Span.CopyTo(...) semantics for bulk Vecto4 conversion in PixelOperations

src/ImageSharp/Formats/Jpeg/Components/Decoder/JpegImagePostProcessor.cs

@@ -159,7 +159,8 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder
 
                 Span<TPixel> destRow = destination.GetPixelRowSpan(yy);
 
-                PixelOperations<TPixel>.Instance.FromVector4(this.rgbaBuffer.GetSpan(), destRow, destination.Width);
+                // TODO: Investigate if slicing is actually necessary
+                PixelOperations<TPixel>.Instance.FromVector4(this.rgbaBuffer.GetSpan().Slice(0, destRow.Length), destRow);
             }
         }
     }

src/ImageSharp/PixelFormats/PixelBlender{TPixel}.cs

@@ -93,12 +93,12 @@ namespace SixLabors.ImageSharp.PixelFormats
                 Span<Vector4> backgroundSpan = buffer.Slice(destination.Length, destination.Length);
                 Span<Vector4> sourceSpan = buffer.Slice(destination.Length * 2, destination.Length);
 
-                PixelOperations<TPixel>.Instance.ToScaledVector4(background, backgroundSpan, destination.Length);
+                PixelOperations<TPixel>.Instance.ToScaledVector4(background, backgroundSpan);
-                PixelOperations<TPixelSrc>.Instance.ToScaledVector4(source, sourceSpan, destination.Length);
+                PixelOperations<TPixelSrc>.Instance.ToScaledVector4(source, sourceSpan);
 
                 this.BlendFunction(destinationSpan, backgroundSpan, sourceSpan, amount);
 
-                PixelOperations<TPixel>.Instance.FromScaledVector4(destinationSpan, destination, destination.Length);
+                PixelOperations<TPixel>.Instance.FromScaledVector4(destinationSpan, destination);
             }
         }
 
@@ -127,12 +127,12 @@ namespace SixLabors.ImageSharp.PixelFormats
                 Span<Vector4> backgroundSpan = buffer.Slice(destination.Length, destination.Length);
                 Span<Vector4> sourceSpan = buffer.Slice(destination.Length * 2, destination.Length);
 
-                PixelOperations<TPixel>.Instance.ToScaledVector4(background, backgroundSpan, destination.Length);
+                PixelOperations<TPixel>.Instance.ToScaledVector4(background, backgroundSpan);
-                PixelOperations<TPixelSrc>.Instance.ToScaledVector4(source, sourceSpan, destination.Length);
+                PixelOperations<TPixelSrc>.Instance.ToScaledVector4(source, sourceSpan);
 
                 this.BlendFunction(destinationSpan, backgroundSpan, sourceSpan, amount);
 
-                PixelOperations<TPixel>.Instance.FromScaledVector4(destinationSpan, destination, destination.Length);
+                PixelOperations<TPixel>.Instance.FromScaledVector4(destinationSpan, destination);
             }
         }
     }

src/ImageSharp/PixelFormats/PixelImplementations/Rgba32.PixelOperations.cs

@@ -19,13 +19,11 @@ namespace SixLabors.ImageSharp.PixelFormats
         internal partial class PixelOperations : PixelOperations<Rgba32>
         {
             /// <inheritdoc />
-            internal override void ToVector4(ReadOnlySpan<Rgba32> sourceColors, Span<Vector4> destinationVectors, int count)
+            internal override void ToVector4(ReadOnlySpan<Rgba32> sourceColors, Span<Vector4> destinationVectors)
             {
-                Guard.MustBeSizedAtLeast(sourceColors, count, nameof(sourceColors));
+                Guard.DestinationShouldNotBeTooShort(sourceColors, destinationVectors, nameof(destinationVectors));
-                Guard.MustBeSizedAtLeast(destinationVectors, count, nameof(destinationVectors));
 
-                sourceColors = sourceColors.Slice(0, count);
+                destinationVectors = destinationVectors.Slice(0, sourceColors.Length);
-                destinationVectors = destinationVectors.Slice(0, count);
 
                 SimdUtils.BulkConvertByteToNormalizedFloat(
                     MemoryMarshal.Cast<Rgba32, byte>(sourceColors),
@@ -33,12 +31,11 @@ namespace SixLabors.ImageSharp.PixelFormats
             }
 
             /// <inheritdoc />
-            internal override void FromVector4(ReadOnlySpan<Vector4> sourceVectors, Span<Rgba32> destinationColors, int count)
+            internal override void FromVector4(ReadOnlySpan<Vector4> sourceVectors, Span<Rgba32> destinationColors)
             {
-                GuardSpans(sourceVectors, nameof(sourceVectors), destinationColors, nameof(destinationColors), count);
+                Guard.DestinationShouldNotBeTooShort(sourceVectors, destinationColors, nameof(destinationColors));
 
