| Name |
| |
| WGL_ARB_create_context |
| WGL_ARB_create_context_profile |
| |
| Name Strings |
| |
| WGL_ARB_create_context |
| WGL_ARB_create_context_profile |
| |
| Contact |
| |
| Jon Leech (jon 'at' alumni.caltech.edu) |
| Michael Gold, NVIDIA (gold 'at' nvidia.com) |
| |
| Notice |
| |
| Copyright (c) 2009-2013 The Khronos Group Inc. Copyright terms at |
| http://www.khronos.org/registry/speccopyright.html |
| |
| Specification Update Policy |
| |
| Khronos-approved extension specifications are updated in response to |
| issues and bugs prioritized by the Khronos OpenGL Working Group. For |
| extensions which have been promoted to a core Specification, fixes will |
| first appear in the latest version of that core Specification, and will |
| eventually be backported to the extension document. This policy is |
| described in more detail at |
| https://www.khronos.org/registry/OpenGL/docs/update_policy.php |
| |
| IP Status |
| |
| No known IP claims. |
| |
| Status |
| |
| Complete. Approved by the ARB on July 28, 2009. |
| Approved by the Khronos Board of Promoters on August 28, 2009. |
| |
| Version |
| |
| July 28, 2009 (version 20) |
| |
| Number |
| |
| ARB Extension #55 (WGL_ARB_create_context) |
| ARB Extension #74 (WGL_ARB_create_context_profile) |
| |
| Dependencies |
| |
| WGL_ARB_extensions_string is required. |
| |
| The presence of an OpenGL 3.2 or later implementation determines |
| whether or not WGL_ARB_create_context_profile is required. |
| |
| Overview |
| |
| With the advent of new versions of OpenGL which deprecate features |
| and/or break backward compatibility with older versions, there is a |
| need and desire to indicate at context creation which interface will |
| be used. These extensions add a new context creation routine with |
| attributes specifying the GL version and context properties |
| requested for the context, and additionally add an attribute |
| specifying the GL profile requested for a context of OpenGL 3.2 or |
| later. |
| |
| New Procedures and Functions |
| |
| HGLRC wglCreateContextAttribsARB(HDC hDC, HGLRC hShareContext, |
| const int *attribList) |
| |
| New Tokens |
| |
| Accepted as an attribute name in <*attribList>: |
| |
| WGL_CONTEXT_MAJOR_VERSION_ARB 0x2091 |
| WGL_CONTEXT_MINOR_VERSION_ARB 0x2092 |
| WGL_CONTEXT_LAYER_PLANE_ARB 0x2093 |
| WGL_CONTEXT_FLAGS_ARB 0x2094 |
| WGL_CONTEXT_PROFILE_MASK_ARB 0x9126 |
| |
| Accepted as bits in the attribute value for WGL_CONTEXT_FLAGS in |
| <*attribList>: |
| |
| WGL_CONTEXT_DEBUG_BIT_ARB 0x0001 |
| WGL_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB 0x0002 |
| |
| Accepted as bits in the attribute value for |
| WGL_CONTEXT_PROFILE_MASK_ARB in <*attribList>: |
| |
| WGL_CONTEXT_CORE_PROFILE_BIT_ARB 0x00000001 |
| WGL_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB 0x00000002 |
| |
| New errors returned by GetLastError: |
| |
| ERROR_INVALID_VERSION_ARB 0x2095 |
| ERROR_INVALID_PROFILE_ARB 0x2096 |
| |
| Additions to the OpenGL / GLX / GLX Protocol Specificaitons |
| |
| None. This specification is written for WGL. |
| |
| Additions to the WGL specification |
| |
| Context Creation |
| ---------------- |
| |
| To create an OpenGL rendering context, call |
| |
| HGLRC wglCreateContextAttribsARB(HDC hDC, HGLRC hshareContext, |
| const int *attribList); |
| |
| If wglCreateContextAttribsARB succeeds, it initializes the context |
| to the initial state defined by the OpenGL specification, and |
| returns a handle to it. The handle can be used (via wglMakeCurrent |
| or wglMakeContextCurrentARB) with any HDC sharing the same pixel |
| format as <hDC>, and created on the same device, subject to |
| constraints imposed by the API version. |
| |
| If <hshareContext> is not 0, then all shareable data (excluding |
| OpenGL texture objects named 0) will be shared by <hshareContext>, |
| all other contexts <hshareContext> already shares with, and the |
| newly created context. An arbitrary number of contexts can share |
| data in this fashion. |
