Previously we were applying the culling optimization to any actor
painted without considering that we may be painting to an offscreen
framebuffer where the stage clip isn't applicable.
For now we simply expose a getter for the current draw framebuffer
and we can assume that a return value of NULL corresponds to the
stage.
Note: This will need to be updated as stages start to be backed by real
CoglFramebuffer objects and so we won't get NULL in those cases.
To give quick visibility to the things going on relating to clipping and
culling this adds some more CLIPPING debug notes to clutter-actor.c and
clutter-stage.c
There's an optimisation in clutter-actor.c to avoid calculating the
last known paint volume whenever culling and clipped redraws are both
disabled. However there was a small thinko in the logic so that it
would also avoid calculating the paint volume whenever only one of the
debug flags is enabled. This fixes it to explicitly check that the two
flags are not both enabled before skipping the paint volume
calculation.
Previously each time we needed to retrieve the model transform for a
given actor we would call the apply_transform vfunc which would build up
a transformation matrix based on the actor's current anchor point, its
scale, its allocation and rotation. The apply_transform implementation
would repeatedly call API like cogl_matrix_rotate, cogl_matrix_translate
and cogl_matrix_scale.
All this micro matrix manipulation APIs were starting to show up in the
profiles of dynamic applications so this adds priv->transform matrix
cache which maintains the combined result of the actors scale, rotation
and anchor point etc. Whenever something like the rotation changes then
then the matrix is marked as dirty, but so long as the matrix isn't
dirty then the apply_transform vfunc now just calls cogl_matrix_multiply
with the cached transform matrix.
This implements a variation of frustum culling whereby we convert screen
space clip rectangles into eye space mini-frustums so that we don't have
to repeatedly transform actor paint-volumes all the way into screen
coordinates to perform culling, we just have to apply the modelview
transform and then determine each points distance from the planes that
make up the clip frustum.
By avoiding the projective transform, perspective divide and viewport
scale for each point culled this makes culling much cheaper.
OpenGL < 4.0 only supports integer based viewports and internally we
have a mixture of code using floats and integers for viewports. This
patch switches all viewports throughout clutter and cogl to be
represented using floats considering that in the future we may want to
take advantage of floating point viewports with modern hardware/drivers.
This is needed if an effect wants to temporarily override the paint
opacity. It needs to be able to restore the old opacity override in
the post_paint handler otherwise it would replace the effect of the
opacity override from any outer effects.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2541
The shader stack held by ClutterMainContext should only be accessed
using functions, and not directly.
Since it's a stack, we can use stack-like operations: push, pop and
peek.
Let's try and start reducing the size of ClutterActorPrivate by moving
some optional, out-of-band data from it to GObject data.
The ShaderData structure is a prime candidate for this migration: it
does not need to be inspected by the actor, and its relationship with an
actor is transient and optional.
By attaching it to the actor's instance through g_object_set_data() we
neatly tie its lifetime to the instance, and we don't have to care
cleaning it up in the finalize()/dispose() implementation of
ClutterActor itself.
In _clutter_actor_queue_redraw_with_clip it has a local variable to
mark when a new paint volume for the clip is created so that it can be
freed when the function returns. However the actual code to free the
paint volume went missing in 3b789490d2 so the variable did
nothing. This patch just adds the free back in.
This time, in Clutter core.
The ObjC standard library provides a type called 'id', which obviously
requires any library to either drop the useful shadowed variable warning
or stop using 'id' as a variable name.
Yes, it's almost unbearably stupid. Well, at least it's not 'index' in
string.h, or 'y2' in math.h.
The 'in_clone_paint' parameter of the private function
_clutter_actor_set_in_clone_paint() shadowed the private function
in_clone_paint(). Rename this parameter to 'is_in_clone_paint' to remove
a compiler warning.
Replace the opacity_parent with an opacity_override variable, to allow
direct overriding of the paint opacity and simplify this mechanism
somewhat.
This also required a new private flag, in_clone_paint, to maintain the
functionality of the public function clutter_actor_is_in_clone_paint()
Don't use ugly "#undef CLUTTER_DISABLE_DEPRECATED" inside source code
using deprecated symbols; we have the handy CLUTTER_COMPILATION define
that we can use as part of the "disable deprecated" conditional.
Use the internal child list for the default map/unmap vfuncs. This removes
the requirement for non-container composite actors to implement their own
map/unmap functions.
