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.
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)
This also replaces use of CoglHandle with a CoglTexturePixmapX11 type
instead.
This patch also ensures the CoglTexturePixmapX11 constructor take an
explicit CoglContext pointer and can return a GError consistent with
other CoglTexture constructors.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
This moves all the cogl_framebuffer_ apis relating to swap buffer
requests into the cogl_onscreen_ namespace since on CoglOnscreen
framebuffers have back buffers that can be swapped.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
cogl_clear depends on the default CoglContext which we are trying to
steer the API away from requiring. cogl_framebuffer_clear4f is
explicitly passed a framebuffer pointer which is implicitly related to a
specific context.
This updates all the examples to use cogl_framebuffer_clear4f instead of
cogl_clear and removes any redundant CoglColor that was previously
passed to cogl_clear.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
It used to be that cogl_framebuffer_allocate() had to be done explicitly
but we have since made Cogl lazily allocate framebuffers when they are
first used if they haven't already been explicitly allocated. Developers
only need to explicitly allocate framebuffers if they are planning to
gracefully handle any errors. In cases where the program will simply
abort due to an allocation error they can simply rely on implicit
allocation which will cause an abort on error.
This updates the examples to not explicitly allocate the framebuffers
since they all just abort on error anyway.
Reviewed-by: Neil Roberts <neil@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>
This namespaces all of the examples and marks them for installation
if --enable-examples-install has been passed to ./configure. This
simplifies packaging the examples which can be quite convenient
for smoke testing Cogl on various platform.
https://bugzilla.gnome.org/show_bug.cgi?id=656755
Reviewed-by: Neil Roberts <neil@linux.intel.com>