| |
| <attribList> specifies a list of attributes for the context. The |
| list consists of a sequence of <name,value> pairs terminated by the |
| value 0. If an attribute is not specified in <attribList>, then the |
| default value specified below is used instead. If an attribute is |
| specified more than once, then the last value specified is used. |
| |
| <attribList> may be NULL or empty (first attribute is 0), in which |
| case all attributes assume their default values as described below. |
| |
| The attribute names WGL_CONTEXT_MAJOR_VERSION_ARB and |
| WGL_CONTEXT_MINOR_VERSION_ARB request an OpenGL context supporting |
| the specified version of the API. If successful, the context |
| returned must be backwards compatible with the context requested. |
| Backwards compatibility is determined as follows: |
| |
| If a version less than or equal to 3.0 is requested, the context |
| returned may implement any of the following versions: |
| |
| * Any version no less than that requested and no greater than 3.0. |
| * Version 3.1, if the GL_ARB_compatibility extension is also |
| implemented. |
| * The compatibility profile of version 3.2 or greater. |
| |
| If version 3.1 is requested, the context returned may implement |
| any of the following versions: |
| |
| * Version 3.1. The GL_ARB_compatibility extension may or may not |
| be implemented, as determined by the implementation. |
| * The core profile of version 3.2 or greater. |
| |
| If version 3.2 or greater is requested, the context returned may |
| implement any of the following versions: |
| |
| * The requested profile of the requested version. |
| * The requested profile of any later version, so long as no |
| features have been removed from that later version and profile. |
| |
| Querying the GL_VERSION string with glGetString (or the |
| GL_MAJOR_VERSION and GL_MINOR_VERSION values with glGetIntegerv, in |
| a 3.0 or later context) will return the actual version supported by |
| a context. |
| |
| The default values for WGL_CONTEXT_MAJOR_VERSION_ARB and |
| WGL_CONTEXT_MINOR_VERSION_ARB are 1 and 0 respectively. In this |
| case, implementations will typically return the most recent version |
| of OpenGL they support which is backwards compatible with OpenGL 1.0 |
| (e.g. 3.0, 3.1 + GL_ARB_compatibility, or 3.2 compatibility profile) |
| |
| The attribute name WGL_CONTEXT_PROFILE_MASK_ARB requests an OpenGL |
| context supporting a specific <profile> of the API. If the |
| WGL_CONTEXT_CORE_PROFILE_BIT_ARB bit is set in the attribute value, |
| then a context implementing the <core> profile of OpenGL is |
| returned. If the WGL_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB bit is |
| set, then a context implementing the <compatibility> profile is |
| returned. If the requested OpenGL version is less than 3.2, |
| WGL_CONTEXT_PROFILE_MASK_ARB is ignored and the functionality of the |
| context is determined solely by the requested version. |
| |
| Querying the value of GL_CONTEXT_PROFILE_MASK with glGetIntegerv |
| will return the profile mask used to create the context. This query |
| is only supported in an OpenGL 3.2 or later context. |
| |
| The default value for WGL_CONTEXT_PROFILE_MASK_ARB is |
| WGL_CONTEXT_CORE_PROFILE_BIT_ARB. All OpenGL 3.2 implementations are |
| required to implement the core profile, but implementation of the |
| compatibility profile is optional. |
| |
| If the core profile is requested, then the context returned cannot |
| implement functionality defined only by the compatibility profile. |
| |
| The attribute name WGL_CONTEXT_LAYER_PLANE specifies the layer plane |
| that the rendering context is bound to. The attribute value has the |
| same meaning and allowed values as the <iLayerPlane> parameter of |
| wglCreateLayerContext. The default value for WGL_CONTEXT_LAYER_PLANE |
| is 0 (the main plane). |
| |
| The attribute name WGL_CONTEXT_FLAGS_ARB specifies a set of flag |
| bits affecting the rendering context. |
| |
