rhi_support.cpp

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// Copyright (C) 2026 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
 
#include "rhi_support_p.h"
 
namespace QtMultimediaTest {
 
using namespace Qt::Literals;
 
#if QT_CONFIG(opengl)
q23::expected<OffscreenGlRhi, QString> createOffscreenGlRhi()
{
    std::unique_ptr<QOffscreenSurface> fallbackSurface{
        QRhiGles2InitParams::newFallbackSurface(),
    };
 
    QRhiGles2InitParams glParams;
    glParams.format = QSurfaceFormat::defaultFormat();
    glParams.fallbackSurface = fallbackSurface.get();
    std::unique_ptr<QRhi> rhi{
        QRhi::create(QRhi::OpenGLES2, &glParams),
    };
    if (!rhi)
        return q23::unexpected(u"QRhi::create failed"_s);
 
    return OffscreenGlRhi{
        std::move(fallbackSurface),
        std::move(rhi),
    };
}
#endif
 
#if QT_CONFIG(metal)
std::unique_ptr<QRhi> createOffscreenMetalRhi()
{
    QRhiMetalInitParams metalParams;
    return std::unique_ptr<QRhi>(QRhi::create(QRhi::Metal, &metalParams));
}
#endif
 
q23::expected<QByteArray, QString> readBackPlane(QRhi &rhi, quint64 handle, QSize planeSize,
                                                 QRhiTexture::Format format)
{
    std::unique_ptr<QRhiTexture> texture(
            rhi.newTexture(format, planeSize, 1, QRhiTexture::UsedAsTransferSource));
    if (!texture->createFrom(QRhiTexture::NativeTexture{ handle, 0 }))
        return q23::unexpected(u"QRhiTexture::createFrom failed"_s);
 
    QRhiResourceUpdateBatch *batch = rhi.nextResourceUpdateBatch();
    QRhiReadbackResult result;
    batch->readBackTexture(texture.get(), &result);
 
    QRhiCommandBuffer *cb = nullptr;
    if (rhi.beginOffscreenFrame(&cb) != QRhi::FrameOpSuccess || !cb)
        return q23::unexpected(u"QRhi::beginOffscreenFrame failed"_s);
    cb->resourceUpdate(batch);
    rhi.endOffscreenFrame();
 
    return result.data;
}
 
} // namespace QtMultimediaTest