wl_buffer has been deprecated in the server API and instead
compositors should be directly passing the wl_resource pointer to
eglQueryWaylandBuffer.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
(cherry picked from commit f13278bcf3f1475b7afc7d55a5218f409d119658)
When running in a purely swrast environment (such as with
LIBGL_ALWAYS_SOFTWARE), the extension is not exposed by mesa,
but wayland is still possible with wl_shm.
https://bugzilla.gnome.org/show_bug.cgi?id=704750
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit 8d4e4b0e8062708cece4d4c929abccc492ee21cc)
_cogl_egl_query_wayland_buffer was using _COGL_RETURN_IF_FAIL but the
function needs to return a CoglBool so it was giving a warning.
(cherry picked from commit d0290eb19fc9bf56fb24f8eab573e19966ea7e1a)
The implementation of cogl_wayland_texture_2d_new_from_buffer now uses
eglQueryWaylandBuffer to query the format of the buffer before trying to
create a texture from the buffer. This makes sure we don't try and
create a texture from YUV buffers for instance that may actually require
multiple textures. We now also report an error when we don't understand
the buffer type or format.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit 79252d4e419e2462c5bc89ea4614b40bddc932c5)
This enables basic Emscripten support in Cogl via the SDL winsys.
Assuming you have setup an emscripten toolchain you can configure Cogl
like this:
emconfigure ./configure --enable-debug --enable-emscripten
Building the examples will build .html files that can be loaded directly
by a WebGL enabled browser.
Note: at this point the emscripten support has just barely been smoke
tested so it's expected that as we continue to build on this we will
learn about more things we need to change in Cogl to full support this
environment.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit a3bc2e7539391b074e697839dfae60b69c37cf10)
cogl_framebuffer_add_fence creates a synchronisation fence, which will
invoke a user-specified callback when the GPU has finished executing all
commands provided to it up to that point in time.
Support is currently provided for GL 3.x's GL_ARB_sync extension, and
EGL's EGL_KHR_fence_sync (when used with OpenGL ES).
Signed-off-by: Daniel Stone <daniel@fooishbar.org>
Reviewed-by: Neil Roberts <neil@linux.intel.com>
Reviewed-by: Robert Bragg <robert@linux.intel.com>
https://bugzilla.gnome.org/show_bug.cgi?id=691752
(cherry picked from commit e6d37470da9294adc1554c0a8c91aa2af560ed9f)
This adds api to be able requests a swap_buffers and also pass a list of
damage rectangles that can be passed on to a compositor to enable it to
minimize how much of the screen it needs to recompose.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit 0d9684c7b7c2018bb42715c369555330d38514a2)
This makes sure the EGL_KHR_create_context enums are always defined in
cogl-winsys-egl.c so we will build with drivers that don't support this
extension. Cogl will do runtime checks to explicitly check that the
extension is available before ever referencing these enums so this is
safe to do.
https://bugzilla.gnome.org/show_bug.cgi?id=694537
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit bd034b7451e7d9c602bcc91f1a00f6aaa7b05ec0)
Similar to commit 2c0cfdefbb9d1 for the SDL2 winsys, the GLX and EGL
window systems need to bind the dummy surface or drawable when the
currently bound onscreen is destroyed so that there will always be a
valid context bound.
Previously I got the idea that this would not be necessary on GLX
because the documentation for glXDestroyDrawable states that the
drawable won't actually be destroyed if it is currently bound until it
becomes unbound. However it doesn't say what happens if the underlying
X window is also destroyed and after testing it seems this causes a
segfault in Mesa in GLX and an XError for EGLX.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
(cherry picked from commit 4a464eec8c5b5832b9fd6b69746ab4ab36229182)
This adds support for the EGL_EXT_buffer_age extension which is a
counterpart to the GLX_EXT_buffer_age extension.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit 92d869764c03d0bac6b51dac833510c22669ac4a)
This adds a new CoglDriver for GL 3 called COGL_DRIVER_GL3. When
requested, the GLX, EGL and SDL2 winsyss will set the necessary
attributes to request a forward-compatible core profile 3.1 context.
