Refactor glyph drawing API and clipping flow

Reworked text rendering entry points to use positioned glyph spans (`glyphIds` + `points`) instead of `GlyphRun` in `DrawingCanvas` and `TextBuilder`, and updated call sites/tests accordingly. Image drawing was also tightened by moving clipping responsibility to callers so `DrawImageCore` now assumes pre-clipped input, reducing duplicate clipping paths and keeping rect mapping consistent. The changes also include small WebGPU/sample cleanup and analyzer-driven modernizations (`_ =` discard assignments, target-typed collection literals, simplified lambdas), plus package version bumps and refreshed image baselines impacted by text output changes.

Author: JimBobSquarePants

samples/WebGPUExternalSurfaceDemo/Scenes/ApplyReadbackScene.cs

@@ -3,7 +3,6 @@
 
 using SixLabors.ImageSharp.Drawing;
 using SixLabors.ImageSharp.Drawing.Processing;
-using SixLabors.ImageSharp.PixelFormats;
 using SixLabors.ImageSharp.Processing;
 using Brushes = SixLabors.ImageSharp.Drawing.Processing.Brushes;
 using Color = SixLabors.ImageSharp.Color;

samples/WebGPUExternalSurfaceDemo/Scenes/ManualTextFlowScene.cs

@@ -452,7 +452,7 @@ private static void AddBandScanLines(
     /// <param name="scanYs">The scanline collection for the current band.</param>
     private static void AddScanY(float y, float bandTop, float bandBottom, List<float> scanYs)
     {
-        const float DuplicateTolerance = 0.5F;
+        const float duplicateTolerance = 0.5F;
 
         // Scanlines exactly on the edge of the row do not tell us whether the
         // row itself is obstructed. The top/bottom samples are added with a small
@@ -467,7 +467,7 @@ private static void AddScanY(float y, float bandTop, float bandBottom, List<floa
         // doing far more work than polygons in this demo.
         for (int i = 0; i < scanYs.Count; i++)
         {
-            if (MathF.Abs(scanYs[i] - y) < DuplicateTolerance)
+            if (MathF.Abs(scanYs[i] - y) < duplicateTolerance)
             {
                 return;
             }

samples/WebGPUExternalSurfaceDemo/Scenes/ShaderEffectsScene.cs

@@ -78,12 +78,11 @@ protected override Control CreateContent(WebGPURenderControl renderControl)
     }
 
     /// <inheritdoc />
-    public override void OnHostLoaded(WebGPUDeviceContext deviceContext)
-    {
+    public override void OnHostLoaded(WebGPUDeviceContext deviceContext) =>
+
         // Compile the immutable WGSL program while the first tab is visible. Uniform values
         // change every frame, but every snapshot shares this cached program and pipeline.
         deviceContext.Precompile(this.shaderEffect);
-    }
 
     /// <inheritdoc />
     public override void Paint(DrawingCanvas canvas, TimeSpan deltaTime)
@@ -369,8 +368,8 @@ fn layer_effect(position: vec2<f32>) -> vec4<f32> {
         /// </summary>
         /// <param name="options">The values shared by the WGSL pass and CPU fallback.</param>
         public LivingNebulaShaderEffect(LivingNebulaShaderOptions options)
-            : base(ShaderSource, UniformLayout, CreateFallback(options))
-        {
+            : base(ShaderSource, UniformLayout, CreateFallback(options)) =>
+
             // The base type creates and freezes the pass. The effect supplies only values
             // matching its declared layout, which is the complete custom-shader workflow.
             this.AddShaderPass(uniforms =>
@@ -384,8 +383,6 @@ public LivingNebulaShaderEffect(LivingNebulaShaderOptions options)
                 uniforms.SetFloat32("pulse_age", options.PulseAge);
             });
 
-        }
-
         /// <summary>
         /// Creates the CPU image operation that reproduces the procedural WGSL pass.
         /// </summary>
@@ -450,7 +447,7 @@ private static Vector3 RenderPixel(Vector2 position, Vector2 resolution, LivingN
             density = MathF.Pow(density, 2.1F);
 
             float wave = 0F;
-            if (options.PulseAge >= 0F && options.PulseAge < 2F)
+            if (options.PulseAge is >= 0F and < 2F)
             {
                 // Evaluate the click in the same aspect-correct space as the clouds. Squaring
                 // the signed distance to the expanding radius produces a narrow Gaussian ring.
@@ -608,7 +605,6 @@ private static Vector2 Rotate(Vector2 position, float angle)
             return new Vector2(
                 (cosine * position.X) - (sine * position.Y),
                 (sine * position.X) + (cosine * position.Y));
-
         }
 
