Add SVG support for asset generation (#326)

## Description

Adds the Svg library as a dependency, and detects svg files on manifest
update-assets command, converting to a Bitmap to generate the new
assets.

## Usage Example

```bash
winapp manifest update-assets .\image.svg
```


## Type of Change

- ✨ New feature

## Checklist
<!-- Delete the ones that do not apply to your changes -->

- [X] New tests added for new functionality (if applicable)
- [X] Tested locally on Windows
- [ ] Main [README.md](../README.md) updated (if applicable)
- [ ] [docs/usage.md](../docs/usage.md) updated (if CLI commands
changed)
- [ ] [Language-specific guides](../docs/guides) updated (if applicable)
- [ ] [Sample projects updated](../samples) to reflect changes (if
applicable)

## AI Description

<!-- ai-description-start -->
This PR adds support for SVG files in the asset generation process of
the winapp CLI. It includes the Svg.Skia library as a dependency and
allows the `manifest update-assets` command to convert SVG files into
bitmap images when generating assets. This enhancement simplifies the
process for developers looking to utilize SVG graphics in their
applications.

Usage example:
```bash
winapp manifest update-assets .\image.svg
```
<!-- ai-description-end -->

---------

Co-authored-by: Nikola Metulev <nmetulev@users.noreply.github.com>
Co-authored-by: Nikola Metulev <711864+nmetulev@users.noreply.github.com>

Author: azchohfi

src/winapp-CLI/Directory.Packages.props

@@ -8,6 +8,7 @@
     <PackageVersion Include="System.CommandLine" Version="2.0.2" />
     <PackageVersion Include="System.Diagnostics.EventLog" Version="10.0.2" />
     <PackageVersion Include="Microsoft.Telemetry.Inbox.Managed" Version="10.0.25148.1001-220626-1600.rs-fun-deploy-dev5" />
+    <PackageVersion Include="Svg.Skia" Version="3.4.1" />
     <PackageVersion Include="System.Drawing.Common" Version="10.0.2" />
   </ItemGroup>
 </Project>

src/winapp-CLI/WinApp.Cli.Tests/ManifestUpdateAssetsCommandTests.cs

@@ -258,4 +258,86 @@ public async Task ManifestUpdateAssetsCommandShouldInferManifestFromCurrentDirec
         var assetsDir = Path.Combine(_tempDirectory.FullName, "Assets");
         Assert.IsTrue(Directory.Exists(assetsDir), "Assets directory should be created");
     }
+
+    [TestMethod]
+    public async Task ManifestUpdateAssetsCommandShouldGenerateAssetsFromSvg()
+    {
+        // Arrange
+        var svgImagePath = Path.Combine(_tempDirectory.FullName, "testlogo.svg");
+        PngHelper.CreateTestSvgImage(svgImagePath);
+
+        var updateAssetsCommand = GetRequiredService<ManifestUpdateAssetsCommand>();
+        var args = new[]
+        {
+            svgImagePath,
+            "--manifest", _testManifestPath
+        };
+
+        // Act
+        var parseResult = updateAssetsCommand.Parse(args);
+        var exitCode = await parseResult.InvokeAsync();
+
+        // Assert
+        Assert.AreEqual(0, exitCode, "Update-assets command should complete successfully with SVG source");
+
+        // Verify Assets directory was created
+        var assetsDir = Path.Combine(_tempDirectory.FullName, "Assets");
+        Assert.IsTrue(Directory.Exists(assetsDir), "Assets directory should be created");
+
+        // Verify assets referenced in manifest were generated
+        var expectedAssets = new[]
+        {
+            "Square44x44Logo.png",
+            "Square150x150Logo.png",
+            "Wide310x150Logo.png",
+            "StoreLogo.png"
+        };
+
+        foreach (var asset in expectedAssets)
+        {
+            var assetPath = Path.Combine(assetsDir, asset);
+            Assert.IsTrue(File.Exists(assetPath), $"Asset {asset} should be generated from SVG source");
+        }
+    }
+
+    [TestMethod]
+    public async Task ManifestUpdateAssetsCommandShouldGenerateCorrectSizesFromSvg()
+    {
+        // Arrange
+        var svgImagePath = Path.Combine(_tempDirectory.FullName, "testlogo.svg");
+        PngHelper.CreateTestSvgImage(svgImagePath);
+
+        var updateAssetsCommand = GetRequiredService<ManifestUpdateAssetsCommand>();
+        var args = new[]
+        {
+            svgImagePath,
+            "--manifest", _testManifestPath
+        };
+
+        // Act
+        var parseResult = updateAssetsCommand.Parse(args);
+        var exitCode = await parseResult.InvokeAsync();
+
+        // Assert
+        Assert.AreEqual(0, exitCode, "Update-assets command should complete successfully with SVG source");
+
+        var assetsDir = Path.Combine(_tempDirectory.FullName, "Assets");
+
+        // Verify scale-200 assets exist with correct dimensions (2x the base size)
+        var scale200_44 = Path.Combine(assetsDir, "Square44x44Logo.scale-200.png");
+        Assert.IsTrue(File.Exists(scale200_44), "Square44x44Logo.scale-200.png should exist when generated from SVG");
+        using (var bmp44 = new System.Drawing.Bitmap(scale200_44))
+        {
+            Assert.AreEqual(88, bmp44.Width, "Square44x44Logo.scale-200 should be 88px wide (44 * 2)");
+            Assert.AreEqual(88, bmp44.Height, "Square44x44Logo.scale-200 should be 88px tall (44 * 2)");
+        }
+
+        var scale200_150 = Path.Combine(assetsDir, "Square150x150Logo.scale-200.png");
+        Assert.IsTrue(File.Exists(scale200_150), "Square150x150Logo.scale-200.png should exist when generated from SVG");
+        using (var bmp150 = new System.Drawing.Bitmap(scale200_150))
+        {
+            Assert.AreEqual(300, bmp150.Width, "Square150x150Logo.scale-200 should be 300px wide (150 * 2)");
+            Assert.AreEqual(300, bmp150.Height, "Square150x150Logo.scale-200 should be 300px tall (150 * 2)");
+        }
+    }
 }

