From 36e6c6f332cf9ff855c79fd5d1c870e055ad7bbb Mon Sep 17 00:00:00 2001
From: cosmonaut <evan@moonside.games>
Date: Tue, 13 Dec 2022 00:52:35 -0800
Subject: [PATCH] optimize AcquireSwapchainTexture

---
 src/Graphics/CommandBuffer.cs     | 14 +++++++-------
 src/Graphics/GraphicsDevice.cs    |  4 ++++
 src/Graphics/GraphicsResource.cs  |  2 +-
 src/Graphics/Resources/Texture.cs |  7 ++++---
 src/Window.cs                     |  2 ++
 5 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/src/Graphics/CommandBuffer.cs b/src/Graphics/CommandBuffer.cs
index 5f9432d..90a3a6b 100644
--- a/src/Graphics/CommandBuffer.cs
+++ b/src/Graphics/CommandBuffer.cs
@@ -1630,13 +1630,13 @@ namespace MoonWorks.Graphics
 				return null;
 			}
 
-			return new Texture(
-				Device,
-				texturePtr,
-				window.SwapchainFormat,
-				width,
-				height
-			);
+			// Override the texture properties to avoid allocating a new texture instance!
+			window.SwapchainTexture.Handle = texturePtr;
+			window.SwapchainTexture.Width = width;
+			window.SwapchainTexture.Height = height;
+			window.SwapchainTexture.Format = window.SwapchainFormat;
+
+			return window.SwapchainTexture;
 		}
 
 		/// <summary>
diff --git a/src/Graphics/GraphicsDevice.cs b/src/Graphics/GraphicsDevice.cs
index e79cae4..2e134df 100644
--- a/src/Graphics/GraphicsDevice.cs
+++ b/src/Graphics/GraphicsDevice.cs
@@ -73,6 +73,10 @@ namespace MoonWorks.Graphics
 			{
 				window.Claimed = true;
 				window.SwapchainFormat = GetSwapchainFormat(window);
+				if (window.SwapchainTexture == null)
+				{
+					window.SwapchainTexture = new Texture(this, IntPtr.Zero, window.SwapchainFormat, 0, 0);
+				}
 			}
 
 			return success;
diff --git a/src/Graphics/GraphicsResource.cs b/src/Graphics/GraphicsResource.cs
index 27343df..2e68546 100644
--- a/src/Graphics/GraphicsResource.cs
+++ b/src/Graphics/GraphicsResource.cs
@@ -5,7 +5,7 @@ namespace MoonWorks.Graphics
 	public abstract class GraphicsResource : IDisposable
 	{
 		public GraphicsDevice Device { get; }
-		public IntPtr Handle { get; protected set; }
+		public IntPtr Handle { get; internal set; }
 
 		public bool IsDisposed { get; private set; }
 		protected abstract Action<IntPtr, IntPtr> QueueDestroyFunction { get; }
diff --git a/src/Graphics/Resources/Texture.cs b/src/Graphics/Resources/Texture.cs
index 124eaef..190ac53 100644
--- a/src/Graphics/Resources/Texture.cs
+++ b/src/Graphics/Resources/Texture.cs
@@ -9,14 +9,15 @@ namespace MoonWorks.Graphics
 	/// </summary>
 	public class Texture : GraphicsResource
 	{
-		public uint Width { get; }
-		public uint Height { get; }
+		public uint Width { get; internal set; }
+		public uint Height { get; internal set; }
 		public uint Depth { get; }
-		public TextureFormat Format { get; }
+		public TextureFormat Format { get; internal set; }
 		public bool IsCube { get; }
 		public uint LevelCount { get; }
 		public TextureUsageFlags UsageFlags { get; }
 
+		// FIXME: this allocates a delegate instance
 		protected override Action<IntPtr, IntPtr> QueueDestroyFunction => Refresh.Refresh_QueueDestroyTexture;
 
 		/// <summary>
diff --git a/src/Window.cs b/src/Window.cs
index 65175d0..194f7d0 100644
--- a/src/Window.cs
+++ b/src/Window.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using MoonWorks.Graphics;
 using SDL2;
 
 namespace MoonWorks
@@ -10,6 +11,7 @@ namespace MoonWorks
 		public ScreenMode ScreenMode { get; private set; }
 		public uint Width { get; private set; }
 		public uint Height { get; private set; }
+		internal Texture SwapchainTexture { get; set; } = null;
 
 		public bool Claimed { get; internal set; }
 		public MoonWorks.Graphics.TextureFormat SwapchainFormat { get; internal set; }