refactored all BufferSpan pointers to ref-s

src/ImageSharp/Colors/Color.BulkOperations.cs

@@ -62,21 +62,20 @@ namespace ImageSharp
 
                 int unpackedRawCount = count * 4;
 
-                uint* src = (uint*)sourceColors.PointerAtOffset;
-                uint* srcEnd = src + count;
+                ref uint src = ref Unsafe.As<Color, uint>(ref sourceColors.DangerousGetPinnableReference());
 
-                using (PinnedBuffer<uint> tempBuf = new PinnedBuffer<uint>(
-                        unpackedRawCount + Vector<uint>.Count))
+                using (PinnedBuffer<uint> tempBuf = new PinnedBuffer<uint>(unpackedRawCount + Vector<uint>.Count))
                 {
                     uint* tPtr = (uint*)tempBuf.Pointer;
                     uint[] temp = tempBuf.Array;
                     float[] fTemp = Unsafe.As<float[]>(temp);
                     UnpackedRGBA* dst = (UnpackedRGBA*)tPtr;
 
-                    for (; src < srcEnd; src++, dst++)
+                    for (int i = 0; i < count; i++)
                     {
                         // This call is the bottleneck now:
-                        dst->Load(*src);
+                        ref uint sp = ref Unsafe.Add(ref src, i);
+                        dst->Load(sp);
                     }
 
                     for (int i = 0; i < unpackedRawCount; i += vecSize)
@@ -123,39 +122,44 @@ namespace ImageSharp
             }
 
             /// <inheritdoc />
-            internal override unsafe void PackFromXyzBytes(BufferSpan<byte> sourceBytes, BufferSpan<Color> destColors, int count)
+            internal override void PackFromXyzBytes(
+                BufferSpan<byte> sourceBytes,
+                BufferSpan<Color> destColors,
+                int count)
             {
-                byte* source = (byte*)sourceBytes;
-                byte* destination = (byte*)destColors;
+                ref RGB24 sourceRef = ref Unsafe.As<byte, RGB24>(ref sourceBytes.DangerousGetPinnableReference());
+                ref Color destRef = ref destColors.DangerousGetPinnableReference();
 
-                for (int x = 0; x < count; x++)
+                for (int i = 0; i < count; i++)
                 {
-                    Unsafe.Write(destination, (uint)(*source << 0 | *(source + 1) << 8 | *(source + 2) << 16 | 255 << 24));
+                    ref RGB24 sp = ref Unsafe.Add(ref sourceRef, i);
+                    ref Color dp = ref Unsafe.Add(ref destRef, i);
 
-                    source += 3;
-                    destination += 4;
+                    Unsafe.As<Color, RGB24>(ref dp) = sp;
+                    dp.A = 255;
                 }
             }
 
             /// <inheritdoc />
-            internal override unsafe void ToXyzBytes(BufferSpan<Color> sourceColors, BufferSpan<byte> destBytes, int count)
+            internal override void ToXyzBytes(BufferSpan<Color> sourceColors, BufferSpan<byte> destBytes, int count)
             {
-                byte* source = (byte*)sourceColors;
-                byte* destination = (byte*)destBytes;
+                ref Color sourceRef = ref sourceColors.DangerousGetPinnableReference();
+                ref RGB24 destRef = ref Unsafe.As<byte, RGB24>(ref destBytes.DangerousGetPinnableReference());
 
-                for (int x = 0; x < count; x++)
+                for (int i = 0; i < count; i++)
                 {
-                    *destination = *(source + 0);
-                    *(destination + 1) = *(source + 1);
-                    *(destination + 2) = *(source + 2);
+                    ref Color sp = ref Unsafe.Add(ref sourceRef, i);
+                    ref RGB24 dp = ref Unsafe.Add(ref destRef, i);
 
-                    source += 4;
-                    destination += 3;
+                    dp = Unsafe.As<Color, RGB24>(ref sp);
                 }
             }
 
             /// <inheritdoc />
-            internal override void PackFromXyzwBytes(BufferSpan<byte> sourceBytes, BufferSpan<Color> destColors, int count)
+            internal override void PackFromXyzwBytes(
+                BufferSpan<byte> sourceBytes,
+                BufferSpan<Color> destColors,
+                int count)
             {
                 BufferSpan.Copy(sourceBytes, destColors, count);
             }
@@ -167,87 +171,132 @@ namespace ImageSharp
             }
 
             /// <inheritdoc />
-            internal override unsafe void PackFromZyxBytes(BufferSpan<byte> sourceBytes, BufferSpan<Color> destColors, int count)
+            internal override void PackFromZyxBytes(
+                BufferSpan<byte> sourceBytes,
+                BufferSpan<Color> destColors,
+                int count)
             {
-                byte* source = (byte*)sourceBytes;
-                byte* destination = (byte*)destColors;
+                ref RGB24 sourceRef = ref Unsafe.As<byte, RGB24>(ref sourceBytes.DangerousGetPinnableReference());
+                ref Color destRef = ref destColors.DangerousGetPinnableReference();
 
-                for (int x = 0; x < count; x++)
+                for (int i = 0; i < count; i++)
                 {
-                    Unsafe.Write(destination, (uint)(*(source + 2) << 0 | *(source + 1) << 8 | *source << 16 | 255 << 24));
+                    ref RGB24 sp = ref Unsafe.Add(ref sourceRef, i);
+                    ref Color dp = ref Unsafe.Add(ref destRef, i);
 
-                    source += 3;
-                    destination += 4;
+                    Unsafe.As<Color, RGB24>(ref dp) = sp.ToZyx();
+                    dp.A = 255;
                 }
             }
 
             /// <inheritdoc />
-            internal override unsafe void ToZyxBytes(BufferSpan<Color> sourceColors, BufferSpan<byte> destBytes, int count)
+            internal override void ToZyxBytes(
+                BufferSpan<Color> sourceColors,
+                BufferSpan<byte> destBytes,
+                int count)
             {
-                byte* source = (byte*)sourceColors;
-                byte* destination = (byte*)destBytes;
+                ref Color sourceRef = ref sourceColors.DangerousGetPinnableReference();
+                ref RGB24 destRef = ref Unsafe.As<byte, RGB24>(ref destBytes.DangerousGetPinnableReference());
 
-                for (int x = 0; x < count; x++)
+                for (int i = 0; i < count; i++)
                 {
-                    *destination = *(source + 2);
-                    *(destination + 1) = *(source + 1);
-                    *(destination + 2) = *(source + 0);
+                    ref Color sp = ref Unsafe.Add(ref sourceRef, i);
+                    ref RGB24 dp = ref Unsafe.Add(ref destRef, i);
 
-                    source += 4;
-                    destination += 3;
+                    dp = Unsafe.As<Color, RGB24>(ref sp).ToZyx();
                 }
             }
 
             /// <inheritdoc />
-            internal override unsafe void PackFromZyxwBytes(BufferSpan<byte> sourceBytes, BufferSpan<Color> destColors, int count)
+            internal override void PackFromZyxwBytes(
+                BufferSpan<byte> sourceBytes,
+                BufferSpan<Color> destColors,
+                int count)
             {
-                byte* source = (byte*)sourceBytes;
-                byte* destination = (byte*)destColors;
+                ref RGBA32 sourceRef = ref Unsafe.As<byte, RGBA32>(ref sourceBytes.DangerousGetPinnableReference());
+                ref Color destRef = ref destColors.DangerousGetPinnableReference();
 
-                for (int x = 0; x < count; x++)
+                for (int i = 0; i < count; i++)
                 {
-                    Unsafe.Write(destination, (uint)(*(source + 2) << 0 | *(source + 1) << 8 | *source << 16 | *(source + 3) << 24));
-
-                    source += 4;
-                    destination += 4;
+                    ref RGBA32 sp = ref Unsafe.Add(ref sourceRef, i);
+                    ref Color dp = ref Unsafe.Add(ref destRef, i);
+                    RGBA32 zyxw = sp.ToZyxw();
+                    dp = Unsafe.As<RGBA32, Color>(ref zyxw);
                 }
             }
 
