internal static IntPtr InitFromStream(Stream stream)
{
if (stream == null)
{
throw new ArgumentNullException(nameof(stream));
}
IntPtr imagePtr;
int st;
// Seeking required
if (!stream.CanSeek)
{
byte[] buffer = new byte[256];
int index = 0;
int count;
do
{
if (buffer.Length < index + 256)
{
byte[] newBuffer = new byte[buffer.Length * 2];
Array.Copy(buffer, newBuffer, buffer.Length);
buffer = newBuffer;
}
count = stream.Read(buffer, index, 256);
index += count;
}while (count != 0);
stream = new MemoryStream(buffer, 0, index);
}
// Unix, with libgdiplus
// We use a custom API for this, because there's no easy way
// to get the Stream down to libgdiplus. So, we wrap the stream
// with a set of delegates.
GdiPlusStreamHelper sh = new GdiPlusStreamHelper(stream, true);
st = Gdip.GdipLoadImageFromDelegate_linux(sh.GetHeaderDelegate, sh.GetBytesDelegate,
sh.PutBytesDelegate, sh.SeekDelegate, sh.CloseDelegate, sh.SizeDelegate, out imagePtr);
return(st == Gdip.Ok ? imagePtr : IntPtr.Zero);
}
private protected static IntPtr InitializeFromStream(Stream stream)
{
if (stream == null)
throw new ArgumentNullException(nameof(stream));
// Unix, with libgdiplus
// We use a custom API for this, because there's no easy way
// to get the Stream down to libgdiplus. So, we wrap the stream
// with a set of delegates.
GdiPlusStreamHelper sh = new GdiPlusStreamHelper(stream, true);
int st = Gdip.GdipLoadImageFromDelegate_linux(sh.GetHeaderDelegate, sh.GetBytesDelegate,
sh.PutBytesDelegate, sh.SeekDelegate, sh.CloseDelegate, sh.SizeDelegate, out IntPtr imagePtr);
// Since we're just passing to native code the delegates inside the wrapper, we need to keep sh alive
// to avoid the object being collected and therefore the delegates would be collected as well.
GC.KeepAlive(sh);
Gdip.CheckStatus(st);
return imagePtr;
}
public void Save(Stream stream, ImageCodecInfo encoder, EncoderParameters encoderParams)
{
Status st;
IntPtr nativeEncoderParams;
Guid guid = encoder.Clsid;
if (encoderParams == null)
{
nativeEncoderParams = IntPtr.Zero;
}
else
{
nativeEncoderParams = encoderParams.ConvertToMemory();
}
try
{
if (GDIPlus.RunningOnUnix())
{
GdiPlusStreamHelper sh = new GdiPlusStreamHelper(stream, false);
st = SafeNativeMethods.Gdip.GdipSaveImageToDelegate_linux(nativeObject, sh.GetBytesDelegate, sh.PutBytesDelegate,
sh.SeekDelegate, sh.CloseDelegate, sh.SizeDelegate, ref guid, nativeEncoderParams);
}
else
{
st = SafeNativeMethods.Gdip.GdipSaveImageToStream(new HandleRef(this, nativeObject),
new ComIStreamWrapper(stream), ref guid, new HandleRef(encoderParams, nativeEncoderParams));
}
}
finally
{
if (nativeEncoderParams != IntPtr.Zero)
{
Marshal.FreeHGlobal(nativeEncoderParams);
}
}
SafeNativeMethods.Gdip.CheckStatus(st);
}
