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reference.h
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1 //
2 // Copyright 2016 Pixar
3 //
4 // Licensed under the Apache License, Version 2.0 (the "Apache License")
5 // with the following modification; you may not use this file except in
6 // compliance with the Apache License and the following modification to it:
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24 #ifndef PXR_USD_SDF_REFERENCE_H
25 #define PXR_USD_SDF_REFERENCE_H
26 
27 /// \file sdf/reference.h
28 
29 #include "pxr/pxr.h"
30 #include "pxr/usd/sdf/api.h"
31 #include "pxr/usd/sdf/assetPath.h"
33 #include "pxr/usd/sdf/path.h"
34 #include "pxr/base/vt/dictionary.h"
35 #include "pxr/base/vt/value.h"
36 
37 #include <hboost/operators.hpp>
38 
39 #include <iosfwd>
40 #include <string>
41 #include <vector>
42 
44 
46 
47 typedef std::vector<SdfReference> SdfReferenceVector;
48 
49 /// \class SdfReference
50 ///
51 /// Represents a reference and all its meta data.
52 ///
53 /// A reference is expressed on a prim in a given layer and it identifies a
54 /// prim in a layer stack. All opinions in the namespace hierarchy
55 /// under the referenced prim will be composed with the opinions in the
56 /// namespace hierarchy under the referencing prim.
57 ///
58 /// The asset path specifies the layer stack being referenced. If this
59 /// asset path is non-empty, this reference is considered an 'external'
60 /// reference to the layer stack rooted at the specified layer. If this
61 /// is empty, this reference is considered an 'internal' reference to the
62 /// layer stack containing (but not necessarily rooted at) the layer where
63 /// the reference is authored.
64 ///
65 /// The prim path specifies the prim in the referenced layer stack from
66 /// which opinions will be composed. If this prim path is empty, it will
67 /// be considered a reference to the default prim specified in the root layer
68 /// of the referenced layer stack -- see SdfLayer::GetDefaultPrim.
69 ///
70 /// The meta data for a reference is its layer offset and custom data. The
71 /// layer offset is an affine transformation applied to all anim splines in
72 /// the referenced prim's namespace hierarchy, see SdfLayerOffset for details.
73 /// Custom data is for use by plugins or other non-tools supplied extensions
74 /// that need to be able to store data associated with references.
75 ///
76 class SdfReference : hboost::totally_ordered<SdfReference> {
77 public:
78  /// Creates a reference with all its meta data. The default reference is an
79  /// internal reference to the default prim. See SdfAssetPath for what
80  /// characters are valid in \p assetPath. If \p assetPath contains invalid
81  /// characters, issue an error and set this reference's asset path to the
82  /// empty asset path.
83  ///
85  const std::string &assetPath = std::string(),
86  const SdfPath &primPath = SdfPath(),
87  const SdfLayerOffset &layerOffset = SdfLayerOffset(),
88  const VtDictionary &customData = VtDictionary());
89 
90  /// Returns the asset path to the root layer of the referenced layer
91  /// stack. This will be empty in the case of an internal reference.
92  ///
93  const std::string &GetAssetPath() const {
94  return _assetPath;
95  }
96 
97  /// Sets the asset path for the root layer of the referenced layer stack.
98  /// This may be set to an empty string to specify an internal reference.
99  /// See SdfAssetPath for what characters are valid in \p assetPath. If \p
100  /// assetPath contains invalid characters, issue an error and set this
101  /// reference's asset path to the empty asset path.
102  void SetAssetPath(const std::string &assetPath) {
103  // Go through SdfAssetPath() to raise an error if \p assetPath contains
104  // illegal characters (i.e. control characters).
105  _assetPath = SdfAssetPath(assetPath).GetAssetPath();
106  }
107 
108  /// Returns the path of the referenced prim.
109  /// This will be empty if the referenced prim is the default prim specified
110  /// in the referenced layer stack.
111  ///
112  const SdfPath &GetPrimPath() const {
113  return _primPath;
114  }
115 
116  /// Sets the path of the referenced prim.
117  /// This may be set to an empty path to specify a reference to the default
118  /// prim in the referenced layer stack.
119  ///
120  void SetPrimPath(const SdfPath &primPath) {
121  _primPath = primPath;
122  }
123 
124  /// Returns the layer offset associated with the reference.
125  ///
127  return _layerOffset;
128  }
129 
130  /// Sets a new layer offset.
131  ///
132  void SetLayerOffset(const SdfLayerOffset &layerOffset) {
133  _layerOffset = layerOffset;
134  }
135 
136  /// Returns the custom data associated with the reference.
137  ///
138  const VtDictionary &GetCustomData() const {
139  return _customData;
140  }
141 
142  /// Sets the custom data associated with the reference.
143  ///
144  void SetCustomData(const VtDictionary &customData) {
145  _customData = customData;
146  }
147 
148  /// Sets a custom data entry for the reference.
149  ///
150  /// If \a value is empty, then this removes the given custom data entry.
151  ///
152  SDF_API void SetCustomData(const std::string &name, const VtValue &value);
153 
154  /// Swaps the custom data dictionary for this reference.
155  void SwapCustomData(VtDictionary &customData) {
156  _customData.swap(customData);
157  }
158 
159  /// Returns \c true in the case of an internal reference.
