dataSourceStageGlobals.h

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//
// Copyright 2020 Pixar
//
// Licensed under the Apache License, Version 2.0 (the "Apache License")
// with the following modification; you may not use this file except in
// compliance with the Apache License and the following modification to it:
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//
// 6. Trademarks. This License does not grant permission to use the trade
//    names, trademarks, service marks, or product names of the Licensor
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//    the License and to reproduce the content of the NOTICE file.
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//     http://www.apache.org/licenses/LICENSE-2.0
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#ifndef PXR_USD_IMAGING_USD_IMAGING_DATA_SOURCE_STAGE_GLOBALS_H
#define PXR_USD_IMAGING_USD_IMAGING_DATA_SOURCE_STAGE_GLOBALS_H

#include "pxr/usd/usd/prim.h"
#include "pxr/usd/usd/timeCode.h"

#include "pxr/imaging/hd/dataSourceLocator.h"

#include "pxr/usd/sdf/path.h"

PXR_NAMESPACE_OPEN_SCOPE

/// \class UsdImagingDataSourceStageGlobals
///
/// This class is used as a context object with global stage information,
/// that gets passed down to datasources to help them answer scene queries.
///
/// It's a pure virtual interface to allow for different use cases to override
/// certain behaviors (like getting the time coordinate, or whether we support
/// time-varying tracking).
/// 
class UsdImagingDataSourceStageGlobals
{
public:
    virtual ~UsdImagingDataSourceStageGlobals();

    // Datasource API

    /// Returns the current time represented in this instance.
    virtual UsdTimeCode GetTime() const = 0;

    /// Flags the given \p hydraPath as time varying at the given locator.
    virtual void FlagAsTimeVarying(
        const SdfPath &hydraPath, 
        const HdDataSourceLocator &locator) const = 0;

    /// Flags the object at \p usdPath as dependent on an asset path.
    /// \p usdPath may point to a prim (e.g., if the prim has asset path
    /// metadata) or an attribute (e.g., if the attribute has an
    /// asset path value).
    virtual void FlagAsAssetPathDependent(
        const SdfPath &usdPath) const = 0;
};


PXR_NAMESPACE_CLOSE_SCOPE

#endif // PXR_USD_IMAGING_USD_IMAGING_DATA_SOURCE_STAGE_GLOBALS_H