| If the WGL_CONTEXT_DEBUG_BIT_ARB flag bit is set in |
| WGL_CONTEXT_FLAGS_ARB, then a <debug context> will be created. Debug |
| contexts are intended for use during application development, and |
| provide additional runtime checking, validation, and logging |
| functionality while possibly incurring performance penalties. The |
| additional functionality provided by debug contexts may vary |
| according to the implementation(fn). In some cases a debug context |
| may be identical to a non-debug context. |
| [fn: The ARB Ecosystem TSG is still defining the expected and |
| required features of debug contexts.] |
| |
| If the WGL_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB is set in |
| WGL_CONTEXT_FLAGS_ARB, then a <forward-compatible> context will be |
| created. Forward-compatible contexts are defined only for OpenGL |
| versions 3.0 and later. They must not support functionality marked |
| as <deprecated> by that version of the API, while a |
| non-forward-compatible context must support all functionality in |
| that version, deprecated or not. |
| |
| The default value of WGL_CONTEXT_FLAGS_ARB is 0. |
| |
| On failure wglCreateContextAttribsARB returns NULL. Extended error |
| information can be obtained with GetLastError. Conditions that cause |
| failure include: |
| |
| * If attributes WGL_CONTEXT_MAJOR_VERSION_ARB and |
| WGL_CONTEXT_MINOR_VERSION_ARB, when considered together with |
| WGL_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB, specify an OpenGL version |
| and feature set that are not defined, then ERROR_INVALID_VERSION_ARB |
| is generated. |
| |
| The defined versions of OpenGL at the time of writing are OpenGL |
| 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 2.0, 2.1, 3.0, 3.1, and 3.2. Feature |
| deprecation was introduced with OpenGL 3.0, so forward-compatible |
| contexts may only be requested for OpenGL 3.0 and above. Thus, |
| examples of invalid combinations of attributes include: |
| |
| - Major version < 1 or > 3 |
| - Major version == 1 and minor version < 0 or > 5 |
| - Major version == 2 and minor version < 0 or > 1 |
| - Major version == 3 and minor version > 2 |
| - Forward-compatible flag set and major version < 3 |
| |
| Because the purpose of forward-compatible contexts is to allow |
| application development on a specific OpenGL version with the |
| knowledge that the app will run on a future version, context |
| creation will fail if WGL_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB is set |
| and the context version returned cannot implement exactly the |
| requested version. |
| |
| * If attribute WGL_CONTEXT_PROFILE_MASK_ARB has no bits set; has any |
| bits set other than WGL_CONTEXT_CORE_PROFILE_BIT_ARB and |
| WGL_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB; has more than one of |
| these bits set; or if the implementation does not supported the |
| requested profile, then ERROR_INVALID_PROFILE_ARB is generated. |
| |
| * If <hShareContext> is neither zero nor a valid context handle, then |
| ERROR_INVALID_OPERATION is generated. |
| |
| * If <hDC> is not a valid device context handle, then |
| ERROR_DC_NOT_FOUND is generated. |
| |
| * If the pixel format associated with <hDC> does not support OpenGL |
| contexts providing the requested API major and minor version, |
| forward-compatible flag, and/or debug context flag, then |
| ERROR_INVALID_PIXEL_FORMAT is generated. |
| |
| * If the OpenGL server context state for <hShareContext> exists in an |
| address space that cannot be shared with the newly created context, |
| if <shareContext> was created on a different device context than the |
| one referenced by <hDC>, or if the contexts are otherwise |
| incompatible (for example, one context being associated with a |
| hardware device driver and the other with a software renderer), then |
| ERROR_INVALID_OPERATION is generated. |
| |
| * If the server does not have enough resources to allocate the new |
| context, then ERROR_NO_SYSTEM_RESOURCES is generated. |
| |
| * If an unrecognized attribute is present in <attribList>, |
| then ERROR_INVALID_PARAMETER is generated. |
| |
| Legacy Context Creation |
| ----------------------- |
| |
| When this extension is supported, calling |
| |
| wglCreateContext(hdc) |
| |
| is equivalent to calling |
| |
| wglCreateContextAttribs(hdc,0,NULL). |
| |
| Calling |
| |
| wglCreateLayerContext(hdc,layer) |
| |
| is equivalent to calling |
| |
| wglCreateContextAttribs(hdc, 0, |
| { WGL_CONTEXT_LAYER_PLANE, layer, 0 }) . |
| |
| The legacy context creation routines can only return OpenGL 3.1 |
| contexts if the GL_ARB_compatibility extension is supported, and can |
| only return OpenGL 3.2 or greater contexts implementing the |
| compatibility profile. This ensures compatibility for existing |
| applications. However, 3.0-aware applications are encouraged to use |
| wglCreateContextAttribsARB instead of the legacy routines. |
| |
| Binding a Context to a Surface |
| ------------------------------ |
| |
| (add to the description of wglMakeCurrent and |
| wglMakeContextCurrentARB) |
| |
| "If the OpenGL context version of <hglrc> is 3.0 or above, and if |
| either the <hdc> parameter of wglMakeCurrent is NULL, or both of the |
| <hDrawDC> and <hReadDC> parameters of wglMakeContextCurrentARB are |
| NULL, then the context is made current, but with no default |
| framebuffer defined. The effects of having no default framebuffer on |
| the GL are defined in Chapter 4 of the OpenGL 3.0 Specification. |
| |
| The first time <ctx> is made current, the viewport and scissor |
| dimensions are set to the size of the draw drawable (as though |
| glViewport(0,0,w,h) and glScissor(0,0,w,h) were called, where <w> |
| and <h> are the width and height of the drawable, respectively). If |
| the first time <ctx> is made current, it is without a default |
| framebuffer, then the viewport and scissor regions are set as though |
| glViewport(0,0,0,0) and glScissor(0,0,0,0) were called." |
| However, the viewport and scissor dimensions are not modified when |
| <ctx> is subsequently made current; it is the client's |
| responsibility to reset the viewport and scissor in this case." |
| |
| Sharing Objects Between Contexts |
| -------------------------------- |
| |
| (add to the description of wglShareLists) |
| |
| Future versions of OpenGL may only support being added to a share |
| group at context creation time. Specifying such a version of a |
| context as either the <hglrc1> or <hglrc2> arguments to |
| wglShareLists will fail. wglShareLists will return FALSE, and |
| GetLastError will return ERROR_INCOMPATIBLE_DEVICE_CONTEXTS_ARB. |
| |
| Dependencies on WGL_ARB_extensions_string |
| |
| Because there is no way to extend wgl, these calls are defined in |
| the ICD and can be called by obtaining the address with |
| wglGetProcAddress. Because this extension is a WGL extension, it is |
| not included in the GL_EXTENSIONS string. Its existence can be |
| determined with the WGL_ARB_extensions_string extension. |
| |
| Dependencies on WGL_ARB_create_context |
| |
| If WGL_ARB_create_context_profile is supported, then |
| WGL_ARB_create_context must also be supported. |
| |
| Dependencies on OpenGL 3.2 and later OpenGL versions |
| |
| If WGL_ARB_create_context is supported, and if the OpenGL |
| implementation supports OpenGL 3.2 or later, then |
| WGL_ARB_create_context_profile must also be supported. If the OpenGL |
| implementation does not support OpenGL 3.2 or later, then |
| WGL_ARB_create_context_profile may or may not be supported. |
| |
| If WGL_ARB_create_context_profile is not supported, then the |
| WGL_CONTEXT_PROFILE_MASK_ARB attribute, the |
| WGL_CONTEXT_CORE_PROFILE_BIT_ARB and |
| WGL_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB bits in that attribute, |
| and the ERROR_INVALID_PROFILE_ARB error are not defined, and |
| specifying the attribute in <attribList> attribute will generate an |
| error. |
| |
| New State |
| |
| None |
| |