That means it will have no deprecated features.
To simplify the explosion of checks for specific combinations of
context->driver, many of these conditionals have now been replaced
with private feature flags that are checked instead. The GL and GLES
drivers now initialise these private feature flags depending on which
driver is used.
The fixed function backends now explicitly check whether the fixed
function private feature is available which means the GL3 driver will
fall back to always using the GLSL progend. Since Rob's latest patches
the GLSL progend no longer uses any fixed function API anyway so it
should just work.
The driver is currently lower priority than COGL_DRIVER_GL so it will
not be used unless it is specificly requested. We may want to change
this priority at some point because apparently Mesa can make some
memory savings if a core profile context is used.
In GL 3, getting the combined extensions string with glGetString is
deprecated so this patch changes it to use glGetStringi to build up an
array of extensions instead. _cogl_context_get_gl_extensions now
returns this array instead of trying to return a const string. The
caller is expected to free the array.
Some issues with this patch:
• GL 3 does not support GL_ALPHA format textures. We should probably
make this a feature flag or something. Cogl uses this to render text
which currently just throws a GL error and breaks so it's pretty
important to do something about this before considering the GL3
driver to be stable.
• GL 3 doesn't support client side vertex buffers. This probably
doesn't matter because CoglBuffer won't normally use malloc'd
buffers if VBOs are available, but it might but worth making
malloc'd buffers a private feature and forcing it not to use them.
• GL 3 doesn't support the default vertex array object. This patch
just makes it create and bind a single non-default vertex array
object which gets used just like the normal default object. Ideally
it would be good to use vertex array objects properly and attach
them to a CoglPrimitive to cache the state.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
(cherry picked from commit 66c9db993595b3a22e63f4c201ea468bc9b88cb6)
The EGL winsys had a special case code path when trying to create a
context where if it failed it would try again except without requesting
a stencil buffer. Historically this code path was to allow Clutter to
run on PowerVR MBX hardware which doesn't support a stencil buffer. It
doesn't really make sense to keep this workaround in Cogl as it would
leave Cogl in a state where the clip stack doesn't work without
providing any feedback to the developer. If we need to support running
on MBX like hardware - probably not very likely these days - then we
should provide developer control over the stencil buffer so the
equivalent workaround could be implemented on top of Cogl.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit a7c391a985e82707b17f2fb1105de5d37822a390)
Although we use GLib internally in Cogl we would rather not leak GLib
api through Cogl's own api, except through explicitly namespaced
cogl_glib_ / cogl_gtype_ feature apis.
One of the benefits we see to not leaking GLib through Cogl's public API
is that documentation for Cogl won't need to first introduce the Glib
API to newcomers, thus hopefully lowering the barrier to learning Cogl.
This patch provides a Cogl specific typedef for reporting runtime errors
which by no coincidence matches the typedef for GError exactly. If Cogl
is built with --enable-glib (default) then developers can even safely
assume that a CoglError is a GError under the hood.
This patch also enforces a consistent policy for when NULL is passed as
an error argument and an error is thrown. In this case we log the error
and abort the application, instead of silently ignoring it. In common
cases where nothing has been implemented to handle a particular error
and/or where applications are just printing the error and aborting
themselves then this saves some typing. This also seems more consistent
with language based exceptions which usually cause a program to abort if
they are not explicitly caught (which passing a non-NULL error signifies
in this case)
Since this policy for NULL error pointers is stricter than the standard
GError convention, there is a clear note in the documentation to warn
developers that are used to using the GError api.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit b068d5ea09ab32c37e8c965fc8582c85d1b2db46)
Note: Since we can't change the Cogl 1.x api the patch was changed to
not rename _error_quark() functions to be _error_domain() functions and
although it's a bit ugly, instead of providing our own CoglError type
that's compatible with GError we simply #define CoglError to GError
unless Cogl is built with glib disabled.