             /// <inheritdoc />
-            internal override unsafe void ToZyxwBytes(BufferSpan<Color> sourceColors, BufferSpan<byte> destBytes, int count)
+            internal override void ToZyxwBytes(
+                BufferSpan<Color> sourceColors,
+                BufferSpan<byte> destBytes,
+                int count)
             {
-                byte* source = (byte*)sourceColors;
-                byte* destination = (byte*)destBytes;
+                ref Color sourceRef = ref sourceColors.DangerousGetPinnableReference();
+                ref RGBA32 destRef = ref Unsafe.As<byte, RGBA32>(ref destBytes.DangerousGetPinnableReference());
 
-                for (int x = 0; x < count; x++)
+                for (int i = 0; i < count; i++)
                 {
-                    *destination = *(source + 2);
-                    *(destination + 1) = *(source + 1);
-                    *(destination + 2) = *(source + 0);
-                    *(destination + 3) = *(source + 3);
-
-                    source += 4;
-                    destination += 4;
+                    ref RGBA32 sp = ref Unsafe.As<Color, RGBA32>(ref Unsafe.Add(ref sourceRef, i));
+                    ref RGBA32 dp = ref Unsafe.Add(ref destRef, i);
+                    dp = sp.ToZyxw();
                 }
             }
 
+            /// <summary>
+            /// Helper struct to manipulate 3-byte RGB data.
+            /// </summary>
+            [StructLayout(LayoutKind.Sequential)]
+            private struct RGB24
+            {
+                private byte x;
+
+                private byte y;
+
+                private byte z;
+
+                [MethodImpl(MethodImplOptions.AggressiveInlining)]
+                public RGB24 ToZyx() => new RGB24 { x = this.z, y = this.y, z = this.x };
+            }
+
+            /// <summary>
+            /// Helper struct to manipulate 4-byte RGBA data.
+            /// </summary>
+            [StructLayout(LayoutKind.Sequential)]
+            private struct RGBA32
+            {
+                private byte x;
+
+                private byte y;
+
+                private byte z;
+
+                private byte w;
+
+                [MethodImpl(MethodImplOptions.AggressiveInlining)]
+                public RGBA32 ToZyxw() => new RGBA32 { x = this.z, y = this.y, z = this.x, w = this.w };
+            }
+
             /// <summary>
             /// Value type to store <see cref="Color"/>-s unpacked into multiple <see cref="uint"/>-s.
             /// </summary>
+            [StructLayout(LayoutKind.Sequential)]
             private struct UnpackedRGBA
             {
                 private uint r;
+
                 private uint g;
+
                 private uint b;
+
                 private uint a;
 
                 [MethodImpl(MethodImplOptions.AggressiveInlining)]
                 public void Load(uint p)
                 {
                     this.r = p;
-                    this.g = p >> Color.GreenShift;
-                    this.b = p >> Color.BlueShift;
-                    this.a = p >> Color.AlphaShift;
+                    this.g = p >> GreenShift;
+                    this.b = p >> BlueShift;
+                    this.a = p >> AlphaShift;
                 }
             }
         }

src/ImageSharp/Colors/Color.cs

@@ -62,6 +62,7 @@ namespace ImageSharp
         /// <param name="g">The green component.</param>
         /// <param name="b">The blue component.</param>
         /// <param name="a">The alpha component.</param>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public Color(byte r, byte g, byte b, byte a = 255)
         {
             this.packedValue = Pack(r, g, b, a);
@@ -74,6 +75,7 @@ namespace ImageSharp
         /// <param name="g">The green component.</param>
         /// <param name="b">The blue component.</param>
         /// <param name="a">The alpha component.</param>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public Color(float r, float g, float b, float a = 1)
         {
             this.packedValue = Pack(r, g, b, a);
@@ -85,6 +87,7 @@ namespace ImageSharp
         /// <param name="vector">
         /// The vector containing the components for the packed vector.
         /// </param>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public Color(Vector3 vector)
         {
             this.packedValue = Pack(ref vector);
@@ -96,6 +99,7 @@ namespace ImageSharp
         /// <param name="vector">
         /// The vector containing the components for the packed vector.
         /// </param>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public Color(Vector4 vector)
         {
             this.packedValue = Pack(ref vector);
@@ -107,6 +111,7 @@ namespace ImageSharp
         /// <param name="packed">
         /// The packed value.
         /// </param>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public Color(uint packed)
         {
             this.packedValue = packed;

src/ImageSharp/Colors/PackedPixel/BulkPixelOperations{TColor}.cs

@@ -13,14 +13,9 @@ namespace ImageSharp
     /// for pixel buffers of type <typeparamref name="TColor"/>.
     /// </summary>
     /// <typeparam name="TColor">The pixel format.</typeparam>
-    public unsafe class BulkPixelOperations<TColor>
+    public class BulkPixelOperations<TColor>
         where TColor : struct, IPixel<TColor>
     {
-        /// <summary>
-        /// The size of <typeparamref name="TColor"/> in bytes
-        /// </summary>
-        private static readonly int ColorSize = Unsafe.SizeOf<TColor>();
-
         /// <summary>
         /// Gets the global <see cref="BulkPixelOperations{TColor}"/> instance for the pixel type <typeparamref name="TColor"/>
         /// </summary>
@@ -37,18 +32,14 @@ namespace ImageSharp
             BufferSpan<TColor> destColors,
             int count)
         {
-            Vector4* sp = (Vector4*)sourceVectors.PointerAtOffset;
-            byte* dp = (byte*)destColors;
+            ref Vector4 sourceRef = ref sourceVectors.DangerousGetPinnableReference();
+            ref TColor destRef = ref destColors.DangerousGetPinnableReference();
 
             for (int i = 0; i < count; i++)
             {
-                Vector4 v = Unsafe.Read<Vector4>(sp);
-                TColor c = default(TColor);
-                c.PackFromVector4(v);
-                Unsafe.Write(dp, c);
-
-                sp++;
-                dp += ColorSize;
+                ref Vector4 sp = ref Unsafe.Add(ref sourceRef, i);
+                ref TColor dp = ref Unsafe.Add(ref destRef, i);
+                dp.PackFromVector4(sp);
             }
         }
 
@@ -63,15 +54,14 @@ namespace ImageSharp
             BufferSpan<Vector4> destVectors,
             int count)
         {
-            byte* sp = (byte*)sourceColors;
-            Vector4* dp = (Vector4*)destVectors.PointerAtOffset;
+            ref TColor sourceRef = ref sourceColors.DangerousGetPinnableReference();
+            ref Vector4 destRef = ref destVectors.DangerousGetPinnableReference();
 
             for (int i = 0; i < count; i++)
             {
-                TColor c = Unsafe.Read<TColor>(sp);
-                *dp = c.ToVector4();
-                sp += ColorSize;
-                dp++;
+                ref TColor sp = ref Unsafe.Add(ref sourceRef, i);
+                ref Vector4 dp = ref Unsafe.Add(ref destRef, i);
+                dp = sp.ToVector4();
             }
         }
 
@@ -86,16 +76,18 @@ namespace ImageSharp
             BufferSpan<TColor> destColors,
             int count)
         {
-            byte* sp = (byte*)sourceBytes;
-            byte* dp = (byte*)destColors.PointerAtOffset;
+            ref byte sourceRef = ref sourceBytes.DangerousGetPinnableReference();
+            ref TColor destRef = ref destColors.DangerousGetPinnableReference();
 
             for (int i = 0; i < count; i++)
             {
-                TColor c = default(TColor);
-                c.PackFromBytes(sp[0], sp[1], sp[2], 255);
-                Unsafe.Write(dp, c);
-                sp += 3;
-                dp += ColorSize;
+                int i3 = i * 3;
+                ref TColor dp = ref Unsafe.Add(ref destRef, i);
+                dp.PackFromBytes(
+                    Unsafe.Add(ref sourceRef, i3),
+                    Unsafe.Add(ref sourceRef, i3 + 1),
+                    Unsafe.Add(ref sourceRef, i3 + 2),
+                    255);
             }
         }
 
@@ -107,14 +99,13 @@ namespace ImageSharp
         /// <param name="count">The number of pixels to convert.</param>
         internal virtual void ToXyzBytes(BufferSpan<TColor> sourceColors, BufferSpan<byte> destBytes, int count)
         {
-            byte* sp = (byte*)sourceColors;
+            ref TColor sourceRef = ref sourceColors.DangerousGetPinnableReference();
             byte[] dest = destBytes.Array;
 
