The OpenXR Specification Copyright (c) 2017-2019 The Khronos Group Inc. Version 1.0.5, Sat, 07 Dec 2019 04:08:43 +0000 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. 8 2.7. API Layers. 9 2.8. Return Codes . 16 2.9. Handles . 22 2.10. Object Handle Types . 22 2.11. Buffer Size Parameters . 23 2.12. Time . 25 2.13. Duration . 26 2.14. Colors. 27 2.15. Coordinate System . 28 2.16. Common Object Types. 31 2.17. Angles . 34 2.18. Prediction Time Limits . 35 2.19. Boolean Values . 35 2.20. Events . 35 3. API Initialization. 41 3.1. Exported Functions . 41 3.2. Function Pointers . 41 4. Instance. 45 4.1. API Layers and Extensions . 45 4.2. Instance Lifecycle . 51 4.3. Instance Information . 55 4.4. Platform-Specific Instance Creation. 57 4.5. Instance Enumerated Type String Functions. 58 5. System . 62 5.1. Form Factors . 62 5.2. Getting the XrSystemId . 63 5.3. System Properties . 66 6. Path Tree and Semantic Paths. 69 6.1. Path Atom Type . 69 6.2. Well-Formed Path Strings . 71 6.3. Reserved Paths . 74 6.4. Interaction Profile Paths . 79 7. Spaces . 86 7.1. Reference Spaces. ..