Note: this patch does technically introduce an API break since it drops
the cogl_error_get_type() symbol generated by glib-mkenum (Since the
CoglError enum was replaced by a CoglSystemError enum) but for now we
are assuming that this will not affect anyone currently using the Cogl
API. If this does turn out to be a problem in practice then we would be
able to fix this my manually copying an implementation of
cogl_error_get_type() generated by glib-mkenum into a compatibility
source file and we could also define the original COGL_ERROR_ enums for
compatibility too.
Note: another minor concern with cherry-picking this patch to the 1.14
branch is that an api scanner would be lead to believe that some APIs
have changed, and for example the gobject-introspection parser which
understands the semantics of GError will not understand the semantics of
CoglError. We expect most people that have tried to use
gobject-introspection with Cogl already understand though that it is not
well suited to generating bindings of the Cogl api anyway and we aren't
aware or anyone depending on such bindings for apis involving GErrors.
(GnomeShell only makes very-very minimal use of Cogl via the gjs
bindings for the cogl_rectangle and cogl_color apis.)
The main reason we have cherry-picked this patch to the 1.14 branch
even given the above concerns is that without it it would become very
awkward for us to cherry-pick other beneficial patches from master.
Previously when pushing the GLES2 context with an onscreen framebuffer
it would just call bind_onscreen. This actually binds it with Cogl's
context so presumably the context isolation wasn't working properly.
This patch splits out bind_onscreen to have a second function called
bind_onscreen_with_context that explicitly takes the EGL context to
use. Cogl now uses this when pushing the GLES2 context.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
(cherry picked from commit 3653c5b10058a3f79900eb2644cb30f4cf1ca47e)
Previously, Cogl was advertising the GLES2 context feature whenever
the EGL winsys was used, even if the winsys was used with the GL
driver. This wasn't working because when the GL context is created the
API is set to GL with eglBindAPI and it is never changed back to GLES
when the GLES2 context is created. That meant that the created context
is actually GL not GLES2. Any rendering would then fail because the GL
context does not understand the precision statement.
It could be possible to fix it so that it will set the API correctly
before creating the context. It would then also need to reset the API
and unbind the previous context whenever switching between GLES2 and
GL contexts. If the context isn't unbound first then eglMakeCurrent
will actually try to bind both contexts at the same time and at least
Mesa detects this situation and reports that the two contexts
conflict. Presumably we would also need to do something more clever
when we retrieve the function pointers for the GLES2 context.
Currently we just copy them from the CoglContext but if the context is
using the GL driver then this would mean the functions came from libGL
not libGLESv2.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
(cherry picked from commit 624dea207cf76ae9ccd7f57c4ebd15d3bd65bff0)
According to the EGL spec, eglGetProcAddress should only be used to
retrieve extension functions. It also says that returning non-NULL
does not mean the extension is available so you could interpret this
as saying that the function is allowed to return garbage for core
functions. This seems to happen at least for the Android
implementation of EGL.
To workaround this the winsys's are now passed down a flag to say
whether the function is from the core API. This information is already
in the gl-prototypes headers as the minimum core GL version and as a
pair of flags to specify whether it is available in core GLES1 and
GLES2. If the function is in core the EGL winsys will now avoid using
eglGetProcAddress and always fallback to querying the library directly
with the GModule API.
The GLX winsys is left alone because glXGetProcAddress apparently
supports querying core API and extension functions.
The WGL winsys could ideally be changed because wglGetProcAddress
should also only be used for extension functions but the situation is
slightly different because WGL considers anything from GL > 1.1 to be
an extension so it would need a bit more information to determine
whether to query the function directly from the library.
The SDL winsys is also left alone because it's not as easy to portably
determine which GL library SDL has chosen to load in order to resolve
the symbols directly.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
(cherry picked from commit 72089730ad06ccdd38a344279a893965ae68cec1)
Since we aren't able to break API on the 1.12 branch
cogl_get_proc_address is still supported but isn't easily able to
determine whether the given name corresponds to a core symbol or
not. For now we just assume the symbol being queried isn't part
of the core GL api and update the documentation accordingly.