-            for (int i = destBytes.Start; i < destBytes.Start + (count * 3); i += 3)
+            for (int i = 0; i < count; i++)
             {
-                TColor c = Unsafe.Read<TColor>(sp);
-                c.ToXyzBytes(dest, i);
-                sp += ColorSize;
+                ref TColor sp = ref Unsafe.Add(ref sourceRef, i);
+                sp.ToXyzBytes(dest, i * 3);
             }
         }
 
@@ -129,16 +120,18 @@ namespace ImageSharp
             BufferSpan<TColor> destColors,
             int count)
         {
-            byte* sp = (byte*)sourceBytes;
-            byte* dp = (byte*)destColors.PointerAtOffset;
+            ref byte sourceRef = ref sourceBytes.DangerousGetPinnableReference();
+            ref TColor destRef = ref destColors.DangerousGetPinnableReference();
 
             for (int i = 0; i < count; i++)
             {
-                TColor c = default(TColor);
-                c.PackFromBytes(sp[0], sp[1], sp[2], sp[3]);
-                Unsafe.Write(dp, c);
-                sp += 4;
-                dp += ColorSize;
+                int i4 = i * 4;
+                ref TColor dp = ref Unsafe.Add(ref destRef, i);
+                dp.PackFromBytes(
+                    Unsafe.Add(ref sourceRef, i4),
+                    Unsafe.Add(ref sourceRef, i4 + 1),
+                    Unsafe.Add(ref sourceRef, i4 + 2),
+                    Unsafe.Add(ref sourceRef, i4 + 3));
             }
         }
 
@@ -153,14 +146,13 @@ namespace ImageSharp
             BufferSpan<byte> destBytes,
             int count)
         {
-            byte* sp = (byte*)sourceColors;
+            ref TColor sourceRef = ref sourceColors.DangerousGetPinnableReference();
             byte[] dest = destBytes.Array;
 
-            for (int i = destBytes.Start; i < destBytes.Start + (count * 4); i += 4)
+            for (int i = 0; i < count; i++)
             {
-                TColor c = Unsafe.Read<TColor>(sp);
-                c.ToXyzwBytes(dest, i);
-                sp += ColorSize;
+                ref TColor sp = ref Unsafe.Add(ref sourceRef, i);
+                sp.ToXyzwBytes(dest, i * 4);
             }
         }
 
@@ -175,16 +167,18 @@ namespace ImageSharp
             BufferSpan<TColor> destColors,
             int count)
         {
-            byte* sp = (byte*)sourceBytes;
-            byte* dp = (byte*)destColors.PointerAtOffset;
+            ref byte sourceRef = ref sourceBytes.DangerousGetPinnableReference();
+            ref TColor destRef = ref destColors.DangerousGetPinnableReference();
 
             for (int i = 0; i < count; i++)
             {
-                TColor c = default(TColor);
-                c.PackFromBytes(sp[2], sp[1], sp[0], 255);
-                Unsafe.Write(dp, c);
-                sp += 3;
-                dp += ColorSize;
+                int i3 = i * 3;
+                ref TColor dp = ref Unsafe.Add(ref destRef, i);
+                dp.PackFromBytes(
+                    Unsafe.Add(ref sourceRef, i3 + 2),
+                    Unsafe.Add(ref sourceRef, i3 + 1),
+                    Unsafe.Add(ref sourceRef, i3),
+                    255);
             }
         }
 
@@ -196,14 +190,13 @@ namespace ImageSharp
         /// <param name="count">The number of pixels to convert.</param>
         internal virtual void ToZyxBytes(BufferSpan<TColor> sourceColors, BufferSpan<byte> destBytes, int count)
         {
-            byte* sp = (byte*)sourceColors;
+            ref TColor sourceRef = ref sourceColors.DangerousGetPinnableReference();
             byte[] dest = destBytes.Array;
 
-            for (int i = destBytes.Start; i < destBytes.Start + (count * 3); i += 3)
+            for (int i = 0; i < count; i++)
             {
-                TColor c = Unsafe.Read<TColor>(sp);
-                c.ToZyxBytes(dest, i);
-                sp += ColorSize;
+                ref TColor sp = ref Unsafe.Add(ref sourceRef, i);
+                sp.ToZyxBytes(dest, i * 3);
             }
         }
 
@@ -218,16 +211,18 @@ namespace ImageSharp
             BufferSpan<TColor> destColors,
             int count)
         {
-            byte* sp = (byte*)sourceBytes;
-            byte* dp = (byte*)destColors.PointerAtOffset;
+            ref byte sourceRef = ref sourceBytes.DangerousGetPinnableReference();
+            ref TColor destRef = ref destColors.DangerousGetPinnableReference();
 
             for (int i = 0; i < count; i++)
             {
-                TColor c = default(TColor);
-                c.PackFromBytes(sp[2], sp[1], sp[0], sp[3]);
-                Unsafe.Write(dp, c);
-                sp += 4;
-                dp += ColorSize;
+                int i4 = i * 4;
+                ref TColor dp = ref Unsafe.Add(ref destRef, i);
+                dp.PackFromBytes(
+                    Unsafe.Add(ref sourceRef, i4 + 2),
+                    Unsafe.Add(ref sourceRef, i4 + 1),
+                    Unsafe.Add(ref sourceRef, i4),
+                    Unsafe.Add(ref sourceRef, i4 + 3));
             }
         }
 
@@ -242,14 +237,13 @@ namespace ImageSharp
             BufferSpan<byte> destBytes,
             int count)
         {
-            byte* sp = (byte*)sourceColors;
+            ref TColor sourceRef = ref sourceColors.DangerousGetPinnableReference();
             byte[] dest = destBytes.Array;
 
-            for (int i = destBytes.Start; i < destBytes.Start + (count * 4); i += 4)
+            for (int i = 0; i < count; i++)
             {
-                TColor c = Unsafe.Read<TColor>(sp);
-                c.ToZyxwBytes(dest, i);
-                sp += ColorSize;
+                ref TColor sp = ref Unsafe.Add(ref sourceRef, i);
+                sp.ToZyxwBytes(dest, i * 4);
             }
         }
     }

src/ImageSharp/Common/Memory/BufferSpan.cs

@@ -6,7 +6,6 @@
 namespace ImageSharp
 {
     using System;
-    using System.Numerics;
     using System.Runtime.CompilerServices;
     using System.Runtime.InteropServices;
 
@@ -49,25 +48,42 @@ namespace ImageSharp
         }
 
         /// <summary>
-        /// Copy 'countInDest' number of <typeparamref name="T"/> elements into 'dest' from a raw byte buffer defined by 'source'.
+        /// Copy 'countInDest' number of <typeparamref name="TDest"/> elements into 'dest' from a raw byte buffer defined by 'source'.
         /// </summary>
-        /// <typeparam name="T">The element type.</typeparam>
+        /// <typeparam name="TDest">The element type.</typeparam>
         /// <param name="source">The raw source buffer to copy from"/></param>
         /// <param name="destination">The destination buffer"/></param>
-        /// <param name="countInDest">The number of <typeparamref name="T"/> elements to copy.</param>
+        /// <param name="countInDest">The number of <typeparamref name="TDest"/> elements to copy.</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static unsafe void Copy<T>(BufferSpan<byte> source, BufferSpan<T> destination, int countInDest)
-            where T : struct
+        public static unsafe void Copy<TDest>(BufferSpan<byte> source, BufferSpan<TDest> destination, int countInDest)
+            where TDest : struct
         {
-            int byteCount = SizeOf<T>(countInDest);
+            // TODO: Refactor this method when Unsafe.CopyBlock(ref T, ref T) gets available!
+            int byteCount = SizeOf<TDest>(countInDest);
 
-            if (byteCount > (int)ByteCountThreshold)
+            if (PerTypeValues<TDest>.IsPrimitiveType)
             {
-                Marshal.Copy(source.Array, source.Start, destination.PointerAtOffset, byteCount);
+                Buffer.BlockCopy(source.Array, source.ByteOffset, destination.Array, destination.ByteOffset, byteCount);
+            }
+            else if (byteCount > ByteCountThreshold)
+            {
+                ref byte destRef = ref Unsafe.As<TDest, byte>(ref destination.DangerousGetPinnableReference());
+
+                fixed (void* pinnedPtr = &destRef)
+                {
+                    Marshal.Copy(source.Array, source.Start, (IntPtr)pinnedPtr, byteCount);
+                }
             }
             else
             {
-                Unsafe.CopyBlock((void*)destination.PointerAtOffset, (void*)source.PointerAtOffset, (uint)byteCount);
+                ref byte srcRef = ref source.DangerousGetPinnableReference();
+                ref byte destRef = ref Unsafe.As<TDest, byte>(ref destination.DangerousGetPinnableReference());
+
+                fixed (void* pinnedSrc = &srcRef)
+                fixed (void* pinnedDest = &destRef)
+                {
+                    Unsafe.CopyBlock(pinnedDest, pinnedSrc, (uint)byteCount);
+                }
             }
         }
 