         /// <summary>

samples/WebGPUExternalSurfaceDemo/Scenes/TigerViewerScene.cs

@@ -128,9 +128,9 @@ protected override Control CreateContent(WebGPURenderControl renderControl)
             Size = new System.Drawing.Size(350, 100),
             BackColor = System.Drawing.Color.FromArgb(160, 0, 0, 0),
             ForeColor = System.Drawing.Color.White,
-            Font = new System.Drawing.Font(System.Drawing.FontFamily.GenericMonospace, 9F),
+            Font = new Font(FontFamily.GenericMonospace, 9F),
             Padding = new Padding(6),
-            Location = new System.Drawing.Point(6, 6),
+            Location = new Point(6, 6),
         };
 
         renderControl.PaintFrame += (_, _) => statusLabel.Text = this.StatusText;

src/ImageSharp.Drawing.WebGPU/WebGPUShaderModuleSource.cs

@@ -19,7 +19,7 @@ internal sealed class WebGPUShaderProgram
 
     // Layouts are normally static declarations owned by an effect type. Weak keys allow dynamically
     // created layouts and their cached programs to be collected together.
-    private static readonly ConditionalWeakTable<WebGPUShaderUniformLayout, ProgramCache> ProgramsByLayout = new();
+    private static readonly ConditionalWeakTable<WebGPUShaderUniformLayout, ProgramCache> ProgramsByLayout = [];
 
     private readonly object moduleSourceSync = new();
     private readonly Dictionary<

src/ImageSharp.Drawing.WebGPU/WebGPUShaderProgram.cs

@@ -20,12 +20,11 @@ internal static unsafe class WebGPUSurfaceFactory
     /// <param name="instance">The instance that owns the surface.</param>
     /// <param name="source">The native window source.</param>
     /// <returns>The created surface, or <see langword="null"/> on failure.</returns>
-    public static WGPUSurfaceImpl* Create(WebGPU api, WGPUInstanceImpl* instance, INativeWindowSource source)
-    {
+    public static WGPUSurfaceImpl* Create(WebGPU api, WGPUInstanceImpl* instance, INativeWindowSource source) =>
+
         // Every backend entry point supplies an initialized window source. The Silk contract makes
         // Native nullable only for source implementations that have not created their window yet.
-        return Create(api, instance, source.Native!, true);
-    }
+        Create(api, instance, source.Native!, true);
 
     /// <summary>
     /// Creates a WebGPU surface for an externally-owned host.
@@ -34,14 +33,14 @@ internal static unsafe class WebGPUSurfaceFactory
     /// <param name="instance">The instance that owns the surface.</param>
     /// <param name="host">The external native host.</param>
     /// <returns>The created surface, or <see langword="null"/> on failure.</returns>
-    public static WGPUSurfaceImpl* Create(WebGPU api, WGPUInstanceImpl* instance, WebGPUSurfaceHost host)
-    {
+    public static WGPUSurfaceImpl* Create(WebGPU api, WGPUInstanceImpl* instance, WebGPUSurfaceHost host) =>
+
         // External hosts model the descriptors accepted by wgpu-native directly. GLFW and SDL are
         // the only toolkit-level entries and are translated before reaching the native C API.
-        return host.Kind switch
+        host.Kind switch
         {
             WebGPUSurfaceHostKind.Glfw => Create(api, instance, new GlfwNativeWindow(GlfwProvider.GLFW.Value, (WindowHandle*)host.Handle0), false),
-            WebGPUSurfaceHostKind.Sdl => Create(api, instance, new SdlNativeWindow(SdlProvider.SDL.Value, (Silk.NET.SDL.Window*)host.Handle0), false),
+            WebGPUSurfaceHostKind.Sdl => Create(api, instance, new SdlNativeWindow(SdlProvider.SDL.Value, (Window*)host.Handle0), false),
             WebGPUSurfaceHostKind.Win32 => CreateWindowsSurface(api, instance, host.Handle0, host.Handle1),
             WebGPUSurfaceHostKind.X11 => CreateXlibSurface(api, instance, host.Handle0, host.Number0),
             WebGPUSurfaceHostKind.Cocoa => CreateCocoaSurface(api, instance, host.Handle0),
@@ -51,7 +50,6 @@ internal static unsafe class WebGPUSurfaceFactory
             WebGPUSurfaceHostKind.Android => CreateAndroidSurface(api, instance, host.Handle0),
             _ => null,
         };
-    }
 
     /// <summary>
     /// Resolves a Silk native window to one of the platform handles represented by the WebGPU C surface descriptors.

