CoglMaterial now sets GL_CLAMP_TO_EDGE if WRAP_MODE_AUTOMATIC is used
unless it is overridden when the material is flushed. The primitives
are still expected to expose repeat semantics so no user visible
changes are made. The idea is that drawing non-repeated textures is
the most common case so if we make clamp_to_ege the default then we
will reduce the number of times we have to override the
material. Avoiding overrides will become important if the overriding
mechanism is replaced with one where the primitive is expected to copy
the material and change that instead.
Previously, Cogl's texture coordinate system was effectively always
GL_REPEAT so that if an application specifies coordinates outside the
range 0→1 it would get repeated copies of the texture. It would
however change the mode to GL_CLAMP_TO_EDGE if all of the coordinates
are in the range 0→1 so that in the common case that the whole texture
is being drawn with linear filtering it will not blend in edge pixels
from the opposite sides.
This patch adds the option for applications to change the wrap mode
per layer. There are now three wrap modes: 'repeat', 'clamp-to-edge'
and 'automatic'. The automatic map mode is the default and it
implements the previous behaviour. The wrap mode can be changed for
the s and t coordinates independently. I've tried to make the
internals support setting the r coordinate but as we don't support 3D
textures yet I haven't exposed any public API for it.
The texture backends still have a set_wrap_mode virtual but this value
is intended to be transitory and it will be changed whenever the
material is flushed (although the backends are expected to cache it so
that it won't use too many GL calls). In my understanding this value
was always meant to be transitory and all primitives were meant to set
the value before drawing. However there were comments suggesting that
this is not the expected behaviour. In particular the vertex buffer
drawing code never set a wrap mode so it would end up with whatever
the texture was previously used for. These issues are now fixed
because the material will always set the wrap modes.
There is code to manually implement clamp-to-edge for textures that
can't be hardware repeated. However this doesn't fully work because it
relies on being able to draw the stretched parts using quads with the
same values for tx1 and tx2. The texture iteration code doesn't
support this so it breaks. This is a separate bug and it isn't
trivially solved.
When flushing a material there are now extra options to set wrap mode
overrides. The overrides are an array of values for each layer that
specifies an override for the s, t or r coordinates. The primitives
use this to implement the automatic wrap mode. cogl_polygon also uses
it to set GL_CLAMP_TO_BORDER mode for its trick to render sliced
textures. Although this code has been added it looks like the sliced
trick has been broken for a while and I haven't attempted to fix it
here.
I've added a constant to represent the maximum number of layers that a
material supports so that I can size the overrides array. I've set it
to 32 because as far as I can tell we have that limit imposed anyway
because the other flush options use a guint32 to store a flag about
each layer. The overrides array ends up adding 32 bytes to each flush
options struct which may be a concern.
http://bugzilla.openedhand.com/show_bug.cgi?id=2063
GL supports setting different wrap modes for the s, t and r
coordinates so we should design the backend interface to support that
also. The r coordinate is not currently used by any of the backends
but we might as well have it to make life easier if we ever add
support for 3D textures.
http://bugzilla.openedhand.com/show_bug.cgi?id=2063
CoglColor and CoglMatrix have public declarations with private members
so that we are free to change the implementation but the structures
could still be allocated on the stack in applications. However it's
quite easy not to realise the members are private and then access them
directly. This patch wraps the members in a macro which redefines the
symbol name when including the header outside of the clutter source.
http://bugzilla.openedhand.com/show_bug.cgi?id=2065
The xx, yx, zx etc fields are meant to be read-only but they were
marked as private with the gtk-doc annotation. This patch moves the
private marker so that the 16 float member fields are public but the
type, inverted matrix, flags and padding are not.
When emitting signals, one can mark arguments as being "static", ie an
indication this argument will not change during the signal emission.
This allows the signal marshalling code to create static GValues, in
this case not to copy the Color.
http://bugzilla.openedhand.com/show_bug.cgi?id=2073
We decide whether the paint() should be a real paint or a paint in pick
mode depending on the global pick_mode value. Using G_UNLIKELY() on an
operation that most likely is going to be executed once every frame is
going to blow a lot of cache lines and frak with the CPU branch
prediction. Not good.
