Description [src]

final class Cogl.Context : GObject.Object
  /* No available fields */

The top level application context.

A CoglContext is the top most sandbox of Cogl state for an application or toolkit. Its main purpose is to act as a sandbox for the memory management of state objects. Normally an application will only create a single context since there is no way to share resources between contexts.

For those familiar with OpenGL or perhaps Cairo it should be understood that unlike these APIs a Cogl context isn’t a rendering context as such. In other words Cogl doesn’t aim to provide a state machine style model for configuring rendering parameters. Most rendering state in Cogl is directly associated with user managed objects called pipelines and geometry is drawn with a specific pipeline object to a framebuffer object and those 3 things fully define the state for drawing. This is an important part of Cogl’s design since it helps you write orthogonal rendering components that can all access the same GPU without having to worry about what state other components have left you with.

Cogl does not maintain internal references to the context for resources that depend on the context so applications. This is to help applications control the lifetime a context without us needing to introduce special api to handle the breakup of internal circular references due to internal resources and caches associated with the context.

One a context has been destroyed then all directly or indirectly dependent resources will be in an inconsistent state and should not be manipulated or queried in any way.

For applications that rely on the operating system to clean up resources this policy shouldn’t affect them, but for applications that need to carefully destroy and re-create Cogl contexts multiple times throughout their lifetime (such as Android applications) they should be careful to destroy all context dependent resources, such as framebuffers or textures etc before unrefing and destroying the context.


hierarchy this CoglContext ancestor_0 GObject ancestor_0--this




Creates a new CoglContext which acts as an application sandbox for any state objects that are allocated.

Instance methods

No description available.


Retrieves the CoglDisplay that is internally associated with the given context. This will return the same CoglDisplay that was passed to cogl_context_new() or if NULL was passed to cogl_context_new() then this function returns a pointer to the display that was automatically setup internally.


This function should only be called if the COGL_FEATURE_ID_TIMESTAMP_QUERY feature is advertised.


This function is used to get support for waiting on previous GPU work through sync fds. It will return a sync fd which will signal when the previous work has completed.

No description available.


Retrieves the CoglRenderer that is internally associated with the given context. This will return the same CoglRenderer that was passed to cogl_display_new() or if NULL was passed to cogl_display_new() or cogl_context_new() then this function returns a pointer to the renderer that was automatically connected internally.

No description available.


Associate a CoglPipeline with a context and key. This will not take a new reference to the pipeline, but will unref all associated pipelines when the context gets destroyed. Similarly, if a pipeline gets overwritten, it will get unreffed as well.

No description available.

Methods inherited from GObject (43)

Please see GObject for a full list of methods.


Signals inherited from GObject (1)

The notify signal is emitted on an object when one of its properties has its value set through g_object_set_property(), g_object_set(), et al.

Class structure

struct CoglContextClass {
  GObjectClass parent_class;

No description available.

Class members
parent_class: GObjectClass

No description available.