The cogl_is_* functions were showing up quite high on profiles due to
iterating through arrays of cogl handles.
This does away with all the handle arrays and implements a simple struct
inheritance scheme. All cogl objects now add a CoglHandleObject _parent;
member to their main structures. The base object includes 2 members a.t.m; a
ref_count, and a klass pointer. The klass in turn gives you a type and
virtual function for freeing objects of that type.
Each handle type has a _cogl_##handle_type##_get_type () function
automatically defined which returns a GQuark of the handle type, so now
implementing the cogl_is_* funcs is just a case of comparing with
obj->klass->type.
Another outcome of the re-work is that cogl_handle_{ref,unref} are also much
more efficient, and no longer need extending for each handle type added to
cogl. The cogl_##handle_type##_{ref,unref} functions are now deprecated and
are no longer used internally to Clutter or Cogl. Potentially we can remove
them completely before 1.0.
* clutter/cogl/gl/cogl.c:
* clutter/cogl/gles/cogl.c:
* clutter/cogl/cogl.h.in: Add cogl_clip_stack_save,
cogl_clip_stack_restore, cogl_viewport and cogl_frustum.
* clutter/cogl/gl/cogl-fbo.h:
* clutter/cogl/gl/cogl-fbo.c: Try to attach a stencil buffer when
creating an FBO.
* clutter/cogl/common/cogl-clip-stack.c: Add functions to save and
restore the whole state of the stack.
* clutter/clutter-texture.c (clutter_texture_paint): When
rendering the FBO source, setup a temporary asymmetric perspective
projection matrix to render it as it would appear on screen.
* clutter/clutter-private.h:
* clutter/clutter-actor.c
(_clutter_actor_apply_modelview_transform_recursive): No longer
static and exported in clutter-private.h