This adds three new API calls:
CoglHandle cogl_path_get()
void cogl_path_set(CoglHandle path)
CoglHandle cogl_path_copy(CoglHandle path)
All of the fields relating to the path have been moved from the Cogl
context to a new CoglPath handle type. The cogl context now just
contains a CoglPath handle. All of the existing path commands
manipulate the data in the current path handle. cogl_path_new now just
creates a new path handle and unrefs the old one.
The path handle can be stored for later with cogl_path_get. The path
can then be copied with cogl_path_copy. Internally it implements
copy-on-write semantics with an extra optimisation that it will only
copy the data if the new path is modified, but not if the original
path is modified. It can do this because the only way to modify a path
is by appending to it so the copied path is able to store its own path
length and only render the nodes up to that length. For this to work
the copied path also needs to keep its own copies of the path extents
because the parent path may change these by adding nodes.
The clip stack now uses the cogl_path_copy mechanism to store paths in
the stack instead of directly copying the data. This should save some
memory and processing time.
Although cogl_multiply_matrix was consistent with OpenGL, after further
consideration it was agreed that cogl_transform is a better name. Given
that it's in the global cogl_ namespace cogl_transform seems more self
documenting.
This adds an example of how to setup a Clutter style 2D coordinate space
and clarifies what state is owned by a framebuffer. (projection,
modelview, viewport and clip stack)
When we expose more cogl_framebuffer API this example will hopefully be
migrated into a more extensive introduction to using framebuffers.
Previously cogl_set_source and cogl_set_source_texture were in
cogl-material.c and the cogl_set_source_color* funcs were in
cogl-color.c. Originally this was because cogl.c was duplicated between
the GL and GLES backends and we didn't want to add to the amount of
duplicated code, but these files have since been consolidated into one
cogl.c.
Quite often it's desirable to be able to multiply the current modelview
matrix by an arbitrary matrix. Currently though you have to first
explicitly call cogl_get_modelview_matrix to get the current modelview
into a temporary variable, then you need to multiply it with your matrix
using cogl_matrix_multiply and finally use cogl_set_modelview_matrix to
make the result be the new modelview. This new convenience function lets
more efficiently skip the first get and last set steps.
Every now and then someone sees the cogl_enable API and gets confused,
thinking its public API so this renames the symbol to be clear that it's
is an internal only API.
ClutterX11TexturePixmap calls get_allocation_box() when queueing a
clipped redraw. If the allocation is not valid, and if we queue a
lot of redraws in response to a series of damage events, the net
result is that we spend all our time in a re-layout. We can
short-circuit this by checking if the actor has a valid allocation, and
if not, just queue a redraw - the actor will be allocated by the time it
is going to be painted.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Add clutter_actor_has_allocation(), a method meant to be used when
deciding whether to call clutter_actor_get_allocation_box() or any
of its wrappers.
The get_allocation_box() method will, in case the allocation is invalid,
perform a costly re-allocation cycle to ensure that the returned box
is valid. The has_allocation() method is meant to be used if we have an
actor calling get_allocation_box() from outside the place where the
allocation is always guaranteed to be valid.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Added new "homogeneous" mode to ClutterBoxLayout, that makes layout children
get all the same size.
This is heavily inspired in the "homogeneous" attribute available in GtkBox,
but simplified as we don't have padding nor borders in box layout, only
spacing.
Also added to test-box-layout a key to set/unset homogeneous mode.
* Coding style fixes.
* Added proper test for homogeneous mode in box layout.
* Fix in homogeneous mode.
http://bugzilla.openedhand.com/show_bug.cgi?id=2034
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Somebody somewhere decided it would be ok to define 'y1' as a global
function in math.h thus condemning us to repeatedly making commits to
fix these obnoxious compiler warnings about aliasing.
glXSwapIntervalSGI only affects buffer swaps to the
current GLX drawable.
