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 6 // compliance with the Apache License and the following modification to it: 7 // Section 6. Trademarks. is deleted and replaced with: 8 // 9 // 6. Trademarks. This License does not grant permission to use the trade 10 // names, trademarks, service marks, or product names of the Licensor 11 // and its affiliates, except as required to comply with Section 4(c) of 12 // the License and to reproduce the content of the NOTICE file. 13 // 14 // You may obtain a copy of the Apache License at 15 // 16 // http://www.apache.org/licenses/LICENSE-2.0 17 // 18 // Unless required by applicable law or agreed to in writing, software 19 // distributed under the Apache License with the above modification is 20 // distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 21 // KIND, either express or implied. See the Apache License for the specific 22 // language governing permissions and limitations under the Apache License. 23 // 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 32 PXR_NAMESPACE_OPEN_SCOPE 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 /// 58 class GlfContextCaps 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 76 77 // GL version 78 int glVersion; // 400 (4.0), 410 (4.1), ... 79 80 // Whether or not we are running with core profile 81 bool coreProfile; 82 83 // Max constants 84 int maxArrayTextureLayers; 85 int maxUniformBlockSize; 86 int maxShaderStorageBlockSize; 87 int maxTextureBufferSize; 88 int uniformBufferOffsetAlignment; 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 107 bool copyBufferEnabled; 108 109 bool floatingPointBuffersEnabled; 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; 119 120 friend class TfSingleton<GlfContextCaps>; 121 }; 122 123 GLF_API_TEMPLATE_CLASS(TfSingleton<GlfContextCaps>); 124 125 PXR_NAMESPACE_CLOSE_SCOPE 126 127 #endif // PXR_IMAGING_GLF_CONTEXT_CAPS_H 128 129