| New Implementation Dependent State |
| |
| None |
| |
| Conformance Tests |
| |
| TBD |
| |
| Sample Code |
| |
| TBD |
| |
| Issues |
| |
| 1) Can different GL context versions share data? |
| |
| PROPOSED: Yes, with restrictions as defined by the supported feature |
| sets. For example, program and shader objects cannot be shared with |
| OpenGL 1.x contexts, which do not support them. |
| |
| NOTE: When the new object model is introduced, sharing must be |
| established at creation time, since the object handle namespace is |
| also shared. wglShareLists would therefore fail if either context |
| parameter to it were to be a context supporting the new object |
| model. |
| |
| 2) Should we introduce a token WGL_NONE to terminate attribute lists, |
| instead of using the value 0, by analogy to GLX and EGL? |
| |
| RESOLVED: No. |
| |
| 3) Should all GL context versions be able to bind to all the same pixel |
| formats? |
| |
| RESOLVED: unlike EGL, we don't expose the version restriction in the |
| pixel format. Instead, wglMakeCurrent may fail when binding contexts |
| to surfaces if the surface type is unrecognized by that context |
| version. No specific examples exist at present, but in a |
| hypothetical future version of the API supporting only the new |
| object model, such an API probably could not bind to pbuffer |
| surfaces. |
| |
| 4) Should there be a way to make a context current without binding |
| it to a window system drawable at the same time? |
| |
| RESOLVED: Yes, but only in OpenGL 3.0 and later. This results in a |
| context with an invalid default framebuffer, the meaning of which is |
| defined in the OpenGL 3.0 specification. |
| |
| NOTE: Apparently on Windows, opengl32.dll makes use of the drawable |
| argument to identify the namespace of the driver, so we may not be |
| able to work around it. |
| |
| 5) Should we add a token to the attrib list for pixel format selection |
| to indicate the GL context version, instead of introducing a new |
| entry point for context creation? |
| |
| RESOLVED: No. We want pixel formats to be portable between |
| feature-incompatible context versions, so that drawables and GL |
| objects that make sense to share, may be shared between such |
| contexts. This is important for code migration and backward |
| compatibility. |
| |
| 6) Do we need a "can be shared" parameter at context creation time? |
| |
| RESOLVED: No. All contexts have potential to share objects (whether |
| they actually can share depends on context version and feature sets, |
| and the address space they're created in). Savings from saying a |
| context cannot share objects are unclear but probably minimal. Such |
| a parameter would default to TRUE if it existed. |
| |
| 7) How are "debug contexts" created? |
| |
| RESOLVED: by specifying the WGL_CONTEXT_DEBUG_BIT_ARB flag in the |
| WGL_CONTEXT_FLAGS_ARB attribute value. |
| |
| DISCUSSION: For the most part, the behavior of debug contexts is |
| being determined by the ARB Ecosystem TSG. However, whatever their |
| behavior, it's clear that "debug contexts" may differ at a basic |
| level from regular contexts. Debug contexts might even go down a |
| completely separate driver path. So it's essential to know at |
| context creation time if a debug context is required. |
| |
| 8) Is wglCreateContextVersion a good name? |
| |
| Ian Romanick suggests wglCreateContextAttribs instead. Changed in |
| version 12. |
| |
| 9) Should the context version be named with separate major and minor |
| number attributes, or as a single (major*100 + minor*10) number as |
| in GLSL (e.g. version == 220 <-> major = 2, minor = 2)? |
| |
| John Kessenich argues for consistency with the existing GLSL naming |
| scheme. |
| |
| 10) How are profiles specified? Why is the profile attribute a bitmask |
| rather than an enum? |
| |
| RESOLVED: Profiles are specified as individual bits passed in a |
| bitmask attribute. This attribute is ignored unless the OpenGL |
