qwindowsd3d11texturebridge_p.h

// Copyright (C) 2026 The Qt Company Ltd.

// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

#ifndef QWINDOWSD3D11TEXTUREBRIDGE_P_H

#define QWINDOWSD3D11TEXTUREBRIDGE_P_H

//

//  W A R N I N G

//  -------------

//

// This file is not part of the Qt API. It exists purely as an

// implementation detail. This header file may change from version to

// version without notice, or even be removed.

//

// We mean it.

//

#include <QtMultimedia/qtmultimediaexports.h>

#include <QtCore/qsize.h>

#include <QtCore/private/qcomptr_p.h>

#include <QtCore/private/quniquehandle_types_p.h>

#include <d3d11.h>

#include <d3d11_1.h>

QT_BEGIN_NAMESPACE

namespace QtMultimediaPrivate {

/*! \internal Utility class for synchronized transfer of a texture between two D3D devices

 * This class is used to copy a texture from one device to another device. This

 * is implemented using a shared texture, along with keyed mutexes to synchronize

 * access to the texture.

 * This is needed because the source and destination may use different D3D devices,

 * for example when copying a decoded frame owned by FFmpeg or the Windows Media

 * Foundation media engine into a texture usable by RHI.

*/

class Q_MULTIMEDIA_EXPORT QWindowsD3D11TextureBridge final

public:

    /** Copy a texture slice at position 'index' belonging to device 'dev'

     * into a shared texture, limiting the texture size to the frame size */

    bool copyToSharedTex(ID3D11Device *, ID3D11DeviceContext *, const ComPtr<ID3D11Texture2D> &,

                         const QSize &frameSize, UINT index = 0);

    bool copyToSharedTex(const ComPtr<ID3D11Device> &, const ComPtr<ID3D11DeviceContext> &,

                         const ComPtr<ID3D11Texture2D> &, const QSize &frameSize, UINT index = 0);

    // Obtain a copy of the texture on a second device.

    ComPtr<ID3D11Texture2D> copyFromSharedTex(const ComPtr<ID3D11Device1> &,

                                              const ComPtr<ID3D11DeviceContext> &);

    // Obtain a copy of the texture on a second device into a caller-provided destination texture.

    bool copyFromSharedTex(const ComPtr<ID3D11Device1> &, const ComPtr<ID3D11DeviceContext> &,

                           const ComPtr<ID3D11Texture2D> &destination);

private:

    bool ensureDestTex(const ComPtr<ID3D11Device1> &dev);

    bool ensureSrcTex(ID3D11Device *dev, const ComPtr<ID3D11Texture2D> &tex,

                      const QSize &frameSize);

    bool isSrcInitialized(const ID3D11Device *dev, const ComPtr<ID3D11Texture2D> &tex,

                          const QSize &frameSize) const;

    bool recreateSrc(ID3D11Device *dev, const ComPtr<ID3D11Texture2D> &tex, const QSize &frameSize);

    QUniqueWin32NullHandle m_sharedHandle{};

    static constexpr UINT kSrcKey = 0;

    static constexpr UINT kDestKey = 1;

    ComPtr<ID3D11Texture2D> m_srcTex;

    ComPtr<IDXGIKeyedMutex> m_srcMutex;

    ComPtr<ID3D11Device1> m_destDevice;

    ComPtr<ID3D11Texture2D> m_destTex;

    ComPtr<IDXGIKeyedMutex> m_destMutex;

    ComPtr<ID3D11Texture2D> m_outputTex;

};

} // namespace QtMultimediaPrivate

QT_END_NAMESPACE

#endif