That means that calling it once in clutter_backend_glx_get_features
isn't sufficent, so set it up in clutter_backend_glx_ensure_context to
make sure it affects buffer swaps for the current drawable.
http://bugzilla.openedhand.com/show_bug.cgi?id=2044
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Move the size check after the NULL check, add the clip height into the
check logic and fix up the comment.
http://bugzilla.openedhand.com/show_bug.cgi?id=2040
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
When printing out the property value during a ClutterScript debug run we
generate the value's content using g_strdup_value_contents() - though we
do it unconditionally. The contents might not be printed (they most
likely won't, actually) and will be freed afterwards. This is
unnecessary: we can allocate the contents string after checking if we're
going to print out the debug note, thus avoiding the whole
allocation/free cycle unless strictly needed.
When setting up the state for a layer, we need to switch texture
units before we do anything that might bind the texture, or
we'll bind the wrong texture to the previous unit.
http://bugzilla.openedhand.com/show_bug.cgi?id=2033
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
* 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>
We need to set up the rowstride and alignment properly in
CoglTexture2D before reading texture data.
http://bugzilla.openedhand.com/show_bug.cgi?id=2036
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
If you forgot to call clutter_init() then you currently end up with a
warning saying that the stage cannot be initialized because the backend
does not support multiple stages. Clearly not useful.
We can catch some of the missing initialization in the features API,
since we will likely end up asking for a feature at some point.
We kind of assume that stuff will break well before during the
ClutterBackend::create_context() implementation if we fail to create a
GL context. We do, however, have error reporting in place inside the
Backend API to catch those cases. Unfortunately, since we switched to
lazy initialization of the Stage, there can be a case of GL context
creation failure that still leads to a successful initialization - and a
segmentation fault later on. This is clearly Not Good™.
Let's try to catch a failure in all the places calling create_context()
and report back to the user the error in a meaningful way, before
crashing and burning.
If you call get_n_columns() during the instance initialization phase but
before set_name()/set_types() have been called, you'll get a (guint) -1.
This is less than ideal.
If columns haven't been initialized we should just return 0, which was
the intent of the API since the beginning.
Based on a patch by: Bastian Winkler <buz@netbuz.org>
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
The int storage, and the initial value of -1, is used as a guard when
subclassing ClutterListModel to allow the sub-class to call
clutter_model_set_names() and clutter_model_set_types().
This reverts commit c274118a8f.
This makes it more likely consumers notice invalid unreferences.
GObject has the same assertion.
http://bugzilla.openedhand.com/show_bug.cgi?id=2029
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
clutter_model_get_n_columns is supposed to return a guint, so the
n_columns field needs to be a guint with the initial value set to 0.
http://bugzilla.openedhand.com/show_bug.cgi?id=2017
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
When entering cogl_texture_2d_new_from_bitmap the internal format can
be COGL_PIXEL_FORMAT_ANY. This was causing _cogl_texture_2d_can_create
to use an invalid GL format type. Mesa apparently ignores this but it
was causing errors when Cogl is compiled with debugging under NVidia.
http://bugzilla.openedhand.com/show_bug.cgi?id=2026
Add a return result from CoglTexture.transform_quad_coords_to_gl(),
so that we can properly determine the nature of repeats in
the face of GL_TEXTURE_RECTANGLE_ARB, where the returned
coordinates are not normalized.
The comment "We also work out whether any of the texture
coordinates are outside the range [0.0,1.0]. We need to do
this after calling transform_coords_to_gl in case the texture
backend is munging the coordinates (such as in the sub texture
backend)." is disregarded and removed, since it's actually
the virtual coordinates that determine whether we repeat,
not the GL coordinates.
Warnings about disregarded layers are used in all cases where
applicable, including for subtextures.
http://bugzilla.openedhand.com/show_bug.cgi?id=2016
Signed-off-by: Neil Roberts <neil@linux.intel.com>
Fix clutter initialisation if argb visuals are enabled, setting a border
color on creating the dummy window. This should avoid BadMatch happening
when the depth of the root window visual is not the same of the depth
of the argb visual.
http://bugzilla.openedhand.com/show_bug.cgi?id=2011
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Backport of the upstream JSON-GLib commit that improved the strictness
of JsonParser.