-                sourceVectors = sourceVectors.Slice(0, count);
+                destinationColors = destinationColors.Slice(0, sourceVectors.Length);
-                destinationColors = destinationColors.Slice(0, count);
 
                 SimdUtils.BulkConvertNormalizedFloatToByteClampOverflows(
                     MemoryMarshal.Cast<Vector4, float>(sourceVectors),
@@ -46,15 +43,17 @@ namespace SixLabors.ImageSharp.PixelFormats
             }
 
             /// <inheritdoc />
-            internal override void ToScaledVector4(ReadOnlySpan<Rgba32> sourceColors, Span<Vector4> destinationVectors, int count)
+            internal override void ToScaledVector4(ReadOnlySpan<Rgba32> sourceColors, Span<Vector4> destinationVectors)
             {
-                this.ToVector4(sourceColors, destinationVectors, count);
+                this.ToVector4(sourceColors, destinationVectors);
             }
 
             /// <inheritdoc />
-            internal override void FromScaledVector4(ReadOnlySpan<Vector4> sourceVectors, Span<Rgba32> destinationColors, int count)
+            internal override void FromScaledVector4(
+                ReadOnlySpan<Vector4> sourceVectors,
+                Span<Rgba32> destinationColors)
             {
-                this.FromVector4(sourceVectors, destinationColors, count);
+                this.FromVector4(sourceVectors, destinationColors);
             }
         }
     }

src/ImageSharp/PixelFormats/PixelImplementations/RgbaVector.PixelOperations.cs

@@ -18,23 +18,27 @@ namespace SixLabors.ImageSharp.PixelFormats
         internal class PixelOperations : PixelOperations<RgbaVector>
         {
             /// <inheritdoc />
-            internal override void FromScaledVector4(ReadOnlySpan<Vector4> sourceVectors, Span<RgbaVector> destinationColors, int count)
+            internal override void FromScaledVector4(
+                ReadOnlySpan<Vector4> sourceVectors,
+                Span<RgbaVector> destinationColors)
             {
-                GuardSpans(sourceVectors, nameof(sourceVectors), destinationColors, nameof(destinationColors), count);
+                Guard.DestinationShouldNotBeTooShort(sourceVectors, destinationColors, nameof(destinationColors));
 
-                MemoryMarshal.Cast<Vector4, RgbaVector>(sourceVectors).Slice(0, count).CopyTo(destinationColors);
+                MemoryMarshal.Cast<Vector4, RgbaVector>(sourceVectors).CopyTo(destinationColors);
             }
 
             /// <inheritdoc />
-            internal override void ToScaledVector4(ReadOnlySpan<RgbaVector> sourceColors, Span<Vector4> destinationVectors, int count)
+            internal override void ToScaledVector4(
-                => this.ToVector4(sourceColors, destinationVectors, count);
+                ReadOnlySpan<RgbaVector> sourceColors,
+                Span<Vector4> destinationVectors)
+                => this.ToVector4(sourceColors, destinationVectors);
 
             /// <inheritdoc />
-            internal override void ToVector4(ReadOnlySpan<RgbaVector> sourceColors, Span<Vector4> destinationVectors, int count)
+            internal override void ToVector4(ReadOnlySpan<RgbaVector> sourceColors, Span<Vector4> destinationVectors)
             {
-                GuardSpans(sourceColors, nameof(sourceColors), destinationVectors, nameof(destinationVectors), count);
+                Guard.DestinationShouldNotBeTooShort(sourceColors, destinationVectors, nameof(destinationVectors));
 
-                MemoryMarshal.Cast<RgbaVector, Vector4>(sourceColors).Slice(0, count).CopyTo(destinationVectors);
+                MemoryMarshal.Cast<RgbaVector, Vector4>(sourceColors).CopyTo(destinationVectors);
             }
         }
     }

src/ImageSharp/PixelFormats/PixelOperations{TPixel}.cs

@@ -26,15 +26,14 @@ namespace SixLabors.ImageSharp.PixelFormats
         /// </summary>
         /// <param name="sourceVectors">The <see cref="Span{T}"/> to the source vectors.</param>
         /// <param name="destinationColors">The <see cref="Span{T}"/> to the destination colors.</param>
-        /// <param name="count">The number of pixels to convert.</param>
+        internal virtual void FromVector4(ReadOnlySpan<Vector4> sourceVectors, Span<TPixel> destinationColors)
-        internal virtual void FromVector4(ReadOnlySpan<Vector4> sourceVectors, Span<TPixel> destinationColors, int count)
         {
-            GuardSpans(sourceVectors, nameof(sourceVectors), destinationColors, nameof(destinationColors), count);
+            Guard.DestinationShouldNotBeTooShort(sourceVectors, destinationColors, nameof(destinationColors));
 
             ref Vector4 sourceRef = ref MemoryMarshal.GetReference(sourceVectors);
             ref TPixel destRef = ref MemoryMarshal.GetReference(destinationColors);
 