@@ -93,37 +109,77 @@ namespace ImageSharp
             => (uint)SizeOf<T>(count);
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        private static unsafe void CopyImpl<T, TDest>(BufferSpan<T> source, BufferSpan<TDest> destination, int count)
+        private static unsafe void CopyImpl<T, TDest>(BufferSpan<T> source, BufferSpan<TDest> destination, int countInSource)
             where T : struct
             where TDest : struct
         {
-            int byteCount = SizeOf<T>(count);
+            // TODO: Refactor this method when Unsafe.CopyBlock(ref T, ref T) gets available!
+            int byteCount = SizeOf<T>(countInSource);
 
-            if (byteCount > ByteCountThreshold)
+            if (PerTypeValues<T>.IsPrimitiveType && PerTypeValues<TDest>.IsPrimitiveType)
             {
-                if (Unsafe.SizeOf<T>() == sizeof(long))
-                {
-                    Marshal.Copy(Unsafe.As<long[]>(source.Array), source.Start, destination.PointerAtOffset, count);
-                    return;
-                }
-                else if (Unsafe.SizeOf<T>() == sizeof(int))
-                {
-                    Marshal.Copy(Unsafe.As<int[]>(source.Array), source.Start, destination.PointerAtOffset, count);
-                    return;
-                }
-                else if (Unsafe.SizeOf<T>() == sizeof(short))
+                Buffer.BlockCopy(source.Array, source.ByteOffset, destination.Array, destination.ByteOffset, byteCount);
+            }
+            else if (byteCount > ByteCountThreshold)
+            {
+                ref byte destRef = ref Unsafe.As<TDest, byte>(ref destination.DangerousGetPinnableReference());
+
+                fixed (void* pinnedPtr = &destRef)
                 {
-                    Marshal.Copy(Unsafe.As<short[]>(source.Array), source.Start, destination.PointerAtOffset, count);
-                    return;
+                    IntPtr ptr = (IntPtr)pinnedPtr;
+                    if (Unsafe.SizeOf<T>() == sizeof(long))
+                    {
+                        Marshal.Copy(Unsafe.As<long[]>(source.Array), source.Start, ptr, countInSource);
+                    }
+                    else if (Unsafe.SizeOf<T>() == sizeof(int))
+                    {
+                        Marshal.Copy(Unsafe.As<int[]>(source.Array), source.Start, ptr, countInSource);
+                    }
+                    else if (Unsafe.SizeOf<T>() == sizeof(short))
+                    {
+                        Marshal.Copy(Unsafe.As<short[]>(source.Array), source.Start, ptr, countInSource);
+                    }
+                    else if (Unsafe.SizeOf<T>() == sizeof(byte))
+                    {
+                        Marshal.Copy(Unsafe.As<byte[]>(source.Array), source.Start, ptr, countInSource);
+                    }
                 }
-                else if (Unsafe.SizeOf<T>() == sizeof(byte))
+            }
+            else
+            {
+                ref byte srcRef = ref Unsafe.As<T, byte>(ref source.DangerousGetPinnableReference());
+                ref byte destRef = ref Unsafe.As<TDest, byte>(ref destination.DangerousGetPinnableReference());
+
+                fixed (void* pinnedSrc = &srcRef)
+                fixed (void* pinnedDest = &destRef)
                 {
-                    Marshal.Copy(Unsafe.As<byte[]>(source.Array), source.Start, destination.PointerAtOffset, count);
-                    return;
+                    Unsafe.CopyBlock(pinnedDest, pinnedSrc, (uint)byteCount);
                 }
             }
+        }
 
-            Unsafe.CopyBlock((void*)destination.PointerAtOffset, (void*)source.PointerAtOffset, (uint)byteCount);
+        /// <summary>
+        /// Per-type static value cache for type 'T'
+        /// </summary>
+        /// <typeparam name="T">The type</typeparam>
+        internal class PerTypeValues<T>
+        {
+            /// <summary>
+            /// Gets a value indicating whether 'T' is a primitive type.
+            /// </summary>
+            public static readonly bool IsPrimitiveType =
+                typeof(T) == typeof(byte) ||
+                typeof(T) == typeof(char) ||
+                typeof(T) == typeof(short) ||
+                typeof(T) == typeof(ushort) ||
+                typeof(T) == typeof(int) ||
+                typeof(T) == typeof(uint) ||
+                typeof(T) == typeof(float) ||
+                typeof(T) == typeof(double) ||
+                typeof(T) == typeof(long) ||
+                typeof(T) == typeof(ulong) ||
+                typeof(T) == typeof(IntPtr) ||
+                typeof(T) == typeof(UIntPtr);
         }
     }
 }

src/ImageSharp/Common/Memory/BufferSpan{T}.cs

@@ -30,13 +30,12 @@ namespace ImageSharp
         /// Initializes a new instance of the <see cref="BufferSpan{T}"/> struct from a pinned array and an start.
         /// </summary>
         /// <param name="array">The pinned array</param>
-        /// <param name="pointerToArray">Pointer to the beginning of the array</param>
         /// <param name="start">The index at which to begin the span.</param>
         /// <param name="length">The length</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public BufferSpan(T[] array, void* pointerToArray, int start, int length)
+        public BufferSpan(T[] array, int start, int length)
         {
-            GuardArrayAndPointer(array, pointerToArray);
+            GuardArray(array);
 
             DebugGuard.MustBeLessThanOrEqualTo(start, array.Length, nameof(start));
             DebugGuard.MustBeLessThanOrEqualTo(length, array.Length - start, nameof(length));
@@ -44,41 +43,36 @@ namespace ImageSharp
             this.Array = array;
             this.Length = length;
             this.Start = start;
-            this.PointerAtOffset = (IntPtr)pointerToArray + (Unsafe.SizeOf<T>() * start);
         }
 
         /// <summary>
         /// Initializes a new instance of the <see cref="BufferSpan{T}"/> struct from a pinned array and an start.
         /// </summary>
         /// <param name="array">The pinned array</param>
-        /// <param name="pointerToArray">Pointer to the beginning of the array</param>
         /// <param name="start">The index at which to begin the span.</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public BufferSpan(T[] array, void* pointerToArray, int start)
+        public BufferSpan(T[] array, int start)
         {
-            GuardArrayAndPointer(array, pointerToArray);
+            GuardArray(array);
             DebugGuard.MustBeLessThanOrEqualTo(start, array.Length, nameof(start));
 
             this.Array = array;
             this.Length = array.Length - start;
             this.Start = start;
-            this.PointerAtOffset = (IntPtr)pointerToArray + (Unsafe.SizeOf<T>() * start);
         }
 
         /// <summary>
         /// Initializes a new instance of the <see cref="BufferSpan{T}"/> struct from a pinned array.
         /// </summary>
         /// <param name="array">The pinned array</param>
-        /// <param name="pointerToArray">Pointer to the start of 'array'</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public BufferSpan(T[] array, void* pointerToArray)
+        public BufferSpan(T[] array)
         {
-            GuardArrayAndPointer(array, pointerToArray);
+            GuardArray(array);
 
             this.Array = array;
             this.Start = 0;
             this.Length = array.Length;
-            this.PointerAtOffset = (IntPtr)pointerToArray;
         }
 
         /// <summary>
@@ -101,11 +95,6 @@ namespace ImageSharp
         /// </summary>
         public int ByteOffset => this.Start * Unsafe.SizeOf<T>();
 
