Cogl already add similar defines but with the CLUTTER namespace
(CLUTTER_COGL_HAS_GL and CLUTTER_COGL_HAS_GLES). Let's just add two
similar defines with the COGL namespace. Removing the CLUTTER_COGL ones
could break applications silently for no real good reason.
While grepping through the public headers looking for invalid use of
private HAVE_* defines, I stumbled upon two out of sync comments. Yes
it's a very minor trivial change.
JSON-GLib provides simple accessors for basic types so that we
can avoid getting the JsonNode out of a complex type. This makes
the code simpler to understand.
Currently, Clutter depends on the internal copy of JSON-GLib for
the ClutterScript parser. This is done to allow building Clutter
on platforms that do not have the library installed on the system.
Just like we use the internal PNG/JPEG loader as a fallback in
case we don't have GdkPixbuf or CoreGraphics available, we should
use the internal copy of JSON-GLib only in case the system copy
is not present.
The change is simply to move the default for the --with-json
configure switch from "internal" to "check".
In order to allow stricter compliance, a third setting should
be present: "system", which fails if the system copy is not
available.
We should also change the introspection generation to avoid
breaking in case we require the installed Json-1.0.gir instead
of the generated ClutterJson.gir
The clutter_actor_pick() function just emits the ::pick signal
on the actor. Nobody should be using it, since the paint() method
is already context sensitive and will result in a ::pick emission
by itself. The clutter_actor_pick() is just confusing things.
In the int-to-float switch for actor properties, the ::size-change signal
was moved to use floats instead of integers. Sub-pixel precision for image
size is meaningless, though, so we should revert it back to ints.
Fixes bug:
http://bugzilla.openedhand.com/show_bug.cgi?id=1659
Instead of using a specific function to check whether the X
server supports the XInput extension we can use the generic
Xlib function XQueryExtension(). This cuts down the extra
checks inside the configure.ac and simplifies the code inside
clutter_x11_register_xinput().
Currently, XInput support requires a function call. In order to
make it easier for people to test it, we can also add a command
line switch that moves the pointer device detection and handling
to XInput. This should ensure that, at least for people building
Clutter with --enable-xinput, applications can be easily migrated
and regressions can be caught.
The StageManager singleton instance is already kept around
by the clutter_stage_manager_get_default() function; there is
no need to have it inside the main Clutter context as well.
Instead of using _clutter_context_get_default() and checking the
is_initialized flag, we should use the newly added private function
that does not cause side effects, especially for functions that have
to be called before any other Clutter function.
The _clutter_context_get_default() function will automatically
create the main Clutter context; if we just want to check whether
Clutter has been initialized this will complicate matters, by
requiring a call to g_type_init() inside the client code.
Instead, we should simply provide an internal API that checks
whether the main Clutter context exists and if it has been
initialized, without any side effect.
The input device API is split halfway thorugh the backends in a very
weird way. The data structures are private, as they should, but most
of the information should be available in the main API since it's
generic enough.
The device type enumeration, for instance, should be common across
every backend; the accessors for device type and id should live in the
core API. The internal API should always use ClutterInputDevice and
not the private X11 implementation when dealing with public structures
like ClutterEvent.
By adding accessors for the device type and id, and by moving the
device type enumeration into the core API we can cut down the amount
of symbols private and/or visible only to the X11 backends; this way
when other backends start implementing multi-pointer support we can
share the same API across the code.
HAVE_COGL_GLES2 is defined in config.h through the configure script and
should not be used in public headers.
The patch makes configure generate the right define that can be used
later in the header.
The clutter_context_get_default() function is private, but shared
across Clutter. For this reason, it should be prefixed by '_' so
that the symbol is hidden from the shared object.
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().
Cairo stores the image data in ARGB native byte order so we need to
upload this as BGRA on little endian architectures and ARGB on big
endian. ClutterTexture doesn't currently expose any flags to describe
ARGB format so until we can fix the Clutter API it now uses the Cogl
API directly.
In order to chain up animations using clutter_actor_animate() and
friends you have to use an idle handler that guarantees that the
main loop spins at least once after the animation pointer has been
detached from the actor.
This has several drawbacks, first and foremost the fact that the
slice of the main loop for the idle handler might be starved by
other operations, like redrawing. This inevitably leads to tricks
with priorities and the like, contributing to the overall complexity.
Instead, we should guarantee that the animation instance created by
clutter_actor_animate() is valid for the ::completed signal until
it reaches its default handler; after that, the animation is detached
from the actor and destroyed. This means that it's possible to
create a new animation after the first is complete by simply using
g_signal_connect_after().
This unfortunately makes it impossible to keep a reference to the
animation pointer attached to the actor by using g_object_ref(); a
way to "fix" this would be to have a clutter_animation_attach()
and a clutter_animation_detach() pair of methods that allow attaching
any animation to an actor. This might overcomplicate what it is
the simple animation API, though, so it's currently not implemented
and left for future versions.
The test-easing interactive demo has been modified to show how
the animation queuing works by adding a command line switch that
recenters the animated actor once the first animation has ended.
Continuing in the tradition on making clutter_actor_animate() the
next g_object_connect(), here's the addition of the signal-after::
and signal-swapped:: modifiers for the automagic signal connection
arguments.
Fixes bug:
http://bugzilla.openedhand.com/show_bug.cgi?id=1646
In order to be ready for the next major version of GLib we need to
disable single header inclusion by using the G_DISABLE_SINGLE_INCLUDES
define in the build process.
We can't short-circuit the emission of ::queue-redraw for not-visible
actors, since ClutterClone uses that signal to know when things need
to be redrawn.
Calling clutter_actor_queue_redraw() out of clutter_actor_real_map() /
clutter_actor_real_unmap() was causing the flag state to get set
incorrectly from _clutter_actor_set_enable_paint_unmapped(), because
a paint queueing a redraw was not expected.
Moving queuing the redraw to clutter_actor_hide()/show() fixes this, and
also fixes a problem where showing a child of a cloned actor wouldn't
cause the clone to be repainted.
http://bugzilla.openedhand.com/show_bug.cgi?id=1484
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
If we have an not-visible texture pixmap, we need to:
- Still update it if it is realized, since it won't be
updated when shown. And it might be also be cloned.