The original upstream commit is:
29881f03468db08bfb404cfcd5b61b4cdc419a87
In _cogl_texture_2d_sliced_foreach_sub_texture_in_region(), don't
assert that the target is GL_TEXTURE_2D; instead conditionalize
normalization on the target.
http://bugzilla.openedhand.com/show_bug.cgi?id=2015
If the EGL context is already created then we shouldn't try to create
another one. This was causing problems where one context would be
created from calling _clutter_feature_init and the other was created
from _clutter_backend_get_features. Cogl would set up its state using
the first context and then assume the state was still valid when the
second context became used so blending was not working correctly.
http://bugzilla.openedhand.com/show_bug.cgi?id=2020
The documentation and name of the get_transformation_matrix function
implies that 'matrix' is purely an out parameter. However it wasn't
initializing the matrix before calling the 'apply_transform' virtual
so it was basically just a wrapper for the virtual. The virtual
assumes the matrix parameter is in/out and applies the actor's
transformation on top of any existing transformations. This causes
unexpected semantics that are inconsistent with the documentation.
This changes clutter_glx_texture_pixmap_update_area so it defers the
call to glXBindTexImageEXT until our pre "paint" signal handler which
makes clutter_glx_texture_pixmap_update_area cheap to call.
The hope is that mutter can switch to reporting raw damage updates to
ClutterGLXTexturePixmap and we can use these to queue clipped redraws.
A new (internal only currently) API, _clutter_actor_queue_clipped_redraw
can be used to queue a redraw along with a clip rectangle in actor
coordinates. This clip rectangle propagates up to the stage and clutter
backend which may optionally use the information to optimize stage
redraws. The GLX backend in particular may scissor the next redraw to
the clip rectangle and use GLX_MESA_copy_sub_buffer to present the stage
subregion.
The intention is that any actors that can naturally determine the bounds
of updates should queue clipped redraws to reduce the cost of updating
small regions of the screen.
Notes:
» If GLX_MESA_copy_sub_buffer isn't available then the GLX backend
ignores any clip rectangles.
» queuing multiple clipped redraws will result in the bounding box of
each clip rectangle being used.
» If a clipped redraw has a height > 300 pixels then it's promoted into
a full stage redraw, so that the GPU doesn't end up blocking too long
waiting for the vsync to reach the optimal position to avoid tearing.
» Note: no empirical data was used to come up with this threshold so
we may need to tune this.
» Currently only ClutterX11TexturePixmap makes use of this new API. This
is done via a new "queue-damage-redraw" signal that is emitted when
the pixmap is updated. The default handler queues a clipped redraw
with the assumption that the pixmap is being painted as a rectangle
covering the actors transformed allocation. If you subclass
ClutterX11TexturePixmap and change how it's painted you now also
need to override the signal handler and queue your own redraw.
Technically this is a semantic break, but it's assumed that no one
is currently doing this.
This still leaves a few unsolved issues with regards to optimizing sub
stage redraws that need to be addressed in further work so this can only
be considered a stepping stone a this point:
» Because we have no reliable way to determine if the painting of any
given actor is being modified any optimizations implemented using
_clutter_actor_queue_redraw_with_clip must be overridable by a
subclass, and technically must be opt-in for existing classes to avoid
a change in semantics. E.g. consider that a user connects to the paint
signal for ClutterTexture and paints a circle instead of a rectangle.
In this case any original logic to queue clipped redraws would be
incorrect.
» Currently only the implementation of an actor has enough information
with which to queue clipped redraws. E.g. It is not possible for
generic code in clutter-actor.c to queue a clipped redraw when hiding
an actor because actors have no way to report a "paint box". (remember
actors can draw outside their allocation and actors with depth may
also be projected outside of their allocation)
» The current plan is to add a actor_class->get_paint_cuboid()
virtual so actors can report a bounding cube for everything they
would draw in their current state and use that to queue clipped
redraws against the stage by projecting the paint cube into stage
coordinates.