-            for (int i = 0; i < count; i++)
+            for (int i = 0; i < sourceVectors.Length; i++)
             {
                 ref Vector4 sp = ref Unsafe.Add(ref sourceRef, i);
                 ref TPixel dp = ref Unsafe.Add(ref destRef, i);
@@ -47,15 +46,14 @@ namespace SixLabors.ImageSharp.PixelFormats
         /// </summary>
         /// <param name="sourceColors">The <see cref="Span{T}"/> to the source colors.</param>
         /// <param name="destinationVectors">The <see cref="Span{T}"/> to the destination vectors.</param>
-        /// <param name="count">The number of pixels to convert.</param>
+        internal virtual void ToVector4(ReadOnlySpan<TPixel> sourceColors, Span<Vector4> destinationVectors)
-        internal virtual void ToVector4(ReadOnlySpan<TPixel> sourceColors, Span<Vector4> destinationVectors, int count)
         {
-            GuardSpans(sourceColors, nameof(sourceColors), destinationVectors, nameof(destinationVectors), count);
+            Guard.DestinationShouldNotBeTooShort(sourceColors, destinationVectors, nameof(destinationVectors));
 
             ref TPixel sourceRef = ref MemoryMarshal.GetReference(sourceColors);
             ref Vector4 destRef = ref MemoryMarshal.GetReference(destinationVectors);
 
-            for (int i = 0; i < count; i++)
+            for (int i = 0; i < sourceColors.Length; i++)
             {
                 ref TPixel sp = ref Unsafe.Add(ref sourceRef, i);
                 ref Vector4 dp = ref Unsafe.Add(ref destRef, i);
@@ -68,15 +66,14 @@ namespace SixLabors.ImageSharp.PixelFormats
         /// </summary>
         /// <param name="sourceVectors">The <see cref="Span{T}"/> to the source vectors.</param>
         /// <param name="destinationColors">The <see cref="Span{T}"/> to the destination colors.</param>
-        /// <param name="count">The number of pixels to convert.</param>
+        internal virtual void FromScaledVector4(ReadOnlySpan<Vector4> sourceVectors, Span<TPixel> destinationColors)
-        internal virtual void FromScaledVector4(ReadOnlySpan<Vector4> sourceVectors, Span<TPixel> destinationColors, int count)
         {
-            GuardSpans(sourceVectors, nameof(sourceVectors), destinationColors, nameof(destinationColors), count);
+            Guard.DestinationShouldNotBeTooShort(sourceVectors, destinationColors, nameof(destinationColors));
 
             ref Vector4 sourceRef = ref MemoryMarshal.GetReference(sourceVectors);
             ref TPixel destRef = ref MemoryMarshal.GetReference(destinationColors);
 
-            for (int i = 0; i < count; i++)
+            for (int i = 0; i < sourceVectors.Length; i++)
             {
                 ref Vector4 sp = ref Unsafe.Add(ref sourceRef, i);
                 ref TPixel dp = ref Unsafe.Add(ref destRef, i);
@@ -89,15 +86,14 @@ namespace SixLabors.ImageSharp.PixelFormats
         /// </summary>
         /// <param name="sourceColors">The <see cref="Span{T}"/> to the source colors.</param>
         /// <param name="destinationVectors">The <see cref="Span{T}"/> to the destination vectors.</param>
-        /// <param name="count">The number of pixels to convert.</param>
+        internal virtual void ToScaledVector4(ReadOnlySpan<TPixel> sourceColors, Span<Vector4> destinationVectors)
-        internal virtual void ToScaledVector4(ReadOnlySpan<TPixel> sourceColors, Span<Vector4> destinationVectors, int count)
         {
-            GuardSpans(sourceColors, nameof(sourceColors), destinationVectors, nameof(destinationVectors), count);
+            Guard.DestinationShouldNotBeTooShort(sourceColors, destinationVectors, nameof(destinationVectors));
 
             ref TPixel sourceRef = ref MemoryMarshal.GetReference(sourceColors);
             ref Vector4 destRef = ref MemoryMarshal.GetReference(destinationVectors);
 
