public static EmfPlusBitmapDataBase GetBitmapData(MetafileReader reader, BitmapDataType type, uint size)
{
EmfPlusBitmapDataBase data;
switch (type)
{
case BitmapDataType.Pixel:
data = new EmfPlusBitmapData(reader, size);
break;
case BitmapDataType.Compressed:
data = new EmfPlusCompressedImage(reader, size);
break;
default:
throw new InvalidOperationException($"Unknown bitmap type 0x{type:X8}.");
}
return(data);
}
internal ClippedBitmapData(IBitmapData source, Rectangle clippingRegion)
{
if (source == null)
{
throw new ArgumentNullException(nameof(source));
}
region = clippingRegion;
// source is already clipped: unwrapping to prevent tiered nesting (not calling Unwrap because other types should not be extracted here)
if (source is ClippedBitmapData parent)
{
BitmapData = parent.BitmapData;
region.Offset(parent.region.Location);
region.Intersect(parent.region);
}
else
{
BitmapData = source;
region.Intersect(new Rectangle(Point.Empty, source.GetSize()));
}
if (region.IsEmpty)
{
throw new ArgumentOutOfRangeException(nameof(clippingRegion), PublicResources.ArgumentOutOfRange);
}
bitmapDataType = BitmapData switch
{
IBitmapDataInternal _ => BitmapDataType.Internal,
IReadWriteBitmapData _ => BitmapDataType.ReadWrite,
IReadableBitmapData _ => BitmapDataType.Readable,
IWritableBitmapData _ => BitmapDataType.Writable,
_ => BitmapDataType.None
};
PixelFormat = BitmapData.PixelFormat;
BackColor = BitmapData.BackColor;
AlphaThreshold = BitmapData.AlphaThreshold;
Palette = BitmapData.Palette;
int bpp = PixelFormat.ToBitsPerPixel();
int maxRowSize = (region.Width * bpp) >> 3;
RowSize = region.Left > 0
// Any clipping from the left disables raw access because ReadRaw/WriteRaw offset depends on size of T,
// which will fail for any T whose size is not the same as the actual pixel size
? 0
// Even one byte padding is disabled to protect the right edge of a region by default
: Math.Min(source.RowSize, maxRowSize);
if (bpp >= 8 || RowSize < maxRowSize)
{
return;
}
// 1/4bpp: Adjust RowSize if needed
// right edge: if not at byte boundary but that is the right edge of the original image, then we allow including padding
if (PixelFormat.IsAtByteBoundary(region.Width) && region.Right == BitmapData.Width)
{
RowSize++;
}
}