src/winapp-CLI/WinApp.Cli.Tests/PngHelper.cs

@@ -25,6 +25,16 @@ internal static void CreateTestImage(string path)
         File.WriteAllBytes(path, pngData);
     }
 
+    internal static void CreateTestSvgImage(string path)
+    {
+        var svgContent = """
+            <svg xmlns="http://www.w3.org/2000/svg" width="100" height="100" viewBox="0 0 100 100">
+              <rect width="100" height="100" fill="blue"/>
+            </svg>
+            """;
+        File.WriteAllText(path, svgContent);
+    }
+
     /// <summary>
     /// Verifies that all pixels in the image are fully transparent (alpha = 0).
     /// </summary>

src/winapp-CLI/WinApp.Cli/Services/ImageAssetService.cs

@@ -1,6 +1,8 @@
 // Copyright (c) Microsoft Corporation and Contributors. All rights reserved.
 // Licensed under the MIT License.
 
+using SkiaSharp;
+using Svg.Skia;
 using System.Drawing;
 using System.Drawing.Drawing2D;
 using System.Drawing.Imaging;
@@ -47,15 +49,7 @@ public async Task GenerateAssetsAsync(FileInfo sourceImagePath, DirectoryInfo ou
         Bitmap sourceImage;
         try
         {
-            if (sourceImagePath.Extension.Equals(".ico", StringComparison.OrdinalIgnoreCase))
-            {
-                using var icon = new Icon(sourceImagePath.FullName);
-                sourceImage = icon.ToBitmap();
-            }
-            else
-            {
-                sourceImage = new Bitmap(sourceImagePath.FullName);
-            }
+            sourceImage = LoadSourceImage(sourceImagePath);
         }
         catch (Exception ex)
         {
@@ -123,15 +117,7 @@ public async Task GenerateAssetsFromManifestAsync(
         Bitmap sourceImage;
         try
         {
-            if (sourceImagePath.Extension.Equals(".ico", StringComparison.OrdinalIgnoreCase))
-            {
-                using var icon = new Icon(sourceImagePath.FullName);
-                sourceImage = icon.ToBitmap();
-            }
-            else
-            {
-                sourceImage = new Bitmap(sourceImagePath.FullName);
-            }
+            sourceImage = LoadSourceImage(sourceImagePath);
         }
         catch (Exception ex)
         {
@@ -214,6 +200,81 @@ public async Task GenerateAssetsFromManifestAsync(
         }
     }
 
