Introduce DrawingCanvas base type and APIs

Author: JimBobSquarePants

samples/DrawingBackendBenchmark/VisualLine.cs

@@ -70,7 +70,7 @@ private static SKColor ToSkiaColor(Color color)
     /// <summary>
     /// Draws the shared benchmark scene into the supplied canvas.
     /// </summary>
-    public static void RenderLinesToCanvas(DrawingCanvas<Bgra32> canvas, ReadOnlySpan<VisualLine> lines)
+    public static void RenderLinesToCanvas(DrawingCanvas canvas, ReadOnlySpan<VisualLine> lines)
     {
         canvas.Restore();
         canvas.Fill(BackgroundBrush);

samples/DrawingBackendBenchmark/WebGpuBenchmarkBackend.cs

@@ -46,7 +46,7 @@ public BenchmarkRenderResult Render(ReadOnlySpan<VisualLine> lines, int width, i
         WebGPURenderTarget<Bgra32> renderTarget = this.EnsureRenderTarget(width, height);
 
         Stopwatch stopwatch = Stopwatch.StartNew();
-        using (DrawingCanvas<Bgra32> canvas = renderTarget.CreateCanvas(new DrawingOptions()))
+        using (DrawingCanvas canvas = renderTarget.CreateCanvas(new DrawingOptions()))
         {
             VisualLine.RenderLinesToCanvas(canvas, lines);
             canvas.Flush();

samples/WebGPUExternalSurfaceDemo/Controls/WebGPURenderControl.cs

@@ -46,7 +46,7 @@ public WebGPURenderControl()
     /// <summary>
     /// Raised each frame once the external surface has acquired a drawable frame.
     /// </summary>
-    public event Action<DrawingCanvas<Bgra32>, TimeSpan>? PaintFrame;
+    public event Action<DrawingCanvas, TimeSpan>? PaintFrame;
 
     /// <inheritdoc />
     protected override void OnHandleCreated(EventArgs e)

samples/WebGPUExternalSurfaceDemo/MainForm.cs

@@ -116,15 +116,15 @@ public MainForm()
         this.Controls.Add(tabs);
     }
 
-    private void OnPaintClock(DrawingCanvas<Bgra32> canvas, TimeSpan delta)
+    private void OnPaintClock(DrawingCanvas canvas, TimeSpan delta)
         => this.clockScene.Paint(canvas, delta);
 
-    private void OnPaintTiger(DrawingCanvas<Bgra32> canvas, TimeSpan delta)
+    private void OnPaintTiger(DrawingCanvas canvas, TimeSpan delta)
     {
         this.tigerScene.Paint(canvas, delta);
         this.tigerStatusLabel.Text = this.tigerScene.StatusText;
     }
 
-    private void OnPaintApply(DrawingCanvas<Bgra32> canvas, TimeSpan delta)
+    private void OnPaintApply(DrawingCanvas canvas, TimeSpan delta)
         => this.applyScene.Paint(canvas, delta);
 }

samples/WebGPUExternalSurfaceDemo/README.md

@@ -7,7 +7,7 @@ It exists to demonstrate:
 - creating a `WebGPUExternalSurface<Bgra32>` from a `WebGPUSurfaceHost`
 - keeping the external surface synchronized with the host control's drawable framebuffer size
 - acquiring `WebGPUSurfaceFrame<TPixel>` instances manually
-- drawing with the normal `DrawingCanvas<TPixel>` API
+- drawing with the normal `DrawingCanvas` API
 - presenting by disposing the acquired frame
 
 ## Running
@@ -113,7 +113,7 @@ The scenes are deliberately ordinary canvas code:
 
 Each scene receives:
 
-- `DrawingCanvas<Bgra32>` for the acquired frame
+- `DrawingCanvas` for the acquired frame
 - elapsed time since the previous frame
 