-            for (int i = 0; i < count; i++)
+            for (int i = 0; i < sourceColors.Length; i++)
             {
                 ref TPixel sp = ref Unsafe.Add(ref sourceRef, i);
                 ref Vector4 dp = ref Unsafe.Add(ref destRef, i);

src/ImageSharp/Processing/Processors/Convolution/Convolution2DProcessor.cs

@@ -75,14 +75,14 @@ namespace SixLabors.ImageSharp.Processing.Processors.Convolution
                             for (int y = rows.Min; y < rows.Max; y++)
                             {
                                 Span<TPixel> targetRowSpan = targetPixels.GetRowSpan(y).Slice(startX);
-                                PixelOperations<TPixel>.Instance.ToVector4(targetRowSpan, vectorSpan, length);
+                                PixelOperations<TPixel>.Instance.ToVector4(targetRowSpan, vectorSpan);
 
                                 for (int x = 0; x < width; x++)
                                 {
                                     DenseMatrixUtils.Convolve2D(in matrixY, in matrixX, source.PixelBuffer, vectorSpan, y, x, maxY, maxX, startX);
                                 }
 
-                                PixelOperations<TPixel>.Instance.FromVector4(vectorSpan, targetRowSpan, length);
+                                PixelOperations<TPixel>.Instance.FromVector4(vectorSpan, targetRowSpan);
                             }
                         });
 

src/ImageSharp/Processing/Processors/Convolution/Convolution2PassProcessor.cs

@@ -93,14 +93,14 @@ namespace SixLabors.ImageSharp.Processing.Processors.Convolution
                         for (int y = rows.Min; y < rows.Max; y++)
                         {
                             Span<TPixel> targetRowSpan = targetPixels.GetRowSpan(y).Slice(startX);
-                            PixelOperations<TPixel>.Instance.ToVector4(targetRowSpan, vectorSpan, length);
+                            PixelOperations<TPixel>.Instance.ToVector4(targetRowSpan, vectorSpan);
 
                             for (int x = 0; x < width; x++)
                             {
                                 DenseMatrixUtils.Convolve(in matrix, sourcePixels, vectorSpan, y, x, maxY, maxX, startX);
                             }
 
-                            PixelOperations<TPixel>.Instance.FromVector4(vectorSpan, targetRowSpan, length);
+                            PixelOperations<TPixel>.Instance.FromVector4(vectorSpan, targetRowSpan);
                         }
                     });
         }

src/ImageSharp/Processing/Processors/Convolution/ConvolutionProcessor.cs

@@ -59,14 +59,14 @@ namespace SixLabors.ImageSharp.Processing.Processors.Convolution
                             for (int y = rows.Min; y < rows.Max; y++)
                             {
                                 Span<TPixel> targetRowSpan = targetPixels.GetRowSpan(y).Slice(startX);
-                                PixelOperations<TPixel>.Instance.ToVector4(targetRowSpan, vectorSpan, length);
+                                PixelOperations<TPixel>.Instance.ToVector4(targetRowSpan, vectorSpan);
 
                                 for (int x = 0; x < width; x++)
                                 {
                                     DenseMatrixUtils.Convolve(in matrix, source.PixelBuffer, vectorSpan, y, x, maxY, maxX, startX);
                                 }
 
-                                PixelOperations<TPixel>.Instance.FromVector4(vectorSpan, targetRowSpan, length);
+                                PixelOperations<TPixel>.Instance.FromVector4(vectorSpan, targetRowSpan);
                             }
                         });
 

src/ImageSharp/Processing/Processors/Dithering/PaletteDitherProcessorBase.cs

@@ -31,7 +31,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Dithering
         {
             this.Palette = palette ?? throw new ArgumentNullException(nameof(palette));
             this.paletteVector = new Vector4[this.Palette.Length];
-            PixelOperations<TPixel>.Instance.ToScaledVector4(this.Palette, this.paletteVector, this.Palette.Length);
+            PixelOperations<TPixel>.Instance.ToScaledVector4(this.Palette, this.paletteVector);
         }
 
         /// <summary>

src/ImageSharp/Processing/Processors/Quantization/FrameQuantizerBase{TPixel}.cs

@@ -79,7 +79,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Quantization
             // Collect the palette. Required before the second pass runs.
             TPixel[] palette = this.GetPalette();
             this.paletteVector = new Vector4[palette.Length];
-            PixelOperations<TPixel>.Instance.ToScaledVector4(palette, this.paletteVector, palette.Length);
+            PixelOperations<TPixel>.Instance.ToScaledVector4(palette, this.paletteVector);
             var quantizedFrame = new QuantizedFrame<TPixel>(image.MemoryAllocator, width, height, palette);
 
             if (this.Dither)

src/ImageSharp/Processing/Processors/Quantization/PaletteFrameQuantizer{TPixel}.cs