-        /// <summary>
-        /// Gets the pointer to the offseted array position
-        /// </summary>
-        public IntPtr PointerAtOffset { get; private set; }
-
         /// <summary>
         /// Returns a reference to specified element of the span.
         /// </summary>
@@ -117,35 +106,14 @@ namespace ImageSharp
             get
             {
                 DebugGuard.MustBeLessThan(index, this.Length, nameof(index));
-
-                byte* ptr = (byte*)this.PointerAtOffset + BufferSpan.SizeOf<T>(index);
-                return ref Unsafe.AsRef<T>(ptr);
+                ref T arrayRef = ref this.DangerousGetPinnableReference();
+                return ref Unsafe.Add(ref arrayRef, this.Start);
             }
         }
 
-        /// <summary>
-        /// Convertes <see cref="BufferSpan{T}"/> instance to a raw 'void*' pointer
-        /// </summary>
-        /// <param name="bufferSpan">The <see cref="BufferSpan{T}"/> to convert</param>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static explicit operator void*(BufferSpan<T> bufferSpan)
-        {
-            return (void*)bufferSpan.PointerAtOffset;
-        }
-
-        /// <summary>
-        /// Converts <see cref="BufferSpan{T}"/> instance to a raw 'byte*' pointer
-        /// </summary>
-        /// <param name="bufferSpan">The <see cref="BufferSpan{T}"/> to convert</param>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static explicit operator byte*(BufferSpan<T> bufferSpan)
-        {
-            return (byte*)bufferSpan.PointerAtOffset;
-        }
-
         /// <summary>
         /// Converts generic <see cref="BufferSpan{T}"/> to a <see cref="BufferSpan{T}"/> of bytes
-        /// setting it's <see cref="Start"/> and <see cref="PointerAtOffset"/> to correct values.
+        /// setting it's <see cref="Start"/> to correct value.
         /// </summary>
         /// <param name="source">The <see cref="BufferSpan{T}"/> to convert</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -154,7 +122,6 @@ namespace ImageSharp
             BufferSpan<byte> result = default(BufferSpan<byte>);
             result.Array = Unsafe.As<byte[]>(source.Array);
             result.Start = source.Start * Unsafe.SizeOf<T>();
-            result.PointerAtOffset = source.PointerAtOffset;
             return result;
         }
 
@@ -164,7 +131,7 @@ namespace ImageSharp
         /// </summary>
         /// <returns>The reference to the 0th element</returns>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public ref T DangerousGetPinnableReference() => ref Unsafe.AsRef<T>((void*)this.PointerAtOffset);
+        public ref T DangerousGetPinnableReference() => ref this.Array[this.Start];
 
         /// <summary>
         /// Forms a slice out of the given BufferSpan, beginning at 'start'.
@@ -179,7 +146,6 @@ namespace ImageSharp
             BufferSpan<T> result = default(BufferSpan<T>);
             result.Array = this.Array;
             result.Start = this.Start + start;
-            result.PointerAtOffset = this.PointerAtOffset + (Unsafe.SizeOf<T>() * start);
             result.Length = this.Length - start;
             return result;
         }
@@ -199,7 +165,6 @@ namespace ImageSharp
             BufferSpan<T> result = default(BufferSpan<T>);
             result.Array = this.Array;
             result.Start = this.Start + start;
-            result.PointerAtOffset = this.PointerAtOffset + (Unsafe.SizeOf<T>() * start);
             result.Length = length;
             return result;
         }
@@ -213,14 +178,8 @@ namespace ImageSharp
         {
             DebugGuard.MustBeLessThanOrEqualTo(count, this.Length, nameof(count));
 
-            if (count < 256)
-            {
-                Unsafe.InitBlock((void*)this.PointerAtOffset, 0, BufferSpan.USizeOf<T>(count));
-            }
-            else
-            {
-                System.Array.Clear(this.Array, this.Start, count);
-            }
+            // TODO: Use Unsafe.InitBlock(ref T) for small arrays, when it get's official
+            System.Array.Clear(this.Array, this.Start, count);
         }
 
         /// <summary>
@@ -233,13 +192,9 @@ namespace ImageSharp
         }
 
         [Conditional("DEBUG")]
-        private static void GuardArrayAndPointer(T[] array, void* pointerToArray)
+        private static void GuardArray(T[] array)
         {
             DebugGuard.NotNull(array, nameof(array));
-            DebugGuard.IsFalse(
-                pointerToArray == (void*)0,
-                nameof(pointerToArray),
-                "pointerToArray should not be null pointer!");
         }
     }
 }

src/ImageSharp/Common/Memory/PinnedBuffer{T}.cs

@@ -126,9 +126,9 @@ namespace ImageSharp
         /// </summary>
         /// <param name="buffer">The <see cref="PinnedBuffer{T}"/> to convert.</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static unsafe implicit operator BufferSpan<T>(PinnedBuffer<T> buffer)
+        public static implicit operator BufferSpan<T>(PinnedBuffer<T> buffer)
         {
-            return new BufferSpan<T>(buffer.Array, (void*)buffer.Pointer, 0, buffer.Length);
+            return new BufferSpan<T>(buffer.Array, 0, buffer.Length);
         }
 
         /// <summary>
@@ -150,9 +150,9 @@ namespace ImageSharp
         /// <param name="start">The start</param>
         /// <returns>The <see cref="BufferSpan{T}"/></returns>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public unsafe BufferSpan<T> Slice(int start)
+        public BufferSpan<T> Slice(int start)
         {
-            return new BufferSpan<T>(this.Array, (void*)this.Pointer, start, this.Length - start);
+            return new BufferSpan<T>(this.Array, start, this.Length - start);
         }
 
         /// <summary>
@@ -162,9 +162,9 @@ namespace ImageSharp
         /// <param name="length">The length of the slice</param>
         /// <returns>The <see cref="BufferSpan{T}"/></returns>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public unsafe BufferSpan<T> Slice(int start, int length)
+        public BufferSpan<T> Slice(int start, int length)
         {
-            return new BufferSpan<T>(this.Array, (void*)this.Pointer, start, length);
+            return new BufferSpan<T>(this.Array, start, length);
         }
 
         /// <summary>

src/ImageSharp/Processing/Processors/Transforms/ResamplingWeightedProcessor.Weights.cs

@@ -41,7 +41,7 @@ namespace ImageSharp.Processing.Processors
             /// <summary>
             /// Gets an unsafe float* pointer to the beginning of <see cref="Span"/>.
             /// </summary>
-            public float* Ptr => (float*)this.Span.PointerAtOffset;
+            public ref float Ptr => ref this.Span.DangerousGetPinnableReference();
 
             /// <summary>
             /// Gets the lenghth of the weights window
@@ -56,19 +56,18 @@ namespace ImageSharp.Processing.Processors
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
             public Vector4 ComputeWeightedRowSum(BufferSpan<Vector4> rowSpan)
             {
-                float* horizontalValues = this.Ptr;
+                ref float horizontalValues = ref this.Ptr;
                 int left = this.Left;
-                Vector4* vecPtr = (Vector4*)rowSpan.PointerAtOffset;
-                vecPtr += left;
+                ref Vector4 vecPtr = ref Unsafe.Add(ref rowSpan.DangerousGetPinnableReference(), left);
 
                 // Destination color components
                 Vector4 result = Vector4.Zero;
 
                 for (int i = 0; i < this.Length; i++)
                 {
-                    float weight = horizontalValues[i];
-                    result += (*vecPtr) * weight;
-                    vecPtr++;
+                    float weight = Unsafe.Add(ref horizontalValues, i);
+                    Vector4 v = Unsafe.Add(ref vecPtr, i);
+                    result += v * weight;
                 }
 
                 return result;
@@ -83,19 +82,18 @@ namespace ImageSharp.Processing.Processors
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
             public Vector4 ComputeExpandedWeightedRowSum(BufferSpan<Vector4> rowSpan)
             {
-                float* horizontalValues = this.Ptr;
+                ref float horizontalValues = ref this.Ptr;
                 int left = this.Left;
-                Vector4* vecPtr = (Vector4*)rowSpan.PointerAtOffset;
-                vecPtr += left;
+                ref Vector4 vecPtr = ref Unsafe.Add(ref rowSpan.DangerousGetPinnableReference(), left);
 
