Small refactor and added unit test for the new ToWriteableBitmapWithDensity method.

Author: dlemstra

src/Magick.NET.AvaloniaMediaImaging/IMagickImageExtentions.cs

@@ -15,34 +15,29 @@ namespace ImageMagick;
 public static partial class IMagickImageExtentions
 {
     /// <summary>
-    /// Converts this instance to a <see cref="WriteableBitmap"/> with a default DPI of 96x96.
+    /// Converts this instance to a <see cref="WriteableBitmap"/> with a default dpi of 96x96.
     /// </summary>
     /// <param name="self">The image.</param>
     /// <typeparam name="TQuantumType">The quantum type.</typeparam>
     /// <returns>A <see cref="WriteableBitmap"/>.</returns>
-    public static unsafe WriteableBitmap ToWriteableBitmap<TQuantumType>(this IMagickImage<TQuantumType> self)
+    public static WriteableBitmap ToWriteableBitmap<TQuantumType>(this IMagickImage<TQuantumType> self)
         where TQuantumType : struct, IConvertible
-    {
-        return self.ToWriteableBitmapInternal(false);
-    }
-    
+        => self.ToWriteableBitmapInternal(new Vector(96, 96));
+
     /// <summary>
     /// Converts this instance to a <see cref="WriteableBitmap"/>.
     /// </summary>
     /// <param name="self">The image.</param>
     /// <typeparam name="TQuantumType">The quantum type.</typeparam>
     /// <returns>A <see cref="WriteableBitmap"/>.</returns>
-    public static unsafe WriteableBitmap ToWriteableBitmapWithDensity<TQuantumType>(this IMagickImage<TQuantumType> self)
+    public static WriteableBitmap ToWriteableBitmapWithDensity<TQuantumType>(this IMagickImage<TQuantumType> self)
         where TQuantumType : struct, IConvertible
-    {
-        return self.ToWriteableBitmapInternal(true);
-    }
+        => self.ToWriteableBitmapInternal(new Vector(self.Density.X, self.Density.Y));
 
-    private static unsafe WriteableBitmap ToWriteableBitmapInternal<TQuantumType>(this IMagickImage<TQuantumType> self, bool withDensity)
+    private static unsafe WriteableBitmap ToWriteableBitmapInternal<TQuantumType>(this IMagickImage<TQuantumType> self, Vector density)
         where TQuantumType : struct, IConvertible
     {
         var size = new PixelSize((int)self.Width, (int)self.Height);
-        var density = withDensity ? new Vector(self.Density.X, self.Density.Y) : new Vector(96, 96);
         var bitmap = new WriteableBitmap(size, density, PixelFormats.Rgba8888, AlphaFormat.Unpremul);
 
         using var framebuffer = bitmap.Lock();

tests/Magick.NET.AvaloniaMediaImaging.Tests/IMagickImageExtentionsTests/TheToWriteableBitmapMethod.cs

@@ -31,6 +31,7 @@ public void ShouldReturnWriteableBitmap()
             var distortion = output.Compare(input, ErrorMetric.RootMeanSquared);
 
             Assert.Equal(0.0, distortion);
+            Assert.Equal(new Vector(96, 96), bitmap.Dpi);
         }
     }
 }

tests/Magick.NET.AvaloniaMediaImaging.Tests/IMagickImageExtentionsTests/TheToWriteableBitmapWithDensityMethod.cs

@@ -0,0 +1,38 @@
+// Copyright Dirk Lemstra https://github.com/dlemstra/Magick.NET.
+// Licensed under the Apache License, Version 2.0.
+
+using System.IO;
+using Avalonia;
+using ImageMagick;
+using Xunit;
+
+namespace Magick.NET.AvaloniaMediaImaging.Tests;
+
+public partial class IMagickImageExtentionsTests
+{
+    public class TheToWriteableBitmapWithDensityMethod
+    {
+        [Fact]
+        public void ShouldReturnWriteableBitmap()
+        {
+            AppBuilder
+                .Configure<Application>()
+                .UsePlatformDetect()
+                .SetupWithoutStarting();
+
+            using var input = new MagickImage(Files.MagickNETIconPNG);
+            input.Density = new Density(150, 300);
+            using var bitmap = input.ToWriteableBitmapWithDensity();
+
+            using var outputStream = new MemoryStream();
+            bitmap.Save(outputStream);
+
+            outputStream.Position = 0;
+            using var output = new MagickImage(outputStream);
+            var distortion = output.Compare(input, ErrorMetric.RootMeanSquared);
+
+            Assert.Equal(0.0, distortion);
+            Assert.Equal(new Vector(150, 300), bitmap.Dpi);
+        }
+    }
+}