When the DRI doesn't parse the event buffer for a while, the X server
may overwrite data that the driver didn't get a chance to look at. The
reemitDrawableInfo callback requests that the X server reemit all info
for the specified drawable. To make use of this, the drive needs to know
the new tail pointer so it know where to start reading from.
This also fixes the problem where the X server does multiple resizes before
the DRI driver gets the events. The obsolete buffer attach events then
reference already destroyed buffer objects.
Instead of passing in a fixed struct, the loader now passes in a list
of __DRIextension structs, to advertise the functionality it can provide
to the driver. Each extension is individually versioned and can be
extended or phased out as the interface develops.
Right now the DRI2 screen constructor takes 3 different versions:
DRI, DDX and DRM. This is mostly useless, though:
DRI: The DRI driver doesn't actually care about the DRI protocol,
it only talks to the loader, which in turn speaks DRI protocol. Thus,
the DRI protocol version is of not interest to the DRI driver, but it
needs to know what functionality the loader provides. At this point
that's reflected in the __DRIinterfaceMethods struct and the
internal_version integer.
DDX: The DDX version number is essentially used to track extensions
to the SAREA. With DRI2 the SAREA consists of a number of versioned,
self-describing blocks, so the DDX version is no longer interesting.
DRM: We have the fd, lets just ask the kernel ourselves.
The DriverAPI is internal to the DRI drivers and GetDrawableMSC
obsoletes GetMSC. Also, since the DRI driver interface has not yet
been released, just drop the getMSC function from the DRI interface
instead using the ABI preserving version mechanism.
Finally, using void pointer privates in the DRI interface is not allowed,
always pass the actual types around (__DRIdrawable in this case) to
enhance type safety and readability of the code.
Consolidate support for synchronizing to and retrieving vblank counters. Also
fix the core vblank code to return monotonic MSC counters, which are required
by some GLX extensions. Adding support for multiple pipes to a low level
driver is fairly easy, the Intel 965 driver provides simple example code (see
intel_buffers.c:intelWindowMoved()).
The new code bumps the media stream counter extension version to 2 and adds a
new getDrawableMSC callback. This callback takes a drawablePrivate pointer,
which is used to calculate the MSC value seen by clients based on the actual
vblank counter(s) returned from the kernel. The new drawable private fields
are as follows:
- vblSeq - used for tracking vblank counts for buffer swapping
- vblFlags - flags (e.g. current pipe), updated by low level driver
- msc_base - MSC counter from the last time the current pipe changed
- vblank_base - kernel DRM vblank counter from the last time the pipe changed
Using the above variables, the core vblank code (in vblank.c) can calculate a
monotonic MSC value. The low level DRI drivers are responsible for updating
the current pipe (by setting VBLANK_FLAG_SECONDARY for example in vblFlags)
along with msc_base and vblank_base whenever the pipe associated with a given
drawable changes (again, see intelWindowMoved for an example of this).
Drivers should fill in the GetDrawableMSC DriverAPIRec field to point to
driDrawableGetMSC32 and add code for pipe switching as outlined above to fully
support the new scheme.
This new API lets the loader examine DRI level extensions provided by the
driver in a forward compatible manner.
Much of the churn in the DRI interface is adding support for new
extensions or removing old, unused extensions. This new extension
mechanism lets the loader query the extensions provided by the driver
and implement the extensions it knows about. Deprecating extensions
is done by not exporting that extension in the list, which doesn't
require keeping old function pointers around to preserve ABI.
This pulls the top level createNewScreen entry point out of the drivers
and rewrites __driUtilCreateNewScreen in dri_util.c to be the new entry point.
The change moves more logic into the common/ layer and changes the
createNewScreen entry point to only be defined in one place.
The entrypoints take a mix of __DRIscreen * and void * (screen private)
arguments (similarly for contexts and drawables). This patch does away
with passing the private void pointer and always only passes the fully
typed __DRIscreen pointer and always as the first argument.
This makes the interface more consistent and increases type safety, and
catches a bug where we would pass a screen private to DRIdrawable::getSBC.
As for createDrawable and destroyDrawable, these functions immediately
upon entry to driCreateNewContext and immediately before exit from
driDestroyContext. Instead of passing function pointers back and forth
just obtain the drm_context_t prior to calling DRIscreen::createNewContext
and pass it as a parameter.
