Cogl 2.0 Reference Manual | ||||
---|---|---|---|---|
Top | Description |
CoglDisplay: Setup a display pipelineCoglDisplay: Setup a display pipeline — Common aspects of a display pipeline |
CoglDisplay; CoglBool cogl_is_display (void *object
); CoglDisplay * cogl_display_new (CoglRenderer *renderer
,CoglOnscreenTemplate *onscreen_template
); CoglRenderer * cogl_display_get_renderer (CoglDisplay *display
); CoglBool cogl_display_setup (CoglDisplay *display
,CoglError **error
); void cogl_gdl_display_set_plane (CoglDisplay *display
,gdl_plane_id_t plane
); void cogl_wayland_display_set_compositor_display (CoglDisplay *display
,struct wl_display *wayland_display
);
The basic intention for this object is to let the application configure common display preferences before creating a context, and there are a few different aspects to this...
Firstly there are options directly relating to the physical display pipeline that is currently being used including the digital to analogue conversion hardware and the screens the user sees.
Another aspect is that display options may constrain or affect how onscreen framebuffers should later be configured. The original rationale for the display object in fact was to let us handle GLX and EGLs requirements that framebuffers must be "compatible" with the config associated with the current context meaning we have to force the user to describe how they would like to create their onscreen windows before we can choose a suitable fbconfig and create a GLContext.
CoglBool cogl_is_display (void *object
);
Gets whether the given object references a CoglDisplay.
|
A CoglObject pointer |
Returns : |
TRUE if the object references a CoglDisplay
and FALSE otherwise. |
Since 1.10
Stability Level: Unstable
CoglDisplay * cogl_display_new (CoglRenderer *renderer
,CoglOnscreenTemplate *onscreen_template
);
Explicitly allocates a new CoglDisplay object to encapsulate the common state of the display pipeline that applies to the whole application.
cogl_display_new()
and can just jump straight to cogl_context_new()
and pass a NULL
display argument so Cogl will automatically
connect and setup a renderer and display.
A display
can only be made for a specific choice of renderer which
is why this takes the renderer
argument.
A common use for explicitly allocating a display object is to
define a template for allocating onscreen framebuffers which is
what the onscreen_template
argument is for, or alternatively
you can use cogl_display_set_onscreen_template()
.
When a display is first allocated via cogl_display_new()
it is in a
mutable configuration mode. It's designed this way so we can
extend the apis available for configuring a display without
requiring huge numbers of constructor arguments.
When you have finished configuring a display object you can
optionally call cogl_display_setup()
to explicitly apply the
configuration and check for errors. Alternaitvely you can pass the
display to cogl_context_new()
and Cogl will implicitly apply your
configuration but if there are errors then the application will
abort with a message. For simple applications with no fallback
options then relying on the implicit setup can be fine.
|
A CoglRenderer |
|
A CoglOnscreenTemplate |
Returns : |
A newly allocated CoglDisplay object in a mutable configuration mode. [transfer full] |
Since 1.10
Stability Level: Unstable
CoglRenderer * cogl_display_get_renderer (CoglDisplay *display
);
Queries the CoglRenderer associated with the given display
.
|
a CoglDisplay |
Returns : |
The associated CoglRenderer. [transfer none] |
Since 1.10
Stability Level: Unstable
CoglBool cogl_display_setup (CoglDisplay *display
,CoglError **error
);
Explicitly sets up the given display
object. Use of this api is
optional since Cogl will internally setup the display if not done
explicitly.
When a display is first allocated via cogl_display_new()
it is in a
mutable configuration mode. This allows us to extend the apis
available for configuring a display without requiring huge numbers
of constructor arguments.
Its possible to request a configuration that might not be supportable on the current system and so this api provides a means to apply the configuration explicitly but if it fails then an exception will be returned so you can handle the error gracefully and perhaps fall back to an alternative configuration.
If you instead rely on Cogl implicitly calling cogl_display_setup()
for you then if there is an error with the configuration you won't
get an opportunity to handle that and the application may abort
with a message. For simple applications that don't have any
fallback options this behaviour may be fine.
|
a CoglDisplay |
|
return location for a CoglError |
Returns : |
Returns TRUE if there was no error, else it returns
FALSE and returns an exception via error . |
Since 1.10
Stability Level: Unstable
void cogl_gdl_display_set_plane (CoglDisplay *display
,gdl_plane_id_t plane
);
Request that Cogl output to a specific GDL overlay plane
.
|
a CoglDisplay |
|
the GDL plane id |
Since 1.10
Stability Level: Unstable
void cogl_wayland_display_set_compositor_display (CoglDisplay *display
,struct wl_display *wayland_display
);
Informs Cogl of a compositor's Wayland display pointer. This enables Cogl to register private wayland extensions required to pass buffers between the clients and compositor.
|
a CoglDisplay |
|
A compositor's Wayland display pointer |
Since 1.10
Stability Level: Unstable