docs: Update the HACKING.backends file

The create_context() and ensure_context() sections should be more clear
on the role of the functions, and their eventual caveats, like being
called multiple times.
This commit is contained in:
Emmanuele Bassi 2010-03-03 18:17:15 +00:00
parent c3a942abde
commit dbe2acc2b1

View File

@ -95,11 +95,18 @@ can be overridden:
by Clutter. Clutter will call this function during the initialization by Clutter. Clutter will call this function during the initialization
phase. A GL (or GLES) context must always be available after the phase. A GL (or GLES) context must always be available after the
initialization, so that Cogl and Clutter can query it for capabilities. initialization, so that Cogl and Clutter can query it for capabilities.
This function might be called multiple times so if a context was
successfully created in a previous call, this function should
short-circuit early and return TRUE
ClutterBackend::ensure_context ClutterBackend::ensure_context
-- This function is used to ensure that the backend drawing context -- This function is used to ensure that the backend drawing context
is made current for passed ClutterStage, using the backend-specific is made current for passed ClutterStage, using the backend-specific
API. API. This function is called each time a new stage is going to
be painted. If the Stage is inside its destruction sequence this
function should either fall back the drawing context to a default
drawing surface or should unset the drawing surface from the
drawing context.
ClutterBackend::redraw ClutterBackend::redraw
-- This function is used to draw the passed ClutterStage; the backend -- This function is used to draw the passed ClutterStage; the backend