Unrealizing an actor is a recursive process that needs to traverse the
children of an actor to ensure they are also unrealized. This maintains
the invariant that if any given actor is marked as unrealized then you
know that all its children have also been unrealized.
The previous implementation would use the container interface's
foreach_with_internals vfunc to explicitly traverse the children of
container actors but this didn't consider composite actors that aren't
containers.
Since clutter-actor now maintains an explicit list of children we can
also handle composite actors that aren't containers using
_clutter_actor_traverse.
This makes it possible to choose the traversal order; either depth first
or breadth first and when visiting actors in a depth first order there
is now a callback called before children are traversed and one called
after. Some tasks such as unrealizing actors need to explicitly control
the traversal order to maintain the invariable that all children of an
actor are unrealized before we actually mark the parent as unrealized.
The callbacks are now passed the relative depth in the graph of the
actor being visited and instead of only being able to return a boolean
to bail out of further traversal it can now do one of: continue,
skip_children or break. To implement something like unrealize it's
desirable to skip children that you find have already been unrealized.
The last_paint_box for an actor represents its "normal" position - we
shouldn't update it or use it to cull drawing if we are painting
a clone of the actor. Tracking whether we are painting a clone is
done by adding _clutter_actor_push/pop_clone_paint() and a global
"clone paint level".
http://bugzilla.clutter-project.org/show_bug.cgi?id=2396
When transforming a paint-volume or transforming allocation vertices we
are transforming more than one point at a time so we can batch those
together with cogl_matrix_transform_points instead of
cogl_matrix_transform_point. Also in both of these cases we don't need
to do a projective transform so using cogl_matrix_transform_points also
lets us reduce the per-vertex computation.
The Behaviour class and its implementations have been replaced by the
new animation framework API and by the constraints for layout-related
animations.
Currently, we need to make tests build, so we undef DISABLE_DEPRECATED
in specific test cases while they get ported.
The paint volume structure is cached in the Actor it references, and
this causes a reference cycle.
The paint volume is going to be used when painting, so the actor must
still be valid - otherwise Clutter will bail out far before than
accessing the actor pointer in ClutterPaintVolume.
Otherwise, we could have used dispose() to check for a valid actor and
remove a reference if the actor field is !NULL; it feels less clean,
though, since we're effectively managing an extra reference on
ourselves.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2431
For internal usage, writing:
clutter_actor_get_name (actor) != NULL
? clutter_actor_get_name (actor)
: G_OBJECT_TYPE_NAME (actor)
is overly verbose and does two type checks. A simple, internal method
for getting the same result without type checks would be much more
appreciated.
Instead of waiting until clutter_actor_paint to check if there are any
handlers connected to the "paint" signal, we now do the check whenever
the paint-volume is requested in _actor_get_paint_volume_mutable().
Previously we checked in clutter_actor_paint(), but at that time we may
already be using a stage clip that could be derived from an invalid
paint-volume. We used to try and handle that by queuing a follow up,
unclipped, redraw but anyway there was an additional problem with the
previous approach because the checking wasn't enough to always catch
invalid volumes involved in culling (considering that containers may
derive their volume from children that haven't yet been painted)
By moving the check to _get_paint_volume time not only do we now
correctly check children in cases where a container derives its volume
from its children's volumes but we no longer need to queue follow up
redraws to cover up artefacts.
Since we now never queue follow up redraws, this in turn means we should
no longer clobber redraws queued with an explicit clip which was
something affecting gnome-shell since it connects a handler to the paint
signal of the stage.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2388
Once an actor had _clutter_stage_queue_redraw_entry_invalidate()
called on it once, then priv->queue_redraw_entry would point to
an entry with entry->actor NULL. _clutter_stage_queue_actor_redraw()
doesn't handle this case and no further redraws would be queued.
To fix this, NULL out priv->queue_redraw_entry() and then make sure
we free the invalidated entry in
_clutter_stage_maybe_finish_queue_redraws() just as we do for
still valid entries.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2389
We need to make sure that redraws queued for actors on a stage are for
actors actually in the stage. So in clutter_actor_unparent() descend
through the children and remove redraws. Just removing the actor itself
isn't good enough since an entire hierarchy can be removed from the
stage without breaking it up into individual actors.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2359
This is based on an original patch from Owen Taylor who debugged the
root cause of this bug; thanks.
Instead of delegating the check for the ActorMeta:enabled property to
the sub-classes of ClutterActorMeta, ClutterActor can do the check prior
to using the ClutterActorMeta instances.