                 // Destination color components
                 Vector4 result = Vector4.Zero;
 
                 for (int i = 0; i < this.Length; i++)
                 {
-                    float weight = horizontalValues[i];
-                    result += (*vecPtr).Expand() * weight;
-                    vecPtr++;
+                    float weight = Unsafe.Add(ref horizontalValues, i);
+                    Vector4 v = Unsafe.Add(ref vecPtr, i);
+                    result += v.Expand() * weight;
                 }
 
                 return result;
@@ -111,7 +109,7 @@ namespace ImageSharp.Processing.Processors
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
             public Vector4 ComputeWeightedColumnSum(PinnedImageBuffer<Vector4> firstPassPixels, int x)
             {
-                float* verticalValues = this.Ptr;
+                ref float verticalValues = ref this.Ptr;
                 int left = this.Left;
 
                 // Destination color components
@@ -119,7 +117,7 @@ namespace ImageSharp.Processing.Processors
 
                 for (int i = 0; i < this.Length; i++)
                 {
-                    float yw = verticalValues[i];
+                    float yw = Unsafe.Add(ref verticalValues, i);
                     int index = left + i;
                     result += firstPassPixels[x, index] * yw;
                 }

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

@@ -7,6 +7,7 @@ namespace ImageSharp.Processing.Processors
 {
     using System;
     using System.Buffers;
+    using System.Runtime.CompilerServices;
     using System.Runtime.InteropServices;
 
     /// <summary>
@@ -111,13 +112,15 @@ namespace ImageSharp.Processing.Processors
                 WeightsWindow ws = result.GetWeightsWindow(i, left, right);
                 result.Weights[i] = ws;
 
-                float* weights = ws.Ptr;
+                ref float weights = ref ws.Ptr;
 
                 for (int j = left; j <= right; j++)
                 {
                     float weight = sampler.GetValue((j - center) / scale);
                     sum += weight;
-                    weights[j - left] = weight;
+
+                    // weights[j - left] = weight:
+                    Unsafe.Add(ref weights, j - left) = weight;
                 }
 
                 // Normalise, best to do it here rather than in the pixel loop later on.
@@ -125,7 +128,9 @@ namespace ImageSharp.Processing.Processors
                 {
                     for (int w = 0; w < ws.Length; w++)
                     {
-                        weights[w] = weights[w] / sum;
+                        // weights[w] = weights[w] / sum:
+                        ref float wRef = ref Unsafe.Add(ref weights, w);
+                        wRef = wRef / sum;
                     }
                 }
             }

tests/ImageSharp.Tests/Common/BufferSpanTests.cs

@@ -1,5 +1,6 @@
 // ReSharper disable ObjectCreationAsStatement
 // ReSharper disable InconsistentNaming
+
 namespace ImageSharp.Tests.Common
 {
     using System;
@@ -8,9 +9,20 @@ namespace ImageSharp.Tests.Common
     using Xunit;
 
     using static TestStructs;
-
+    
     public unsafe class BufferSpanTests
     {
+        // ReSharper disable once ClassNeverInstantiated.Local
+        private class Assert : Xunit.Assert
+        {
+            public static void SameRefs<T1, T2>(ref T1 a, ref T2 b)
+            {
+                ref T1 bb = ref Unsafe.As<T2, T1>(ref b);
+
+                True(Unsafe.AreSame(ref a, ref bb), "References are not same!");
+            }
+        }
+
         [Fact]
         public void AsBytes()
         {
@@ -19,10 +31,10 @@ namespace ImageSharp.Tests.Common
             using (PinnedBuffer<Foo> colorBuf = new PinnedBuffer<Foo>(fooz))
             {
                 BufferSpan<Foo> orig = colorBuf.Slice(1);
-                BufferSpan<byte> asBytes = (BufferSpan < byte > )orig;
+                BufferSpan<byte> asBytes = (BufferSpan<byte>)orig;
 
                 Assert.Equal(asBytes.Start, sizeof(Foo));
-                Assert.Equal(orig.PointerAtOffset, asBytes.PointerAtOffset);
+                Assert.SameRefs(ref orig.DangerousGetPinnableReference(), ref asBytes.DangerousGetPinnableReference());
             }
         }
 
@@ -32,16 +44,14 @@ namespace ImageSharp.Tests.Common
             public void Basic()
             {
                 Foo[] array = Foo.CreateArray(3);
-                fixed (Foo* p = array)
-                {
-                    // Act:
-                    BufferSpan<Foo> span = new BufferSpan<Foo>(array, p);
 
-                    // Assert:
-                    Assert.Equal(array, span.Array);
-                    Assert.Equal((IntPtr)p, span.PointerAtOffset);
-                    Assert.Equal(3, span.Length);
-                }
+                // Act:
+                BufferSpan<Foo> span = new BufferSpan<Foo>(array);
+
+                // Assert:
+                Assert.Equal(array, span.Array);
+                Assert.Equal(3, span.Length);
+                Assert.SameRefs(ref array[0], ref span.DangerousGetPinnableReference());
             }
 
             [Fact]
@@ -49,17 +59,15 @@ namespace ImageSharp.Tests.Common
             {
                 Foo[] array = Foo.CreateArray(4);
                 int start = 2;
-                fixed (Foo* p = array)
-                {
-                    // Act:
-                    BufferSpan<Foo> span = new BufferSpan<Foo>(array, p, start);
-
-                    // Assert:
-                    Assert.Equal(array, span.Array);
-                    Assert.Equal(start, span.Start);
-                    Assert.Equal((IntPtr)(p + start), span.PointerAtOffset);
-                    Assert.Equal(array.Length - start, span.Length);
-                }
+
+                // Act:
+                BufferSpan<Foo> span = new BufferSpan<Foo>(array, start);
+
+                // Assert:
+                Assert.Equal(array, span.Array);
+                Assert.Equal(start, span.Start);
+                Assert.SameRefs(ref array[start], ref span.DangerousGetPinnableReference());
+                Assert.Equal(array.Length - start, span.Length);
             }
 
             [Fact]
@@ -68,17 +76,14 @@ namespace ImageSharp.Tests.Common
                 Foo[] array = Foo.CreateArray(10);
                 int start = 2;
                 int length = 3;
-                fixed (Foo* p = array)
-                {
-                    // Act:
-                    BufferSpan<Foo> span = new BufferSpan<Foo>(array, p, start, length);
-
-                    // Assert:
-                    Assert.Equal(array, span.Array);
-                    Assert.Equal(start, span.Start);
-                    Assert.Equal((IntPtr)(p + start), span.PointerAtOffset);
-                    Assert.Equal(length, span.Length);
-                }
+                // Act:
+                BufferSpan<Foo> span = new BufferSpan<Foo>(array, start, length);
+
+                // Assert:
+                Assert.Equal(array, span.Array);
+                Assert.Equal(start, span.Start);
+                Assert.SameRefs(ref array[start], ref span.DangerousGetPinnableReference());
+                Assert.Equal(length, span.Length);
             }
         }
 
@@ -92,19 +97,16 @@ namespace ImageSharp.Tests.Common
                 int start1 = 2;
                 int totalOffset = start0 + start1;
 
-                fixed (Foo* p = array)
-                {
-                    BufferSpan<Foo> span = new BufferSpan<Foo>(array, p, start0);
+                BufferSpan<Foo> span = new BufferSpan<Foo>(array, start0);
 
-                    // Act:
-                    span = span.Slice(start1);
+                // Act:
+                span = span.Slice(start1);
 
-                    // Assert:
-                    Assert.Equal(array, span.Array);
-                    Assert.Equal(totalOffset, span.Start);
-                    Assert.Equal((IntPtr)(p + totalOffset), span.PointerAtOffset);
-                    Assert.Equal(array.Length - totalOffset, span.Length);
-                }
+                // Assert:
+                Assert.Equal(array, span.Array);
+                Assert.Equal(totalOffset, span.Start);
+                Assert.SameRefs(ref array[totalOffset], ref span.DangerousGetPinnableReference());
+                Assert.Equal(array.Length - totalOffset, span.Length);
             }
 
             [Fact]
@@ -116,24 +118,19 @@ namespace ImageSharp.Tests.Common
                 int totalOffset = start0 + start1;
                 int sliceLength = 3;
 
-                fixed (Foo* p = array)
-                {
-                    BufferSpan<Foo> span = new BufferSpan<Foo>(array, p, start0);
+                BufferSpan<Foo> span = new BufferSpan<Foo>(array, start0);
 
-                    // Act:
-                    span = span.Slice(start1, sliceLength);
+                // Act:
+                span = span.Slice(start1, sliceLength);
 
