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.
The screenConfigs field of __DRIscreen points back to the containing
__GLXscreenConfigs struct. This is a serious abstraction violation; it
assumes that the loader is libGL and that there *is* a __GLXscreenConfigs
type in the loader.
Using the containerOf macro, we can get from the __DRIscreen pointer to
the containing __GLXscreenConfigs struct, at a place in the stack
where the above is a valid assumption. Besides, the __DRI* structs shouldn't
hold state other than the private pointer.
__glXinitialize() can't be called with the GLX lock held. Just
pass in the __GLXscreenConfigs pointer so we don't have to look it
up in __GLXdisplayPrivate.
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.
In the process, fix some alignment issues:
- Scratch space allocation was aligned into units of 1KB, while the allocation
wanted units of bytes, so we never allocated enough space for scratch.
- GRF register count was programmed as ALIGN(val - 1, 16) / 16 instead of
ALIGN(val, 16) / 16 - 1, which overcounted for val != 16n+1.
