1Name 2 3 ANGLE_request_extension 4 5Name Strings 6 7 GL_ANGLE_request_extension 8 9Contributors 10 11 Geoff Lang 12 James Darpinian 13 14Contact 15 16 Geoff Lang (geofflang 'at' google.com) 17 18Notice 19 20 Copyright (c) 2016 The Khronos Group Inc. Copyright terms at 21 http://www.khronos.org/registry/speccopyright.html 22 23Status 24 25 Draft 26 27Version 28 29 Version 2, October 4, 2019 30 31Number 32 33 OpenGL ES Extension #?? 34 35Dependencies 36 37 Requires OpenGL ES 2.0 38 39 Written against the OpenGL ES 3.0 specification. 40 41Overview 42 43 This extension allows the client to query extensions that can be enabled and 44 explicitly request that an extension be enabled or disabled. 45 46New Procedures and Functions 47 48 void RequestExtension(const char *name) 49 50 void DisableExtension(const char *name) 51 52New Tokens 53 54 Accepted by the <name> parameter of GetString and GetStringi: 55 56 REQUESTABLE_EXTENSIONS_ANGLE 0x93A8 57 58 Accepted by the <value> parameter of the GetInteger* functions: 59 60 NUM_REQUESTABLE_EXTENSIONS_ANGLE 0x93A9 61 62Additions to the OpenGL ES 3.0 Specification 63 64 Add the following paragraph to the end paragraph 4 of section 6.1.6, String 65 Queries: 66 67 "REQUESTABLE_EXTENSIONS_ANGLE returns a list of extensions that can be 68 enabled at runtime by calling RequestExtension." 69 70 Change the following section of paragraph 6 of section 6.1.6, String Queries: 71 72 - "name may only be EXTENSIONS, indicating that the extension name 73 - corresponding to the indexth supported extension should be returned. 74 - <index> may range from zero to the value of NUM_EXTENSIONS minus one" 75 + "name may be EXTENSIONS or REQUESTABLE_EXTENSIONS_ANGLE, indicating that 76 + the extension name corresponding to the indexth supported or requestable 77 + extension should be returned. <index> may range from zero to the value of 78 + NUM_EXTENSIONS and NUM_REQUESTABLE_EXTENSIONS_ANGLE minus one" 79 80 The commands 81 82 void RequestExtension(const char *name) 83 void DisableExtension(const char *name) 84 85 enable or disable the requestable OpenGL ES extension named <name>. If the 86 requested extension was not requestable or disablable, INVALID_OPERATION is 87 generated. Not all requestable extensions can be disabled. There is 88 currently no query for disablable extensions. This operation is not thread 89 safe, and the application is responsible for ensuring no other context in 90 the share group is accessed by another thread during this operation. 91 92New State 93 94 Add to Table 6.30 (Implementation Dependent Version and Extension Support) 95 96 Get value Type Get Cmd Min Value Description Sec. 97 -------------------------------- ---- ----------- --------- -------------------------------- ----- 98 NUM_REQUESTABLE_EXTENSIONS_ANGLE Z+ GetIntegerv - Number of individual requestable 6.1.6 99 extension names 100 101Interactions with the OpenGL ES 2.0 specification: 102 103 Remove all references to GetStringi and NUM_REQUESTABLE_EXTENSIONS_ANGLE. 104 105Issues 106 107 (1) How can the user determine which extensions can be enabled without 108 potentially generating errors? 109 110 This can be solved by: 111 a) Never generate an error in EnableExtensions, simply return false when 112 the extension is not recognized or cannot be enabled. 113 b) Add another query for the extensions that the context supports 114 enabling. 115 116 RESOLVED: Use (b) because it allows the context to explicity advertise 117 which extensions support enabling and doesn't generate errors in the 118 normal use case. 119 120Revision History 121 122 Rev. Date Author Changes 123 ---- ------------- --------- ---------------------------------------- 124 1 Nov 28, 2016 geofflang Initial version 125 2 Oct 4, 2019 jdarpinian Add DisableExtension 126