This adds a new renderer constraint enum:
COGL_RENDERER_CONSTRAINT_SUPPORTS_GLES2_CONTEXT
that can be used by applications to ensure the renderer they connect to
has support for creating a GLES2 context via cogl_gles2_context_new().
The cogl-gles2-context and cogl-gles2-gears examples and the conformance
tests have been updated to use this constraint.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit ed61463d7194354b26624e8014859f0fbfc06a12)
This makes it possible to integrate existing GLES2 code with
applications using Cogl as the rendering api.
Currently all GLES2 usage is handled with separate GLES2 contexts to
ensure that GLES2 api usage doesn't interfere with Cogl's own use of
OpenGL[ES]. The api has been designed though so we can provide tighter
integration later.
The api would allow us to support GLES2 virtualized on top of an
OpenGL/GLX driver as well as GLES2 virtualized on the core rendering api
of Cogl itself. Virtualizing the GLES2 support on Cogl will allow us to
take advantage of Cogl debugging facilities as well as let us optimize
the cost of allocating multiple GLES2 contexts and switching between
them which can both be very expensive with many drivers.
As as a side effect of this patch Cogl can also now be used as a
portable window system binding API for GLES2 as an alternative to EGL.
Parts of this patch are based on work done by Tomeu Vizoso
<tomeu.vizoso@collabora.com> who did the first iteration of adding GLES2
API support to Cogl so that WebGL support could be added to
webkit-clutter.
This patch adds a very minimal cogl-gles2-context example that shows how
to create a gles2 context, clear the screen to a random color and also
draw a triangle with the cogl api.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit 4bb6eff3dbd50d8fef7d6bdbed55c5aaa70036a8)
The coding style has for a long time said to avoid using redundant glib
data types such as gint or gchar etc because we feel that they make the
code look unnecessarily foreign to developers coming from outside of the
Gnome developer community.
Note: When we tried to find the historical rationale for the types we
just found that they were apparently only added for consistent syntax
highlighting which didn't seem that compelling.
Up until now we have been continuing to use some of the platform
specific type such as gint{8,16,32,64} and gsize but this patch switches
us over to using the standard c99 equivalents instead so we can further
ensure that our code looks familiar to the widest range of C developers
who might potentially contribute to Cogl.
So instead of using the gint{8,16,32,64} and guint{8,16,32,64} types this
switches all Cogl code to instead use the int{8,16,32,64}_t and
uint{8,16,32,64}_t c99 types instead.
Instead of gsize we now use size_t
For now we are not going to use the c99 _Bool type and instead we have
introduced a new CoglBool type to use instead of gboolean.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit 5967dad2400d32ca6319cef6cb572e81bf2c15f0)
Instead of creating FBOs on the GL side, the KMS EGL platform uses the
latest changes to Mesa to create an EGL surface using a GBM surface as
the native surface type. This removes some of the special vtable hooks
that the KMS platform needed because it is now much more similar to
the other platforms.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
The cogl.h header is meant to be the public header for including the 1.x
api used by Clutter so we should stop using that as a convenient way to
include all likely prototypes and typedefs. Actually we already do a
good job of listing the specific headers we depend on in each of the .c
files we have so mostly this patch just strip out the redundant
includes for cogl.h with a few fixups where that broke the build.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
This adds cogl_onscreen_template_set_swap_throttled() api that allows
developers to specify their preference for swap buffer throttling
up-front as part of the onscreen template that is used to create a
CoglDisplay when initializing Cogl. This is desirable because some
platforms may not support configuring swap throttling on a per
framebuffer basis and also since applications often want to apply the
same policy to all onscreen framebuffers anyway.
This allows applications to specify certain constraints that feed into
the process of selecting a CoglRenderer backend. For example
applications might depend on x11 for handling input and so they require
a backend that's also based on x11.