- Queue a redraw if even if not visible, since it
it might be cloned.
http://bugzilla.openedhand.com/show_bug.cgi?id=1647
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
My patch to choose a premultiplied format when the user gives
COGL_PIXEL_FORMAT_ANY for the internal_format broke the case where the data
in question doesn't have and alpha channel.
This was accidentally missed when merging the premultiplication branch
since I merged a local version of the branch that missed this commit.
Although the underlying materials should allow layers with INVALID_HANDLES
it shouldn't be necissary to expose that via cogl_set_source_texture() and
it's easier to resolve a warning/crash here than odd artefacts/crashes later
in the pipeline.
Merge branch 'premultiplication'
[cogl-texture docs] Improves the documentation of the internal_format args
[test-premult] Adds a unit test for texture upload premultiplication semantics
[fog] Document that fogging only works with opaque or unmultipled colors
[test-blend-strings] Explicitly request RGBA_888 tex format for test textures
[premultiplication] Be more conservative with what data gets premultiplied
[bitmap] Fixes _cogl_bitmap_fallback_unpremult
[cogl-bitmap] Fix minor copy and paste error in _cogl_bitmap_fallback_premult
Avoid unnecesary unpremultiplication when saving to local data
Don't unpremultiply Cairo data
Default to a blend function that expects premultiplied colors
Implement premultiplication for CoglBitmap
Use correct texture format for pixmap textures and FBO's
Add cogl_color_premultiply()
Clarifies that if you give COGL_PIXEL_FORMAT_ANY as the internal format for
cogl_texture_new_from_file or cogl_texture_new_from_data then Cogl will
choose a premultiplied internal format.
The fixed function fogging provided by OpenGL only works with unmultiplied
colors (or if the color has an alpha of 1.0) so since we now premultiply
textures and colors by default a note to this affect has been added to
clutter_stage_set_fog and cogl_set_fog.
test-depth.c no longer uses clutter_stage_set_fog for this reason.
In the future when we can depend on fragment shaders we should also be
able to support fogging of premultiplied primitives.
We don't want to force texture data to be premultipled if the user
explicitly specifies a non premultiplied internal_format such as
COGL_PIXEL_FORMAT_RGBA_8888. So now Cogl will only automatically
premultiply data when COGL_PIXEL_FORMAT_ANY is given for the
internal_format, or a premultiplied internal format such as
COGL_PIXEL_FORMAT_RGBA_8888_PRE is requested but non-premultiplied source
data is given.
This approach is consistent with OpenVG image formats which have already
influenced Cogl's pixel format semantics.
The _cogl_unpremult_alpha_{first,last} functions which
_cogl_bitmap_fallback_unpremult depends on were incorrectly casting each
of the byte components of a texel to a gulong and performing shifts as
if it were dealing with the whole texel.
It now just uses array indexing to access the byte components without
needing to cast or manually shift any bits around.
Even though we used to depend on unpremult whenever we used a
ClutterCairoTexture, clutter_cairo_texture_context_destroy had it's own
unpremult code which worked which is why this bug wouldn't have been noticed
before.
Now that we typically have premultiplied data stored in Cogl
textures, when fetching a texture into local data for temporary
storage, use a premultiplied format to avoid an unpremultiply/
premultiply roundtrip.
http://bugzilla.openedhand.com/show_bug.cgi?id=1406
Signed-off-by: Robert Bragg <robert@linux.intel.com>
Instead of unpremultiplying the Cairo data, pass it directly to Cogl
in premultiplied form; we now *prefer* premultiplied data.
http://bugzilla.openedhand.com/show_bug.cgi?id=1406
Signed-off-by: Robert Bragg <robert@linux.intel.com>
Many operations, like mixing two textures together or alpha-blending
onto a destination with alpha, are done most logically if texture data
is in premultiplied form. We also have many sources of premultiplied
texture data, like X pixmaps, FBOs, cairo surfaces. Rather than trying
to work with two different types of texture data, simplify things by
always premultiplying texture data before uploading to GL.
Because the default blend function is changed to accommodate this,
uses of pure-color CoglMaterial need to be adapted to add
premultiplication.
gl/cogl-texture.c gles/cogl-texture.c: Always premultiply
non-premultiplied texture data before uploading to GL.
cogl-material.c cogl-material.h: Switch the default blend functions
to ONE, ONE_MINUS_SRC_ALPHA so they work correctly with premultiplied
data.
cogl.c: Make cogl_set_source_color() premultiply the color.
cogl.h.in color-material.h: Add some documentation about
premultiplication and its interaction with color values.
cogl-pango-render.c clutter-texture.c tests/interactive/test-cogl-offscreen.c:
Use premultiplied colors.
http://bugzilla.openedhand.com/show_bug.cgi?id=1406
Signed-off-by: Robert Bragg <robert@linux.intel.com>
cogl-bitmap.c cogl-bitmap-pixbuf.c cogl-bitmap-fallback.c cogl-bitmap-private.h:
Add _cogl_bitmap_can_premult(), _cogl_bitmap_premult() and implement
a reasonably fast implementation in the "fallback" code.
http://bugzilla.openedhand.com/show_bug.cgi?id=1406
Signed-off-by: Robert Bragg <robert@linux.intel.com>
RGBA data in X pixmaps and in FBOs is already premultiplied; use
the right format when creating cogl textures.
http://bugzilla.openedhand.com/show_bug.cgi?id=1406
Signed-off-by: Robert Bragg <robert@linux.intel.com>
Since commit d743aeaa updated the internal copy of JSON-GLib and
added a new private header file, we need to fix the build to avoid
a distcheck failure.
