public static DXGI_MODE_DESC1?FindClosestMatchingMode1(this IDXGIOutput1 output, DXGI_MODE_DESC1 modeToMatch, object concernedDevice)
{
if (output == null)
{
throw new ArgumentNullException(nameof(output));
}
var closest = new DXGI_MODE_DESC1();
if (output.FindClosestMatchingMode1(ref modeToMatch, out closest, ComObject.Unwrap(concernedDevice)).IsError)
{
return(null);
}
return(closest);
}
public static ComObject <IDXGIOutputDuplication> DuplicateOutput(this IDXGIOutput1 output, object device, bool throwOnError = true)
{
if (output == null)
{
throw new ArgumentNullException(nameof(output));
}
if (device == null)
{
throw new ArgumentNullException(nameof(device));
}
device = ComObject.Unwrap(device);
// this wonderful magic (mess) is because of a horrible bug in DXGI
// https://social.msdn.microsoft.com/Forums/windowsdesktop/en-US/0c28328a-100a-4d6f-9a08-44a452d3ca6a/idxgioutputduplication-implementation-bug?forum=windowssdk#0c28328a-100a-4d6f-9a08-44a452d3ca6a
output.DuplicateOutput(device, out var unk).ThrowOnError(throwOnError);
if (unk == IntPtr.Zero)
{
return(null);
}
// we copy the original COM's vtable to our process
var vtablePtr = Marshal.ReadIntPtr(unk);
var vtable = new IDXGIOutputDuplicationVTable();
Marshal.PtrToStructure(vtablePtr, vtable);
// patch QueryInterface so it works (route to our code)
var wrapper = new Wrapper(unk);
vtable.QueryInterfacePtr = Marshal.GetFunctionPointerForDelegate <QueryInterfaceFn>(wrapper.QueryInterface);
using (var newVtablePtr = new ComMemory(Marshal.SizeOf <IDXGIOutputDuplicationVTable>()))
{
Marshal.StructureToPtr(vtable, newVtablePtr.Pointer, false);
// create a new vtable for the CLR
using (var newUnk = new ComMemory(IntPtr.Size))
{
Marshal.WriteIntPtr(newUnk.Pointer, newVtablePtr.Pointer);
var dup = (IDXGIOutputDuplication)Marshal.GetObjectForIUnknown(newUnk.Pointer);
return(new ComObject <IDXGIOutputDuplication>(dup));
}
}
}