CoglTexture2D had an assert to verify that the EGL winsys was being
used. This doesn't make any sense any more because the EGL winsys
can't be used directly but instead it is just a base winsys for the
platform winsys's. To fix this this patch adds a set of 'criteria'
flags to each winsys, one of which is 'uses EGL'. CoglTexture2D can
use this to determine if the winsys is supported.
Eventually we might want to expose these flags publically so that an
application can select a winsys based on certain conditions. For
example, an application may need a winsys that uses X or EGL but
doesn't care exactly which one it is.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
This moves all of the code specific to the Android platform out of
cogl-winsys-egl. It is completely untested apart from that it
compiles using a dummy android/native_window.h header.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
This moves all of the code specific to the gdl winsys out of
cogl-winsys-egl. It is completely untested apart from that it
compiles.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
The GLX and EGL winsys backends had a check for when onscreen==NULL
in which case they would instead try to bind the dummy surface. This
wouldn't work however because it would have already crashed by that
point when it tried to get the Cogl context out of the onscreen. The
function needs a bit of refactoring before it could support this but
presumably nothing is relying on this anyway because it wouldn't work
so for now we can just remove it.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
CoglXlibDisplay just contained one member called dummy_xwin. This was
not shared outside of the respective winsys's so I don't think it
really makes sense to have a separate shared struct for it. It seems
more like an implementation detail that is specific to the winsys
because for example it may be that the EGL winsys could use the
surfaceless extension and not bother with a dummy window. This will
also make it easier to factor out the Xlib-specific data in
CoglDisplayEGL to the platform data.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
Previously the Xlib renderer data was meant to be the first member of
whatever the winsys data is. This doesn't work well for the EGL winsys
because it only needs the Xlib data if the X11 platform is used. The
Xlib renderer data is now instead created on demand and connected to
the object using cogl_object_set_user_data. There is a new function to
get access to it.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
Instead of having #ifdefs to hook into the normal EGL winsys, the KMS
winsys now overrides any winsys functions that it wants. Where the
winsys wants to hook into a point within a function provided by the
EGL winsys there is a EGL-platform vtable which gets set on the EGL
renderer data during renderer_connect. The KMS-specific data on all of
the structures is now allocated separately by the KMS winsys and is
pointed to by a new 'platform' pointer in the EGL data.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
The #ifdefs in cogl-winsys-egl have been changed so that they
additionally check renderer->winsys_vtable->id for the corresponding
winsys ID so that multiple EGL platforms can be enabled.
The is a stop-gap solution until we can move all of the EGL platforms
into their own winsys files with overrides of the EGL vtable. However
with this approach we can move one platform at a time which will make
it easier.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
Instead of just having an "EGL" renderer, there is now a separate
winsys for each platform. Currently they just directly copy the vtable
for the EGL platform so it is still only possible to have one EGL
platform compiled into Cogl. However the intention is that the
winsys-specific code for each platform will be moved into override
functions in the corresponding platform winsys.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
Requests for the shell to manipulate it's state for the surface are now
abstracted through a wl_shell_surface object rather through wl_shell as
before.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
There were two problems stopping the KMS winsys from working with a
GLES2 driver:
• When creating the EGL context, it was missing the attribute to
select the client version so it would end up with the GLES1 API.
• When creating the depth buffer for the framebuffer it was using
GL_DEPTH_COMPONENT but only GL_DEPTH_COMPONENT16 is supported on
GLES. cogl-framebuffer already unconditionally uses this so it
probably makes sense to do the same here.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
Since the wayland protocol doesn't currently provide a way to
retrospectively query the interfaces that get notified when a client
first connects then when using a foreign display with Cogl then we also
need api for telling cogl what compositor and shell objects to use. We
already had api for setting a foreign compositor so this patch just adds
api for setting a foreign shell.