Merge branch 'master-clock-updates'
* master-clock-updates: (22 commits)
Change the paint forcing on the Text cache text
[timelines] Improve marker hit check and don't fudge the delta
Revert "[timeline] Don't clamp the elapsed time when a looping tl reaches the end"
[tests] Don't add a newline to the end of g_test_message calls
[test-timeline] Add a marker at the beginning of the timeline
[timeline] Don't clamp the elapsed time when a looping tl reaches the end
[master-clock] Throttle if no redraw was performed
[docs] Update Clutter's API reference
Force a paint instead of calling clutter_redraw()
Fix clutter_redraw() to match the redraw cycle
Run the repaint functions inside the redraw cycle
Remove useless manual timeline ticking
Move elapsed-time calculations into ClutterTimeline
Limit the frame rate when not syncing to VBLANK
Decrease the main-loop priority of the frame cycle
Avoid motion-compression in test-picking test
Compress events as part of the frame cycle
Remove stage update idle and do updates from the master clock
Call g_main_context_wakeup() when we start running timelines
Remove unused msecs_delta member
...
Markers added at the start of the timeline need to be special cased
because we effectively check whether the marker time is greater than
the old frame time or less than or equal to the new frame time but we
never actually emit a frame for the start of the timeline.
If the timeline is looping then it adjusts the position to interpolate
a wrapped around position. However we do not emit a new frame after
setting this position so we need to check for markers again there.
clutter_timeline_get_delta should return the actual wall clock time
between emissions of the new-frame signal - even if the elapsed time
has been fudged at the end of the timeline. To make this work it no
longer directly manipulates priv->msecs_delta but instead passes a
delta value to check_markers.
Someone might hide the previously focused actor in the focus-out signal
handler and as key focus still appears to be on that actor we'd get
re-entrant call and get glib critical from g_object_weak_unref
This changes clutter_stage_get_key_focus() to return stage/NULL during
focus-out signal emission. It used to be the actor focus-out was being
emitted on.
Fixes bug:
http://bugzilla.openedhand.com/show_bug.cgi?id=1547
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
This reverts commit 9c5663d671.
The patch was causing problems for applications that expect the
elapsed_time to be at either end of the timeline when the completed
signal is fired. For example test-behave swaps the direction of the
timeline in the completed handler but if the time has overflowed the
end then the timeline would only take a short time to get back the
beginning. This caused the animation to just vibrate around the
beginning.
The new-frame signal of a timeline was previously guaranteed to be
emitted with the elapsed_time set to the end before it emits the
completed signal. This doesn't necessarily make sense for looping
timelines because it would cause the elapsed time to be clamped to a
slightly off value whenever the timeline restarts. This patch makes it
perform the wrap around before emitting the new-frame signal so that
the elapsed time always corresponds to the time elapsed since the
timeline was started.
Additionally it no longer fudges the msecs_delta property to make the
marker check work so clutter_timeline_get_delta will always return the
wall clock time since the last frame.
A flag in the master clock is now set whenever the dispatch caused an
actual redraw of a stage. If this flag is not set during the prepare
and check functions then it will resort to limiting the redraw
attempts to the default frame rate as if vblank syncing was
disabled. Otherwise if a timeline is running that does not cause the
scene to change then it would busy-wait with 100% CPU until the next
frame.
This fix was suggested by Owen Taylor in:
http://bugzilla.openedhand.com/show_bug.cgi?id=1637
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
We do not need the whole redraw machinery inside
clutter_stage_read_pixels(): instead, we want Clutter to drop everything,
paint and call glReadPixels() with the current buffer.
The clutter_redraw() function is used by embedding toolkits to
force a redraw on a stage. Since everything is performed by
toggling a flag inside the Stage itself and then letting the
master clock advance, we need a ClutterStage method to ensure
that we start the master clock and redraw.
Instead of calculating a delta in the master clock, and passing that
into each timeline, make each timeline individually responsible for
remembering the last time and computing the delta.
This:
- Fixes a problem where we could spin infinitely processing
timeline-only frames with < 1msec differences.
- Makes timelines consistently start timing on the first frame;
instead of doing different things for the first started timeline
and other timelines.
- Improves accuracy of elapsed time computations by avoiding
accumulating microsecond => millisecond truncation errors.
http://bugzilla.openedhand.com/show_bug.cgi?id=1637
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
clutter-master-clock.c clutter-master-clock.h: When the
SYNC_TO_VBLANK feature is not available, wait for 1/frame_rate
seconds since the start of the last frame before drawing the next
frame. Add _clutter_master_clock_start_running() to abstract
the usage of g_main_context_wakeup()
clutter-stage.c: Add _clutter_master_clock_start_running()
clutter-main.c: Update docs for clutter_set_default_frame_rate()
clutter_get_default_frame_rate() to no longer talk about timeline
frame rates.
test-text-perf.c test-text.c: Set a frame rate of 1000fps so that
frame-rate limiting doesn't affect the result.
http://bugzilla.openedhand.com/show_bug.cgi?id=1637
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Change CLUTTER_PRIORITY_REDRAW to be lower than the GTK+ resize
and relayout priorities to avoid starving GTK+ when run in the
same process as clutter.
Remove the unused CLUTTER_PRIORITY_TIMELINE
http://bugzilla.openedhand.com/show_bug.cgi?id=1637
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Instead of trying to guess about which motion events are
extraneous, queue up all events until we process a frame.
This allows us to look ahead and reliably compress consecutive
sequence of motion events.
clutter-main.c: Feed received events to the stage for queueing.
Remove old compression code. Remove clutter_get_motion_events_frequency()
clutter_set_motion_events_frequency()
clutter-stage.c: Keep a queue of pending events.
clutter-master-clock.c: Add processng of queued events to the
clock source dispatch function.
http://bugzilla.openedhand.com/show_bug.cgi?id=1637
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
When a redraw is queued on a stage, simply set a flag; then in
the check/prepare functions of the master clock source, check
for stages that need redrawing.
This avoids the complexity of having multiple competing sources
at the same priority and makes the update ordering more reliable and
understandable.
http://bugzilla.openedhand.com/show_bug.cgi?id=1637
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
If a timeline is added from a different thread, we need to
call g_main_context_wakeup() to wake the main thread up to
start updating the timeline.
http://bugzilla.openedhand.com/show_bug.cgi?id=1637
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Instead of keeping a list of all timelines, and connecting to
signals and weak notifies, simply keep a list of running timelines;
this greatly simplifies both the book-keeping, and also determining
if there are any running timelines.
http://bugzilla.openedhand.com/show_bug.cgi?id=1637
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Remove code to advance the master clock after drawing a frame; if
there are any running timelines the master clock will do another
frame by itself, and the clock will be advanced before running
that frame.
