feat: Use XamlRoot.RasterizationScale in GTK renderers

jeromelaban · Apr 22, 2024 · 267be8c · 267be8c
1 parent 1fb6bf3
commit 267be8c
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Showing 3 changed files with 42 additions and 22 deletions.
diff --git a/src/Uno.UI.Runtime.Skia.Gtk/Helpers/Dpi/DpiHelper.cs b/src/Uno.UI.Runtime.Skia.Gtk/Helpers/Dpi/DpiHelper.cs
@@ -3,13 +3,15 @@
 using Gtk;
 using Uno.Helpers;
 using Uno.UI.Runtime.Skia.Gtk.Helpers.Windows;
+using Uno.UI.Runtime.Skia.Gtk.UI.Controls;
 using Windows.Graphics.Display;
 
 namespace Uno.UI.Runtime.Skia.Gtk.Helpers.Dpi;
 
 internal class DpiHelper
 {
 	private readonly StartStopEventWrapper<EventHandler> _dpiChangedWrapper;
+	private readonly UnoGtkWindow _window;
 
 	private float? _dpi;
 
@@ -18,6 +20,11 @@ public DpiHelper()
 		_dpiChangedWrapper = new(StartDpiChanged, StopDpiChanged);
 	}
 
+	public DpiHelper(UnoGtkWindow window) : this()
+	{
+		_window = window;
+	}
+
 	public event EventHandler DpiChanged
 	{
 		add => _dpiChangedWrapper.AddHandler(value);
@@ -43,7 +50,7 @@ private void StopDpiChanged()
 		GetWindow().Screen.SizeChanged -= OnScreenSizeChanged;
 	}
 
-	private Window GetWindow() => GtkHost.Current.InitialWindow;
+	private Window GetWindow() => _window ?? GtkHost.Current.InitialWindow;
 
 	private void OnWindowConfigure(object o, ConfigureEventArgs args) => CheckDpiUpdate();
 
@@ -83,4 +90,6 @@ internal float GetNativeDpi()
 		}
 		return dpi;
 	}
+
+	internal float RasterizationScale => (_dpi ?? GetNativeDpi()) / DisplayInformation.BaseDpi;
 }
diff --git a/src/Uno.UI.Runtime.Skia.Gtk/Rendering/GLRenderSurfaceBase.cs b/src/Uno.UI.Runtime.Skia.Gtk/Rendering/GLRenderSurfaceBase.cs
@@ -13,6 +13,7 @@
 using Uno.UI.Hosting;
 using Microsoft.UI.Composition;
 using Uno.UI.Runtime.Skia.Gtk.Hosting;
+using Microsoft.UI.Xaml;
 
 namespace Uno.UI.Runtime.Skia.Gtk
 {
@@ -32,7 +33,6 @@ internal abstract partial class GLRenderSurfaceBase : GLArea, IGtkRenderer
 		/// </summary>
 		private const int GuardBand = 1;
 
-		private readonly DisplayInformation _displayInformation;
 		private readonly IGtkXamlRootHost _host;
 
 		private float? _scale = 1;
@@ -47,14 +47,14 @@ internal abstract partial class GLRenderSurfaceBase : GLArea, IGtkRenderer
 		/// In order to avoid virtual calls to <see cref="ClearOpenGL"/> and <see cref="FlushOpenGL"/> for performance reasons.
 		/// </remarks>
 		protected bool _isGLES;
+		private readonly XamlRoot _xamlRoot;
 
 		public SKColor BackgroundColor { get; set; }
 
 		public GLRenderSurfaceBase(IGtkXamlRootHost host)
 		{
-			var xamlRoot = GtkManager.XamlRootMap.GetRootForHost(host);
-			_displayInformation = WUX.XamlRoot.GetDisplayInformation(xamlRoot);
-			_displayInformation.DpiChanged += OnDpiChanged;
+			_xamlRoot = GtkManager.XamlRootMap.GetRootForHost(host) ?? throw new InvalidOperationException("XamlRoot must not be null when renderer is initialized");
+			_xamlRoot.Changed += OnXamlRootChanged;
 			UpdateDpi();
 
 			// Set some event handlers
@@ -180,9 +180,6 @@ private void GLFlush()
 
 		protected abstract GRContext TryBuildGRContext();
 
-		private void OnDpiChanged(DisplayInformation sender, object args) =>
-			UpdateDpi();
-
 		public void TakeScreenshot(string filePath)
 		{
 			if (_surface != null)
@@ -195,10 +192,16 @@ public void TakeScreenshot(string filePath)
 			}
 		}
 
