Merge branch 'js/canvas-api' of https://github.com/SixLabors/ImageSharp.Drawing into js/canvas-api

Author: JimBobSquarePants

src/ImageSharp.Drawing/Processing/Backends/DefaultDrawingBackend.cs

@@ -87,12 +87,10 @@ private static void ExecuteScene<TPixel>(
         }
 
         int requestedParallelism = configuration.MaxDegreeOfParallelism;
-        int partitionCount = ParallelExecutionHelper.GetPartitionCount(requestedParallelism, scene.RowCount);
-
         _ = Parallel.For(
             fromInclusive: 0,
             toExclusive: scene.RowCount,
-            parallelOptions: ParallelExecutionHelper.CreateParallelOptions(requestedParallelism, partitionCount),
+            parallelOptions: ParallelExecutionHelper.CreateParallelOptions(requestedParallelism, scene.RowCount),
             localInit: () => new WorkerState<TPixel>(configuration.MemoryAllocator, destinationFrame.Width, scene.MaxLayerDepth + 1),
             body: (rowIndex, _, state) =>
             {

src/ImageSharp.Drawing/Processing/Backends/ParallelExecutionHelper.cs

@@ -48,7 +48,7 @@ public static int GetPartitionCount(int maxDegreeOfParallelism, int workItemCoun
     /// <param name="partitionCount">The computed number of useful partitions for the operation.</param>
     /// <returns>The <see cref="ParallelOptions"/> instance for the operation.</returns>
     public static ParallelOptions CreateParallelOptions(int maxDegreeOfParallelism, int partitionCount)
-        => new() { MaxDegreeOfParallelism = maxDegreeOfParallelism == -1 ? -1 : Math.Min(maxDegreeOfParallelism, partitionCount) };
+        => new() { MaxDegreeOfParallelism = Math.Min(maxDegreeOfParallelism, partitionCount) };
 
     /// <summary>
     /// Computes the internal partition-planning cap for the configured parallelism setting.