160  ///
161  /// An internal reference is a reference with an empty asset path.
162  ///
163  SDF_API bool IsInternal() const;
164 
165  friend inline size_t hash_value(const SdfReference &r) {
166  size_t h = 0;
167  hboost::hash_combine(h, r._assetPath);
168  hboost::hash_combine(h, r._primPath);
169  hboost::hash_combine(h, r._layerOffset);
170  hboost::hash_combine(h, r._customData);
171  return h;
172  }
173 
174  /// Returns whether this reference equals \a rhs.
175  SDF_API bool operator==(const SdfReference &rhs) const;
176 
177  /// Returns whether this reference is less than \a rhs. The meaning
178  /// of less than is somewhat arbitrary.
179  SDF_API bool operator<(const SdfReference &rhs) const;
180 
181  /// Struct that defines equality of SdfReferences based on their
182  /// identity (the asset path and prim path).
183  ///
184  struct IdentityEqual {
185  bool operator()(const SdfReference &lhs, const SdfReference &rhs) const {
186  return lhs._assetPath == rhs._assetPath &&
187  lhs._primPath == rhs._primPath;
188  }
189  };
190 
191  /// Struct that defines a strict weak ordering of SdfReferences based on
192  /// their identity (the asset path and prim path).
193  ///
195  bool operator()(const SdfReference &lhs, const SdfReference &rhs) const {
196  return lhs._assetPath < rhs._assetPath ||
197  (lhs._assetPath == rhs._assetPath &&
198  lhs._primPath < rhs._primPath);
199  }
200  };
201 
202 private:
203  // The asset path to the external layer.
204  std::string _assetPath;
205 
206  // The path to the referenced prim in the external layer.
207  SdfPath _primPath;
208 
209  // The layer offset to transform time.
210  SdfLayerOffset _layerOffset;
211 
212  // The custom data associated with the reference.
213  VtDictionary _customData;
214 };
215 
216 /// Convenience function to find the index of the reference in \a references
217 /// that has the same identity as the given reference \a referenceId.
218 ///
219 /// A reference's identity is given by its asset path and prim path alone
220 /// (i.e. the layer offset and custom data is ignored).
221 ///
222 /// If no reference with the same identity exists in \a reference, -1 is
223 /// returned. If more than one reference with the same identity exist in
224 /// \a references the index of the first one is returned.
225 ///
227  const SdfReferenceVector &references,
228  const SdfReference &referenceId);
229 
230 /// Writes the string representation of \a SdfReference to \a out.
231 SDF_API std::ostream & operator<<( std::ostream &out,
232  const SdfReference &reference );
233 
235 
236 #endif // PXR_USD_SDF_REFERENCE_H
const VtDictionary & GetCustomData() const
Definition: reference.h:138
bool operator()(const SdfReference &lhs, const SdfReference &rhs) const
Definition: reference.h:195
SDF_API std::ostream & operator<<(std::ostream &out, const SdfReference &reference)
Writes the string representation of SdfReference to out.
SDF_API bool IsInternal() const
void SetPrimPath(const SdfPath &primPath)
Definition: reference.h:120
GLenum const void GLuint GLint reference
Definition: glew.h:13927
GLuint const GLchar * name
Definition: glcorearb.h:786
const std::string & GetAssetPath() const
Definition: reference.h:93
bool operator()(const SdfReference &lhs, const SdfReference &rhs) const
Definition: reference.h:185
void SetAssetPath(const std::string &assetPath)
Definition: reference.h:102
void SetLayerOffset(const SdfLayerOffset &layerOffset)
Definition: reference.h:132
GLsizei const GLchar *const * string
Definition: glcorearb.h:814
Definition: path.h:290
friend size_t hash_value(const SdfReference &r)
Definition: reference.h:165
SDF_API SdfReference(const std::string &assetPath=std::string(), const SdfPath &primPath=SdfPath(), const SdfLayerOffset &layerOffset=SdfLayerOffset(), const VtDictionary &customData=VtDictionary())
#define SDF_API
Definition: api.h:40
GLfloat GLfloat GLfloat GLfloat h
Definition: glcorearb.h:2002
std::vector< SdfReference > SdfReferenceVector
Definition: reference.h:45
PXR_NAMESPACE_CLOSE_SCOPE PXR_NAMESPACE_OPEN_SCOPE
Definition: path.h:1394
const SdfPath & GetPrimPath() const
Definition: reference.h:112
SDF_API bool operator<(const SdfReference &rhs) const
const SdfLayerOffset & GetLayerOffset() const
Definition: reference.h:126
void SetCustomData(const VtDictionary &customData)
Definition: reference.h:144
const std::string & GetAssetPath() const
Return the asset path.
Definition: assetPath.h:111
#define PXR_NAMESPACE_CLOSE_SCOPE
Definition: pxr.h:91
SDF_API bool operator==(const SdfReference &rhs) const
Returns whether this reference equals rhs.
Definition: core.h:1131
SDF_API int SdfFindReferenceByIdentity(const SdfReferenceVector &references, const SdfReference &referenceId)
VT_API void swap(VtDictionary &dict)
Swaps the contents of two VtDictionaries.
GLboolean r
Definition: glcorearb.h:1222
Definition: value.h:166
void SwapCustomData(VtDictionary &customData)
Swaps the custom data dictionary for this reference.
Definition: reference.h:155