src/ImageSharp.Drawing.WebGPU/WebGPUSurfaceFactory.cs

@@ -40,14 +40,9 @@
     <None Include="..\..\shared-infrastructure\branding\icons\imagesharp.drawing\sixlabors.imagesharp.drawing.128.png" Pack="true" PackagePath="" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="SixLabors.Fonts" Version="3.0.1-alpha.0.8" />
-    <PackageReference Include="SixLabors.ImageSharp" Version="4.0.1-alpha.0.11" />
-    <PackageReference Include="SixLabors.PolygonClipper" Version="1.0.1-alpha.0.5" />
-  </ItemGroup>
-  <ItemGroup>
-    <!--<ProjectReference Include="..\..\..\Fonts\src\SixLabors.Fonts\SixLabors.Fonts.csproj" />
-    <ProjectReference Include="..\..\..\ImageSharp\src\ImageSharp\ImageSharp.csproj" />
-    <ProjectReference Include="..\..\..\PolygonClipper\src\PolygonClipper\PolygonClipper.csproj" />-->
+    <PackageReference Include="SixLabors.Fonts" Version="3.0.1-alpha.0.15" />
+    <PackageReference Include="SixLabors.ImageSharp" Version="4.0.1-alpha.0.20" />
+    <PackageReference Include="SixLabors.PolygonClipper" Version="1.0.1-alpha.0.6" />
   </ItemGroup>
 
   <!--

src/ImageSharp.Drawing/ImageSharp.Drawing.csproj

@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+using System.Numerics;
 using SixLabors.Fonts;
 using SixLabors.ImageSharp.Drawing.Processing.Backends;
 using SixLabors.ImageSharp.Drawing.Text;
@@ -379,15 +380,12 @@ public abstract void DrawText(
     /// <summary>
     /// Draws positioned glyphs onto this canvas.
     /// </summary>
-    /// <param name="glyphRun">The positioned glyphs.</param>
+    /// <param name="glyphIds">The glyph identifiers.</param>
+    /// <param name="points">The absolute glyph origins in pixel units.</param>
     /// <param name="options">The glyph rendering options, including the font and optional glyph paint.</param>
     /// <param name="brush">Default brush used to fill glyphs when <see cref="RichGlyphOptions.Brush"/> is not set.</param>
     /// <param name="pen">Default pen used to outline glyphs when <see cref="RichGlyphOptions.Pen"/> is not set.</param>
-    public abstract void DrawText(
-        GlyphRun glyphRun,
-        RichGlyphOptions options,
-        Brush? brush,
-        Pen? pen);
+    public abstract void DrawText(ReadOnlySpan<ushort> glyphIds, ReadOnlySpan<Vector2> points, RichGlyphOptions options, Brush? brush, Pen? pen);
 
     /// <summary>
     /// Draws layered glyph geometry.

src/ImageSharp.Drawing/Processing/DrawingCanvas.cs

@@ -460,7 +460,7 @@ private int SaveEffectLayerCore(GraphicsOptions layerOptions, IPath region, Laye
                 bool pushed = options is not null;
                 if (pushed)
                 {
-                    this.Save(options!);
+                    _ = this.Save(options!);
                 }
 
                 this.ApplyCore(region, effect.CreateOperation(), effect, effect.WriteBackOptions, effect.WriteBackOffset);
@@ -994,17 +994,13 @@ public override void DrawText(
     }
 
     /// <inheritdoc />
-    public override void DrawText(
-        GlyphRun glyphRun,
-        RichGlyphOptions options,
-        Brush? brush,
-        Pen? pen)
+    public override void DrawText(ReadOnlySpan<ushort> glyphIds, ReadOnlySpan<Vector2> points, RichGlyphOptions options, Brush? brush, Pen? pen)
     {
         this.EnsureNotDisposed();
-        Guard.NotNull(glyphRun, nameof(glyphRun));
         Guard.NotNull(options, nameof(options));
+        Guard.IsTrue(glyphIds.Length == points.Length, nameof(points), "Glyph id and point counts must match.");
 
-        if (glyphRun.Count == 0)
+        if (glyphIds.IsEmpty)
         {
             return;
         }
@@ -1016,7 +1012,7 @@ public override void DrawText(
 
         using RichTextGlyphRenderer glyphRenderer = new(effectiveOptions, path: null, pen, brush, this.textCache, this.textOperations);
         TextRenderer renderer = new(glyphRenderer);
-        renderer.Render(glyphRun, options);
+        renderer.Render(glyphIds, points, options);
 
         this.DrawTextOperations(this.BatchGlyphRunOperations(glyphRenderer.DrawingOperations), effectiveOptions);
     }
@@ -1137,7 +1133,7 @@ public override void DrawImage(
 
         if (image is Image<TPixel> specificImage)
         {
-            this.DrawImageCore(specificImage, sourceRect, destinationRect, sampler, wrapX, wrapY, ownsSourceImage: false);
+            this.DrawImage(specificImage, sourceRect, destinationRect, wrapX, wrapY, sampler);
             return;
         }
 
