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contextCaps.h
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1 //
2 // Copyright 2018 Pixar
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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 GlfGlewInit().
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 
76 
77  // GL version
78  int glVersion; // 400 (4.0), 410 (4.1), ...
79 
80  // Whether or not we are running with core profile
82 
83  // Max constants
89 
90  // GL extensions (ordered by version)
91  bool arrayTexturesEnabled; // EXT_texture_array (3.0)
92  bool shaderStorageBufferEnabled; // ARB_shader_storage_buffer_object (4.3)
93  bool bufferStorageEnabled; // ARB_buffer_storage (4.4)
94  bool directStateAccessEnabled; // ARB_direct_state_access (4.5)
95  bool multiDrawIndirectEnabled; // ARB_multi_draw_indirect (4.5)
96 
97  bool bindlessTextureEnabled; // ARB_bindless_texture
98  bool bindlessBufferEnabled; // NV_shader_buffer_load
99 
100  // GLSL version and extensions
101  int glslVersion; // 400, 410, ...
102  bool explicitUniformLocation; // ARB_explicit_uniform_location (4.3)
103  bool shadingLanguage420pack; // ARB_shading_language_420pack (4.2)
104  bool shaderDrawParametersEnabled; // ARB_shader_draw_parameters (4.5)
105 
106  // workarounds for driver issues
108 
110 
111 private:
112  void _LoadCaps();
113  GlfContextCaps();
114  ~GlfContextCaps() = default;
115 
116  // Disallow copies
117  GlfContextCaps(const GlfContextCaps&) = delete;
118  GlfContextCaps& operator=(const GlfContextCaps&) = delete;
119 
121 };
122 
124 
126 
127 #endif // PXR_IMAGING_GLF_CONTEXT_CAPS_H
128 
bool directStateAccessEnabled
Definition: contextCaps.h:94
bool shadingLanguage420pack
Definition: contextCaps.h:103
int uniformBufferOffsetAlignment
Definition: contextCaps.h:88
static GLF_API const GlfContextCaps & GetInstance()
int maxTextureBufferSize
Definition: contextCaps.h:87
#define GLF_API
Definition: api.h:40
bool multiDrawIndirectEnabled
Definition: contextCaps.h:95
bool shaderStorageBufferEnabled
Definition: contextCaps.h:92
bool bindlessBufferEnabled
Definition: contextCaps.h:98
static GLF_API void InitInstance()
int maxUniformBlockSize
Definition: contextCaps.h:85
bool floatingPointBuffersEnabled
Definition: contextCaps.h:109
bool explicitUniformLocation
Definition: contextCaps.h:102
bool arrayTexturesEnabled
Definition: contextCaps.h:91
GLF_API_TEMPLATE_CLASS(TfSingleton< GlfContextCaps >)
bool copyBufferEnabled
Definition: contextCaps.h:107
bool bindlessTextureEnabled
Definition: contextCaps.h:97
bool bufferStorageEnabled
Definition: contextCaps.h:93
PXR_NAMESPACE_CLOSE_SCOPE PXR_NAMESPACE_OPEN_SCOPE
Definition: path.h:1346
int maxShaderStorageBlockSize
Definition: contextCaps.h:86
#define PXR_NAMESPACE_CLOSE_SCOPE
Definition: pxr.h:91
int maxArrayTextureLayers
Definition: contextCaps.h:84
bool shaderDrawParametersEnabled
Definition: contextCaps.h:104