 ## Files

samples/WebGPUExternalSurfaceDemo/Scenes/ApplyReadbackScene.cs

@@ -35,7 +35,7 @@ internal sealed class ApplyReadbackScene : RenderScene
 
     public override string DisplayName => "Apply";
 
-    public override void Paint(DrawingCanvas<Bgra32> canvas, TimeSpan deltaTime)
+    public override void Paint(DrawingCanvas canvas, TimeSpan deltaTime)
     {
         Size viewportSize = canvas.Bounds.Size;
 
@@ -77,7 +77,7 @@ public override void OnMouseWheel(MouseEventArgs e)
         this.regionScale = Math.Clamp(this.regionScale * factor, .5F, 2.4F);
     }
 
-    private static void DrawPattern(DrawingCanvas<Bgra32> canvas, Size viewportSize)
+    private static void DrawPattern(DrawingCanvas canvas, Size viewportSize)
     {
         float stripeWidth = Math.Max(18F, viewportSize.Width / 18F);
         float height = viewportSize.Height;

samples/WebGPUExternalSurfaceDemo/Scenes/ClockScene.cs

@@ -52,7 +52,7 @@ public ClockScene()
 
     public override string DisplayName => "Clock";
 
-    public override void Paint(DrawingCanvas<Bgra32> canvas, TimeSpan deltaTime)
+    public override void Paint(DrawingCanvas canvas, TimeSpan deltaTime)
     {
         Size viewportSize = canvas.Bounds.Size;
 
@@ -134,7 +134,7 @@ public override void Paint(DrawingCanvas<Bgra32> canvas, TimeSpan deltaTime)
     }
 
     private static void DrawHand(
-        DrawingCanvas<Bgra32> canvas,
+        DrawingCanvas canvas,
         float cx,
         float cy,
         float angleRadiansFromNoon,

samples/WebGPUExternalSurfaceDemo/Scenes/RenderScene.cs

@@ -23,7 +23,7 @@ internal abstract class RenderScene
     /// </summary>
     /// <param name="canvas">The per-frame drawing canvas bound to the external surface's swap-chain texture.</param>
     /// <param name="deltaTime">Elapsed time since the previous frame. Scenes that render from absolute state can ignore it.</param>
-    public abstract void Paint(DrawingCanvas<Bgra32> canvas, TimeSpan deltaTime);
+    public abstract void Paint(DrawingCanvas canvas, TimeSpan deltaTime);
 
     /// <summary>
     /// Handles a mouse-button press. Default implementation is a no-op.

samples/WebGPUExternalSurfaceDemo/Scenes/TigerViewerScene.cs

@@ -71,7 +71,7 @@ public string StatusText
         }
     }
 
-    public override void Paint(DrawingCanvas<Bgra32> canvas, TimeSpan deltaTime)
+    public override void Paint(DrawingCanvas canvas, TimeSpan deltaTime)
     {
         Size viewportSize = canvas.Bounds.Size;
 

samples/WebGPUWindowDemo/Program.cs

@@ -149,7 +149,7 @@ private void OnUpdate(TimeSpan deltaTime)
         /// </remarks>
         private void OnRender(WebGPUSurfaceFrame<Bgra32> frame)
         {
-            DrawingCanvas<Bgra32> canvas = frame.Canvas;
+            DrawingCanvas canvas = frame.Canvas;
             Rectangle bounds = canvas.Bounds;
             canvas.Fill(Brushes.Solid(Color.FromPixel(new Bgra32(30, 30, 40, 255))));
 
@@ -180,7 +180,7 @@ private void OnRender(WebGPUSurfaceFrame<Bgra32> frame)
         /// <param name="canvas">The destination canvas for the current frame.</param>
         /// <param name="width">The current framebuffer width.</param>
         /// <param name="height">The current framebuffer height.</param>
-        private void DrawScrollingText(DrawingCanvas<Bgra32> canvas, int width, int height)
+        private void DrawScrollingText(DrawingCanvas canvas, int width, int height)
         {
             if (this.scrollTextHeight <= 0)
             {