/****************************************************************************
**
** Copyright (C) 2008-2012 NVIDIA Corporation.
** Copyright (C) 2017 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of Qt 3D Studio.
**
** $QT_BEGIN_LICENSE:GPL$
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** accordance with the commercial license agreement provided with the
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** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 or (at your option) any later version
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** the Free Software Foundation and appearing in the file LICENSE.GPL3
** included in the packaging of this file. Please review the following
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#include "foundation/Qt3DSMat44.h"
#include "render/Qt3DSRenderContext.h"
#include "foundation/Utils.h"
#include "EASTL/set.h"
#include "EASTL/utility.h"
#include "render/Qt3DSRenderShaderProgram.h"

using namespace qt3ds;
using namespace qt3ds::render;
using namespace eastl;

namespace qt3ds {
namespace render {

NVRenderContext &NVRenderContext::CreateGL(NVFoundationBase &foundation,
                                           IStringTable &inStringTable,
                                           const QSurfaceFormat &format)
{
    NVRenderContext *retval = NULL;

    QT3DS_ASSERT(format.majorVersion() >= 2);

    // create backend
    NVScopedRefCounted<IStringTable> theStringTable(inStringTable);
    NVScopedRefCounted<NVRenderBackend> theBackend;
    bool isES = format.renderableType() == QSurfaceFormat::OpenGLES;

    static int envBE = qEnvironmentVariableIntValue("QT3DS_FORCE_OPENGL_BACKEND");
    if (envBE == 1) {
        theBackend = QT3DS_NEW(foundation.getAllocator(), NVRenderBackendGLES2Impl)(
                    foundation, *theStringTable, format);
    } else if (envBE == 2) {
        theBackend = QT3DS_NEW(foundation.getAllocator(), NVRenderBackendGL3Impl)(
                    foundation, *theStringTable, format);
    } else if (envBE == 3) {
        theBackend = QT3DS_NEW(foundation.getAllocator(), NVRenderBackendGL4Impl)(
                    foundation, *theStringTable, format);
    } else {
        if (isES && (format.majorVersion() == 2
                     || (format.majorVersion() == 3 && format.minorVersion() == 0))) {
            theBackend = QT3DS_NEW(foundation.getAllocator(), NVRenderBackendGLES2Impl)(
                        foundation, *theStringTable, format);
        } else if (format.majorVersion() == 3 && format.minorVersion() >= 1 && !isES) {
            theBackend = QT3DS_NEW(foundation.getAllocator(), NVRenderBackendGL3Impl)(
                        foundation, *theStringTable, format);
        } else if (format.majorVersion() == 4
            || (isES && format.majorVersion() == 3 && format.minorVersion() >= 1)) {
#ifdef Q_OS_MACOS
            // TODO: macOS crashes with glTextStorage2DMultisample, so fall back to OpenGL3
            // for now (QT3DS-590)
            theBackend = QT3DS_NEW(foundation.getAllocator(), NVRenderBackendGL3Impl)(
                        foundation, *theStringTable, format);
#else
            theBackend = QT3DS_NEW(foundation.getAllocator(), NVRenderBackendGL4Impl)(
                        foundation, *theStringTable, format);
#endif
        } else {
            QT3DS_ASSERT(false);
            qCCritical(INTERNAL_ERROR) << "Can't find a suitable OpenGL version for" << format;
        }
    }

    retval = QT3DS_NEW(foundation.getAllocator(), NVRenderContextImpl)(foundation, *theBackend,
                                                                    *theStringTable);

    return *retval;
}

}
}