This change also lets us keep the DRI context XID in the libGL loader only.
All the DRI driver did was call the createDrawable callback immediately
upon entry to DRIscreen::createNewDrawable to get the drm_drawable_t.
We can just call that before calling into the DRI driver and pass the
returned drm_drawable_t as an argument to the DRI entry point.
Likewise for destroyDrawable.
Also, DRIdrawablePrivate::draw isn't used anywhere, and since the
driver no longer needs the XID of the drawable we can now drop that.
Many DRI entry points took a __DRInativeDisplay pointer and a screen
index as arguments. The only use for the native display pointer was to
pass it back to the loader when looking up the __DRIscreen for the given
screen index.
Instead, let's just pass in the __DRIscreen pointer directly, which
let's drop the __DRInativeDisplay type and the getScreen function.
The assumption is now that the loader will be able to retrieve context
from the __DRIscreen pointer when necessary.
With this, tools like ximagesrc in gstreamer correctly see updates from GL
rendering. Support requires that the Xdamage library be current (but will be
disabled if not present) plus a new X Server with support for the new
XDamagePost request. libGL now has a new interface version, and also links
against libXdamage and libXfixes to support it, but backwards compatibility
is retained.
Currently, all drivers report damage at SwapBuffers time through common code --
front buffer rendering doesn't result in damage being reported. Also, the
damage is against the root window, as our drivers don't yet render to backing
store when they should (composited environments).
The weak version of _glapi_DispatchTSD was removed from dri_util.c. As
stated in the bug report, this was only needed to support versions of libGL
that did not have this symbol. Versions of libGL without this symbol are no
longer supported at all, so it is totally irrelevant.
that are currently obtained via glXGetProcAddress and all of the XF86DRI
functions are replaced with a funciton table. This table will be passed to
__driCreateNewScreen.
One of the functions in the table is getProcAddress. This allows some
loaders to expose functionality not in all loaders. This will be immediatly
used for glxEnableExtension (formerly known to drivers as
__glXScrEnableExtension). libGL (and in the future libglx) expose this
function so that drivers can enable GLX extensions. libEGL should exposed
eglEnableExtension to enable EGL extensions. The same function cannot be
used for both because the extensions have different names and (possibly)
different semantics. Drivers can optionally use one, both, or neither.
The key parts are in the __DRIinterfaceMethodsRec structure in
dri_interface.h. A pointer to one of these structures is passed into
__driCreateNewScreen. Because of this, the version of the API is bumped to
20050725. Since the previous version(s) were never in a release, their
existance is erased.
I was actually a little surprised by how much code this cuts from the
drivers. A lot of glXGetProcAddress calls disappear, and a lot of
version checks go with them. Nice.
The one thing I'm not sure of is removing __glXInitialize. For some
reason that function was in the glXGetProcAddress table, but *nothing*
in the Mesa tree used it. Did something with DRI conf. use this
function? It seems odd...
1,402 lines of code to be removed from Mesa (drivers and libGL). The
big winner is dri_util.c.
Primary changes are:
1. Remove all "deprecated" entry-points from the various structures in
dri_interface.h.
2. Rename the remaining fields to removed "version numbers." So,
bindContext3 becomes bindContext. Functions with "New" in the name
(e.g., CreateNewContext) were *not* changed, but that is an option.
Having "New" in the name is less annoying to me than having "3" in the name.
3. Remove all compatibility code that handles cases where the driver or
the loader is too old to support the latest interfaces.
4. Append the API version to the __driCreateNewScreen function name.
This is currently done by hand. In the future (i.e., the next time we
make an incompatible change to the interface) we'll want to come up with
a better way to do this. This prevents old loaders from being able to load
new (incompatible) drivers.
5. Bump the API version to 20050722. All drivers (by way of dri_util.c)
require this version.
6. All drivers are *required* to expose GLX_SGIX_fbconfig and
GLX_OML_swap_method (or the moral equivalents). Support for these
functions in implicit in the use of the "new" interface.
7. Some cases still exist that need to be compiled differently in a loader
or core Mesa versus in a driver. These are identified by the define
IN_DRI_DRIVER.
