/// <summary>
/// Creates a clean instance of <see cref="PinnedBuffer{T}"/> initializing it's elements with 'default(T)'.
/// </summary>
/// <param name="count">The desired count of elements. (Minimum size for <see cref="Array"/>)</param>
/// <returns>The <see cref="PinnedBuffer{T}"/> instance</returns>
public static PinnedBuffer <T> CreateClean(int count)
{
PinnedBuffer <T> buffer = new PinnedBuffer <T>(count);
buffer.Clear();
return(buffer);
}
/// <summary>
/// SIMD optimized bulk implementation of <see cref="IPixel.PackFromVector4(Vector4)"/>
/// that works only with `count` divisible by <see cref="Vector{UInt32}.Count"/>.
/// </summary>
/// <param name="sourceColors">The <see cref="BufferSpan{T}"/> to the source colors.</param>
/// <param name="destVectors">The <see cref="BufferSpan{T}"/> to the dstination vectors.</param>
/// <param name="count">The number of pixels to convert.</param>
/// <remarks>
/// Implementation adapted from:
/// <see>
/// <cref>http://stackoverflow.com/a/5362789</cref>
/// </see>
/// TODO: We can replace this implementation in the future using new Vector API-s:
/// <see>
/// <cref>https://github.com/dotnet/corefx/issues/15957</cref>
/// </see>
/// </remarks>
internal static unsafe void ToVector4SimdAligned(
BufferSpan <Color> sourceColors,
BufferSpan <Vector4> destVectors,
int count)
{
if (!Vector.IsHardwareAccelerated)
{
throw new InvalidOperationException(
"Color.BulkOperations.ToVector4SimdAligned() should not be called when Vector.IsHardwareAccelerated == false!");
}
int vecSize = Vector <uint> .Count;
DebugGuard.IsTrue(
count % vecSize == 0,
nameof(count),
"Argument 'count' should divisible by Vector<uint>.Count!");
Vector <float> bVec = new Vector <float>(256.0f / 255.0f);
Vector <float> magicFloat = new Vector <float>(32768.0f);
Vector <uint> magicInt = new Vector <uint>(1191182336); // reinterpreded value of 32768.0f
Vector <uint> mask = new Vector <uint>(255);
int unpackedRawCount = count * 4;
uint *src = (uint *)sourceColors.PointerAtOffset;
uint *srcEnd = src + 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++)
{
// This call is the bottleneck now:
dst->Load(*src);
}
for (int i = 0; i < unpackedRawCount; i += vecSize)
{
Vector <uint> vi = new Vector <uint>(temp, i);
vi &= mask;
vi |= magicInt;
Vector <float> vf = Vector.AsVectorSingle(vi);
vf = (vf - magicFloat) * bVec;
vf.CopyTo(fTemp, i);
}
BufferSpan.Copy <uint>(tempBuf, (BufferSpan <byte>)destVectors, unpackedRawCount);
}
}
/// <summary>
/// Initializes a new instance of the <see cref="PixelAccessor{TColor}" /> class.
/// </summary>
/// <param name="width">The width of the image represented by the pixel buffer.</param>
/// <param name="height">The height of the image represented by the pixel buffer.</param>
/// <param name="pixels">The pixel buffer.</param>
private PixelAccessor(int width, int height, PinnedBuffer <TColor> pixels)
{
Guard.NotNull(pixels, nameof(pixels));
Guard.MustBeGreaterThan(width, 0, nameof(width));
Guard.MustBeGreaterThan(height, 0, nameof(height));
this.SetPixelBufferUnsafe(width, height, pixels);
this.ParallelOptions = Configuration.Default.ParallelOptions;
}
/// <summary>
/// Sets the pixel buffer in an unsafe manor this should not be used unless you know what its doing!!!
/// </summary>
/// <param name="width">The width.</param>
/// <param name="height">The height.</param>
/// <param name="pixels">The pixel buffer</param>
private void SetPixelBufferUnsafe(int width, int height, PinnedBuffer <TColor> pixels)
{
this.pixelBuffer = pixels;
this.pixelsBase = (byte *)pixels.Pointer;
this.Width = width;
this.Height = height;
this.PixelSize = Unsafe.SizeOf <TColor>();
this.RowStride = this.Width * this.PixelSize;
}
/// <summary>
/// Initializes a new instance of the <see cref="PixelArea{TColor}"/> class.
/// </summary>
/// <param name="width">The width.</param>
/// <param name="height">The height.</param>
/// <param name="componentOrder">The component order.</param>
/// <param name="padding">The number of bytes to pad each row.</param>
public PixelArea(int width, int height, ComponentOrder componentOrder, int padding)
{
this.Width = width;
this.Height = height;
this.ComponentOrder = componentOrder;
this.RowStride = (width * GetComponentCount(componentOrder)) + padding;
this.Length = this.RowStride * height;
this.byteBuffer = new PinnedBuffer <byte>(this.Length);
this.PixelBase = (byte *)this.byteBuffer.Pointer;
}
/// <summary>
/// Initializes a new instance of the <see cref="PixelArea{TColor}"/> class.
/// </summary>
/// <param name="width">The width.</param>
/// <param name="height">The height.</param>
/// <param name="bytes">The bytes.</param>
/// <param name="componentOrder">The component order.</param>
/// <exception cref="ArgumentOutOfRangeException">
/// Thrown if <paramref name="bytes"></paramref> is the incorrect length.
/// </exception>
public PixelArea(int width, int height, byte[] bytes, ComponentOrder componentOrder)
{
this.CheckBytesLength(width, height, bytes, componentOrder);
this.Width = width;
this.Height = height;
this.ComponentOrder = componentOrder;
this.RowStride = width * GetComponentCount(componentOrder);
this.Length = bytes.Length; // TODO: Is this the right value for Length?
this.byteBuffer = new PinnedBuffer <byte>(bytes);
this.PixelBase = (byte *)this.byteBuffer.Pointer;
}
public static unsafe BufferPointer <T> Slice <T>(this PinnedBuffer <T> buffer)
where T : struct
{
return(new BufferPointer <T>(buffer.Array, (void *)buffer.Pointer));
}
/// <summary>
/// Initializes a new instance of the <see cref="PixelAccessor{TColor}"/> class.
/// </summary>
/// <param name="width">The width of the image represented by the pixel buffer.</param>
/// <param name="height">The height of the image represented by the pixel buffer.</param>
public PixelAccessor(int width, int height)
: this(width, height, PinnedBuffer <TColor> .CreateClean(width * height))
{
}