Make PixelSize accept a scaling factor for conversions.

For conversions between `PixelSize` and `Size` use a scaling factor by default; rename the DPI overloads to have a `WithDpi` suffix.

src/Avalonia.Visuals/Media/Imaging/Bitmap.cs

@@ -75,7 +75,7 @@ namespace Avalonia.Media.Imaging
         public Vector Dpi => PlatformImpl.Item.Dpi;
 
         /// <inheritdoc/>
-        public Size Size => PlatformImpl.Item.PixelSize.ToSize(Dpi);
+        public Size Size => PlatformImpl.Item.PixelSize.ToSizeWithDpi(Dpi);
 
         /// <inheritdoc/>
         public PixelSize PixelSize => PlatformImpl.Item.PixelSize;

src/Avalonia.Visuals/Media/PixelSize.cs

@@ -72,7 +72,7 @@ namespace Avalonia
         /// <returns>The <see cref="PixelSize"/>.</returns>
         public static PixelSize Parse(string s)
         {
-            using (var tokenizer = new StringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage: "Invalid Size"))
+            using (var tokenizer = new StringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage: "Invalid PixelSize"))
             {
                 return new PixelSize(
                     tokenizer.ReadInt32(),
@@ -126,13 +126,29 @@ namespace Avalonia
         /// <returns>The new <see cref="PixelSize"/>.</returns>
         public PixelSize WithHeight(int height) => new PixelSize(Width, height);
 
+        /// <summary>
+        /// Converts the <see cref="PixelSize"/> to a device-independent <see cref="Size"/> using the
+        /// specified scaling factor.
+        /// </summary>
+        /// <param name="scale">The scaling factor.</param>
+        /// <returns>The device-independent size.</returns>
+        public Size ToSize(double scale) => new Size(Width / scale, Height / scale);
+
+        /// <summary>
+        /// Converts the <see cref="PixelSize"/> to a device-independent <see cref="Size"/> using the
+        /// specified scaling factor.
+        /// </summary>
+        /// <param name="scale">The scaling factor.</param>
+        /// <returns>The device-independent size.</returns>
+        public Size ToSize(Vector scale) => new Size(Width / scale.X, Height / scale.Y);
+
         /// <summary>
         /// Converts the <see cref="PixelSize"/> to a device-independent <see cref="Size"/> using the
         /// specified dots per inch (DPI).
         /// </summary>
         /// <param name="dpi">The dots per inch.</param>
         /// <returns>The device-independent size.</returns>
-        public Size ToSize(double dpi) => new Size(Width / (dpi / 96), Height / (dpi / 96));
+        public Size ToSizeWithDpi(double dpi) => ToSize(dpi / 96);
 
         /// <summary>
         /// Converts the <see cref="PixelSize"/> to a device-independent <see cref="Size"/> using the
@@ -140,7 +156,27 @@ namespace Avalonia
         /// </summary>
         /// <param name="dpi">The dots per inch.</param>
         /// <returns>The device-independent size.</returns>
-        public Size ToSize(Vector dpi) => new Size(Width / (dpi.X / 96), Height / (dpi.Y / 96));
+        public Size ToSizeWithDpi(Vector dpi) => ToSize(new Vector(dpi.X / 96, dpi.Y / 96));
+
+        /// <summary>
+        /// Converts a <see cref="Size"/> to device pixels using the specified scaling factor.
+        /// </summary>
+        /// <param name="size">The size.</param>
+        /// <param name="scale">The scaling factor.</param>
+        /// <returns>The device-independent size.</returns>
+        public static PixelSize FromSize(Size size, double scale) => new PixelSize(
+            (int)Math.Ceiling(size.Width * scale),
+            (int)Math.Ceiling(size.Height * scale));
+
+        /// <summary>
+        /// Converts a <see cref="Size"/> to device pixels using the specified scaling factor.
+        /// </summary>
+        /// <param name="size">The size.</param>
+        /// <param name="scale">The scaling factor.</param>
+        /// <returns>The device-independent size.</returns>
+        public static PixelSize FromSize(Size size, Vector scale) => new PixelSize(
+            (int)Math.Ceiling(size.Width * scale.X),
+            (int)Math.Ceiling(size.Height * scale.Y));
 
         /// <summary>
         /// Converts a <see cref="Size"/> to device pixels using the specified dots per inch (DPI).
@@ -148,9 +184,7 @@ namespace Avalonia
         /// <param name="size">The size.</param>
         /// <param name="dpi">The dots per inch.</param>
         /// <returns>The device-independent size.</returns>
-        public static PixelSize FromSize(Size size, double dpi) => new PixelSize(
-            (int)(size.Width * (dpi / 96)),
-            (int)(size.Height * (dpi / 96)));
+        public static PixelSize FromSizeWithDpi(Size size, double dpi) => FromSize(size, dpi / 96);
 
         /// <summary>
         /// Converts a <see cref="Size"/> to device pixels using the specified dots per inch (DPI).
@@ -158,9 +192,7 @@ namespace Avalonia
         /// <param name="size">The size.</param>
         /// <param name="dpi">The dots per inch.</param>
         /// <returns>The device-independent size.</returns>
-        public static PixelSize FromSize(Size size, Vector dpi) => new PixelSize(
-            (int)Math.Ceiling(size.Width * (dpi.X / 96)),
-            (int)Math.Ceiling(size.Height * (dpi.Y / 96)));
+        public static PixelSize FromSizeWithDpi(Size size, Vector dpi) => FromSize(size, new Vector(dpi.X / 96, dpi.Y / 96));
 