» Our heuristics for promoting clipped redraws into full redraws to
avoid blocking the GPU while we wait for the vsync need improving:
» vsync issues aren't relevant for redirected/composited applications
so they should use different heuristics. In this case we instead
need to trade off the cost of blitting when using glXCopySubBuffer
vs promoting to a full redraw and flipping instead.
commit 511e5ceb51 accidentally removed the #ifdef COGL_ENABLE_DEBUG
guards around the "cogl-debug" and "cogl-no-debug" cogl_args[] which
this patch restores.
The FlowLayout fails to provide a preferred size in case no sizing is
specified on one axis. It should, instead, have the preferred size of
the sum of its children, depending on the orientation property.
http://bugzilla.openedhand.com/show_bug.cgi?id=2013
Some EGL drivers for embedded devices require a specific framebuffer
device to be opened and passed to eglCreateWindowSurface(). Since it's
optional, we can provide an environment variabled called
CLUTTER_FB_DEVICE that can be used to specify the path of the device
to be opened.
http://bugzilla.openedhand.com/show_bug.cgi?id=1997
Update the EGL native framebuffer backend to be 1.2-ready:
» create the EGL context and the surface inside the create_context()
implementation so that a context is always available
» simplify the StageWindow implementation
» clean up old code
http://bugzilla.openedhand.com/show_bug.cgi?id=1997
Just like _cogl_texture_2d_new_with_size(),
_cogl_texture_2d_new_from_bitmap() needs to check if an unsliced
texture can be created at the given size, or if hardware
limitations prevent this.
http://bugzilla.openedhand.com/show_bug.cgi?id=2014
Signed-off-by: Neil Roberts <neil@linux.intel.com>
cogl_read_pixels() no longer asserts that the format passed in is
RGBA_8888 but instead accepts any format. The appropriate GL enums for
the format are passed to glReadPixels so OpenGL should be perform a
conversion if neccessary.
It currently assumes glReadPixels will always give us premultiplied
data. This will usually be correct because the result of the default
blending operations for Cogl ends up with premultiplied data in the
framebuffer. However it is possible for the framebuffer to be in
whatever format depending on what CoglMaterial is used to render to
it. Eventually we may want to add a way for an application to inform
Cogl that the framebuffer is not premultiplied in case it is being
used for some special purpose.
If the requested format is not premultiplied then Cogl will convert
it. The tests have been changed to read the data as premultiplied so
that they won't be affected by the conversion. Picking in Clutter has
been changed to use COGL_PIXEL_FORMAT_RGB_888 because it doesn't need
the alpha component. clutter_stage_read_pixels is left unchanged
because the application can't specify a format for that so it seems to
make most sense to store unpremultiplied values.
http://bugzilla.openedhand.com/show_bug.cgi?id=1959
* stage-min-size-rework:
docs: Update minimum size accessors
actor: Use the TOPLEVEL flag instead of a type check
[stage] Use min-width/height props for min size
The clutter-profile.c print_report() code would crash if no stats had
been gathered because uprof would return NULL for the "Redrawing" timer
which we then dereferenced.
This changes the code to start by checking for the "Mainloop",
"Redrawing" and "Do Pick" timers and if none are present it returns
immediately without generating any report.
Since using addresses that might change is something that finally
the FSF acknowledge as a plausible scenario (after changing address
twice), the license blurb in the source files should use the URI
for getting the license in case the library did not come with it.
Not that URIs cannot possibly change, but at least it's easier to
set up a redirection at the same place.
As a side note: this commit closes the oldes bug in Clutter's bug
report tool.
http://bugzilla.openedhand.com/show_bug.cgi?id=521
There is no need for us to check for low-level functions and header
files, especially since we haven't been checking the results until
now. This makes cross-compiling slightly more bearable.
If the actor is an internal child of another actor then we should call
unparent() when destroying it, like clutter_actor_reparent() does;
otherwise we'll leak the actor, since the parent holds a reference to
it.
http://bugzilla.openedhand.com/show_bug.cgi?id=2009
Instead of shadowing these properties with different properties with the
same names on stage, actually use them. Behaviour should be identical,
except the minimum stage size can now be enforced by setting the
min-width/height properties as well as using the set_minimum_size
function.