-                    // Assert:
-                    Assert.Equal(array, span.Array);
-                    Assert.Equal(totalOffset, span.Start);
-                    Assert.Equal((IntPtr)(p + totalOffset), span.PointerAtOffset);
-                    Assert.Equal(sliceLength, span.Length);
-                }
+                // Assert:
+                Assert.Equal(array, span.Array);
+                Assert.Equal(totalOffset, span.Start);
+                Assert.SameRefs(ref array[totalOffset], ref span.DangerousGetPinnableReference());
+                Assert.Equal(sliceLength, span.Length);
             }
         }
 
-
-
         [Theory]
         [InlineData(4)]
         [InlineData(1500)]
@@ -142,21 +139,17 @@ namespace ImageSharp.Tests.Common
             Foo[] array = Foo.CreateArray(count + 42);
 
             int offset = 2;
-            fixed (Foo* p = array)
-            {
-                BufferSpan<Foo> ap = new BufferSpan<Foo>(array, p, offset);
+            BufferSpan<Foo> ap = new BufferSpan<Foo>(array, offset);
 
-                // Act:
-                ap.Clear(count);
+            // Act:
+            ap.Clear(count);
 
-                Assert.NotEqual(default(Foo), array[offset-1]);
-                Assert.Equal(default(Foo), array[offset]);
-                Assert.Equal(default(Foo), array[offset + count-1]);
-                Assert.NotEqual(default(Foo), array[offset + count]);
-            }
+            Assert.NotEqual(default(Foo), array[offset - 1]);
+            Assert.Equal(default(Foo), array[offset]);
+            Assert.Equal(default(Foo), array[offset + count - 1]);
+            Assert.NotEqual(default(Foo), array[offset + count]);
         }
 
-
         public class Indexer
         {
             public static readonly TheoryData<int, int, int> IndexerData =
@@ -175,14 +168,11 @@ namespace ImageSharp.Tests.Common
             public void Read(int length, int start, int index)
             {
                 Foo[] a = Foo.CreateArray(length);
-                fixed (Foo* p = a)
-                {
-                    BufferSpan<Foo> span = new BufferSpan<Foo>(a, p, start);
+                BufferSpan<Foo> span = new BufferSpan<Foo>(a, start);
 
-                    Foo element = span[index];
+                Foo element = span[index];
 
-                    Assert.Equal(a[start + index], element);
-                }
+                Assert.Equal(a[start + index], element);
             }
 
             [Theory]
@@ -190,14 +180,11 @@ namespace ImageSharp.Tests.Common
             public void Write(int length, int start, int index)
             {
                 Foo[] a = Foo.CreateArray(length);
-                fixed (Foo* p = a)
-                {
-                    BufferSpan<Foo> span = new BufferSpan<Foo>(a, p, start);
+                BufferSpan<Foo> span = new BufferSpan<Foo>(a, start);
 
-                    span[index] = new Foo(666, 666);
+                span[index] = new Foo(666, 666);
 
-                    Assert.Equal(new Foo(666, 666), a[start + index]);
-                }
+                Assert.Equal(new Foo(666, 666), a[start + index]);
             }
         }
 
@@ -208,13 +195,10 @@ namespace ImageSharp.Tests.Common
         public void DangerousGetPinnableReference(int start, int length)
         {
             Foo[] a = Foo.CreateArray(length);
-            fixed (Foo* p = a)
-            {
-                BufferSpan<Foo> span = new BufferSpan<Foo>(a, p, start);
-                ref Foo r = ref span.DangerousGetPinnableReference();
+            BufferSpan<Foo> span = new BufferSpan<Foo>(a, start);
+            ref Foo r = ref span.DangerousGetPinnableReference();
 
-                Assert.True(Unsafe.AreSame(ref a[start], ref r));
-            }
+            Assert.True(Unsafe.AreSame(ref a[start], ref r));
         }
 
         public class Copy
@@ -253,14 +237,10 @@ namespace ImageSharp.Tests.Common
                 Foo[] source = Foo.CreateArray(count + 2);
                 Foo[] dest = new Foo[count + 5];
 
-                fixed (Foo* pSource = source)
-                fixed (Foo* pDest = dest)
-                {
-                    BufferSpan<Foo> apSource = new BufferSpan<Foo>(source, pSource, 1);
-                    BufferSpan<Foo> apDest = new BufferSpan<Foo>(dest, pDest, 1);
+                BufferSpan<Foo> apSource = new BufferSpan<Foo>(source, 1);
+                BufferSpan<Foo> apDest = new BufferSpan<Foo>(dest, 1);
 
-                    BufferSpan.Copy(apSource, apDest, count-1);
-                }
+                BufferSpan.Copy(apSource, apDest, count - 1);
 
                 AssertNotDefault(source, 1);
                 AssertNotDefault(dest, 1);
@@ -268,7 +248,7 @@ namespace ImageSharp.Tests.Common
                 Assert.NotEqual(source[0], dest[0]);
                 Assert.Equal(source[1], dest[1]);
                 Assert.Equal(source[2], dest[2]);
-                Assert.Equal(source[count-1], dest[count-1]);
+                Assert.Equal(source[count - 1], dest[count - 1]);
                 Assert.NotEqual(source[count], dest[count]);
             }
 
@@ -280,14 +260,10 @@ namespace ImageSharp.Tests.Common
                 AlignedFoo[] source = AlignedFoo.CreateArray(count + 2);
                 AlignedFoo[] dest = new AlignedFoo[count + 5];
 
-                fixed (AlignedFoo* pSource = source)
-                fixed (AlignedFoo* pDest = dest)
-                {
-                    BufferSpan<AlignedFoo> apSource = new BufferSpan<AlignedFoo>(source, pSource, 1);
-                    BufferSpan<AlignedFoo> apDest = new BufferSpan<AlignedFoo>(dest, pDest, 1);
+                BufferSpan<AlignedFoo> apSource = new BufferSpan<AlignedFoo>(source, 1);
+                BufferSpan<AlignedFoo> apDest = new BufferSpan<AlignedFoo>(dest, 1);
 
-                    BufferSpan.Copy(apSource, apDest, count - 1);
-                }
+                BufferSpan.Copy(apSource, apDest, count - 1);
 
                 AssertNotDefault(source, 1);
                 AssertNotDefault(dest, 1);
@@ -304,17 +280,13 @@ namespace ImageSharp.Tests.Common
             [InlineData(1500)]
             public void IntToInt(int count)
             {
-                int[] source = CreateTestInts(count+2);
+                int[] source = CreateTestInts(count + 2);
                 int[] dest = new int[count + 5];
 
-                fixed (int* pSource = source)
-                fixed (int* pDest = dest)
-                {
-                    BufferSpan<int> apSource = new BufferSpan<int>(source, pSource, 1);
-                    BufferSpan<int> apDest = new BufferSpan<int>(dest, pDest, 1);
+                BufferSpan<int> apSource = new BufferSpan<int>(source, 1);
+                BufferSpan<int> apDest = new BufferSpan<int>(dest, 1);
 
-                    BufferSpan.Copy(apSource, apDest, count -1);
-                }
+                BufferSpan.Copy(apSource, apDest, count - 1);
 
                 AssertNotDefault(source, 1);
                 AssertNotDefault(dest, 1);
@@ -332,17 +304,13 @@ namespace ImageSharp.Tests.Common
             public void GenericToBytes(int count)
             {
                 int destCount = count * sizeof(Foo);
-                Foo[] source = Foo.CreateArray(count+2);
-                byte[] dest = new byte[destCount + sizeof(Foo)*2];
+                Foo[] source = Foo.CreateArray(count + 2);
+                byte[] dest = new byte[destCount + sizeof(Foo) * 2];
 
-                fixed (Foo* pSource = source)
-                fixed (byte* pDest = dest)
-                {
-                    BufferSpan<Foo> apSource = new BufferSpan<Foo>(source, pSource, 1);
-                    BufferSpan<byte> apDest = new BufferSpan<byte>(dest, pDest, sizeof(Foo));
+                BufferSpan<Foo> apSource = new BufferSpan<Foo>(source, 1);
+                BufferSpan<byte> apDest = new BufferSpan<byte>(dest, sizeof(Foo));
 
-                    BufferSpan.Copy(apSource, apDest, count - 1);
-                }
+                BufferSpan.Copy(apSource, apDest, count - 1);
 
