resolveInfo.h

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//
// Copyright 2016 Pixar
//
// Licensed under the terms set forth in the LICENSE.txt file available at
// https://openusd.org/license.
//
#ifndef PXR_USD_USD_RESOLVE_INFO_H
#define PXR_USD_USD_RESOLVE_INFO_H
 
 
#include "pxr/pxr.h"
#include "pxr/usd/usd/api.h"
#include "pxr/usd/usd/stage.h"
#include "pxr/base/ts/spline.h"
#include "pxr/usd/sdf/layerOffset.h"
#include "pxr/usd/sdf/path.h"
#include "pxr/usd/pcp/node.h"
 
#include "pxr/base/tf/declarePtrs.h"
 
#include <limits>
#include <memory>
#include <optional>
 
PXR_NAMESPACE_OPEN_SCOPE
 
TF_DECLARE_WEAK_PTRS(PcpLayerStack);
 
enum UsdResolveInfoSource
{
    UsdResolveInfoSourceNone,            
 
    UsdResolveInfoSourceFallback,        
    UsdResolveInfoSourceDefault,         
    UsdResolveInfoSourceTimeSamples,     
    UsdResolveInfoSourceValueClips,      
    UsdResolveInfoSourceSpline,          
};
 
class UsdResolveInfo
{
public:
    UsdResolveInfo()
        : _source(UsdResolveInfoSourceNone)
        , _valueIsBlocked(false)
        , _defaultCanCompose(false)
        , _defaultCanComposeOverWeakerTimeVaryingSources(false)
    {
    }
 
    UsdResolveInfoSource GetSource() const {
        return _source;
    }
    
    bool HasAuthoredValueOpinion() const {
        return
            _source == UsdResolveInfoSourceDefault ||
            _source == UsdResolveInfoSourceTimeSamples ||
            _source == UsdResolveInfoSourceValueClips ||
            _source == UsdResolveInfoSourceSpline ||
            _valueIsBlocked;
    }
 
    bool HasAuthoredValue() const {
        return
            _source == UsdResolveInfoSourceDefault ||
            _source == UsdResolveInfoSourceTimeSamples ||
            _source == UsdResolveInfoSourceValueClips ||
            _source == UsdResolveInfoSourceSpline;
    }
 
    PcpNodeRef GetNode() const {
        return _node;
    }
 
    bool ValueIsBlocked() const {
        return _valueIsBlocked;
    }
 
    bool ValueSourceMightBeTimeVarying() const {
        if (_source == UsdResolveInfoSourceTimeSamples ||
            _source == UsdResolveInfoSourceSpline ||
            _source == UsdResolveInfoSourceValueClips) {
            return true;
        }
        if (HasNextWeakerInfo()) {
            return GetNextWeakerInfo()->ValueSourceMightBeTimeVarying();
        }
        return _source == UsdResolveInfoSourceDefault &&
            _defaultCanComposeOverWeakerTimeVaryingSources;
    }
 
    bool HasNextWeakerInfo() const {
        return static_cast<bool>(_nextWeaker);
    }
 
    UsdResolveInfo const *GetNextWeakerInfo() const {
        return _nextWeaker.get();
    }
 
private:
 
    // Helper to chain an additional weaker info onto this one.
    USD_API
    UsdResolveInfo *_AddNextWeakerInfo();
    
    PcpLayerStackPtr _layerStack;
 
    SdfLayerHandle _layer;
 
    PcpNodeRef _node;
 
    SdfLayerOffset _layerToStageOffset;
 
    SdfPath _primPathInLayerStack;
 
    std::optional<TsSpline> _spline;
 
    std::shared_ptr<UsdResolveInfo> _nextWeaker;
    
    UsdResolveInfoSource _source;
 
    bool _valueIsBlocked;
 
    bool _defaultCanCompose;
    
    bool _defaultCanComposeOverWeakerTimeVaryingSources;
 
    friend class UsdAttribute;
    friend class UsdAttributeQuery;
    friend class UsdStage;
    friend class UsdStage_ResolveInfoAccess;
    friend class Usd_Resolver;
};
 
 
PXR_NAMESPACE_CLOSE_SCOPE
 
#endif // PXR_USD_USD_RESOLVE_INFO_H