         /// <summary>
         /// Returns the string representation of the size.

src/Skia/Avalonia.Skia/DrawingContextImpl.cs

@@ -401,15 +401,15 @@ namespace Avalonia.Skia
         /// <param name="tileBrushImage">Tile brush image.</param>
         private void ConfigureTileBrush(ref PaintWrapper paintWrapper, Size targetSize, ITileBrush tileBrush, IDrawableBitmapImpl tileBrushImage)
         {
-            var calc = new TileBrushCalculator(tileBrush, tileBrushImage.PixelSize.ToSize(_dpi), targetSize);
+            var calc = new TileBrushCalculator(tileBrush, tileBrushImage.PixelSize.ToSizeWithDpi(_dpi), targetSize);
             var intermediate = CreateRenderTarget(calc.IntermediateSize);
 
             paintWrapper.AddDisposable(intermediate);
 
             using (var context = intermediate.CreateDrawingContext(null))
             {
-                var sourceRect = new Rect(tileBrushImage.PixelSize.ToSize(96));
-                var targetRect = new Rect(tileBrushImage.PixelSize.ToSize(_dpi));
+                var sourceRect = new Rect(tileBrushImage.PixelSize.ToSizeWithDpi(96));
+                var targetRect = new Rect(tileBrushImage.PixelSize.ToSizeWithDpi(_dpi));
 
                 context.Clear(Colors.Transparent);
                 context.PushClip(calc.IntermediateClip);
@@ -634,7 +634,7 @@ namespace Avalonia.Skia
         /// <returns></returns>
         private SurfaceRenderTarget CreateRenderTarget(Size size, PixelFormat? format = null)
         {
-            var pixelSize = PixelSize.FromSize(size, _dpi);
+            var pixelSize = PixelSize.FromSizeWithDpi(size, _dpi);
             var createInfo = new SurfaceRenderTarget.CreateInfo
             {
                 Width = pixelSize.Width,

src/Windows/Avalonia.Direct2D1/Media/DrawingContextImpl.cs

@@ -330,7 +330,7 @@ namespace Avalonia.Direct2D1.Media
             {
                 var platform = AvaloniaLocator.Current.GetService<IPlatformRenderInterface>();
                 var dpi = new Vector(_deviceContext.DotsPerInch.Width, _deviceContext.DotsPerInch.Height);
-                var pixelSize = PixelSize.FromSize(size, dpi);
+                var pixelSize = PixelSize.FromSizeWithDpi(size, dpi);
                 return platform.CreateRenderTargetBitmap(pixelSize, dpi);
             }
         }
@@ -438,12 +438,12 @@ namespace Avalonia.Direct2D1.Media
                         // D2D alters the DPI of the render target, which messes stuff up. PixelSize.FromSize
                         // will do the rounding for us.
                         var dpi = new Vector(_deviceContext.DotsPerInch.Width, _deviceContext.DotsPerInch.Height);
-                        var pixelSize = PixelSize.FromSize(intermediateSize, dpi);
+                        var pixelSize = PixelSize.FromSizeWithDpi(intermediateSize, dpi);
 
                         using (var intermediate = new BitmapRenderTarget(
                             _deviceContext,
                             CompatibleRenderTargetOptions.None,
-                            pixelSize.ToSize(dpi).ToSharpDX()))
+                            pixelSize.ToSizeWithDpi(dpi).ToSharpDX()))
                         {
                             using (var ctx = new RenderTarget(intermediate).CreateDrawingContext(_visualBrushRenderer))
                             {

src/Windows/Avalonia.Direct2D1/Media/ImageBrushImpl.cs

@@ -21,7 +21,7 @@ namespace Avalonia.Direct2D1.Media
             Size targetSize)
         {
             var dpi = new Vector(target.DotsPerInch.Width, target.DotsPerInch.Height);
-            var calc = new TileBrushCalculator(brush, bitmap.PixelSize.ToSize(dpi), targetSize);
+            var calc = new TileBrushCalculator(brush, bitmap.PixelSize.ToSizeWithDpi(dpi), targetSize);
 
             if (!calc.NeedsIntermediate)
             {
@@ -101,7 +101,7 @@ namespace Avalonia.Direct2D1.Media
             using (var context = new RenderTarget(result).CreateDrawingContext(null))
             {
                 var dpi = new Vector(target.DotsPerInch.Width, target.DotsPerInch.Height);
-                var rect = new Rect(bitmap.PixelSize.ToSize(dpi));
+                var rect = new Rect(bitmap.PixelSize.ToSizeWithDpi(dpi));
 
                 context.Clear(Colors.Transparent);
                 context.PushClip(calc.IntermediateClip);

src/Windows/Avalonia.Direct2D1/Media/Imaging/D2DRenderTargetBitmapImpl.cs

@@ -61,8 +61,8 @@ namespace Avalonia.Direct2D1.Media.Imaging
                     dc.DrawImage(
                         RefCountable.CreateUnownedNotClonable(this),
                         1,
-                        new Rect(PixelSize.ToSize(Dpi.X)),
-                        new Rect(PixelSize.ToSize(Dpi.X)));
+                        new Rect(PixelSize.ToSizeWithDpi(Dpi.X)),
+                        new Rect(PixelSize.ToSizeWithDpi(Dpi.X)));
                 }
 
                 wic.Save(stream);