+    private static Bitmap LoadSourceImage(FileInfo sourceImagePath)
+    {
+        if (sourceImagePath.Extension.Equals(".ico", StringComparison.OrdinalIgnoreCase))
+        {
+            using var icon = new Icon(sourceImagePath.FullName);
+            return icon.ToBitmap();
+        }
+
+        if (sourceImagePath.Extension.Equals(".svg", StringComparison.OrdinalIgnoreCase))
+        {
+            return LoadSvgAsBitmap(sourceImagePath);
+        }
+
+        return new Bitmap(sourceImagePath.FullName);
+    }
+
+    private static Bitmap LoadSvgAsBitmap(FileInfo sourceImagePath)
+    {
+        var svg = new SKSvg();
+        using var stream = File.OpenRead(sourceImagePath.FullName);
+        svg.Load(stream);
+
+        var picture = svg.Picture ?? throw new InvalidOperationException(
+            $"Failed to render SVG image: {sourceImagePath.FullName}. The file may be corrupted or contain unsupported SVG features.");
+        var bounds = picture.CullRect;
+
+        int width = (int)Math.Ceiling(bounds.Width);
+        int height = (int)Math.Ceiling(bounds.Height);
+
+        if (width <= 0 || height <= 0)
+        {
+            throw new InvalidOperationException(
+                $"SVG image has invalid dimensions ({width}x{height}): {sourceImagePath.FullName}. Ensure the SVG has a valid viewBox or width/height attributes.");
+        }
+
+        // Render at a reasonable minimum size for quality when scaling down to asset sizes
+        const float minRenderDimension = 1024f;
+        float scaleFactor = 1f;
+        if (width < minRenderDimension || height < minRenderDimension)
+        {
+            scaleFactor = Math.Max(minRenderDimension / width, minRenderDimension / height);
+            width = (int)Math.Ceiling(bounds.Width * scaleFactor);
+            height = (int)Math.Ceiling(bounds.Height * scaleFactor);
+        }
+
+        // Render SVG to SKBitmap, then convert to System.Drawing.Bitmap
+        using var skBitmap = new SKBitmap(width, height);
+        using (var canvas = new SKCanvas(skBitmap))
+        {
+            canvas.Clear(SKColors.Transparent);
+
+            // Translate to handle non-zero origin bounds, then scale
+            if (bounds.Left != 0 || bounds.Top != 0)
+            {
+                canvas.Translate(-bounds.Left * scaleFactor, -bounds.Top * scaleFactor);
+            }
+
+            if (scaleFactor > 1f)
+            {
+                canvas.Scale(scaleFactor);
+            }
+
+            canvas.DrawPicture(picture);
+            canvas.Flush();
+        }
+
+        using var image = SKImage.FromBitmap(skBitmap);
+        using var data = image.Encode(SKEncodedImageFormat.Png, 100);
+
+        // Create the Bitmap from a fresh MemoryStream that it will own.
+        // Bitmap keeps a reference to the stream, so we must NOT dispose it.
+        var ms = new MemoryStream(data.ToArray());
+        return new Bitmap(ms);
+    }
+
     private static async Task GenerateAssetAsync(Bitmap sourceImage, string outputPath, int targetWidth, int targetHeight, CancellationToken cancellationToken)
     {
         await Task.Run(() =>

src/winapp-CLI/WinApp.Cli/WinApp.Cli.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
@@ -26,7 +26,7 @@
     <TrimMode>full</TrimMode>
     <CsWin32RunAsBuildTask>true</CsWin32RunAsBuildTask>
     <DisableRuntimeMarshalling>true</DisableRuntimeMarshalling>
-
+    
     <!-- Faster startup for single-file -->
     <IncludeNativeLibrariesForSelfExtract>false</IncludeNativeLibrariesForSelfExtract>
     <DebuggerSupport>false</DebuggerSupport>
@@ -54,6 +54,7 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
     <PackageReference Include="Spectre.Console" />
+    <PackageReference Include="Svg.Skia" />
     <PackageReference Include="System.CommandLine" />
     <PackageReference Include="System.Diagnostics.EventLog" />
     <PackageReference Include="System.Drawing.Common" />