+		private void OnXamlRootChanged(XamlRoot sender, XamlRootChangedEventArgs args) => UpdateDpi();
+
 		private void UpdateDpi()
 		{
-			_scale = (float)_displayInformation.RawPixelsPerViewPixel;
-			InvalidateRender();
+			var newScale = (float)_xamlRoot.RasterizationScale;
+			if (_scale != newScale)
+			{
+				_scale = newScale;
+				InvalidateRender();
+			}
 		}
 	}
 }
diff --git a/src/Uno.UI.Runtime.Skia.Gtk/Rendering/SoftwareRenderSurface.cs b/src/Uno.UI.Runtime.Skia.Gtk/Rendering/SoftwareRenderSurface.cs
@@ -14,20 +14,21 @@
 using Windows.Graphics.Display;
 using Microsoft.UI.Xaml;
 using Uno.UI.Runtime.Skia.Gtk.Hosting;
+using Pango;
+using Context = Cairo.Context;
 
 namespace Uno.UI.Runtime.Skia.Gtk;
 
 internal class SoftwareRenderSurface : DrawingArea, IGtkRenderer
 {
-	private readonly DisplayInformation _displayInformation;
 	private SKSurface? _surface;
 	private SKBitmap? _bitmap;
 	private int _bheight, _bwidth;
 	private ImageSurface? _gtkSurface;
 	private int renderCount;
 
-	private float _dpi = 1;
-
+	private float _scale = 1;
+	private XamlRoot _xamlRoot;
 	private readonly SKColorType _colorType;
 	private readonly IGtkXamlRootHost _host;
 
@@ -36,9 +37,8 @@ internal class SoftwareRenderSurface : DrawingArea, IGtkRenderer
 
 	public SoftwareRenderSurface(IGtkXamlRootHost host)
 	{
-		var xamlRoot = GtkManager.XamlRootMap.GetRootForHost(host);
-		_displayInformation ??= XamlRoot.GetDisplayInformation(xamlRoot);
-		_displayInformation.DpiChanged += OnDpiChanged;
+		_xamlRoot = GtkManager.XamlRootMap.GetRootForHost(host) ?? throw new InvalidOperationException("XamlRoot must not be null when renderer is initialized");
+		_xamlRoot.Changed += OnXamlRootChanged;
 		UpdateDpi();
 
 		_colorType = SKImageInfo.PlatformColorType;
@@ -57,8 +57,6 @@ public SoftwareRenderSurface(IGtkXamlRootHost host)
 
 	public void InvalidateRender() => QueueDrawArea(0, 0, 10000, 10000);
 
-	private void OnDpiChanged(DisplayInformation sender, object args) => UpdateDpi();
-
 	protected override bool OnDrawn(Context cr)
 	{
 		Stopwatch? sw = null;
@@ -69,8 +67,8 @@ protected override bool OnDrawn(Context cr)
 			this.Log().Trace($"Render {renderCount++}");
 		}
 
-		var scaledWidth = (int)(AllocatedWidth * _dpi);
-		var scaledHeight = (int)(AllocatedHeight * _dpi);
+		var scaledWidth = (int)(AllocatedWidth * _scale);
+		var scaledHeight = (int)(AllocatedHeight * _scale);
 
 		// reset the surfaces (skia/cairo) and bitmap if the size has changed
 		if (_surface == null || scaledWidth != _bwidth || scaledHeight != _bheight)
@@ -93,7 +91,7 @@ protected override bool OnDrawn(Context cr)
 		using (new SKAutoCanvasRestore(canvas, true))
 		{
 			canvas.Clear(BackgroundColor);
-			canvas.Scale(_dpi);
+			canvas.Scale(_scale);
 
 			if (_host.RootElement?.Visual is { } rootVisual)
 			{
@@ -130,5 +128,15 @@ public void TakeScreenshot(string filePath)
 		_bitmap?.Encode(wstream, SKEncodedImageFormat.Png, 100);
 	}
 
-	private float UpdateDpi() => _dpi = (float)_displayInformation.RawPixelsPerViewPixel;
+	private void OnXamlRootChanged(XamlRoot sender, XamlRootChangedEventArgs args) => UpdateDpi();
+
+	private void UpdateDpi()
+	{
+		var newScale = (float)_xamlRoot.RasterizationScale;
+		if (_scale != newScale)
+		{
+			_scale = newScale;
+			InvalidateRender();
+		}
+	}
 }