This patch also adds documentation for all the wayland specific apis.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
For some reason the EGL spec says that the surface passed to
eglSwapBuffers must be bound as the current surface for the swap to
work. Mesa validates that this is the case and returns an error from
the swap buffers call if not.
https://bugzilla.gnome.org/show_bug.cgi?id=665604
Reviewed-by: Robert Bragg <robert@linux.intel.com>
Since _cogl_winsys_kms_display_setup was basically just calling
setup_kms() it made sense to fold the code of setup_kms() back into the
_cogl_winsys_kms_display_setup() function.
Reviewed-by: Rob Bradford <rob@linux.intel.com>
So that the various internal Cogl*EGL typedefs can be available to
cogl-winsys-kms.c this moves them into cogl-winsys-egl-private.h
Reviewed-by: Rob Bradford <rob@linux.intel.com>
To start with this backend only supports creating a single CoglOnscreen
framebuffer and will automatically set is up to display fullscreen on
the first suitable crtc it can find.
To compile this backend - get some dribbly black candles, sacrifice a
goat and configure with: --enable-kms-egl-platform
Note: There is currently a problem with using GLES2 with this winsys
so you need to run with EGL_DRIVER=gl
Note: If you have problems with mesa crashing in XCB during
eglInitialize then you may need to explicitly run with EGL_PLATFORM=gbm
Reviewed-by: Robert Bragg <robert@linux.intel.com>
This change is one logical update to update the Wayland support. This
comprises of the following parts:
* Binding to both the shell and compositor global objects - necessary since
the API for setting top level status moved to the wl_shell interface
* The Wayland visual API went away and instead you setup the EGL surface
appropriately
* The message handling was refined to reflect the current behaviour - now
obsolete comments were removed and new comments updated
Reviewed-by: Robert Bragg <robert@linux.intel.com>
Xlib headers define many trivially named objects which can later cause
name collision problems when only cogl.h header is included in a program
or library. Xlib headers are now only included through including the
standalone header cogl-xlib.h.
https://bugzilla.gnome.org/show_bug.cgi?id=661174
Reviewed-by: Robert Bragg <robert@linux.intel.com>
It's useful to be able to query back the number of
point_samples_per_pixel that may have previously be chosen using
cogl_framebuffer_set_samples_per_pixel().
Reviewed-by: Neil Roberts <neil@linux.intel.com>
Since we've had several developers from admirable projects say they
would like to use Cogl but would really prefer not to pull in
gobject,gmodule and glib as extra dependencies we are investigating if
we can get to the point where glib is only an optional dependency.
Actually we feel like we only make minimal use of glib anyway, so it may
well be quite straightforward to achieve this.
This adds a --disable-glib configure option that can be used to disable
features that depend on glib.
Actually --disable-glib doesn't strictly disable glib at this point
because it's more helpful if cogl continues to build as we make
incremental progress towards this.
The first use of glib that this patch tackles is the use of
g_return_val_if_fail and g_return_if_fail which have been replaced with
equivalent _COGL_RETURN_VAL_IF_FAIL and _COGL_RETURN_IF_FAIL macros.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
This factors out the CoglOnscreen code from cogl-framebuffer.c so we now
have cogl-onscreen.c, cogl-onscreen.h and cogl-onscreen-private.h.
Notably some of the functions pulled out are currently namespaced as
cogl_framebuffer but we know we are planning on renaming them to be in
the cogl_onscreen namespace; such as cogl_framebuffer_swap_buffers().
Reviewed-by: Neil Roberts <neil@linux.intel.com>
Currently features are represented as bits in a 32bit mask so we
obviously can't have more than 32 features with that approach. The new
approach is to use the COGL_FLAGS_ macros which lets us handle bitmasks
without a size limit and we change the public api to accept individual
feature enums instead of a mask. This way there is no limit on the
number of features we can add to Cogl.
Instead of using cogl_features_available() there is a new
cogl_has_feature() function and for checking multiple features there is
cogl_has_features() which takes a zero terminated vararg list of
features.
In addition to being able to check for individual features this also
adds a way to query all the features currently available via
cogl_foreach_feature() which will call a callback for each feature.
Since the new functions take an explicit context pointer there is also
no longer any ambiguity over when users can first start to query
features.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
