ClutterContent is an interface for creating delegate objects that handle
what an actor is going to paint.
Since they are a newly added type, they only hook into the new PaintNode
based API.
The position and size of the content is controlled in part by the
content's own preferred size, and by the ClutterContentGravity
enumeration.
Now that we have a proper scene graph API, we should split out the
rendering part from the logical and event handling part.
ClutterPaintNode is a lightweight fundamental type that encodes only the
paint operations: pipeline state and geometry. At its most simple, is a
way to structure setting up the programmable pipeline using a
CoglPipeline, and submitting Cogl primitives. The important take away
from this API is that you are not allowed to call Cogl API like
cogl_set_source() or cogl_primitive_draw() directly.
The interesting approach to this is that, in the future, we should be
able to move to a purely retained mode: we will decide which actors need
to be painted, they will update their own branch of the render graph,
and we'll take the render graph and build all the rendering commands
from that.
For the 1.x API, we will have to maintain invariants and the existing
behaviour, but as soon as we can break API, the old paint signal will
just go away, and Actors will only be allowed to manipulate the render
tree.
As a convenience for the C API.
Language bindings should already be using the GValue variants.
This commit also moves the custom progress functions out of the
clutter-interval.c, as they are meant to be generic interpolation
functions and not ClutterInterval-specific.
Creating PaintVolume instances is not possible, and it's not recommended
anyway. It is, though, necessary to union paint volumes, especially with
2D boxes, in some cases.
Clutter should provide a simple convenience function that allows
unioning volumes to boxes in a moderately efficient way.
https://bugzilla.gnome.org/show_bug.cgi?id=670021
This should avoid trying to fix the origin of a paint volume set from
the allocation's origin, and thus breaking everything.
A PaintVolume for an actor is defined to be relative to the actor's
modelview unless specifically modified by internal functions; the origin
of an actor's allocation is, on the other hand, parent-relative.
Iterating over children and ancestors of an actor is a relatively common
operation. Currently, you only have one option: start a for() loop, get
the first child of the actor, and advance to the next sibling for the
list of children; or start a for() loop and advance to the parent of the
actor.
These operations can be easily done through the ClutterActor API, but
they all require going through the public API, and performing multiple
type checks on the arguments.
Along with the DOM API, it would be nice to have an ancillary, utility
API that uses an iterator structure to hold the state, and can be
advanced in a loop.
https://bugzilla.gnome.org/show_bug.cgi?id=668669
We need to queue a relayout when removing a visible child from a visible
parent.
We also need to insert the child at the right position (depending on the
depth) so that newly added actors will be painted on top.
The actor class should be able to hold the margin offsets like it does
for expand and alignment flags.
Instead of filling the private data structure with data, we should be
able to use an ancillary data structure, given that all this data is
optional and might never be set in the first place.
Now that ClutterActor implements the Container contract we can actually
defer the size negotiation to a ClutterLayoutManager directly from the
default implementation of the Actor's virtual functions.
Add a public version of the clipped queue redraw, using a 2D clip. This
allows implementing actors with trackable 2D clipped regions, like the
ClutterX11TexturePixmap, outside of Clutter itself.
https://bugzilla.gnome.org/show_bug.cgi?id=660997
Just like GLIB_DEPRECATED and GLIB_DEPRECATED_FOR, Clutter should have
its own wrappers for G_DEPRECATED and G_DEPRECATED_FOR, to allow opting
out of deprecation warnings.
Deprecation warnings are enabled by default, now, even when building
Clutter.
This moves a couple of definitions to the common types header, and makes
sure that ClutterBehaviour subclasses include clutter-behaviour.h first,
so that their types can be fully expanded without necessarily have the
ClutterBehaviour header header included by their public headers. This is
the necessary prelude to have clutter-behaviour.[ch] moved to the
deprecated section.
We already have two mechanisms for controlling the font rendering
quality on a per-application basis:
• ClutterSettings properties
• clutter_backend_set_font_options()
The font flags were always a stop-gap solution, and one that tried to
simplify a fairly complex issue beyond the point of actually being
useful.
https://bugzilla.gnome.org/show_bug.cgi?id=660786
With the instantiatable ClutterShaderEffect, the only reason for
ClutterShader to exist is to make the ClutterActor::paint implementation
miserable.