| version requested defines profiles (OpenGL 3.2 and later). While |
| only a single profile can be specified today, it is not unlikely |
| that eventually there will be profiles defined than can be |
| implemented in the same context. In that case we will need to be |
| able to specify multiple profiles at context creation and in the GL |
| context profile query, for which a bitmask is appropriate. |
| |
| 11) Why is the value of WGL_CONTEXT_PROFILE_MASK_ARB in the GL |
| core enumerant range? |
| |
| RESOLVED: The token value for the context profile mask and for the |
| context profile bits should be shared by GL, GLX, and WGL to ease |
| implementation and reduce programming errors. These values are drawn |
| from the GL token ranges. |
| |
| 12) What errors can result from requesting a profile? |
| |
| RESOLVED: Only a single profile can currently be requested. |
| Requesting no profile, more than one profile, or an unrecognized |
| profile are all errors. |
| |
| 13) How does the profile request interact with older GL versions? |
| |
| RESOLVED: It does not. The profile mask is ignored unless the |
| requested GL version is >= 3.2. |
| |
| DISCUSSION: Bruce had proposed using the profile mask to control |
| whether or not GL_ARB_compatibility was provided in earlier GL |
| versions, but general feeling was that apps had already had to sort |
| this out, and it's difficult to see how to define a default value |
| that can always be implemented (core profile) without changing the |
| existing behavior of wglCreateContextAttribsARB on implementations |
| which implement GL_ARB_compatibility by default when an OpenGL 3.1 |
| context is requested. |
| |
| 14) How does the profile request interact with the forward compatibility |
| bit? |
| |
| RESOLVED: Nothing special need be done here. If the forward |
| compatibility bit is set, the returned context must not implement |
| deprecated functionality in that profile (nothing is deprecated |
| from the OpenGL 3.2 compatibility profile, so a forward-compatible |
| compatibility profile has exactly the same functionality as |
| a non-forward-compatible compatibility profile, while a |
| forward-compatible core profile would leave out only the handful |
| of features - wide lines and two queries - deprecated from core |
| OpenGL 3.2). |
| |
| 15) How is context sharing between contexts of different versions |
| handled? |
| |
| RESOLVED: It's up to the implementation whether or not to allow |
| this, and to define behavior when shared objects include state or |
| behaviors not described by one of the contexts sharing them (for |
| example, textures with nonzero width borders shared by 3.2 core and |
| compatibility profile contexts). |
| |
| 16) Is the GL_ARB_compatibility extension equivalent to the |
| compatibility profile? |
| |
| RESOLVED: No. The extension refers specifically to functionality |
| removed from OpenGL 3.1 and restored by this extension. The |
| compatibility profile also restores this functionality, but may |
| define additional interactions between new features in version 3.N |
| and the functionality removed in OpenGL 3.1. |
| |
| In other words, the extension is a subset of the compatibility |
| profile. A context implementing the compatibility profile for OpenGL |
| 3.2 or greater may (and probably will) choose to export |
| GL_ARB_compatibility, but this is not required. |
| |
| 17) If the core profile is requested, what additional functionality |
| can be provided? |
| |
| RESOLVED: Functionality defined only by the compatibility profile |
| cannot be implemented by a context supporting the core profile. For |
| example, if a 3.2 core profile is requested, that context cannot |
| implement the GL_ARB_compatibility extension. However, any desired |
| new functionality may be exposed via vendor or ARB extensions in the |
| normal fashion. |
| |
| |
| Revision History |
| |
| Version 20, 2009/07/28 - Correct issue 14 to note that the 3.2 |
| compatibility profile does not deprecated anything. |
| |
