public IntPtr MarshalManagedToNative(object ManagedObj)
{
if (ManagedObj == null)
{
return(IntPtr.Zero);
}
String obj = ManagedObj as String;
if (obj == null)
{
throw new MarshalDirectiveException(
"UTF8StringMarshaler must be used on a string.");
}
// not null terminated
byte[] buffer = Encoding.UTF8.GetBytes(obj);
IntPtr nativeUTF8Str = DjvuMarshal.AllocHGlobal((uint)buffer.Length + 1);
Marshal.Copy(buffer, 0, nativeUTF8Str, buffer.Length);
// write the terminating null
Marshal.WriteByte(nativeUTF8Str, buffer.Length, 0);
return(nativeUTF8Str);
}
public void CleanUpNativeData(IntPtr pNativeData)
{
try
{
DjvuMarshal.FreeHGlobal(pNativeData);
}
catch (AccessViolationException ex)
{
System.Diagnostics.Debug.WriteLine(ex.ToString());
}
}
public IntPtr RenderPage(RenderMode mode, ref DjvuRectangle targetRect)
{
IntPtr format = NativeMethods.CreateDjvuFormat(FormatStyle.BGR24, 0, IntPtr.Zero);
NativeMethods.SetDjvuFormatRowOrder(format, 1);
NativeMethods.SetDjvuFormatYDirection(format, 1);
NativeMethods.SetDjvuFormatDitherBits(format, 24);
DjvuRectangle pageRect = new DjvuRectangle
{
X = 0,
Y = 0,
Height = (uint)Height,
Width = (uint)Width
};
IntPtr buffer = DjvuMarshal.AllocHGlobal((uint)(Width * 3 * Height));
int result = 0;
try
{
result = NativeMethods.RenderDjvuPage(Page, mode, ref pageRect, ref targetRect,
format, (uint)Width * 3, buffer);
if (result == 0)
{
throw new DjvuLibreException(
$"Failed to render image at this time - result: {result}. Try later again.");
}
}
catch (Exception ex)
{
DjvuMarshal.FreeHGlobal(buffer);
buffer = IntPtr.Zero;
NativeMethods.ReleaseDjvuFormat(format);
format = IntPtr.Zero;
string message = "Error while rendering page. Check InnerException message for details.";
if (ex is DjvuLibreException)
{
throw new DjvuLibreException(message, ex);
}
throw new AggregateException(message, ex);
}
return(buffer);
}
public IntPtr RenderPage(RenderMode mode, ref DjvuRectangle pageRect, ref DjvuRectangle targetRect, IntPtr format)
{
if (pageRect.Width <= 0 || pageRect.Height <= 0)
{
pageRect = new DjvuRectangle
{
X = 0,
Y = 0,
Height = (uint)Height,
Width = (uint)Width
};
}
IntPtr buffer = DjvuMarshal.AllocHGlobal((uint)(Width * 3 * Height));
int result = 0;
try
{
result = NativeMethods.RenderDjvuPage(Page, mode, ref pageRect, ref targetRect,
format, (uint)Width * 3, buffer);
if (result == 0)
{
throw new DjvuLibreException(
$"Failed to render image this time - result: {result}. Try again later.");
}
}
catch (Exception ex)
{
DjvuMarshal.FreeHGlobal(buffer);
buffer = IntPtr.Zero;
NativeMethods.ReleaseDjvuFormat(format);
format = IntPtr.Zero;
string message = "Error while rendering page. Check InnerException message for details.";
if (ex is DjvuLibreException)
{
throw new DjvuLibreException(message, ex);
}
throw new AggregateException(message, ex);
}
return(buffer);
}
