The first vertex in the triangle vertices used in the cogl-hello
example (which were copied into a few other examples) for some reason
has a semi-transparent alpha component. However the colour needs to be
pre-multiplied and the red component was still 0xff so the colour is
effectively invalid and the transparency isn't shown. This patch just
sets the alpha component to 0xff to make it less confusing.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
(cherry picked from commit 461879986ec012556b4e680b73e36d440927faaa)
The two SDL examples now throttle their rendering to the
COGL_FRAME_EVENT_SYNC event. Previously the examples would redraw
whenever a mouse motion event is received but now they additionally
wait for the sync event which means that if another mouse event comes
immediately after rendering the last frame it theoretically could
avoid blocking waiting for the last frame to complete. In practice
however the SDL winsys doesn't support swap events so it will get the
sync event immediately anyway, but it's nice to have the code as an
example and a test.
This patch also changes the mainloop a bit to do the equivalent steps
without the outer main loop which I think makes it a bit easier to
follow.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
(cherry picked from commit 97cdd832dded2ebfaa42ee4bc43319cb8648d01b)
This SDL example were unnecessarily including <glib.h> but they don't
actually depend on glib so now they are built even if Cogl is being
built with --disable-glib.
(cherry picked from commit 1d3bce7f68b0a6885c10a29cd9836a3541a1b653)
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 re-works the SDL integration api to simplify the integration for
application developers and also allow Cogl to know when the application
is about to go idle waiting for events so it can perform idle
book-keeping work.
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>
As we move towards Cogl 2.0 we are aiming to remove the need for a
default global CoglContext and so everything should be explicitly
related to a context somehow. CoglPipelines are top level objects and
so this patch adds a context argument to cogl_pipeline_new().
Reviewed-by: Neil Roberts <neil@linux.intel.com>
All CoglBuffer constructors now take an explicit CoglContext
constructor. This is part of the on going effort to adapt to Cogl API so
it no longer depends on a global, default context.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
This adds cogl_framebuffer_ apis for drawing attributes and primitives
that replace corresponding apis that depend on the default CoglContext.
This is part of the on going effort to adapt the Cogl api so it no
longer depends on a global context variable.
All the new drawing functions also take an explicit pipeline argument
since we are also aiming to avoid being a stateful api like Cairo and
OpenGL. Being stateless makes it easier for orthogonal components to
share access to the GPU. Being stateless should also minimize any
impedance miss-match for those wanting to build higher level stateless
apis on top of Cogl.
Note: none of the legacy, global state options such as
cogl_set_depth_test_enabled(), cogl_set_backface_culling_enabled() or
cogl_program_use() are supported by these new drawing apis and if set
will simply be silently ignored.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
Instead of using apis like cogl_push/pop_matrix, cogl_rotate,
cogl_translate and cogl_scale all the examples now use the
cogl_framebuffer_* equivalents. Our aim is to remove the need for the
default CoglContext and so we are switching towards apis that
are explicitly tied to a specific context.
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>
The aim is that it should be a requirement that all Cogl applications
hook their mainloops into Cogl so we should lead by examples. Most of
the examples now just call cogl_poll_get_info and then g_poll with a
zero timeout so that they can continue to constantly redraw.
The SDL example is a bit special because SDL makes it very difficult
to wait on either a timeout or any file descriptors. The SDL winsys is
documented not to require blocking on any file descriptors so we can
ignore that. It implements the timeout by adding an SDL timer which
pushes an event to the queue to wake up SDL_GetEvent.
The Cogland example was already using the glib main loop so that one
has been updated to add the CoglGLibSource to it.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
This adds a simple example based on the hello example but that forces
the SDL winsys and listens for mouse motion events to move the
triangle.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