With this change, there is no point in queueing an extra frame
redraw after completing a timeline, since we are always advancing
the timeline *before* redrawing, so remove that code as well.
(This does mean that calling clutter_timeline_stop() won't implicitly
cause the stage to be redrawn; this doesn't seem like something
an app should rely on in any case.)
http://bugzilla.openedhand.com/show_bug.cgi?id=1637
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
The clutter_stage_fullscreen() and clutter_stage_unfullscreen() are
a GDK-ism. The underlying implementation is already using an accessor
with a boolean parameter.
This should take the amount of collisions between properties, methods
and signals to zero.
The :fullscreen property is very much confusing as it is implemented.
It can be written to a value, but the whole process might fail. If we
set:
g_object_set (stage, "fullscreen", TRUE, NULL);
and the fullscreen process fails or it is not implemented, the value
will be reset to FALSE (if we're lucky) or left TRUE (most of the
times).
The writability is just a shorthand for invoking clutter_stage_fullscreen()
or clutter_stage_unfullscreen() depending on a boolean value without
using an if.
The :fullscreen property also greatly confuses high level languages,
since the same symbol is used:
- for a method name (Clutter.Stage.fullscreen())
- for a property name (Clutter.Stage.fullscreen)
- for a signal (Clutter.Stage::fullscreen)
For these reasons, the :fullscreen should be renamed to :fullscreen-set
and be read-only. Implementations of the Stage should only emit the
StageState event to change from normal to fullscreen, and the Stage
will automatically update the value of the property and emit a notify
signal for it.
There have been changes in JSON-GLib upstream to clean up the
data structures, and facilitate introspection.
We still not use the updated JsonParser with the (private) JsonScanner
code, since it's a fork of GLib's GScanner.
Otherwise if there is an error before the slices are created it will
try to free the first_pixels array and crash.
It now also checks whether first_pixels has been created before using
it to update the mipmaps. This should only happen for
cogl_texture_new_from_foreign and doesn't matter if the FBO extension
is available. It would be better in this case to fetch the first pixel
using glGetTexImage as Owen mentioned in the last commit.
tex->first_pixels was never set for foreign textures, leading
to a crash when the texture object is freed.
As a quick fix, simply set to NULL. A more complete fix would
require remembering if we had ever seen the first pixel uploaded,
and if not, doing a glReadPixel to get it before triggering the
mipmap update.
http://bugzilla.openedhand.com/show_bug.cgi?id=1645
Signed-off-by: Neil Roberts <neil@linux.intel.com>
It's very common that there's no reasonable fallback to do if the
blend or combine string you set isn't supported. So, rather than
requiring everybody to pass in a GError purely to catch syntax erorrs,
automatically g_warning() if a parse error is encountered and @error
is NULL.
http://bugzilla.openedhand.com/show_bug.cgi?id=1642
Signed-off-by: Robert Bragg <robert@linux.intel.com>
When we complete a timeline, we clamp the elapsed_time variable
to the range of the timeline. We need to adjust msecs_delta so that
when we check for hit markers we have the correct interval.
http://bugzilla.openedhand.com/show_bug.cgi?id=1641
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
The Animation should be referenced during the notification of the
alpha value, since the callback is invoked depending on the Alpha
and it won't vivify the Animation instance for us.
Fixes bug:
http://bugzilla.openedhand.com/show_bug.cgi?id=1537
ClutterEvent is not really gobject-introspection friendly because
of the whole discriminated union thing. In particular, if you get
a ClutterEvent in a signal handler, you probably can't access the
event-type-specific fields, and you probably can't call methods
like clutter_key_event_symbol() either, because you can't cast the
ClutterEvent to a ClutterKeyEvent.
The cleanest solution is to turn every accessor into ClutterEvent
methods, accepting a ClutterEvent* and internally checking the event
type.
Fixes bug:
http://bugzilla.openedhand.com/show_bug.cgi?id=1585
According to clutter_texture_set_cogl_texture you should unref the handle as
the texture takes its own.
Signed-off-by: Robert Bragg <robert@linux.intel.com>
The OpenGL spec states that if you create a pixmap using glXCreatePixmap you
should use glXDestroyPixmap to destroy it.
Signed-off-by: Robert Bragg <robert@linux.intel.com>
Setting the pixmap for an unrealized ClutterGLXTexturePixmap should
not cause it to be realized, and certainly shouldn't cause the the
REALIZED flag to be set without using clutter_actor_realize().
This patch uses the simple approach that;
- pixmap changes on an unrealized ClutterGLXTexturePixmap
are ignored
- when the ClutterGLXTexturePixmap is realized, we then create
the GLXPixmap and the corresponding texture.
The call to clutter_glx_texture_pixmap_update_area() is moved
from create_cogl_texture() to
clutter_glx_texture_pixmap_create_glx_pixmap() since
create_cogl_texture() is only called from one place, and updating
the area is really something we do *after* creating the texture,
not part of creating the texture.
clutter_glx_texture_pixmap_create_glx_pixmap() is reorganized a
bit to avoid debug-logging confusingly if it's called before a pixmap
has been set, and for readability.
http://bugzilla.openedhand.com/show_bug.cgi?id=1635
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
An implementaton of realize() never needs to set the
CLUTTER_ACTOR_REALIZED flag, though it can unset the flag if
things fail unexpectedly. (Previously, stage backend implementations
had to do this since clutter_actor_realize() wasn't used; this
is no longer the case.)
http://bugzilla.openedhand.com/show_bug.cgi?id=1634
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Due to the accumulation of floating point errors, natural_width
and min_width can diverge significantly even if the math for
computing them is correct. So just clamp natural_width to
min_width instead of warning about it.
http://bugzilla.openedhand.com/show_bug.cgi?id=1632
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
If we use float temporaries when computing the bounds of
a group, then, depending on what variables are kept in registers
and what stored on the stack, the accumulated difference between
natural_width and min_width can be more than FLOAT_EPSILON.
Using double temporaries will eliminate the difference in most
cases, or, very rarely, reduce it to a last-bit error.
http://bugzilla.openedhand.com/show_bug.cgi?id=1632
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
If we are cloning an source actor with an unmapped parent, then when
we temporarily map the source actor:
- We need to skip the check that a mapped actor has a mapped
parent.