@@ -1152,13 +1148,13 @@ public override void DrawImage(
         if (clippedSourceRect == image.Bounds)
         {
             Image<TPixel> convertedImage = image.CloneAs<TPixel>();
-            this.DrawImageCore(convertedImage, sourceRect, destinationRect, sampler, wrapX, wrapY, ownsSourceImage: true);
+            this.DrawImageCore(convertedImage, clippedSourceRect, clippedDestinationRect, sampler, wrapX, wrapY, true);
             return;
         }
 
         using Image croppedSource = image.Clone(ctx => ctx.Crop(clippedSourceRect));
         Image<TPixel> convertedRegion = croppedSource.CloneAs<TPixel>();
-        this.DrawImageCore(convertedRegion, convertedRegion.Bounds, clippedDestinationRect, sampler, wrapX, wrapY, ownsSourceImage: true);
+        this.DrawImageCore(convertedRegion, convertedRegion.Bounds, clippedDestinationRect, sampler, wrapX, wrapY, true);
     }
 
     /// <inheritdoc cref="DrawingCanvas.DrawImage(Image, Rectangle, RectangleF, IResampler?)" />
@@ -1180,7 +1176,13 @@ public void DrawImage(
     {
         this.EnsureNotDisposed();
         Guard.NotNull(image, nameof(image));
-        this.DrawImageCore(image, sourceRect, destinationRect, sampler, wrapX, wrapY, ownsSourceImage: false);
+
+        if (!TryGetDrawImageClip(sourceRect, destinationRect, image.Bounds, out Rectangle clippedSourceRect, out RectangleF clippedDestinationRect))
+        {
+            return;
+        }
+
+        this.DrawImageCore(image, clippedSourceRect, clippedDestinationRect, sampler, wrapX, wrapY, false);
     }
 
     /// <inheritdoc />
@@ -1260,12 +1262,12 @@ public override void CopyPixelsFrom(DrawingCanvas source, Rectangle sourceRectan
     }
 
     /// <summary>
-    /// Normalizes an image draw into an image-brush fill: source pixels are cropped/scaled,
+    /// Normalizes a pre-clipped image draw into an image-brush fill: source pixels are cropped/scaled,
     /// then baked through the canvas transform, and the result is queued as a rectangle fill.
     /// </summary>
     /// <param name="image">The source image in the target pixel format.</param>
-    /// <param name="sourceRect">The source rectangle within <paramref name="image"/>.</param>
-    /// <param name="destinationRect">The destination rectangle in local canvas coordinates.</param>
+    /// <param name="clippedSourceRect">The source rectangle, already clipped to the bounds of <paramref name="image"/>.</param>
+    /// <param name="clippedDestinationRect">The destination rectangle matching <paramref name="clippedSourceRect"/>, in local canvas coordinates.</param>
     /// <param name="sampler">Optional resampler used when scaling or transforming the image.</param>
     /// <param name="wrapX">The horizontal wrap mode applied when sampling beyond the destination rectangle.</param>
     /// <param name="wrapY">The vertical wrap mode applied when sampling beyond the destination rectangle.</param>
@@ -1275,8 +1277,8 @@ public override void CopyPixelsFrom(DrawingCanvas source, Rectangle sourceRectan
     /// </param>
     private void DrawImageCore(
         Image<TPixel> image,
-        Rectangle sourceRect,
-        RectangleF destinationRect,
+        Rectangle clippedSourceRect,
+        RectangleF clippedDestinationRect,
         IResampler? sampler,
         WrapMode wrapX,
         WrapMode wrapY,
@@ -1291,11 +1293,6 @@ private void DrawImageCore(
         Image<TPixel>? ownedImage = null;
         try
         {
-            if (!TryGetDrawImageClip(sourceRect, destinationRect, image.Bounds, out Rectangle clippedSourceRect, out RectangleF clippedDestinationRect))
-            {
-                return;
-            }
-
             Size scaledSize = new(
                 Math.Max(1, (int)MathF.Ceiling(clippedDestinationRect.Width)),
                 Math.Max(1, (int)MathF.Ceiling(clippedDestinationRect.Height)));