/// <summary>
/// Removes from the bitmap's allow list all code points which aren't mapped to defined characters
/// or which are otherwise always disallowed.
/// </summary>
/// <remarks>
/// Always-disallowed categories include Cc, Cs, Co, Cn, Zs [except U+0020 SPACE], Zl, and Zp.
/// </remarks>
public void ForbidUndefinedCharacters()
{
fixed(uint *pBitmap = Bitmap)
{
ReadOnlySpan <byte> definedCharsBitmapAsLittleEndian = UnicodeHelpers.GetDefinedBmpCodePointsBitmapLittleEndian();
Span <uint> thisAllowedCharactersBitmap = new Span <uint>(pBitmap, BitmapLengthInDWords);
Debug.Assert(definedCharsBitmapAsLittleEndian.Length == thisAllowedCharactersBitmap.Length * sizeof(uint));
#if NETCOREAPP
if (Vector.IsHardwareAccelerated && BitConverter.IsLittleEndian)
{
while (!definedCharsBitmapAsLittleEndian.IsEmpty)
{
(new Vector <uint>(definedCharsBitmapAsLittleEndian) & new Vector <uint>(thisAllowedCharactersBitmap)).CopyTo(thisAllowedCharactersBitmap);
definedCharsBitmapAsLittleEndian = definedCharsBitmapAsLittleEndian.Slice(Vector <byte> .Count);
thisAllowedCharactersBitmap = thisAllowedCharactersBitmap.Slice(Vector <uint> .Count);
}
Debug.Assert(thisAllowedCharactersBitmap.IsEmpty, "Both vectors should've been fully consumed.");
return;
}
#endif
// Not Core, or not little-endian, or not SIMD-optimized.
for (int i = 0; i < thisAllowedCharactersBitmap.Length; i++)
{
thisAllowedCharactersBitmap[i] &= BinaryPrimitives.ReadUInt32LittleEndian(definedCharsBitmapAsLittleEndian.Slice(i * sizeof(uint)));
}
}
}