- We need to realize the actor's parents before mapping it,
or we'll get an assertion failure in clutter_actor_update_map_state()
because an actor with an unmapped parent is !may_be_realized.
http://bugzilla.openedhand.com/show_bug.cgi?id=1633
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Setting the stage size using clutter_actor_set_size() is almost always
wrong: the X11 stage implementation should save the size and queue a
relayout -- like it does when receiving a ConfigureNotify. The same
should happen when setting it to be full screen.
Since we build the Cogl GIR inside /clutter/cogl we should be looking
there when building the Clutter GIR. Otherwise g-ir-scanner will look
inside the gir directory -- and if you never built Clutter before it
will error out.
Fixes bug:
http://bugzilla.openedhand.com/show_bug.cgi?id=1638
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
The load-finished signal has a GError* argument which is meant to
signify whether the loading was successful. However many of the
places in ClutterTexture that emit this signal directly pass their
'error' variable which is a GError** and will be NULL or not
completely independently of whether there was an error. If the
argument was dereferenced it would probably crash.
The test-texture-async interactive test case should also verify
that the ::load-finished signal is correctly emitted.
Fixes bug:
http://bugzilla.openedhand.com/show_bug.cgi?id=1622
Correctly apply De Morgan's laws to the short-circuit test in
clutter_timeline_pause(); it was short-circuiting always and
never actually pausing.
http://bugzilla.openedhand.com/show_bug.cgi?id=1629
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
The commit 2c95b378 prevents clutter_animation_setup_property from being
called with fixed:: property names. This patch adds a additional
parameter "is_fixed" to clutter_animation_setup_property instead of
searching for "fixed::" in property_name.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
It should be possible render a single PangoLayout with different
colors without recalculating the layout. This was not working because
the color used at the first edit was being stored in the display
list. This broke changing the opacity on a ClutterText.
Now each node in the display list has a 'color override' flag which
marks whether it should use the base color or not. The base color is
now passed in from _cogl_pango_display_list_render_texture. The alpha
value is always taken from the base color.
The clutter_redraw() function is used by libraries embedding
Clutter inside another toolkit, instead of queueing a redraw
on the embedded stage. This means that clutter_redraw() should
perform the same sequence of actions done by the redraw idle
callback.
Clutter short-circuits painting when an actor's opacity is
zero. However if the actor is being painted from a ClutterClone then
it will be painted using the clone's opacity instead so the test was
broken.
* 1.0-integration: (138 commits)
[x11] Disable XInput by default
[xinput] Invert the XI extension version check
[cogl-primitives] Fix an unused variable warning when building GLES
[clutter-stage-egl] Pass -1,-1 to clutter_stage_x11_fix_window_size
Update the GLES backend to have the layer filters in the material
[gles/cogl-shader] Add a missing semicolon
[cogl] Move the texture filters to be a property of the material layer
[text] Fix Pango unit to pixels conversion
[actor] Force unrealization on destroy only for non-toplevels
[x11] Rework map/unmap and resizing
[xinput] Check for the XInput entry points
[units] Validate units against the ParamSpec
[actor] Add the ::allocation-changed signal
[actor] Use flags to control allocations
[units] Rework Units into logical distance value
Remove a stray g_value_get_int()
Remove usage of Units and macros
[cogl-material] Allow setting a layer with an invalid texture handle
[timeline] Remove the concept of frames from timelines
[gles/cogl-shader] Fix parameter spec for cogl_shader_get_info_log
...
Conflicts:
configure.ac
The XInput support in Clutter is still using XI 1.x. This will never
work correctly, and we are all waiting for XInput 2 anyway. The changes
internally should be minimal, so we can leave everything in place, but
it's better to disable XInput support by default -- at least for the
time being.
The texture filters are now a property of the material layer rather
than the texture object. Whenever a texture is painted with a material
it sets the filters on all of the GL textures in the Cogl texture. The
filter is cached so that it won't be changed unnecessarily.
The automatic mipmap generation has changed so that the mipmaps are
only generated when the texture is painted instead of every time the
data changes. Changing the texture sets a flag to mark that the
mipmaps are dirty. This works better if the FBO extension is available
because we can use glGenerateMipmap. If the extension is not available
it will temporarily enable automatic mipmap generation and reupload
the first pixel of each slice. This requires tracking the data for the
first pixel.
The COGL_TEXTURE_AUTO_MIPMAP flag has been replaced with
COGL_TEXTURE_NO_AUTO_MIPMAP so that it will default to
auto-mipmapping. The mipmap generation is now effectively free if you
are not using a mipmap filter mode so you would only want to disable
it if you had some special reason to generate your own mipmaps.
ClutterTexture no longer has to store its own copy of the filter
mode. Instead it stores it in the material and the property is
directly set and read from that. This fixes problems with the filters
getting out of sync when a cogl handle is set on the texture
directly. It also avoids the mess of having to rerealize the texture
if the filter quality changes to HIGH because Cogl will take of
generating the mipmaps if needed.
The mapping and unmapping of the X11 stage implementation is
a bit bong. It's asynchronous, for starters, when it really
can avoid it by tracking the state internally.
The ordering of the map/unmap sequence is also broken with
respect to the resizing.
By tracking the state internally into StageX11 we can safely
remove the MapNotify and UnmapNotify X event handling.
In theory, we should use _NET_WM_STATE a lot more, and reuse
the X11 state flags for fullscreening as well.
Apparently, the XInput extension is using the same pkg-config
file ('xi') for both the 1.x and the 2.x API, so we need to
check for both the 1.x XGetExtensionVersion and the 2.x
XQueryInputVersion.
When declaring a property using ClutterParamSpecUnits we pass a
default type to limit the type of units we accept as valid values
for the property.
This means that we need to add the unit type check as part of the
validation process.
Sometimes it is useful to be able to track changes in the allocation
flags, like the absolute origin, inside children of a container.
Using the notify::allocation signal is not enough, in these cases, so
we need a specific signal that gives us both the allocation box and the
allocation flags.
