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 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)
Removing CoglHandle has been an on going goal for quite a long time now
and finally this patch removes the last remaining uses of the CoglHandle
type and the cogl_handle_ apis.
Since the big remaining users of CoglHandle were the cogl_program_ and
cogl_shader_ apis which have replaced with the CoglSnippets api this
patch removes both of these apis.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit 6ed3aaf4be21d605a1ed3176b3ea825933f85cf0)
Since the original patch was done after removing deprecated API
this back ported patch doesn't affect deprecated API and so
actually this cherry-pick doesn't remove all remaining use of
CoglHandle as it did for the master branch of Cogl.
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>
Instead of having each winsys implement its own list of callbacks the
list is now just attached directly to the CoglOnscreen using code in
cogl-onscreen.c. The winsys's can invoke this list of callbacks by
calling _cogl_onscreen_notify_swap_buffers(). All of the winsys's
would probably have a very similar implementation for this anyway and
I don't think it makes much sense to try and save the cost of a list
pointer in the CoglOnscreen struct.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
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.
This adds two new functions:
void
cogl_poll_get_info (CoglContext *context,
CoglPollFD **poll_fds,
int *n_poll_fds,
gint64 *timeout);
void
cogl_poll_dispatch (CoglContext *context,
const CoglPollFD *poll_fds,
int n_poll_fds);
The application is expected to call the first function whenever it is
about to block to go idle, and the second function whenever it comes
out of idle. This gives Cogl winsys's the ability poll file
descriptors for events. For example when handing swap complete
notifications, it can report that it needs to block on a file
descriptor.
The two functions are backed by winsys virtual functions. There are
currently no implementations. The default handler for get_info just
reports no file descriptors and an infinite timeout.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
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 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>
Cogl aims to consistently put the origin of 2D objects at the top-left
instead of the bottom left as OpenGL does, but there was an oversight
and the experimental cogl_framebuffer_swap_region API was accepting
coordinates relative to the bottom left. Cogl will now flip the user's
given rectangles to be relative to the bottom of the framebufffer before
sending them to APIs like glXCopySubBuffer and glBlitFramebuffer.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
Previously, _cogl_get_proc_address had a fallback to resolve the
symbol using g_module_open(NULL) to get the symbol from anywhere in
the address space. The EGL backend ends up using this on some drivers
because eglGetProcAddress isn't meant to return a pointer for core
functions. This causes problems if something in the process is linking
against a different GL library, for example Cairo may be linking
against libGL itself. In this case it may end up resolving symbols
from the GL library even if GLES is being used.
This patch removes the fallback. The EGL version now has its own
fallback instead which passes the existing libgl_module from the
renderer to g_module_symbol so that it should only get symbols from
that library or its dependency chain. The GLX and WGL winsys only call
glXGetProcAddress and wglGetProcAddress. The stub winsys does however
continue using the global symbol lookup.
The internal _cogl_get_proc_address function has been renamed to
_cogl_renderer_get_proc_address because it needs a connected renderer
to work so it could be considered to be a renderer method. The pointer
to the renderer is passed down to the winsys backends so that it can
use the data attached to the renderer to get the module pointers.
https://bugzilla.gnome.org/show_bug.cgi?id=655412
Reviewed-by: Robert Bragg <robert@linux.intel.com>
This adds API to let you override the choice of Cogl's winsys backend.
Previously it was only possible to override the winsys using the
COGL_RENDERER environment variable, but it's useful for something like
Clutter to be able to control the winsys via API without needing
environment variable tricks. This also adds API to query back the
winsys chosen by Cogl, in case you don't set an explicit override.
Signed-off-by: Neil Roberts <neil@linux.intel.com>
Some of the virtual functions in CoglWinsysVtable only need to be
implemented for specific backends or when a specific feature is
advertised. This splits the vtable struct into two commented sections
marking which are optional and which are required. Wherever an
optional function is used there is now a g_return_if_fail to ensure
there is an implementation.
This adds Cogl API to show and hide onscreen framebuffers. We don't want
to go too far down the road of abstracting window system APIs with Cogl
since that would be out of its scope but the previous idea that we would
automatically map framebuffers on allocation except for those made from
foreign windows wasn't good enough. The problem is that we don't want to
make Clutter always create stages from foreign windows but with the
automatic map semantics then Clutter doesn't get an opportunity to
select for all the events it requires before mapping. This meant that we
wouldn't be delivered a mouse enter event for windows mapped underneath
the cursor which would break Clutters handling of button press events.
So that we can dynamically select what winsys backend to use at runtime
we need to have some indirection to how code accesses the winsys instead
of simply calling _cogl_winsys* functions that would collide if we
wanted to compile more than one backend into Cogl.
This moves the GLX specific code from cogl-texture-pixmap-x11.c into
cogl-winsys-glx.c. If we want the winsys components to by dynamically
loadable then we can't have GLX code scattered outside of
cogl-winsys-glx.c. This also sets us up for supporting the
EGL_texture_from_pixmap extension which is almost identical to the
GLX_texture_from_pixmap extension.
As was recently done for the GLX window system code, this commit moves
the EGL window system code down from the Clutter backend code into a
Cogl winsys.
Note: currently the cogl/configure.ac is hard coded to only build the GLX
winsys so currently this is only available when building Cogl as part
of Clutter.
This migrates all the GLX window system code down from the Clutter
backend code into a Cogl winsys. Moving OpenGL window system binding
code down from Clutter into Cogl is the biggest blocker to having Cogl
become a standalone 3D graphics library, so this is an important step in
that direction.
This tries to make the naming style of files under cogl/winsys/
consistent with other cogl source files. In particular private header
files didn't have a '-private' infix.