                 AssertNotDefault(source, 1);
 
@@ -362,14 +330,10 @@ namespace ImageSharp.Tests.Common
                 AlignedFoo[] source = AlignedFoo.CreateArray(count + 2);
                 byte[] dest = new byte[destCount + sizeof(AlignedFoo) * 2];
 
-                fixed (AlignedFoo* pSource = source)
-                fixed (byte* pDest = dest)
-                {
-                    BufferSpan<AlignedFoo> apSource = new BufferSpan<AlignedFoo>(source, pSource, 1);
-                    BufferSpan<byte> apDest = new BufferSpan<byte>(dest, pDest, sizeof(AlignedFoo));
+                BufferSpan<AlignedFoo> apSource = new BufferSpan<AlignedFoo>(source, 1);
+                BufferSpan<byte> apDest = new BufferSpan<byte>(dest, sizeof(AlignedFoo));
 
-                    BufferSpan.Copy(apSource, apDest, count - 1);
-                }
+                BufferSpan.Copy(apSource, apDest, count - 1);
 
                 AssertNotDefault(source, 1);
 
@@ -386,17 +350,13 @@ namespace ImageSharp.Tests.Common
             public void IntToBytes(int count)
             {
                 int destCount = count * sizeof(int);
-                int[] source = CreateTestInts(count+2);
+                int[] source = CreateTestInts(count + 2);
                 byte[] dest = new byte[destCount + sizeof(int) + 1];
 
-                fixed (int* pSource = source)
-                fixed (byte* pDest = dest)
-                {
-                    BufferSpan<int> apSource = new BufferSpan<int>(source, pSource);
-                    BufferSpan<byte> apDest = new BufferSpan<byte>(dest, pDest);
+                BufferSpan<int> apSource = new BufferSpan<int>(source);
+                BufferSpan<byte> apDest = new BufferSpan<byte>(dest);
 
-                    BufferSpan.Copy(apSource, apDest, count);
-                }
+                BufferSpan.Copy(apSource, apDest, count);
 
                 AssertNotDefault(source, 1);
 
@@ -413,15 +373,11 @@ namespace ImageSharp.Tests.Common
                 int srcCount = count * sizeof(Foo);
                 byte[] source = CreateTestBytes(srcCount);
                 Foo[] dest = new Foo[count + 2];
-                
-                fixed(byte* pSource = source)
-                fixed (Foo* pDest = dest)
-                {
-                    BufferSpan<byte> apSource = new BufferSpan<byte>(source, pSource);
-                    BufferSpan<Foo> apDest = new BufferSpan<Foo>(dest, pDest);
 
-                    BufferSpan.Copy(apSource, apDest, count);
-                }
+                BufferSpan<byte> apSource = new BufferSpan<byte>(source);
+                BufferSpan<Foo> apDest = new BufferSpan<Foo>(dest);
+
+                BufferSpan.Copy(apSource, apDest, count);
 
                 AssertNotDefault(source, sizeof(Foo) + 1);
                 AssertNotDefault(dest, 1);
@@ -438,7 +394,7 @@ namespace ImageSharp.Tests.Common
                 Color[] colors = { new Color(0, 1, 2, 3), new Color(4, 5, 6, 7), new Color(8, 9, 10, 11), };
 
                 using (PinnedBuffer<Color> colorBuf = new PinnedBuffer<Color>(colors))
-                using (PinnedBuffer<byte> byteBuf = new PinnedBuffer<byte>(colors.Length*4))
+                using (PinnedBuffer<byte> byteBuf = new PinnedBuffer<byte>(colors.Length * 4))
                 {
                     BufferSpan.Copy<Color>(colorBuf, byteBuf, colorBuf.Length);
 
@@ -451,7 +407,6 @@ namespace ImageSharp.Tests.Common
                 }
             }
 
-
             internal static bool ElementsAreEqual(Foo[] array, byte[] rawArray, int index)
             {
                 fixed (Foo* pArray = array)

tests/ImageSharp.Tests/Common/PinnedBufferTests.cs

@@ -11,6 +11,19 @@
 
     public unsafe class PinnedBufferTests
     {
+        private class Assert : Xunit.Assert
+        {
+            public static void SpanPointsTo<T>(IntPtr ptr, BufferSpan<T> span)
+                where T : struct
+            {
+                ref byte r = ref Unsafe.As<T, byte>(ref span.DangerousGetPinnableReference());
+
+                void* p = Unsafe.AsPointer(ref r);
+
+                Assert.Equal(ptr, (IntPtr)p);
+            }
+        }
+
         [Theory]
         [InlineData(42)]
         [InlineData(1111)]
@@ -121,7 +134,7 @@
 
             Assert.True(buffer.IsDisposedOrLostArrayOwnership);
         }
-
+        
         [Theory]
         [InlineData(7)]
         [InlineData(123)]
@@ -133,7 +146,7 @@
 
                 Assert.Equal(buffer.Array, span.Array);
                 Assert.Equal(0, span.Start);
-                Assert.Equal(buffer.Pointer, span.PointerAtOffset);
+                Assert.SpanPointsTo(buffer.Pointer, span);
                 Assert.Equal(span.Length, bufferLength);
             }
         }
@@ -147,7 +160,7 @@
 
                 Assert.Equal(buffer.Array, span.Array);
                 Assert.Equal(0, span.Start);
-                Assert.Equal(buffer.Pointer, span.PointerAtOffset);
+                Assert.SpanPointsTo(buffer.Pointer, span);
                 Assert.Equal(span.Length, 42);
             }
         }
@@ -166,7 +179,7 @@
 
                     Assert.Equal(buffer.Array, span.Array);
                     Assert.Equal(start, span.Start);
-                    Assert.Equal(buffer.Pointer + start * Unsafe.SizeOf<Foo>(), span.PointerAtOffset);
+                    Assert.SpanPointsTo(buffer.Pointer + start * Unsafe.SizeOf<Foo>(), span);
                     Assert.Equal(span.Length, bufferLength - start);
                 }
             }
@@ -182,7 +195,7 @@
 
                     Assert.Equal(buffer.Array, span.Array);
                     Assert.Equal(start, span.Start);
-                    Assert.Equal(buffer.Pointer + start * Unsafe.SizeOf<Foo>(), span.PointerAtOffset);
+                    Assert.SpanPointsTo(buffer.Pointer + start * Unsafe.SizeOf<Foo>(), span);
                     Assert.Equal(span.Length, spanLength);
                 }
             }

tests/ImageSharp.Tests/Common/PinnedImageBufferTests.cs

@@ -1,6 +1,7 @@
 // ReSharper disable InconsistentNaming
 namespace ImageSharp.Tests.Common
 {
+    using System;
     using System.Runtime.CompilerServices;
 
     using Xunit;
@@ -9,6 +10,20 @@ namespace ImageSharp.Tests.Common
 
     public unsafe class PinnedImageBufferTests
     {
+        // ReSharper disable once ClassNeverInstantiated.Local
+        private class Assert : Xunit.Assert
+        {
+            public static void SpanPointsTo<T>(IntPtr ptr, BufferSpan<T> span)
+                where T : struct
+            {
+                ref byte r = ref Unsafe.As<T, byte>(ref span.DangerousGetPinnableReference());
+
+                void* p = Unsafe.AsPointer(ref r);
+
+                Assert.Equal(ptr, (IntPtr)p);
+            }
+        }
+
         [Theory]
         [InlineData(7, 42)]
         [InlineData(1025, 17)]
@@ -65,7 +80,7 @@ namespace ImageSharp.Tests.Common
 
                 Assert.Equal(width * y, span.Start);
                 Assert.Equal(width, span.Length);
-                Assert.Equal(buffer.Pointer + sizeof(Foo) * width * y, span.PointerAtOffset);
+                Assert.SpanPointsTo(buffer.Pointer + sizeof(Foo) * width * y, span);
             }
         }
 
@@ -81,7 +96,7 @@ namespace ImageSharp.Tests.Common
 
                 Assert.Equal(width * y + x, span.Start);
                 Assert.Equal(width - x, span.Length);
-                Assert.Equal(buffer.Pointer + sizeof(Foo) * (width * y + x), span.PointerAtOffset);
+                Assert.SpanPointsTo(buffer.Pointer + sizeof(Foo) * (width * y + x), span);
             }
         }