Instead of passing a boolean value, the ::allocate virtual function
should use a bitmask and flags. This gives us room for expansion
without breaking API/ABI, and allows to encode more information to
the allocation process instead of just changes of absolute origin.
Units as they have been implemented since Clutter 0.4 have always been
misdefined as "logical distance unit", while they were just pixels with
fractionary bits.
Units should be reworked to be opaque structures to hold a value and
its unit type, that can be then converted into pixels when Clutter needs
to paint or compute size requisitions and perform allocations.
The previous API should be completely removed to avoid collisions, and
a new type:
ClutterUnits
should be added; the ability to install GObject properties using
ClutterUnits should be maintained.
It was previously possible to create a material layer with no texture
by setting some property on it such as the matrix. However it was not
possible to get back to that state without removing the layer and
recreating it. It is useful to be able to remove the texture to free
resources without forgetting the state of the layer so we can put a
different texture in later.
Timelines no longer work in terms of a frame rate and a number of
frames but instead just have a duration in milliseconds. This better
matches the working of the master clock where if any timelines are
running it will redraw as fast as possible rather than limiting to the
lowest rated timeline.
Most applications will just create animations and expect them to
finish in a certain amount of time without caring about how many
frames are drawn. If a frame is going to be drawn it might as well
update all of the animations to some fraction of the total animation
rather than rounding to the nearest whole frame.
The 'frame_num' parameter of the new-frame signal is now 'msecs' which
is a number of milliseconds progressed along the
timeline. Applications should use clutter_timeline_get_progress
instead of the frame number.
Markers can now only be attached at a time value. The position is
stored in milliseconds rather than at a frame number.
test-timeline-smoothness and test-timeline-dup-frames have been
removed because they no longer make sense.
The clutter_actor_map and unmap functions need to be called to
properly update the mapped state. This matches the changes to the X11
stage in 125bded8.
If the application code calls for destruction of an actor we need
to make sure that the actor is unrealized before running the dispose
sequence; otherwise, we might trigger an assertion failure on composite
actors.
The commit 762873e79e is completely
and utterly wrong and I should have never pushed it.
Serves me well for trying to work on three different branches and
on three different things.
Currently, the clock source spins a redraw every time there is at
least a timeline running. If the timelines were not advanced in
the previous frame, though, because their interval is larger than
the vblanking interval then this will lead to excessive redraws of
the scenegraph even if nothing has changed.
To avoid this a simple guard should be set by the MasterClock::advance
method in case no timeline was effectively advanced, and checked
before dispatching the stage redraws.
When creating a Cogl texture from a Cogl bitmap it would steal the
data by setting the bitmap_owner flag and clearing the data pointer
from the bitmap. The data would be freed by the time the
new_from_bitmap is finished. There is no reason to do this because the
data will be freed when the Cogl bitmap is unref'd and it is confusing
not to be able to reuse the bitmap for creating multiple textures.
clutter_color_from_string() only supported the "#rrggbbaa" format with
alpha channel, this patch adds support for "#rgba".
Colors in "#rrggbb" format were parsed manually, this is now left to
the pango color parsing fallback, since that's handling it just fine.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
The cogl_shader_get_info_log() function is very inconvenient for
language bindings and for regular use, as it requires a static
buffer to be filled -- basically just providing a wrapper around
glGetInfoLogARB().
Since COGL aims to be a more convenient API than raw GL we should
just make cogl_shader_get_info_log() return an allocated string
with the GLSL compiler log.
Instead of using GL_TRIANGLES and uploading the indices every time, it
now uses GL_QUADS instead on OpenGL. Under GLES it still uses indices
but it uses the new cogl_vertex_buffer_indices_get_for_quads function
to avoid uploading the vertices every time.
This requires the _cogl_vertex_buffer_indices_pointer_from_handle
function to be exposed privately to the rest of Cogl.
The static_indices array has been removed from the Cogl context.
The GIR file for Clutter still contains symbols from COGL, even
though we provide a Cogl GIR as well. The Clutter GIR should
depend on the Cogl GIR instead.
All the underlying implementation and the public entry points have
been switched to floats; the only missing bits are the Actor properties
that deal with positioning and sizing.
This usually means a major pain when dealing with GValues and varargs
functions. While GValue will warn you when dealing with the wrong
conversions, varags will simply die an horrible (and hard to debug)
death via segfault. Nothing much to do here, except warn people in the
release notes and hope for the best.
The documentation for ClutterTexture's set_from_rgb_data() and
set_from_yuv_data() says:
Note: This function is likely to change in future versions.
This is not true, since they'll remain for the whole 1.x API cycle.
Now that CoglVertexBuffers support indices we can use them with GLES
to avoid duplicating vertices. Regular GL still uses GL_QUADS because
it is shown to still have a performance benefit over indices with the
Intel drivers.
This function can be used as an efficient way of drawing groups of
quads without using GL_QUADS. It generates a VBO containing the
indices needed to render using pairs of GL_TRIANGLES. The VBO is
globally cached so that it only needs to be uploaded whenever more
indices are requested than ever before.
The allocate_available_size() method is a convenience method in
the same spirit as allocate_preferred_size(). While the latter
will allocate the preferred size of an actor regardless of the
available size provided by the actor's parent -- and thus it's
suitable for simple fixed layout managers like ClutterGroup -- the
former will take into account the available size provided by the
parent and never allocate more than that; it is, thus, suitable
for simple fluid layout managers.
The cogl-enum-types.h file is created by glib-mkenums under
/clutter/cogl/common, and then copied in /clutter/cogl in order
to make the inclusion of that file work inside cogl.h.
Since we're copying it in a different location, the Makefile
for that location has to clean up the copy.
Notifications should be fired off from both the internal timeline and
the wrapping animation here, so notifiers should be frozen around these
property setters.
Signed-off-by: Jonas Bonn <jonas@southpole.se>
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Just a couple of final cleanups after the reimplementation of the
Animation model.
i) _set_mode does not need to set the timeline on the alpha
ii) freeze notifications around the setting of a new alpha
Signed-off-by: Jonas Bonn <jonas@southpole.se>
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
The "started" signal is sent first after the timeline has been set to the
'running' state. For this reason, checking if the clock has any running
timelines running will always return true in the "started" signal handler:
the timeline that sent the signal is running.