@@ -41,7 +41,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Quantization
             Guard.MustBeBetweenOrEqualTo(colors.Length, 1, 256, nameof(colors));
             this.palette = colors;
             this.paletteVector = new Vector4[this.palette.Length];
-            PixelOperations<TPixel>.Instance.ToScaledVector4(this.palette, this.paletteVector, this.palette.Length);
+            PixelOperations<TPixel>.Instance.ToScaledVector4(this.palette, this.paletteVector);
         }
 
         /// <inheritdoc/>

src/ImageSharp/Processing/Processors/Transforms/ResizeProcessor.cs

@@ -257,7 +257,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Transforms
                                 Span<TPixel> sourceRow = source.GetPixelRowSpan(y);
                                 Span<Vector4> tempRowSpan = tempRowBuffer.Span;
 
-                                PixelOperations<TPixel>.Instance.ToVector4(sourceRow, tempRowSpan, sourceRow.Length);
+                                PixelOperations<TPixel>.Instance.ToVector4(sourceRow, tempRowSpan);
                                 Vector4Utils.Premultiply(tempRowSpan);
 
                                 ref Vector4 firstPassBaseRef = ref firstPassPixelsTransposed.Span[y];
@@ -309,7 +309,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Transforms
                                 }
 
                                 Span<TPixel> targetRowSpan = destination.GetPixelRowSpan(y);
-                                PixelOperations<TPixel>.Instance.FromVector4(tempRowSpan, targetRowSpan, tempRowSpan.Length);
+                                PixelOperations<TPixel>.Instance.FromVector4(tempRowSpan, targetRowSpan);
                             }
                         });
             }

tests/ImageSharp.Tests/PixelFormats/PixelOperationsTests.cs

@@ -269,7 +269,7 @@ namespace SixLabors.ImageSharp.Tests.PixelFormats
                 {
                     this.Measure(
                         times,
-                        () => PixelOperations<Rgba32>.Instance.ToVector4(source.GetSpan(), dest.GetSpan(), count));
+                        () => PixelOperations<Rgba32>.Instance.ToVector4(source.GetSpan(), dest.GetSpan()));
                 }
             }
         }
@@ -367,7 +367,7 @@ namespace SixLabors.ImageSharp.Tests.PixelFormats
             TestOperation(
                 source,
                 expected,
-                (s, d) => Operations.FromVector4(s, d.GetSpan(), count)
+                (s, d) => Operations.FromVector4(s, d.GetSpan())
             );
         }
 
@@ -381,7 +381,7 @@ namespace SixLabors.ImageSharp.Tests.PixelFormats
             TestOperation(
                 source,
                 expected,
-                (s, d) => Operations.FromScaledVector4(s, d.GetSpan(), count)
+                (s, d) => Operations.FromScaledVector4(s, d.GetSpan())
             );
         }
 
@@ -417,7 +417,7 @@ namespace SixLabors.ImageSharp.Tests.PixelFormats
             TestOperation(
                 source,
                 expected,
-                (s, d) => Operations.ToVector4(s, d.GetSpan(), count)
+                (s, d) => Operations.ToVector4(s, d.GetSpan())
             );
         }
 
@@ -431,7 +431,7 @@ namespace SixLabors.ImageSharp.Tests.PixelFormats
             TestOperation(
                 source,
                 expected,
-                (s, d) => Operations.ToScaledVector4(s, d.GetSpan(), count)
+                (s, d) => Operations.ToScaledVector4(s, d.GetSpan())
             );
         }
 

tests/ImageSharp.Tests/TestUtilities/TestImageExtensions.cs

@@ -39,7 +39,7 @@ namespace SixLabors.ImageSharp.Tests
                     {
                         Span<TPixel> pixelSpan = frame.GetPixelSpan();
 
-                        PixelOperations<TPixel>.Instance.ToScaledVector4(pixelSpan, tempSpan, pixelSpan.Length);
+                        PixelOperations<TPixel>.Instance.ToScaledVector4(pixelSpan, tempSpan);
 
                         for (int i = 0; i < tempSpan.Length; i++)
                         {
@@ -47,7 +47,7 @@ namespace SixLabors.ImageSharp.Tests
                             v.W = 1F;
                         }
 
-                        PixelOperations<TPixel>.Instance.FromScaledVector4(tempSpan, pixelSpan, pixelSpan.Length);
+                        PixelOperations<TPixel>.Instance.FromScaledVector4(tempSpan, pixelSpan);
                     }
                 }
             });