From dabbd7089d67f3c0e29ab6d074dc4c1d9c057800 Mon Sep 17 00:00:00 2001
From: Matthew Leibowitz <mattleibow@live.com>
Date: Tue, 30 Mar 2021 17:30:48 +0200
Subject: [PATCH] Swap the buffers after a resize (#1668)

Swap the buffers after a resize to get the current buffer to be the new, correct size. Fixes #1377, #914, #722
---
 native/uwp/build.cake                             | 10 ++++++----
 .../SkiaSharp.Views.UWP/AngleSwapChainPanel.cs    | 15 +++++++++++++++
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/native/uwp/build.cake b/native/uwp/build.cake
index f56fc9408..bb151ad10 100644
--- a/native/uwp/build.cake
+++ b/native/uwp/build.cake
@@ -114,14 +114,16 @@ Task("ANGLE")
     {
         if (Skip(arch)) return;
 
+        var d = CONFIGURATION.ToLower() == "release" ? "" : "debug/";
+
         RunProcess (vcpkg, $"install angle:{arch}-uwp");
 
         var outDir = OUTPUT_PATH.Combine(arch);
         EnsureDirectoryExists(outDir);
-        CopyFileToDirectory(VCPKG_PATH.CombineWithFilePath ($"installed/{arch}-uwp/bin/libEGL.dll"), outDir);
-        CopyFileToDirectory(VCPKG_PATH.CombineWithFilePath ($"installed/{arch}-uwp/bin/libEGL.pdb"), outDir);
-        CopyFileToDirectory(VCPKG_PATH.CombineWithFilePath ($"installed/{arch}-uwp/bin/libGLESv2.dll"), outDir);
-        CopyFileToDirectory(VCPKG_PATH.CombineWithFilePath ($"installed/{arch}-uwp/bin/libGLESv2.pdb"), outDir);
+        CopyFileToDirectory(VCPKG_PATH.CombineWithFilePath ($"installed/{arch}-uwp/{d}bin/libEGL.dll"), outDir);
+        CopyFileToDirectory(VCPKG_PATH.CombineWithFilePath ($"installed/{arch}-uwp/{d}bin/libEGL.pdb"), outDir);
+        CopyFileToDirectory(VCPKG_PATH.CombineWithFilePath ($"installed/{arch}-uwp/{d}bin/libGLESv2.dll"), outDir);
+        CopyFileToDirectory(VCPKG_PATH.CombineWithFilePath ($"installed/{arch}-uwp/{d}bin/libGLESv2.pdb"), outDir);
     }
 });
 
diff --git a/source/SkiaSharp.Views/SkiaSharp.Views.UWP/AngleSwapChainPanel.cs b/source/SkiaSharp.Views/SkiaSharp.Views.UWP/AngleSwapChainPanel.cs
index 1afe7485d..d33a4d34e 100644
--- a/source/SkiaSharp.Views/SkiaSharp.Views.UWP/AngleSwapChainPanel.cs
+++ b/source/SkiaSharp.Views/SkiaSharp.Views.UWP/AngleSwapChainPanel.cs
@@ -33,6 +33,8 @@ namespace SkiaSharp.Views.UWP
 
 		private bool enableRenderLoop;
 
+		private bool pendingSizeChange = false;
+
 		public AngleSwapChainPanel()
 		{
 			glesContext = null;
@@ -148,6 +150,8 @@ namespace SkiaSharp.Views.UWP
 
 		private void OnCompositionChanged(SwapChainPanel sender, object args)
 		{
+			pendingSizeChange = true;
+
 			ContentsScale = CompositionScaleX;
 
 			DestroyRenderSurface();
@@ -157,6 +161,8 @@ namespace SkiaSharp.Views.UWP
 
 		private void OnSizeChanged(object sender, SizeChangedEventArgs e)
 		{
+			pendingSizeChange = true;
+
 			EnsureRenderSurface();
 			Invalidate();
 		}
@@ -189,6 +195,15 @@ namespace SkiaSharp.Views.UWP
 				return;
 
 			glesContext.MakeCurrent();
+
+			if (pendingSizeChange)
+			{
+				pendingSizeChange = false;
+
+				if (!EnableRenderLoop)
+					glesContext.SwapBuffers();
+			}
+
 			glesContext.GetSurfaceDimensions(out var panelWidth, out var panelHeight);
 			glesContext.SetViewportSize(panelWidth, panelHeight);