What needs to be checked in the signal handler is if there are any
timelines running other than the one that emitted the ::started signal,
which we know is running anyway.
This prevents frames from being lost at the beginning of an animation when
a timeline is started after a quiescent period.
Fixes bug:
http://bugzilla.openedhand.com/show_bug.cgi?id=1617
Signed-off-by: Jonas Bonn <jonas@southpole.se>
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
We avoid rebuilding cogl-enum-types.h and cogl-enum-types.c by
using a "guard" -- a stamp file that will block Makefile. Since
we need cogl-enum-types.h into /clutter/cogl as well for the
cogl.h include to work, if we copy the cogl-enum-types.h
unconditionally it will cause a rebuild of the whole COGL; which
will cause a full rebuild.
To solve this, we can copy the header file when generating it
under the stamp file.
The libclutter-cogl internal object should be the only dependency
for Clutter, since we are already copying it inside clutter/cogl
for the introspection scanner. For this reason, the backend-specific,
real internal object should be built with the backend encoded into
the file name, like libclutter-common. This makes the build output
a little bit more clear: instead of having two:
LINK libclutter-cogl-common.la
...
LINK libclutter-cogl.la
LINK libclutter-cogl.la
We'll have:
LINK libclutter-cogl-common.la
...
LINK libclutter-cogl-gl.la
LINK libclutter-cogl.la
Same applies for the GLES backend.
Just like we do with GObject types and G_DEFINE_TYPE, we should
use the g_once_init_enter/g_once_init_leave mechanism to make the
GType registration of enumeration types thread safe.
The setup_viewport() function should only be used by Clutter and
not by application code.
It can be emulated by changing the Stage size and perspective and
requeueing a redraw after calling clutter_stage_ensure_viewport().
The backface culling enabling function was split and renamed, just
like the depth testing one, so we need to add the macro to the
cogl-deprecated.h header.
Previously indices were tightly bound to a particular Cogl vertex buffer
but we would like to be able to share indices so now we have
cogl_vertex_buffer_indices_new () which returns a CoglHandle.
In particular we could like to have a shared set of indices for drawing
lists of quads that can be shared between the pango renderer and the
Cogl journal.
At the moment Cogl doesn't do much batching of quads so most of the time we
are flushing a single quad at a time. This patch simplifies how we submit
those quads to OpenGL by using glDrawArrays with GL_TRIANGLE_FAN mode
instead of sending indexed vertices using GL_TRIANGLES mode.
Note: I hope to follow up soon with changes that improve our batching and
also move the indices into a VBO so they don't need to be re-validated every
time we call glDrawElements.
To assist people porting code from 0.8, the cogl_texture_* functions that
have been replaced now have defines that give some hint as to how they
should be replaced.
cogl_enable_depth_test and cogl_enable_backface_culling have been renamed
and now have corresponding getters, the new functions are:
cogl_set_depth_test_enabled
cogl_get_depth_test_enabled
cogl_set_backface_culling_enabled
cogl_get_backface_culling_enabled
This adds cogl_matrix api for multiplying matrices either by a perspective
or ortho projective transform. The internal matrix stack and current-matrix
APIs also have corresponding support added.
New public API:
cogl_matrix_perspective
cogl_matrix_ortho
cogl_ortho
cogl_set_modelview_matrix
cogl_set_projection_matrix
cogl_create_context is dealt with internally when _cogl_get_default context
is called, and cogl_destroy_context is currently never called.
It might be nicer later to get an object back when creating a context so
Cogl can support multiple contexts, so these functions are being removed
from the API until we get a chance to address context management properly.
For now cogl_destroy_context is still exported as _cogl_destroy_context so
Clutter could at least install a library deinit handler to call it.
Originally cogl_vertex_buffer_add_indices let the user pass in their own unique
ID for the indices; now the Id is generated internally and returned to the
caller.
It's now possible to add arrays of indices to a Cogl vertex buffer and
they will be put into an OpenGL vertex buffer object. Since it's quite
common for index arrays to be static it saves the OpenGL driver from
having to validate them repeatedly.
This changes the cogl_vertex_buffer_draw_elements API: It's no longer
possible to provide a pointer to an index array at draw time. So
cogl_vertex_buffer_draw_elements now takes an indices identifier that
should correspond to an idendifier returned when calling
cogl_vertex_buffer_add_indices ()
This is being removed before we release Clutter 1.0 since the implementation
wasn't complete, and so we assume no one is using this yet. Util we have
someone with a good usecase, we can't pretend to support breaking out into
raw OpenGL.
There were a number of functions intended to support creating of new
primitives using materials, but at this point they aren't used outside of
Cogl so until someone has a usecase and we can get feedback on this
API, it's being removed before we release Clutter 1.0.
This removes the following API:
cogl_material_set_blend_factors
cogl_material_set_layer_combine_function
cogl_material_set_layer_combine_arg_src
cogl_material_set_layer_combine_arg_op
These were rather awkward to use, so since it's expected very few people are
using them at this point and it should be straight forward to switch over
to blend strings, the API is being removed before we release Clutter 1.0.
Setting up layer combine functions and blend modes is very awkward to do
programatically. This adds a parser for string based descriptions which are
more consise and readable.
E.g. a material layer combine function could now be given as:
"RGBA = ADD (TEXTURE[A], PREVIOUS[RGB])"
or
"RGB = REPLACE (PREVIOUS)"
"A = MODULATE (PREVIOUS, TEXTURE)"
The simple syntax and grammar are only designed to expose standard fixed
function hardware, more advanced combining must be done with shaders.
This includes standalone documentation of blend strings covering the aspects
that are common to blending and texture combining, and adds documentation
with examples specific to the new cogl_material_set_blend() and
cogl_material_layer_set_combine() functions.
Note: The hope is to remove the now redundant bits of the material API
before 1.0
After long deliberation, the Animation class handling of the
:mode, :duration and :loop properties, as well as the conditions
for creating the Alpha and Timeline instances, came out as far too
complicated for their own good.
