The OpenXR Specification Copyright (c) 2017-2021, The Khronos Group Inc. Version 1.0.19, Tue, 24 Aug 2021 16:39:15 +0000: from git ref release-1.0.19 commit: 808fdcd5fbf02c9f4b801126489b73d902495ad9 Table of Contents 1. Introduction . 2 1.1. What is OpenXR?. 2 1.2. The Programmer’s View of OpenXR. 2 1.3. The Implementor’s View of OpenXR . 2 1.4. Our View of OpenXR. 3 1.5. Filing Bug Reports. 3 1.6. Document Conventions . 3 2. Fundamentals . 5 2.1. API Version Numbers and Semantics. 5 2.2. String Encoding . 7 2.3. Threading Behavior . 7 2.4. Multiprocessing Behavior . 8 2.5. Runtime . 8 2.6. Extensions. 9 2.7. API Layers. 9 2.8. Return Codes . 16 2.9. Handles . 23 2.10. Object Handle Types . 24 2.11. Buffer Size Parameters . 25 2.12. Time . 27 2.13. Duration . 28 2.14. Prediction Time Limits . 29 2.15. Colors. 29 2.16. Coordinate System . 30 2.17. Common Object Types. 33 2.18. Angles . 36 2.19. Boolean Values . 37 2.20. Events . 37 2.21. System resource lifetime. 42 3. API Initialization. 43 3.1. Exported Functions . 43 3.2. Function Pointers . 43 4. Instance. 47 4.1. API Layers and Extensions . 47 4.2. Instance Lifecycle . 53 4.3. Instance Information . 58 4.4. Platform-Specific Instance Creation. 60 4.5. Instance Enumerated Type String Functions. 61 5. System . 64 5.1. Form Factors . 64 5.2. Getting the XrSystemId . 65 5.3. System Properties . 68 6. Path Tree and Semantic Paths. 72 6.1. Path Atom Type . 72 6.2. Well-Formed Path Strings . 74 6.3. Reserved Paths . 77 6.4. Interaction Profile Paths . 82 7. Spaces . ..