| Name |
| |
| EXT_import_context |
| |
| Name Strings |
| |
| GLX_EXT_import_context |
| |
| Version |
| |
| Version 3, May 20, 2015 |
| |
| Number |
| |
| 47 |
| |
| Dependencies |
| |
| This extension affects the definition of SGIX_FBConfig. |
| |
| Overview |
| |
| This extension allows multiple X clients to share an indirect |
| rendering context. |
| |
| Additional convenience procedures to get the current Display* |
| bound to a context as well as other context information are |
| also added. |
| |
| Issues |
| |
| Does glXImportGLXContext also need to take an XVisualInfo*? |
| |
| No. This information will be retrieved from the server. |
| |
| New Procedures and Functions |
| |
| Display *glXGetCurrentDisplayEXT(); |
| |
| int glXQueryContextInfoEXT(Display *dpy, GLXContext context, |
| int attribute,int *value); |
| |
| GLXContextID glXGetContextIDEXT(const GLXContext context); |
| |
| GLXContext glXImportContextEXT(Display *dpy, GLXContextID contextID); |
| |
| void glXFreeContextEXT(Display *dpy, GLXContext context); |
| |
| New Tokens |
| |
| Accepted by the <attribute> parameter of glXQueryContextInfoEXT: |
| |
| GLX_SHARE_CONTEXT_EXT 0x800A |
| GLX_VISUAL_ID_EXT 0x800B |
| GLX_SCREEN_EXT 0x800C |
| |
| Additions to Chapter 2 of the 1.0 Specification (OpenGL Operation) |
| |
| None |
| |
| Additions to Chapter 3 of the 1.0 Specification (Rasterization) |
| |
| None |
| |
| Additions to Chapter 4 of the 1.0 Specification (Per-Fragment Operations |
| and the Frame Buffer) |
| |
| None |
| |
| Additions to Chapter 5 of the 1.0 Specification (Special Functions) |
| |
| None |
| |
| Additions to Chapter 6 of the 1.0 Specification (State and State Requests) |
| |
| None |
| |
| Additions to the GLX Specification |
| |
| [Add the following to Section 3.2.4 of the GLX Specification |
| (Rendering Contexts)] |
| |
| To get the display associated with the current context, use |
| |
| Display *glXGetCurrentDisplayEXT(); |
| |
| If there is no current context, NULL is returned. No round trip |
| is forced to the server; unlike most X calls that return a value, |
| glXGetCurrentDisplayEXT does not flush any pending events. |
| |
| To obtain the value of a context's attribute, use |
| |
| int glXQueryContextInfoEXT(Display *dpy, GLXContext context, |
| int attribute, int *value); |
| |
| glxQueryContextInfoEXT returns through <value> the value of |
| <attribute> for <context>. It may cause a round trip to the |
| server. |
| |
| The values and types corresponding to each GLX context attribute |
| are listed in the table below. |
| |
| GLX context attribute type context information |
| --------------------- ---- ------------------- |
| GLX_SHARE_CONTEXT_EXT XID xid of the share list context |
| GLX_VISUAL_ID_EXT XID visual id |
| GLX_SCREEN_EXT int screen number |
| |
| glxQueryContextInfoEXT returns GLX_BAD_ATTRIBUTE if <attribute> |
| is not a valid GLX context attribute or GLX_BAD_CONTEXT if <context> |
| is invalid, otherwise it returns Success. |
| |
| To obtain the XID of a GLXContext, use |
| |
| GLXContextID glXGetContextIDEXT(const GLXContext context); |
| |
| No round trip is forced to the server; unlike most X calls that |
| return a value, glXGetContextIDEXT does not flush any pending |
| events. If <context> is NULL, None is returned. If <context> is not |
| NULL and is not a valid GLXContext name, behavior is undefined. |
| |
| To create a GLXContext given the XID of an existing GLXContext, use |
| |
| GLXContext glXImportContextEXT(Display *dpy, |
| GLXContextID contextID); |
| |
| glXImportContextEXT may be used in place of glXCreateContext to |
| share another process's indirect rendering context. |
| |
| Only the server-side context information can be shared between |
| X clients; client-side state, such as pixel storage modes, |
| cannot be shared. Thus, glXImportContextEXT, must allocate |
| memory to store client-side information. This memory is freed |
| by calling glXFreeContextEXT. |
| |
| This call does not create a new XID. It merely makes an |
| existing object available to the importing client (Display *). |
| Like any XID, it goes away when the creating client drops its |
| connection or the ID is explicitly deleted. Note that this is |
| when the XID goes away. The object goes away when the XID |
| goes away AND the context is not current to any thread. |
| |
| If <contextID> does not refer to a valid context, then |
| a BadContext error is generated; if <contextID> refers to |
| direct rendering context then no error is generated but |
| glXImportContextEXT returns NULL. |
| |
| To free the client-side part of a GLXContext that was created |
| with glXImportContext, use |
| |
| void glXFreeContextEXT(Display *dpy, GLXContext context); |
| |
| glXFreeContext does not free the server-side context information |
| or the XID associated with the server-side context. |
| |
| [Add the following clarification to glXMakeCurrent] |
| |
| Change: |
| If <context> is current to some other thread, then glXMakeCurrent |
| will generate a BadAccess error. |
| |
| To: |
| If <context> is current to some other thread or process, then |
| glXMakeCurrent will generate a BadAccess error. |
| |
| GLX Protocol |
| |
| One new GLX protocol command is added. |
| |
| QueryContextInfo |
| 1 CARD8 opcode (X assigned) |
| 1 17 GLX opcode (glXVendorPrivateWithReply) |
| 2 4 request length |
| 4 1024 vendor specific opcode |
| 4 unused corresponds to context tag in header |
| 4 GLX_CONTEXT context id |
| => |
| 1 1 Reply |
| 1 unused |
| 2 CARD16 sequence number |
| 4 2*n reply length |
| 4 CARD32 n |
| 20 unused |
| 8*n LISTofCARD32 attribute, value pairs |
| |
| Errors |
| |
| None |
| |
| New State |
| |
| None |
| |
| New Implementation Dependent State |
| |
| None |
| |
| Revision History |
| |
| Version 3, 2015/05/20 - Specify behavior of glXGetContextIDEXT when an |
| invalid <context> is passed (Bug 8344). |
| |
| Version 2, 2006/08/24 - Fixed opcode for QueryContextInfo per Ian |
| Romanick (opcode is 1024 per glx.spec, which is used to generate |
| glxproto.h - not 15 as has been in the extension spec since 1995). |
| |
| Version 1.14, 1995/10/14 - Last update from SGI. |
| |