This is a rework of the API/parameters matrix and behaviour:
- :mode accessors will create an Alpha, if needed
- :duration and :loop accessors will create an Alpha and a Timeline
if needed
- :alpha will set or unset the Alpha
- :timeline will set or unset the Timeline
Plus, more documentation on the Animation class itself.
Many thanks to Jonas Bonn <jonas@southpole.se> for the feedback
and the ideas.
The Animatable interface implementation will always have the computed
value applied, whilst the non-Animatable objects go through the
interval validation first to avoid incurring in assertions and
warnings.
The Animatable::animate_property() should also be able to validate the
property it's supposed to interpolate, and eventually discard it. This
requires adding a return value to the virtual function (and its wrapper
function).
The Animation code will then apply the computed value only if the
animate_property() returns TRUE -- unifying the code path with the
non-Animatable objects.
The Animation class should proxy the :mode, :duration and :loop
properties whenever possible, to avoid them going out of sync when
changed using the Alpha and Timeline instances directly.
Currently, if Timeline:duration is changed, querying Animation:duration
will yield the old value, but the animation itself (being driven by
the Timeline) will use the Timeline's :duration new value. This holds
for the :loop and :mode properties as well.
Instead, the getters for the Animation's :duration, :loop and
:mode properties should ask the relevant object -- if any. The
loop, duration and mode values inside AnimationPrivate should only
be used if no Timeline or no Alpha instances are available, or
when creating new instances.
The Animation should not directly manipulate a Timeline instance,
but it should defer to the Alpha all handling of the timeline.
This means that:
- set_duration() and set_loop() will either create a Timeline or
will set the :duration and :loop properties on the Timeline; if
the Timeline must be created, and no Alpha instance is available,
then a new Alpha instance will be created as well and the newly
create Timeline will be assigned to the Alpha
- if set_mode() on an Animation instance without an Alpha, the
Alpha will be created; a Timeline will also be created
- set_alpha() will replace the Alpha; if the new Alpha does not
have a Timeline associated then a Timeline will be created using
the current :duration and :loop properties of Animation; otherwise,
if the replaced Alpha had a timeline, the timeline will be
transferred to the new one
The CoglTexture constructors expose the "max-waste" argument for
controlling the maximum amount of wasted areas for slicing or,
if set to -1, disables slicing.
Slicing is really relevant only for large images that are never
repeated, so it's a useful feature only in controlled use cases.
Specifying the amount of wasted area is, on the other hand, just
a way to mess up this feature; 99% the times, you either pull this
number out of thin air, hoping it's right, or you try to do the
right thing and you choose the wrong number anyway.
Instead, we can use the CoglTextureFlags to control whether the
texture should not be sliced (useful for Clutter-GST and for the
texture-from-pixmap actors) and provide a reasonable value for
enabling the slicing ourself. At some point, we might even
provide a way to change the default at compile time or at run time,
for particular platforms.
Since max_waste is gone, the :tile-waste property of ClutterTexture
becomes read-only, and it proxies the cogl_texture_get_max_waste()
function.
Inside Clutter, the only cases where the max_waste argument was
not set to -1 are in the Pango glyph cache (which is a POT texture
anyway) and inside the test cases where we want to force slicing;
for the latter we can create larger textures that will be bigger than
the threshold we set.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Signed-off-by: Robert Bragg <robert@linux.intel.com>
Signed-off-by: Neil Roberts <neil@linux.intel.com>
Sometimes it is necessary for third party code to have a
function called during the redraw process, so that you can
update the scenegraph before it is painted.
If we are short-circuiting the paint when the opacity is zero we still
need to clear the queued_redraw flag otherwise it won't be possible to
queue another redraw of the actor until something else has caused a
paint first.
* master:
[cogl-vertex-buffer] Ensure the clip state before rendering
[test-text-perf] Small fix-ups
Add a test for text performance
[build] Ensure that cogl-debug is disabled by default
[build] The cogl GE macro wasn't passing an int according to the format string
Use the right internal format for GL_ARB_texture_rectangle
[actor_paint] Ensure painting is a NOP for actors with opacity = 0
Make backface culling work with vertex buffers
Before any rendering is done by Cogl it needs to ensure the clip stack
is set up correctly by calling cogl_clip_ensure. This was not being
done for the Cogl vertex buffer so it would still use the clip from
the previous render.
Now that everything is float, the marsharlling function of the
size-change signal should reflect that fact.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
GLES doesn't support GL_QUADS. This patch makes it use GL_TRIANGLES
instead in that case. Unfortunately this means submitting two extra
vertices per quad. It could be better to use indexed elements once
CoglVertexBuffers gains support for that.
When ClutterGLXTexturePixmap uses GL_ARB_texture_rectangle,
it needs to pass the right internal format (GL_RGB or GL_RGBA)
when it initializes the texture with glTexImage2D() or later
handling won't recognize the alpha channel.
http://bugzilla.openedhand.com/show_bug.cgi?id=1586
Signed-off-by: Robert Bragg <robert@linux.intel.com>
Since it is convenient to use geometry with an opacity of 0 for input only
purposes it's a worthwhile optimization to avoid submitting anything
for such actors while painting.
Backface culling is enabled as part of cogl_enable so the different
rendering functions in Cogl need to explicitly opt-in to have backface
culling enabled. Cogl vertex buffers should allow backface culling so
they should check whether it is enabled and then set the appropriate
cogl_enable flag.
In order to cope with the situation where an application renders with
a PangoLayout, makes some changes and then renders again with the same
layout, CoglPangoRenderer needs to detect that the changes have
occured so that it can recreate the display list. This is acheived by
keeping a reference to the first line of the layout. When the layout
is changed Pango will clear the layout pointer in the first line and
create a new line. So if the layout pointer in the line becomes NULL
then we know the layout has changed. This trick was suggested by
Behdad Esfahbod in this email:
http://mail.gnome.org/archives/gtk-i18n-list/2009-May/msg00019.html
When a position is given to cogl_pango_render_layout_subpixel it
translates the GL matrix by the coordinates. However it was not
dividing by PANGO_SCALE so the coordinates were completely wrong.
Most of the operations involving the texture's allocated area require
floats -- either for computations or for setting the geometry into
COGL. So it doesn't make any sense to use get_allocation_coords() and
cast everything to floats.