Yes, ClutterShader doesn't use a FBO, so it's "more efficient" on
ClutterTextures. It's also generally wrong unless you know *exactly* how
the actor's pipeline is set up — something we cannot even guarantee
internally unless we start doing lame type checks.
This is a lump commit that is fairly difficult to break down without
either breaking bisecting or breaking the test cases.
The new design for handling X11 event translation works this way:
- ClutterBackend::translate_event() has been added as the central
point used by a ClutterBackend implementation to translate a
native event into a ClutterEvent;
- ClutterEventTranslator is a private interface that should be
implemented by backend-specific objects, like stage
implementations and ClutterDeviceManager sub-classes, and
allows dealing with class-specific event translation;
- ClutterStageX11 implements EventTranslator, and deals with the
stage-relative X11 events coming from the X11 event source;
- ClutterStageGLX overrides EventTranslator, in order to
deal with the INTEL_GLX_swap_event extension, and it chains up
to the X11 default implementation;
- ClutterDeviceManagerX11 has been split into two separate classes,
one that deals with core and (optionally) XI1 events, and the
other that deals with XI2 events; the selection is done at run-time,
since the core+XI1 and XI2 mechanisms are mutually exclusive.
All the other backends we officially support still use their own
custom event source and translation function, but the end goal is to
migrate them to the translate_event() virtual function, and have the
event source be a shared part of Clutter core.
This is a fairly extensive second pass at exposing paint volumes for
actors.
The API has changed to allow clutter_actor_get_paint_volume to fail
since there are times - such as when an actor isn't a descendent of the
stage - when the volume can't be determined. Another example is when
something has connected to the "paint" signal of the actor and we simply
have no way of knowing what might be drawn in that handler.
The API has also be changed to return a const ClutterPaintVolume pointer
(transfer none) so we can avoid having to dynamically allocate the
volumes in the most common/performance critical code paths. Profiling was
showing the slice allocation of volumes taking about 1% of an apps time,
for some fairly basic tests. Most volumes can now simply be allocated on
the stack; for clutter_actor_get_paint_volume we return a pointer to
&priv->paint_volume and if we need a more dynamic allocation there is
now a _clutter_stage_paint_volume_stack_allocate() mechanism which lets
us allocate data which expires at the start of the next frame.
The API has been extended to make it easier to implement
get_paint_volume for containers by using
clutter_actor_get_transformed_paint_volume and
clutter_paint_volume_union. The first allows you to query the paint
volume of a child but transformed into parent actor coordinates. The
second lets you combine volumes together so you can union all the
volumes for a container's children and report that as the container's
own volume.
The representation of paint volumes has been updated to consider that
2D actors are the most common.
The effect apis, clutter-texture and clutter-group have been update
accordingly.
An actor has an implicit "paint volume", that is the volume in 3D space
occupied when painting itself.
The paint volume is defined as a cuboid with the origin placed at the
top-left corner of the actor; the size of the cuboid is given by three
vectors: width, height and depth.
ClutterActor provides API to convert the paint volume into a 2D box in
screen coordinates, to compute the on-screen area that an actor will
occupy when painted.
Actors can override the default implementation of the get_paint_volume()
virtual function to provide a different volume.
By default, ShaderEffect creates a fragment shader; in order to be able
to deprecate ClutterShader we need a way for ShaderEffect sub-classes to
create a vertex shader if needed - By using a write-only, constructor
only property.
ClutterShader has, internally, a ClutterShaderType enumeration that can
be used exactly for this. We just need to expose it and create a GObject
property for ClutterShaderEffect.
The Constraint base, abstract class should be used to implement Actor
modifiers that affect the way an actor is sized or positioned inside a
fixed layout manager.
ClutterAction is an abstract class that should be used as the ancestor
for objects that change how an actor behaves when dealing with events
coming from user input.
ClutterActorMeta is a base, abstract class that can be used to derive
classes that are attached to a ClutterActor instance in order to modify
the way an actor is painted, sized/positioned or responds to events.
A typed container for ActorMeta instances is also provided to the
sub-classes can be attached to an Actor.
* Add new clutter_geometry_union(), because writing union intersection
is harder than it looks. Fixes two problems with the inline code in
clutter_stage_glx_add_redraw_clip().
1) The ->x and ->y of were reassigned to before using them to
compute the new width and height.
2) since ClutterGeometry has unsigned width, x + width is unsigned,
and comparison goes wrong if either rectangle has a negative
x + width. (We fixed width for GdkRectangle to be signed for GTK+-2.0,
this is a potent source of bugs.)
* Use in clutter_stage_glx_add_redraw_clip()
* Account for the case where the incoming rectangle is empty, and don't
end up with the stage being entirely redrawn.
* Account for the case where the stage already has a degenerate
width and don't end up with redrawing only the new rectangle and not
the rest of the stage.
The better fix here for the second two problems is to stop using a 0
width to mean the entire stage, but this should work for now.
http://bugzilla.openedhand.com/show_bug.cgi?id=2040
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Embedding toolkits most likely will disable the event handling, so all
the input device code will not be executed. Unfortunately, the newly
added synthetic event generation of ENTER and LEAVE event pairs depends
on having input devices.
In order to unbreak things without reintroducing the madness of the
previous code we should allow embedding toolkits to just update the
state of an InputDevice by using the data contained inside the
ClutterEvent. This strategy has two obvious reasons:
• the embedding toolkit is creating a ClutterEvent by translating
a toolkit-native event anyway
• this is exactly what ClutterStage does when processing events
We are, essentially, deferring input device handling to the embedding
toolkits, just like we're deferring event handling to them.
ClutterAnimator is a class for managing the animation of multiple
properties of multiple actors over time with keyframing of values.
The Animator class is meant to be used to effectively describe
animations using the ClutterScript definition format, and to construct
complex implicit animations from the ground up.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
ClutterActorBox should have an interpolate() method that allows to
compute the intermediate values between two states, given a progress
value, e.g.:
clutter_actor_box_interpolate (start, end, alpha, &result);
Another utility method, useful for layout managers, is a modifier
that clamps the members of the actor box to the nearest integer
value.
Instead of overloading ClutterChildMeta with both container and layout
metadata and delegate to every LayoutManager implementation to keep a
backpointer to the layout manager instance, we can simply subclass
ChildMeta into LayoutMeta and presto! everything works out pretty well
for everyone.
ActorBox should have methods for easily extracting the X and Y
coordinates of the origin, and the width and height separately.
These methods will make it easier for high-level language bindings
to manipulate ActorBox instances and avoid the Geometry type.
The Vertex and ActorBox boxed types are meant to be used across
the API, but are fairly difficult to bind. Their memory management
is also unclear, and has to go through the indirection of
g_boxed_copy() and g_boxed_free().
With the recent change to internal floating point values, ClutterUnit
has become a redundant type, defined to be a float. All integer entry
points are being internally converted to floating point values to be
passed to the GL pipeline with the least amount of conversion.
ClutterUnit is thus exposed as just a "pixel with fractionary bits",
and not -- as users might think -- as generic, resolution and device
independent units. not that it was the case, but a definitive amount
of people was convinced it did provide this "feature", and was flummoxed
about the mere existence of this type.
So, having ClutterUnit exposed in the public API doubles the entry
points and has the following disadvantages:
- we have to maintain twice the amount of entry points in ClutterActor
- we still do an integer-to-float implicit conversion
- we introduce a weird impedance between pixels and "pixels with
fractionary bits"
- language bindings will have to choose what to bind, and resort
to manually overriding the API
+ *except* for language bindings based on GObject-Introspection, as
they cannot do manual overrides, thus will replicate the entire
set of entry points
For these reason, we should coalesces every Actor entry point for
pixels and for ClutterUnit into a single entry point taking a float,
like:
void clutter_actor_set_x (ClutterActor *self,
gfloat x);
void clutter_actor_get_size (ClutterActor *self,
gfloat *width,
gfloat *height);
gfloat clutter_actor_get_height (ClutterActor *self);
etc.
The issues I have identified are:
- we'll have a two cases of compiler warnings:
- printf() format of the return values from %d to %f
- clutter_actor_get_size() taking floats instead of unsigned ints
- we'll have a problem with varargs when passing an integer instead
of a floating point value, except on 64bit platforms where the
size of a float is the same as the size of an int
To be clear: the *intent* of the API should not change -- we still use
pixels everywhere -- but:
- we remove ambiguity in the API with regard to pixels and units
- we remove entry points we get to maintain for the whole 1.0
version of the API
- we make things simpler to bind for both manual language bindings
and automatic (gobject-introspection based) ones
- we have the simplest API possible while still exposing the
capabilities of the underlying GL implementation
