidget.cs

@@ -124,8 +124,8 @@ namespace OpenRA.Widgets
 			// Scissor when the text overflows
 			if (textSize.X > Bounds.Width - LeftMargin - RightMargin)
 			{
-				Game.Renderer.EnableScissor(pos.X + LeftMargin, pos.Y,
+				Game.Renderer.EnableScissor(new Rectangle(pos.X + LeftMargin, pos.Y,
-					Bounds.Width - LeftMargin - RightMargin, Bounds.Bottom);
+					Bounds.Width - LeftMargin - RightMargin, Bounds.Bottom));
 			}
 
 			var color = disabled ? DisabledColor : TextColor;

OpenRA.Game/Widgets/ScrollPanelWidget.cs

@@ -115,7 +115,7 @@ namespace OpenRA.Widgets
 			WidgetUtils.DrawRGBA(ChromeProvider.GetImage("scrollbar", DownPressed || downDisabled ? "down_pressed" : "down_arrow"),
 				new float2(downButtonRect.Left + downOffset, downButtonRect.Top + downOffset));
 
-			Game.Renderer.EnableScissor(backgroundRect.X + 1, backgroundRect.Y + 1, backgroundRect.Width - 2, backgroundRect.Height - 2);
+			Game.Renderer.EnableScissor(backgroundRect.InflateBy(-1, -1, -1, -1));
 
 			foreach (var child in Children)
 				child.DrawOuter();

OpenRA.Game/Widgets/TextFieldWidget.cs

@@ -216,8 +216,8 @@ namespace OpenRA.Widgets
 				if (HasKeyboardFocus)
 					textPos += new int2(Bounds.Width - LeftMargin - RightMargin - textSize.X, 0);
 
-				Game.Renderer.EnableScissor(pos.X + LeftMargin, pos.Y,
+				Game.Renderer.EnableScissor(new Rectangle(pos.X + LeftMargin, pos.Y,
-					Bounds.Width - LeftMargin - RightMargin, Bounds.Bottom);
+					Bounds.Width - LeftMargin - RightMargin, Bounds.Bottom));
 			}
 
 			var color = disabled ? DisabledColor : TextColor;

OpenRA.Mods.Cnc/Widgets/ProductionTabsWidget.cs

@@ -157,7 +157,7 @@ namespace OpenRA.Mods.Cnc.Widgets
 				new float2(rightButtonRect.Left + 2, rightButtonRect.Top + 2));
 
 			// Draw tab buttons
-			Game.Renderer.EnableScissor(leftButtonRect.Right, rb.Y + 1, rightButtonRect.Left - leftButtonRect.Right - 1, rb.Height);
+			Game.Renderer.EnableScissor(new Rectangle(leftButtonRect.Right, rb.Y + 1, rightButtonRect.Left - leftButtonRect.Right - 1, rb.Height));
 			var origin = new int2(leftButtonRect.Right - 1 + (int)listOffset, leftButtonRect.Y);
 			SpriteFont font = Game.Renderer.Fonts["TinyBold"];
 			contentWidth = 0;

OpenRA.Mods.RA/Widgets/RadarWidget.cs

@@ -156,7 +156,7 @@ namespace OpenRA.Mods.RA.Widgets
 				var tl = CellToMinimapPixel(worldRenderer.Position(worldRenderer.Viewport.TopLeft).ToCPos());
 				var br = CellToMinimapPixel(worldRenderer.Position(worldRenderer.Viewport.BottomRight).ToCPos());
 
-				Game.Renderer.EnableScissor(mapRect.Left, mapRect.Top, mapRect.Width, mapRect.Height);
+				Game.Renderer.EnableScissor(mapRect);
 				Game.Renderer.LineRenderer.DrawRect(tl, br, Color.White);
 				Game.Renderer.DisableScissor();
 			}