If we do not unset the Stage we will have stale data, and the Crossing
event when re-entering a Stage will not be emitted, as the actor under
the pointer might be the same as before.
This adds a COGL_INDICES_TYPE_UNSIGNED_INT enum value so that unsigned
ints can be used with cogl_vertex_buffer_indices_new. Unsigned ints
are not supported in core on GLES so a feature flag has also been
added to advertise this. GLES only sets the feature if the
GL_OES_element_index_uint extension is available. It is an error to
call indices_new() with unsigned ints unless the feature is
advertised.
http://bugzilla.openedhand.com/show_bug.cgi?id=1998
Allow a ClutterModel to be constructed through the ClutterScript API.
Currently this allows a model to be generated like like this:
{
"id" : "test-model",
"type" : "ClutterListModel",
"columns" : [
[ "text-column", "gchararray" ],
[ "int-column", "gint" ],
[ "actor-column", "ClutterRectangle" ]
]
}
where 'columns' is an array containing arrays of column-name,
column-type pairs.
http://bugzilla.openedhand.com/show_bug.cgi?id=2007
The code has gotten really complicated to follow.
As soon as we have a sync-to-vblank mechanism we should just bail out.
Also, __GL_SYNC_TO_VBLANK (which is used by nVidia) should be assumed
equivalent to a CLUTTER_VBLANK_GLX_SWAP.
We should explain what a "key frame" is for ClutterAnimator, possibly
with some sort of visual cue.
This allows me to demonstrate my poor skills at using Inkscape, as well
as my overall bad taste for graphics design.
The top-level types list was comically out of date, and it was only
determining whether the type we were constructing was initially unowned
or a full object. We can safely replace it with a simple type check.
It would be useful to be able to share the Timeline across different
animator instances, or with different animation constructs. Also this
allows sharing definitions of Timelines in ClutterScript.
The arguments for remove_key() can be NULL, but there is an extraneous
assertion that fails if they are. The pre-conditions should match the
documentation, in this case.
A sub-class of ClutterBox might add ChildMeta support, and since
pack_at() does not go through clutter_container_add_actor(), we
need to manually call the create_child_meta() ourselves.
It is conceivable that Container implementations might add children
outside of the Container::add() implementation - e.g. for packing at
a specific index. Since the addition (and removal) might happen outside
the common path we need to expose all the API that is implicitly called
by ClutterContainer when adding and removing a child - namely the
ChildMeta creation and destruction.
Previously the GLES2 backend needed a special wrapper for
glBindTexture because it needed to know the internal GL format of the
texture in order to correctly implement the GL_MODULATE texture env
mode. When GL_MODULATE is used then the RGB values are taken from the
previous texture layer rather than being fetched from the
texture. However since the material API was added Cogl no longer uses
the GL_MODULATE texture env mode but instead always uses GL_COMBINE.
Compiling the GLES2 backend broke since the more-texture-backends
branch merge because the cogl_get_internal_gl_format function was
removed and there was one place in GLES2 specific code that was using
this to bind the texture.
The texture layer combine functions are now hard coded to GL_COMBINE
instead of GL_MODULATE. The combine function can be customized with
all the parameters of GL_COMBINE. A shader is generated to implement
the given parameters.
Currently it will try to generate code for the constant color but it
will use a uniform which does not exist.
The GLES2 backend for Cogl is failing to compile because
GL_MAX_TEXTURE_UNITS is not defined. Let's define it and provide a
wrapper which uses GL_MAX_TEXTURE_IMAGE_UNITS or
COGL_GLES2_MAX_TEXTURE_UNITS, whichever is the smallest.
A bogus ClutterInterpolation argument had been carried from
clutter_animator_set_interpolation to clutter_animator_get_interpolation
in copy and paste.
GLib 2.24 (but starting from the 2.23.2 unstable release) added a new
macro for collecting GValues from a va_list.
The newly added G_VALUE_COLLECT_INIT() macro should be used in place
of initializing the GValue and calling G_VALUE_COLLECT(), and improves
the collection performances by avoiding multiple checks, free and
initialization calls.
