Hi, I've been working on updating the DRI interface (GL/internal/dri_interface.h) the last few days and I though I'd post a heads up to the lists to get some feedback. The work I've been doing starts out with the patches in bug 5714, implements Ians suggestions in comment #20, and quite a bit more. I haven't added Alans frontbuffer mapping patches yet; I wanted to get this work done first before breaking DDX compatibility, but they're next.
The work is on the dri2 branch in git.freedesktop.org/~krh/mesa.git or browsable here: http://people.freedesktop.org/krh-cgi/cgit?r=_home_krh_mesa.git&p=log&h=dri2 The changes are mostly a series of cleanup as described below, but there is a new concept in there: the DRI extension. Much of the churn in the DRI interface structs is from adding and removing functions pertaining to GLX extensions, most recently GLX_MESA_copy_sub_buffer and probably soon GLX_EXT_texture_from_pixmap. The DRI extension mechanism should allow us to add and remove support for extensions as they come and go, in a way that doesn't break ABI or API. The idea here is that only the core GLX 1.4 features should be part of the __DRI{screen,context,drawable} structs and everything else must be exposed as a __DRIextension. The list of __DRIextensions is available using __DRIscreen::getExtensions; const __DRIextension **(*getExtensions)(__DRIscreen *screen); All extensions have a common "baseclass" that just is the name of the extension (just a string): struct __DRIextensionRec { const char *name; }; If the name matches that of an extension known to the loader, the loader can cast the struct to a more specific extension struct that has the function pointers that provide access to the functionality. For example: #define __DRI_COPY_SUB_BUFFER "DRI_CopySubBuffer" struct __DRIcopySubBufferExtensionRec { __DRIextension base; void (*copySubBuffer)(__DRIdrawable *drawable, int x, int y, int w, int h); }; The presence of an extension means that the driver can provide some extra functionality. Based of these extra hooks, the loader will be able to implement and advertise a number of GLX extensions. The DRI extension name space is private to the DRI interface, and is orthogonal to the GLX extension name space. The logic here is that one DRI extension can enable a number of GLX extensions, and the loader, since it has to implement the entry points, will know exactly which GLX extensions to enable. For example, the DRI_SwapControl extension: #define __DRI_SWAP_CONTROL "DRI_SwapControl" struct __DRIswapControlExtensionRec { __DRIextension base; void (*setSwapInterval)(__DRIdrawable *drawable, unsigned int inteval); unsigned int (*getSwapInterval)(__DRIdrawable *drawable); }; enables the loader to implement both GLX_SGI_swap_control and GLX_MESA_swap_control. Aside from the new extension mechanism, the branch cleans up a number of things in the DRI interface: 1) Move XIDs out of the interface and make libGL handle XID -> __DRIdrawable etc mapping. I've pulled the hashtable from libdrm into mesa to do this, which should allow us to drop the hashtable and the skip list from drm eventually. 2) Drop the display notion from the interface. A DRI driver only handles one screen and 3) Remove getProcAddress (only needed by the old extension mechanism), create/destroyContext, create/destroyDrawable (instead of calling back from the DRI driver, just have the loader create the context first and pass the drm_context_t into the driver). 4) Remove variables from the __DRI* structs except the private pointer. We should never share state across the DRI driver boundary, all access should go through functions. 5) Misc cleanups: pull the createNewScreen out of the driver backends and into dri/common (more code sharing, simpler interface between dri/common and drivers), always use the __DRI* types instead of private void pointers (type safety, interface is more self-documenting), generate entry point name using macros instead of duplication the version number in a few places, drop now unused __DRIid typedef. cheers, Kristian ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel
