If the DragAction has a drag handle that gets destroyed inside the
::drag-end signal handler, the destruction sequence will trigger a
callback we have in place to check if the handle is being destroyed
mid-drag, e.g. from a ::drag-motion event.
The callback on the drag handle destruction will check if we are still
in the middle of a drag and emit the ::drag-end signal to allow cleaning
up; the callback erroneously uses the drag handle as the argument for
the emit_drag_end() function — instead of the actor to which the drag
action has been attached. Also, by the time we emit the ::drag-end, we
are not dragging the actor any more, so we shouldn't be emitted the
::drag-end signal twice.
The fix is, thus, made of two parts:
- reset the in_drag boolean before emitting the ::drag-end signal
so that destroying the drag handle will not result in a double
signal emission;
- use the correct actor when calling emit_drag_end().
https://bugzilla.gnome.org/show_bug.cgi?id=681814
If the actor has a fixed position set, but it's not using the BinLayout
alignment enumeration to set its alignment, then we force the alignment
factor to 0.0; this is consistent with what happens with an explicit
alignment of CLUTTER_BIN_ALIGNMENT_FIXED.
https://bugzilla.gnome.org/show_bug.cgi?id=682265
Event handling should only apply to editable ClutterText actors, but we
also have the :selectable property to care about.
The button/touch press should position the cursor inside an editable
ClutterText; the :selectable property should be used to allow selecting
the text, either through pointer or touch dragging, via the keyboard, or
by multiple pointer clicks. If neither of these two conditions are met,
the ClutterText should just propagate the event handling further.
Allow setting a ClutterRect on the drag action and force the
dragged actor's position to be always within that rectangle (relative
to the actor's parent).
https://bugzilla.gnome.org/show_bug.cgi?id=681168
The boolean_handled accumulator will stop the signal emission if TRUE is
returned by a signal handler; the boolean_continue accumulator will stop
the signal emission if FALSE is returned. The first one is used for
event-related signals, while the latter is used for action-related
signals.
Only the signal connection. When using G_ENABLE_DIAGNOSTIC there will be
a warning for every signal connection.
We should try and discourage people from ever using the paint signal
ever again, until we can safely remove it in Clutter 2.0.
We cannot fully deprecate Geometry, because ClutterActor and ClutterText
are actually using the type in signals and properties; but we can
deprecate the API that uses this type, so that 2.0 will be able to avoid
it entirely.
The :clip property still uses ClutterGeometry, which is a very bad
rectangle type. Since we cannot change the type of the property
compatibly, we should introduce a new property using ClutterRect
instead. This also matches the ClutterActor.set_clip() API, which uses a
decomposed rectangle with floating point values, like we do with
set_position() and set_size().
Instead of only relying on the (now) deprecated BinAlignment.FIXED
enumeration value, we just ask the actor if a fixed position has been
explicitly set, under the assumption that if a developer decided to call
set_x(), set_y(), or set_position() on an actor inside a BinLayout then
she wanted the fixed position to be honoured.
This removes the last (proper) use of the BinAlignment enumeration.
The Geometry type is an *awful* representation of a integer rectangle,
as it uses unsigned integers for its size, leading to overflow issues
when unioning and intersecting. We have better rectangle types in
Cairo and Clutter, these days.
When dragging/scrolling using touch events, we want the same behaviour
than for motion events. We need to honor the user's calls to
clutter_stage_set_motion_events_enabled() to deactive event
bubbling/captured sequences on the actor located under the pointer and
just transmit events to the stage/grab actor.
https://bugzilla.gnome.org/show_bug.cgi?id=680751
We need to make sure that ClutterActor::transition-stopped is emitted
after the transition was removed from the actor's list of transitions.
We cannot just remove the TransitionClosure from the hash table that
holds the transitions associated to an actor, and let the
TransitionClosure free function stop the timeline, thus emitting the
::transition-stopped signal - otherwise, stopping the timeline will end
up trying to remove the transition from the hash table, and we'll get
either a warning or a segfault.
Since we know we're removing the timeline anyway, we can emit the signal
ourselves in case the timeline is playing, in both the implicit and
explicit cases.
The :transform property controls the modelview matrix of an actor; it
can be used to set a custom modelview matrix on the actor, as opposed
to the decomposed transformations (rotation, scaling, translation)
provided by the ClutterActor class.
The transitions we create implicitly should be removed from the set of
transitions associated to an actor; the transitions explicitly
associated to an actor, though, have to survive the emission of their
'stopped' signal.
We can remove the update_transition() private method, and move its
functionality inside the create_transition() private method, thereby
removing lots of duplicated code, as well as redundant checks on the
existence of a transition. This will allow handling transition updates
atomically in the future.
Another progress function from the CSS3 Transitions specification, using
a parametrices cubic bezier curve between (0, 0) and (1, 1) with two
control points.
(sadly, no ASCII art can approximate a cubic bezier, so no graph)
The cubic-bezier() progress function comes with a bunch of preset easing
modes: ease, ease-in, ease-out, and ease-in-out, that we can map to
enumeration values.
The CSS3 Transitions specification from the W3C defines the possibility
of using a parametrized step() timing function, with the following
prototype:
steps(n_steps, [ start | end ])
where @n_steps represents the number of steps used to divide an interval
between 0 and 1; the 'start' and 'end' tokens describe whether the value
change should happen at the start of the transition, or at the end.
For instance, the "steps(3, start)" timing function has the following
profile:
1 | x
| |
| x---|
| ' |
| x---' |
| ' |
0 |---' |
Whereas the "steps(3, end)" timing function has the following profile:
1 | x---|
| ' |
| x---' |
| ' |
x---' |
| |
0 | |
Since ClutterTimeline uses an enumeration for controlling the progress
mode, we need additional API to define the parameters of the steps()
progress; for this reason, we need a CLUTTER_STEPS enumeration value,
and a method for setting the number of steps and the value transition
policy.
The CSS3 Transitions spec helpfully also defines a step-start and a
step-end shorthands, which expand to step(1, start) and step(1, end)
respectively; we can provide a CLUTTER_STEP_START and CLUTTER_STEP_END
enumeration values for those.
This patch brings 'enter-event' and 'leave-event' generation for touch
based devices. This leads to adding a new API to retrieve coordinates
of a touch point.
https://bugzilla.gnome.org/show_bug.cgi?id=679797
We use floorf() for the allocation origin, and ceilf() for the
allocation size. Swapping the two introduces rounding errors if
the original allocation is not clamped to the nearest pixel.
This reverts commit 7f6b17bc50.
ClutterLayoutManager implementations should just defer the easing state
set up to the child, and not try to impose a global one.
This reverts commit 793bde9143.
ClutterLayoutManager implementations should just defer the easing state
set up to the child, and not try to impose a global one.
This reverts commit 320fb156b4.
ClutterLayoutManager implementations should just defer the easing state
set up to the child, and not try to impose a global one.
This reverts commit 58a1854b57.
ClutterLayoutManager implementations should just defer the easing state
set up to the child, and not try to impose a global one.
This reverts commit 03ec016faa.
ClutterLayoutManager implementations should just defer the easing state
set up to the child, and not try to impose a global one.
ClutterTexture is full of side effects that have been picked up over the
years; they make improving ClutterTexture harder than necessary, as well
as making subclassing impossible without introducing weird behaviours in
the child classes as well.
Since Clutter 1.10 we have the ClutterImage content type, which is
side-effects free, given that it just paints texture data using the
state of the actor.
Sadly, we still have subclasses of ClutterTexture, both deprecated and
not, so we cannot deprecate ClutterTexture right out; the type and
structures will still be available, like we do for ClutterGroup, but the
whole API should be moved to the deprecated section, waiting for the
time in which we can get rid of it all.
We need an alternative to the translation performed by the anchor point,
one that possibly applies to all three axes and is relative to the
pivot-point.
https://bugzilla.gnome.org/show_bug.cgi?id=677853
For some transformations we need to be able to set the Z component of
the pivot point.
Unlike :pivot-point, the Z coordinate is not normalized because actors
are 2D surfaces.
https://bugzilla.gnome.org/show_bug.cgi?id=677853
Given that the rotation transformations are now affected by the pivot
point, the Actor class should provide an accessors pair only for the
angle of rotation on a given axis.
https://bugzilla.gnome.org/show_bug.cgi?id=677853
The pivot point is a point in normalized coordinates space around which
all transformations revolve.
It supercedes the anchor point and the per-transformation center points
as well as the gravity settings, and tries to sort out the mess that
is the modelview matrix set up in ClutterActor.
https://bugzilla.gnome.org/show_bug.cgi?id=677853
The ClutterActor:depth property has always been a bit of a misnomer:
actors are 2D flat surfaces, so they cannot have "depth"; the property
defines the position on the Z axis.
Another side effect of the :depth property is that it decides the
default paint and allocation order on insertion, and that setting it
will call the ClutterContainer.sort_depth_order() method. This has
proven to be a fairly bad design decision that we strung along from the
0.x days, as it gives a false impression of being able to change the
paint and allocation order simply by changing the position on the Z
axis — something that, in reality, requires depth testing to be enabled
during the paint sequence of an actor's parent.
For 2.0 we need a clean break from the side effects, and a better
defined interface.
ClutterActor:z-position is essentially what ClutterActor:depth is, but
doesn't call into ClutterContainer, and has a more apt name.
https://bugzilla.gnome.org/show_bug.cgi?id=679465
The :position property on ClutterText clashes with the same property on
ClutterActor; it's also badly named, given that it represents the
cursor's position inside the text; finally, it does not match its
accessors, violating the API style conventions.
https://bugzilla.gnome.org/show_bug.cgi?id=679457
Overriding the default behaviour of ClutterDragAction::drag-motion is
currently a pain; you either need to subclass the ClutterDragAction and
override the class closure for the signal, or you need to connect to the
signal and call g_signal_stop_emission_by_name() - neither option being
particularly nice or clean. The established pattern for these cases
would be to have a boolean return value on the ::drag-motion signal, but
we cannot do that without breaking ABI.
To solve the issue in a backward compatible way, we should introduce a
new signal, ::drag-progress, with a boolean return value. If the signal
emission chain returns TRUE, the ::drag-motion signal will be emitted,
and the default behaviour will be honoured; if the signal emission chain
returns FALSE, instead, the ::drag-motion signal will not be emitted.
https://bugzilla.gnome.org/show_bug.cgi?id=679451
Acquiring the Clutter lock to mark critical sections is not portable,
and not recommended to implement threaded applications with Clutter.
The recommended pattern is to use worker threads, and schedule UI
updates inside idle or timeout handlers within the main loop. We should
enforce this pattern by deprecating the threads_enter()/leave()
functions. For compatibility concerns, we need internal API to acquire
the main lock during frame processing dispatch.
https://bugzilla.gnome.org/show_bug.cgi?id=679450
It can be useful to check whether a ClutterActorIter is currently valid,
i.e. if the iterator has been initialized *and* if the actor to which it
refers to hasn't been updated.
We can also use the is_valid() method in the conformance test suite to
check that initialization has been successful, and that changing the
children list through the ClutterActorIter API leaves the iterator in a
valid state.
The dispose sequence will keep the object alive, and we need to release
the last reference held by the StageManager before releasing control to
GObject.
The build should not add deprecated/ into the default INCLUDE paths, so
that deprecated headers are clearly separated; this will make it easier
to get rid of them when we branch out for 2.0.
Copy and paste of the implementation done at Gtk+ based on pango. This
should be moved to a common library, like the old GailTextUtil. Ideally
on pango itself.
https://bugzilla.gnome.org/show_bug.cgi?id=677221
It is possible that we get a DeviceChanged event for a device
that is not in the hash table yet. E.g. I've seen this when
using xrandr to change screen resolution. Prevent a crash in
this case.
https://bugzilla.gnome.org/review?bug=678439
* clutter/clutter-cairo-texture.c (clutter_cairo_texture_emit_draw):
Always update the Cogl texture after emitting ::draw, since we control
the dynamic extent in which drawing should happen on the cairo_t.
Fixes#677966.
If the Interval used has a different type than the property we are
animating through a PropertyTransition then we should transform the
interpolated value before applying it, to avoid warnings down the
line.
The compute() method will cache the result, to avoid multiple
allocations and copies; this means, though, that we need to unset the
GValue when destroying the Interval.
Now that the interval can transform the initial and final values to the
type declared when constructing it, there is no need to check for the
value type inside set_initial_value() and set_final_value().
It's possible that GValues passed to a ClutterInterval setter are not
of the same type as the interval - for instance, if they come from
language bindings, or from untrusted sources; we can use the same
transformation functions we already use inside ClutterTransition to
ensure that the ClutterInterval always stores values of the same type
used to create the interval itself.
The ::stopped signal should be emitted at the end of the Timeline, after
the last ::completed signal emission, in order to have a proper
chronological progress of signal emissions:
started → new-frame → [ ... ] → completed → stopped
This way, ::stopped can perform a proper teardown of the state set up
during ::started, without interfering with the potential cyclical
emission of ::completed.
Calling clutter_point_free(clutter_point_zero()) or calling
clutter_rect_free(clutter_rect_zero()) should be safe, exactly like it's
safe to call those functions with a NULL argument.
The implicit animations only apply to properties that are documented as
'animatable'; the explicit animations apply to any property defined
through GObject or ClutterAnimatable.
For 1.x, we still have a duration of 0 msecs, but we have a valid easing
state, so we can change the easing parameters without calling save and
restore.
By checking if the interval is valid inside compute_value() we can catch
the cases where the interval values of a PropertyTransition are set
after the transition has been added to an Animatable instance - i.e. the
following code:
let transition = new Clutter.PropertyTransition();
transition.set_property_name('opacity');
actor.add_transition('opacityAnim', transition);
transition.set_to_value(0);
should be equivalent to:
let transition = new Clutter.PropertyTransition();
transition.set_property_name('opacity');
transition.set_to_value(0);
actor.add_transition('opacityAnim', transition);
instead of emitting a warning.
Once a ClutterPropertyTransition is attached to a ClutterAnimatable, if
no interval is set we can simply use the current state of the property
to define the from and to values. This allows the creation of property
transitions from the current state of the Animatable instance without
excessive verbosity.
ClutterContent implementations may allow repeating their contents when
painting; we should provide the repeat policy on the actor, like we do
for scaling filters and content gravity.
ClutterActor's x-align and y-align properties should be used to control
the alignment of the PangoLayout when painting it within a larger
allocation, and the ClutterText has the x-expand or the y-expand flags
set.
Fixed positions are defined to be initialized at 0,0 whenever
enabled, by setting fixed_position_enabled to true, or by setting
just one of x/y. This normally happens in the defaults, but we need
to make sure it also happens if a fixed position was once set but
then disabled. We do this by always resetting it back to 0,0 when
fixed_position_set is unset.
Instead of showing the full timestamp for debugging messages that happen
within a second, showing the delta from the previous full timestamp can
be more useful when debugging; this allows immediately seeing the time
difference, instead of doing the math in our heads.
Only for debug builds, the debug name should include a) actor name, b)
type name, and c) pointer address.
For non-debug builds we can live with the actor/type name.
ClutterGridLayout is port of GtkGrid to a Clutter layout manager. All
the logic is taken from gtkgrid.c, so all the credits should go to
Matthias Clasen for writing this nice piece of code.
ClutterGridLayout supports adding children with it's own methods
GridLayout.attach() and GridLayout.attach_next_to() as well as
Actor.add_child() and friends. The latter adds children in a similar
fashion to ClutterBoxLayout
https://bugzilla.gnome.org/show_bug.cgi?id=677372
The plain C bytes array, while convenient from a C perspective, is not
well handled by language bindings: the length of the array is not
specified, and it's only just implied by the image data size, rowstride,
and pixel format.
GBytes is a read-only bytes buffer that has an implicit length; we can
use it as the storage medium so that language bindings can actually
function correctly.
This will ensure that we have a CoglContext, albeit the stub winsys one,
on Mac.
Tested-by: Roland Peffer <gdevel@clixxun.com>
Tested-by: Laszlo Pandy <laszlok2@gmail.com>
The ::stopped signal is emitted when the timeline has been completely
exhausted or when the timeline has been programmatically stopped by
using clutter_timeline_stop(); the notification at the end of the
timeline run allows to write handlers without having to check whether
the current repeat is the last one, like we are forced to do when using
the ::completed signal.
Based on the patch by: Jasper St. Pierre <jstpierre@mecheye.net>
https://bugzilla.gnome.org/show_bug.cgi?id=676854
Ensure that resizing transitions smoothly when switching between major
axis; the allocation aspect ratio is not important: it's the size of the
allocation that dictates the major axis.
It's similar to to the implicit animation API of ClutterActor and
compatible to deprecated API of ClutterBoxLayout and
ClutterTableLayout.
It adds :use-animations, :easing-mode, :easing-duration and
:easing-delay properties to control animations when allocation of a
child has changed. Layout manager implementers should call
use_animations = clutter_layout_manager_get_easing_state (manager,
&mode,
&duration,
&delay);
from the allocate() virtual function to access these values.
https://bugzilla.gnome.org/show_bug.cgi?id=676827
The z coordinate of the origin should be checked against the same
coordinate of the vertex behind it. Given that most actors are flat
surfaces, this check should always succeed.
https://bugzilla.gnome.org/show_bug.cgi?id=675396
Instead of going through clutter_event_get_state() and checking if the
modifier mask is set, we can provide simple convenience functions to do
it for us.
When creating a FlowLayout container, setting a specific size on it, and
adding a child to it, as per the attached testcase, it crashes. The line
on the backtrace doesn't really make sense, but from looking over it, it
appears that it's probably because priv->line_natural is NULL. The
attached patch makes it so in this case, priv->line_natural is
allocated.
https://bugzilla.gnome.org/show_bug.cgi?id=676068
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
-Don't include unistd.h and stdint.h unconditionally as not all Windows
compilers have them around.
-Only include cogl/cogl-xlib.h when it is really supported by Cogl and GDK.
-sys/ioctl.h is not available on Windows (MinGW/MSVC).
-Correct the call to cogl_renderer_set_winsys_id:
(backend_cogl->cogl_renderer, COGL_WINSYS_ID_WGL) ->
(renderer, COGL_WINSYS_ID_WGL)
The property uses an array with the following CSS style syntax
[ top, right, bottom, left ] or
[ top, left/right, bottom ] or
[ top/bottom, left/right ] or
[ top/right/bottom/left ]
https://bugzilla.gnome.org/show_bug.cgi?id=676367
Passing a NULL buffer to clutter_text_set_text() does not behave the same
way as passing an empty string "" (as specified in the documentation).
This was working as expected previously, but somehow the behaviour changed
at some point and created 2 new issues:
- Passing a NULL pointer will not reset the string
- If the ClutterText is editable, it will segfault in strcmp
Validations have been added to prevent this.
https://bugzilla.gnome.org/show_bug.cgi?id=675890
This fixes drop_action_unregister() to not call g_object_get_data()
on priv->stage if not yet resolved. This can happen if the action's
actor was destroyed before ever being mapped.
When the transition was removed from the scroll-actor manually,
to cancel a not-finished animation, the transition struct member
wasn't reset to NULL.
This fixes this problem, and removes the need for the struct member
to be reset manually when animation has completed.
https://bugzilla.gnome.org/show_bug.cgi?id=676334
When setting up the transition manually by calling
clutter_keyframe_transition_set_key_frame (transition, n, keys);
clutter_keyframe_transition_set_values (transition, n, values);
clutter_keyframe_transition_set_modes (transition, n, modes);
the frame doesn't have a valid interval when calling set_keys(), so we
need to check its existence and create it if necessary.
https://bugzilla.gnome.org/show_bug.cgi?id=676031
Chaining up to the parent's implementation of pick() is not enough: we
need to paint our children explicitly because of the compatibility mode
checks we use to avoid breaking custom containers.
https://bugzilla.gnome.org/show_bug.cgi?id=676088
We need to clip the children during picking as well as we do when
painting, to avoid reactive children outside of the visible area
receiving events.
This also allows us to refactor some common code into proper functions.
-Add configuration in Clutter projects to add option to build Clutter with
the GDK3 backend in addition to the Win32 backend
-Add another preconfigured clutter-config.h.win32_GDK which contains
backend configs for both GDK3 and Win32 windowing and input.
When asking for the preferred width and height of an actor, in case
only one of either the minimum or the natural width is set, the margin
offsets should also be applied.
When getting touch events, the device manager would try
to pass an invalid device to translate_axes().
clutter_event_set_device() will only update event->touch.device
for touch events, not event->motion.device, as used.
Fixes Totem crashing on mouse motion/button press when using
a touchpad.
https://bugzilla.gnome.org/show_bug.cgi?id=675371
The drop-cancel signal allows the drop action to cleanup its
state if the can-drop signal is refused. This is especially
useful if the drop action (or its target actor) is managing
any drop target animations.
https://bugzilla.gnome.org/show_bug.cgi?id=675336
The example code that is meant to be XIncluded into the API reference
should not be part of the interactive test suite: it's code that it is
meant to be used as a reference implementation - whereas the interactive
test suite should be allowed to be lean and test behaviour even in nasty
ways. In short: the test suite should not be the place where we show off
idiomatic code for educational purposes.
The introspection scanner has become slightly more annoying, in the hope
that people start fixing their annotations. As it turns out, it was the
right move.
It's time. Now that we have clutter_actor_allocate() respecting the
easing state of an actor, and that the LayoutManager animation virtual
functions have been deprecated, we can put ClutterAlpha on the chopping
block, and be done with it, once and for all.
So long, ClutterAlpha; and thanks for all the fish.
This semi-aborted API was broken for various reasons:
- it strongly depended on ClutterAlpha, a class we're trying to
deprecate;
- it requires a lot of boilerplate and copy-and-paste code;
- it requires a full relayout of the actor tree for something
that ought to be automatically handled by ClutterActor.
Now that clutter_actor_allocate() handles transitions using the easing
state of the actor, we can deprecate the LayoutManager API for the 1.x
series, and remove it for the 2.x series.
BoxLayout will use the easing state of the children it's allocating; the
current API is re-implemented in terms of an implicit easing state
forced on each child prior to allocating it.
Calling clutter_actor_allocate() should transition between the current
allocation and the new allocation, by using the defined implementation
of the easing state.
This means that:
clutter_actor_save_easing_state (actor);
clutter_actor_allocate (actor, &new_alloc, flags);
clutter_actor_restore_easing_state (actor);
will cause "actor" to transition between the current allocation and the
desired new allocation.
The trick is to ensure that this happens without invalidating the
entire actor tree, but only the portion of the tree that has the
transitioned actor as the local root. For this reason, we just call the
allocate() implementation from within the transition frame advancement,
without invalidating flags: the actor, after all, *has* a valid
allocation for the duration of the transition.
The :x-expand and :y-expand flags on ClutterActor are used to signal
that an actor should expand horizontally and/or vertically - i.e. that
its parent's layout management policy should try to assign extra space
to the actor when allocating it.
The expand flags are automatic: when set on a leaf node in the actor
tree, they will bubble up through the parent and grandparents up to the
top level actor; during allocation, the actors with children will lazily
compute whether their children needs to expand.
The TransitionGroup class is a logical container for running multiple
transitions.
TransitionGroup is not a Score: it is a Transition that advances each
Transition it contains using the delta between frames, and ensures that
all transitions are in a consistent state; these transitions are not
advanced by the master clock.
There are cases when we want to advance a timeline from another time
source. We cannot use _clutter_timeline_do_tick() directly, as that
assumes that the timeline is already playing, so we'll need to create a
wrapper that toggles the playing flag around it.
Given that we can create a ClutterInterval without an initial and final
values using g_object_new(), it stands to reason that we ought to be
able to create an instance when passing NULL GValue pointers to the
new_with_values() constructor as well.
We tend to use float comparison for structured data types like Vertex,
Point, and Size; we should take into consideration fluctuations in the
floating point representation as well.
Instead of a single new() constructor that both allocates and
initializes, split the allocation and initialization into two separate
functions for types that are typically used on the stack, and rarely
allocated on the heap, like ClutterPoint and friends.
This is also applied retroactively to ClutterActorBox and ClutterVertex,
given that the same considerations on usage apply to them as well; we
can add a return value to clutter_actor_box_init() and
clutter_vertex_init() in an ABI-compatible way, so that
clutter_actor_box_new() and clutter_vertex_new() can be effectively
reimplemented as "init (alloc ())".
Using a compound type property for position and size has various
advantages: it reduces the amount of checks; it reduces the amount
of notify signals to connect to; it reduces the amount of transitions
generated.
The ClutterCanvas content implementation should be used instead, to
avoid stringing along the ClutterTexture API and implementation.
This change requires some minor surgery, as the deprecated section
already contains an header for the previously deprecated methods; plus,
we don't want to deprecate clutter_cairo_set_source_color(). This means
creating a new header to be used for Cairo-related API.
The get_distance() API uses machine integers to compute the distance;
this means that on 32bit we can overflow the integer size. This gets
hidden by the fact that get_distance() returns an unsigned integer as
well.
In reality, ClutterPath is an unmitigated mess, and the only way to
actually fix it is to break API.
https://bugzilla.gnome.org/show_bug.cgi?id=652521
