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schema.h
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2 // Copyright 2021 Pixar
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24 
25 #ifndef PXR_IMAGING_HD_SCHEMA_H
26 #define PXR_IMAGING_HD_SCHEMA_H
27 
28 #include "pxr/imaging/hd/api.h"
29 
31 
33 
34 // ----------------------------------------------------------------------------
35 
36 /// Schema classes represent a structured view of the inherently unstructured
37 /// container data source passed into the constructor. They're used to
38 /// represent what fields a given object is expected to have.
39 /// Note that a schema can be applied to a container which doesn't contain
40 /// all of the named fields; in that case, some of the field accessors will
41 /// return null, and the caller should use default values for those fields.
42 class HdSchema
43 {
44 public:
45  HdSchema(HdContainerDataSourceHandle container)
46  : _container(container) {}
47 
48 
49  /// Returns the container data source that this schema is interpreting.
50  HD_API
51  HdContainerDataSourceHandle GetContainer();
52  HD_API
53  bool IsDefined() const;
54 
55  /// Returns \c true if this schema is applied on top of a non-null
56  /// container.
57  explicit operator bool() const { return IsDefined(); }
58 
59 
60 protected:
61  HdContainerDataSourceHandle _container;
62 
63  /// Returns a datasource of the requested type for the given name:
64  /// schema implementations can use this to ask for child containers,
65  /// sampled values, vectors, etc. If the key has the wrong type, this
66  /// function returns null.
67  template <typename T>
69  return _container ? T::Cast(
70  _container->Get(name)) : nullptr;
71  }
72 };
73 
75 
76 #endif
T::Handle _GetTypedDataSource(TfToken name)
Definition: schema.h:68
HD_API bool IsDefined() const
#define HD_API
Definition: api.h:40
GLuint const GLchar * name
Definition: glcorearb.h:786
Definition: token.h:87
HD_API HdContainerDataSourceHandle GetContainer()
Returns the container data source that this schema is interpreting.
HdContainerDataSourceHandle _container
Definition: schema.h:61
HdSchema(HdContainerDataSourceHandle container)
Definition: schema.h:45
PXR_NAMESPACE_CLOSE_SCOPE PXR_NAMESPACE_OPEN_SCOPE
Definition: path.h:1394
#define PXR_NAMESPACE_CLOSE_SCOPE
Definition: pxr.h:91
void * Handle
Definition: plugin.h:27