Remove Present method; auto-present on Dispose

Author: JimBobSquarePants

samples/WebGPUWindowDemo/README.md

@@ -108,7 +108,7 @@ Separating animation from rendering keeps the sample structure close to a normal
 this.window.Run(this.OnRender);
 ```
 
-`WebGPUWindow<TPixel>.Run(...)` acquires one `WebGPUSurfaceFrame<TPixel>` per render callback and disposes it automatically after your callback returns. In this sample that means you do not call `Present()` or `Flush()` yourself.
+`WebGPUWindow<TPixel>.Run(...)` acquires one `WebGPUSurfaceFrame<TPixel>` per render callback and disposes it automatically after your callback returns. In this sample that means you do not call `Flush()` yourself.
 
 Inside `OnRender(...)` the sample:
 
@@ -154,7 +154,7 @@ This sample uses the `Run(Action<WebGPUSurfaceFrame<TPixel>>)` overload, so fram
 Two practical consequences:
 
 - you do not need to call `canvas.Flush()` in this sample
-- you only need `frame.Present()` if you are driving frames manually and want to present before disposal
+- manual frame loops should dispose each acquired frame exactly once
 
 ## What actually runs on the GPU
 
@@ -186,7 +186,7 @@ Notes:
 
 - a `false` result is normal retry behavior, not necessarily an error
 - this can happen when the surface is outdated, lost, timed out, or the framebuffer is currently zero-sized
-- disposing the frame is normally enough; explicit `Present()` is optional
+- disposing the frame flushes queued canvas work, presents the surface, and releases per-frame resources
 
 ## Resize behavior
 

src/ImageSharp.Drawing.WebGPU/WebGPUSurfaceFrame{TPixel}.cs

@@ -8,8 +8,7 @@ namespace SixLabors.ImageSharp.Drawing.Processing.Backends;
 
 /// <summary>
 /// A single acquired drawable frame returned by a WebGPU surface.
-/// Use the <see cref="Canvas"/> to draw the frame contents, then either call <see cref="Present"/> or dispose
-/// the frame to show it on screen.
+/// Use the <see cref="Canvas"/> to draw the frame contents, then dispose the frame to show it on screen.
 /// </summary>
 /// <typeparam name="TPixel">The canvas pixel format.</typeparam>
 public sealed unsafe class WebGPUSurfaceFrame<TPixel> : IDisposable
@@ -21,7 +20,6 @@ public sealed unsafe class WebGPUSurfaceFrame<TPixel> : IDisposable
     private readonly WebGPUTextureViewHandle textureViewHandle;
     private readonly Action? onDisposed;
     private bool isDisposed;
-    private bool presented;
 
     internal WebGPUSurfaceFrame(
         WebGPU api,
@@ -45,27 +43,7 @@ internal WebGPUSurfaceFrame(
     public DrawingCanvas<TPixel> Canvas { get; }
 
     /// <summary>
-    /// Flushes pending canvas work and presents the frame on screen.
-    /// </summary>
-    /// <remarks>
-    /// This method finalizes the current frame. If you do not call it explicitly, <see cref="Dispose"/>
-    /// will flush and present the frame automatically.
-    /// </remarks>
-    public void Present()
-    {
-        ObjectDisposedException.ThrowIf(this.isDisposed, this);
-        if (this.presented)
-        {
-            return;
-        }
-
-        this.Canvas.Flush();
-        this.api.SurfacePresent((Surface*)this.surfaceReference.Handle);
-        this.presented = true;
-    }
-
-    /// <summary>
-    /// Disposes the frame, flushing and presenting it if needed, then releasing the per-frame WebGPU resources.
+    /// Disposes the frame, flushing and presenting it, then releasing the per-frame WebGPU resources.
     /// </summary>
     public void Dispose()
     {
@@ -76,12 +54,8 @@ public void Dispose()
 
         try
         {
-            if (!this.presented)
-            {
-                this.Canvas.Flush();
-                this.api.SurfacePresent((Surface*)this.surfaceReference.Handle);
-                this.presented = true;
-            }
+            this.Canvas.Flush();
+            this.api.SurfacePresent((Surface*)this.surfaceReference.Handle);
         }
         finally
         {