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contextCaps.h
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1 //
2 // Copyright 2018 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
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24 #ifndef PXR_IMAGING_GLF_CONTEXT_CAPS_H
25 #define PXR_IMAGING_GLF_CONTEXT_CAPS_H
26 
27 #include "pxr/pxr.h"
28 #include "pxr/imaging/glf/api.h"
29 #include "pxr/base/tf/singleton.h"
30 
31 
33 
34 
35 /// \class GlfContextCaps
36 ///
37 /// This class is intended to be a cache of the capabilites
38 /// (resource limits and features) of the underlying
39 /// GL context.
40 ///
41 /// It serves two purposes. Firstly to reduce driver
42 /// transition overhead of querying these values.
43 /// Secondly to provide access to these values from other
44 /// threads that don't have the context bound.
45 ///
46 /// In the event of failure (InitInstance() wasn't called
47 /// or an issue accessing the GL context), a reasonable
48 /// set of defaults, based on GL minimums, is provided.
49 ///
50 ///
51 /// TO DO (bug #124971):
52 /// - LoadCaps() should be called whenever the context
53 /// changes.
54 /// - Provide a mechanism where other Hd systems can
55 /// subscribe to when the caps changes, so they can
56 /// update and invalidate.
57 ///
59 {
60 public:
61 
62  /// InitInstance queries the GL context for its capabilities.
63  /// It should be called by the application before using systems
64  /// that depend on the caps, such as Hydra. A good example would be
65  /// to pair the call to initialize after a call to initialize GL
66  GLF_API
67  static void InitInstance();
68 
69  /// GetInstance() returns the filled capabilities structure.
70  /// This function will not populate the caps and will issue a
71  /// coding error if it hasn't been filled.
72  GLF_API
73  static const GlfContextCaps &GetInstance();
74 
75  // GL version
76  int glVersion; // 400 (4.0), 410 (4.1), ...
77 
78  // Whether or not we are running with core profile
80 
81  // Max constants
83 
84 private:
85  void _LoadCaps();
87  ~GlfContextCaps() = default;
88 
89  // Disallow copies
90  GlfContextCaps(const GlfContextCaps&) = delete;
91  GlfContextCaps& operator=(const GlfContextCaps&) = delete;
92 
93  friend class TfSingleton<GlfContextCaps>;
94 };
95 
97 
99 
100 #endif // PXR_IMAGING_GLF_CONTEXT_CAPS_H
101 
static GLF_API const GlfContextCaps & GetInstance()
#define GLF_API
Definition: api.h:40
static GLF_API void InitInstance()
GLF_API_TEMPLATE_CLASS(TfSingleton< GlfContextCaps >)
PXR_NAMESPACE_CLOSE_SCOPE PXR_NAMESPACE_OPEN_SCOPE
Definition: path.h:1441
#define PXR_NAMESPACE_CLOSE_SCOPE
Definition: pxr.h:91
int maxArrayTextureLayers
Definition: contextCaps.h:82