| Version 19, 2009/07/27 - Add profiled context creation functionality |
| (WGL_CONTEXT_PROFILE_MASK_ARB and the associated bit tokens, error |
| code, and issues 10-16). Clarify that if the core profile is |
| requested, the returned context cannot restore functionality from |
| the compatibility profile (issue 17 and corresponding spec |
| language). Add ERROR_INVALID_PARAMETER error if an unrecognized |
| attribute is specified. Specify the interdependencies between the |
| two WGL extensions defined here and OpenGL 3.2, including the |
| requirement that WGL_ARB_create_context_profile be supported if an |
| OpenGL 3.2 or later implementation is supported. |
| |
| Version 18, 2009/07/24 - Specify that repeated attribute values |
| always result in the last specified value being used. |
| |
| Version 17, 2009/07/23 - Update the extension to clarify |
| interactions with OpenGL 3.1 and greater, allow returning 3.0 and |
| greater contexts from the legacy context creation routines so long |
| as they're backwards compatible, and mandate that requesting a |
| forward-compatible context always return exactly the requested |
| version (bugs 5112, 5349). |
| |
| Version 16, 2008/08/21 - Add initial viewport/scissor setting |
| behavior (cloned from GLX, including the case when no default |
| framebuffer is made current. |
| |
| Version 15, 2008/08/10 - Assign enumerant values and extension |
| number. |
| |
| Version 14, 2008/07/10 - Add trailing zero to array attributes in |
| wglCreateLayerContext example (Pat Brown). |
| |
| Version 13, 2008/07/03 - Update versioning behavior so asking for <= |
| 2.1 will return <= 2.1, asking for 3.0 will return 3.0, and noting |
| that we must update interactions with GL once 3.1 is defined. |
| Mandated behavior of legacy context creation APIs when this |
| extension is supported (bug 3595). |
| |
| Version 12, 2008/07/02 - Rename WGL_PREVIEW_BIT to |
| WGL_CONTEXT_FORWARD_COMPATIBLE_BIT and other replace "preview |
| context" with "forward-compatible context". Rename |
| wglCreateContextVersion to wglCreateContextAttribs. |
| |
| Version 11, 2008/06/12 - Use ARB suffix. Raise ERROR_INVALID_VERSION |
| instead of ERROR_INVALID_DATA on a bad version/preview combination. |
| |
| Version 10, 2008/04/08 - Changed "lite" to "preview" (still open for |
| discussion however), and changed version "2.2" to "3.0" following |
| the marketing TSG recommendation. Changed definition of preview |
| contexts so that deprecated functionality *must not* be supported. |
| Added issue 10 about how to handle profiles. |
| |
| Version 9, 2008/02/07 - Added version naming issue 9. |
| |
| Version 8, 2008/02/07 - Added naming issue 8. Removed reference to |
| GL version 3 in "Sharing Objects Between Contexts". |
| |
| Version 7, 2008/02/01 - Rewrote issues list in light of new API |
| direction, and reopened some issues. Added separate major and minor |
| version attributes and "lite" API flag. |
| |
| Version 6, 2007/05/22 - Resolve issue 4, although the exact |
| mechanism is still unknown. |
| |
| Version 5, 2007/04/09 - Added WGL_CONTEXT_FLAGS attribute and |
| WGL_CONTEXT_DEBUG_BIT flag, and a high-level description of the |
| concept of "debug contexts". |
| |
| Version 4, 2007/02/06 - Removed CreateContextVersion error when GL2 |
| and Longs Peak contexts are placed in the same share group, and |
| referred to the GL_EXT_bind_image extension in issue 1. Added issues |
| 6 ("can be shared" attribute) and 7 (creation of debug contexts) per |
| discussion at the Atlanta F2F ARB meeting. Added error condition for |
| wglShareLists if passed a Longs Peak context handle. |
| |
| Version 3, 2007/01/22 - added issue 5. |
| |
| Version 2, 2007/01/17 - change to the same style as |
| eglCreateContext, using an attribute list. Add wglMakeCurrent |
| language disallowing current 3.x contexts bound to pbuffers, and |
| allowing current 3.x context without a window-system provided |
| framebuffer. |
| |
| Version 1, 2007/1/17 - First draft |
