Current parsing of units has a number of shortcomings:
* a number followed by trailing space (without any unit specified) was
not recognized,
* "5 emeralds" was parsed as 5em,
* the way we parse the digits after the separator makes us lose
precision for no good reason (5.0 is parsed as 5.00010014...f which
makes g_assert_cmpfloat() fail)
Let's define a stricter grammar we can recognize and try to do so. The
description is in EBNF form, removing the optional <> which is a pain
when having to write DocBook, and using '' for the terminal symbols.
Last step, add more ClutterUnits unit test to get a better coverage of
the grammar we want to parse.
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
Parse #rgb and #rrggbb in addition to forms with the alpha channel
specified. This allows conversion of colour strings from documents such as
CSS where the alpha channel is not specified when using '#' notation.
This patch also adds the relevant conformance test.
The user-initiated resize is conflicting with the allocated size. This
happens because we change the size of the stage's X Window behind the
back of the size allocation machinery.
Instead, we should change the size of the actor whenever we receive a
ConfigureNotify event to reflect the new size of the actor.
I just wasted a silly amount time trying to bisect an apparently broken
cogl-test-multitexture until I realized it was just silently failing to load
any textures.
This unit verifies that an Actor class will invoke the get_preferred_*
virtual functions unless the caching is in effect; it also verifies
that the cached values are correctly evicted.
The size requisition and allocation mechanisms should be thoroughly
tested to avoid unwanted regressions.
For starters, we can test the explicit size setting and the side
effects of calling clutter_actor_set_size().
The test-script.json UI definition still used old types, like
ClutterLabel and ClutterCloneTexture. It should move to the classes
that have replaced them.
We need to test that the depth sorting of ClutterGroup works correctly
in case we wish to change the data structure that stores the children,
and do so without changing the default behaviour.
in tests/interactive/Makefile.am add wrapper.sh to EXTRA_DIST otherwise
interactive unit tests wont be runnable when building from distributed
tarballs.
We should follow the convention for boxed types initializers of:
<type_name>_from_<another_type> (boxed, value)
For ClutterUnits as well; so:
clutter_units_pixels -> clutter_units_from_pixels
clutter_units_em -> clutter_units_from_em
...
We should still keep the short-hand version as a macro, though.
The ClutterColor conformance test should have a unit for verifying
the RGB<->HLS conversion code, especially the ability to roundtrip
between the two colorspaces.
AM_LDFLAGS is ignored by the LDFLAGS target, and it's also not the right
place to put the libraries used by the linker.
Thanks to Vincent Untz for spotting this.
The perspective test was used essentially to determine whether the
perspective set up in COGL worked correctly. The perspective code
has been changed a lot since Clutter 0.3: we rely on client-side
matrices and we use floating point; so, all the conditions the test
was supposed to verify do not exist anymore.
Fixes and adds a unit test for creating and drawing using materials with
COGL_INVALID_HANDLE texture layers.
This may be valid if for example the user has set a texture combine string
that only references a constant color.
_cogl_material_flush_layers_gl_state will bind the fallback texture for any
COGL_INVALID_HANDLE layer, later though we could explicitly check when the
current blend mode does't actually reference a texture source in which case
binding the fallback texture is redundant.
This tests drawing using cogl_rectangle, cogl_polygon and
cogl_vertex_buffer_draw.
To allow for flushing of batched geometry within Cogl we can't support users
directly calling glReadPixels. glReadPixels is also awkward, not least
because it returns upside down image data.
All the unit tests have been swithed over and clutter_stage_read_pixels now
sits on top of this too.
test-cogl-tex-getset was assuming it was dealing with
COGL_PIXEL_FORMAT_RGBA_8888 but since merging the premultiplcation branch
the pixel format is actually COGL_PIXEL_FORMAT_RGBA_8888_PRE
Texture data is now in premultiplied format and the shader should
output a premultiplied color if the default blend mode is being
used. Shaders that directly manipulate the rgb values now
unpremultiply and premultiply again afterwards.
Now that we can safely check for an uninitialized Clutter we
don't have side effects in calling one of the functions like
clutter_x11_enable_xinput(), which require to be called before
any other Clutter function.
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.
The test-easing interactive demo for the high-level animation API
is a bit "flat". Instead of using a Rectangle actor we should
probably be using something more "interesting" -- like a CairoTexture
with a gradient.
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.
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.
The test has been broken since the change to use floats instead of
fixed point because it was passing degrees to sin and cos but they
expect radians.
It was further broken since the timeline changes because it was
directly using the parameter of the new-frame signal as a frame number
but it now represents the elapsed time.
We need to fix the VBO premultiplication; we also do not need to
forcibly queue a redraw in an idle handler: the timeline and the
master clock will do that for us.
The test-actors test (and its clones, test-actor-clone and
test-paint-wrapper) was written a long time ago for a different API
and has been tweaked to bits. We should probably have something a
little bit more complicated, but at least we should not use semantics
and coding patterns from Clutter 0.2, otherwise we won't be testing
anything except that Clutter 0.2 worked.
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()
cogl_texture_new_from_data lets you specify a source format for the users given
data, and an internal format which the user wants the GPU to see. This unit
test verifies that the users data is premultiplied, un-premultiplied or
left alone for a number of (source format, internal format) pairs.
cogl_texture_set_region allows specifying a source format, and the internal
format is determined from the texture being updated. As above we test
a number of format pairs and check Cogl is converting data correctly.
The test verifies that if the user allows COGL_FORMAT_ANY for the
internal_format then by default Cogl will choose a premultipled format for
RGBA textures.
Note: Currently this only tests cogl_texture_new_from_data and
cogl_texture_set_region, we should also test cogl_texture_new_from_file,
cogl_texture_new_from_bitmap and cogl_texture_new_from_foreign.
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.
This test assumes that the textures will be stored internally with exactly
the color given so that specific texture combining arithmetic can be
tested. Using COGL_PIXEL_FORMAT_ANY allows Cogl to internally premultiply
the textures, so we have to explicitly request an unmultiplied format.
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>
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
...
The changes in the master clock and the repaint cycle have been
changed, and broke the way the test for the Text actor cache of
PangoLayouts forces a redraw.
We have to call clutter_actor_paint() on the Stage embedding the
Text actor we want to test; this is kinda fugly because if the
Layout has changed it will end up causing a reallocation cycle
in the middle of the Text actor paint. Since it's a test case,
and since forcing redraws is a bit of a hack as well, we can
close both our eyes on that.
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.
The master clock now works fine whether or not there are any stages,
so in the timeline conformance tests don't need to set up their
own times.
Set CLUTTER_VBLANK=none for the conformance tests, which in addition
to removing an test-environment dependency, will result in the ticking
for timeline tests being throttled to the default frame rate.
http://bugzilla.openedhand.com/show_bug.cgi?id=1637
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
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>
Using clutter_stage_get_actor_at_pos() rather than synthesizing
events; the synthesized events were being compressed, so we were
only tesitng one pick per frame.
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.
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
The test was quiting after the 2nd frame but it should be the third frame because
the test doesn't actually check results until the third frame due to the workaround
for drivers with broken glReadPixels.
(When first written the test would have been verified with the
clutter_main_quit() commented out which gives visual feedback of what the
test does, so the off by one would have snuck in just before uncommenting
and pushing.)
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
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.
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.
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.
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.
If it doesn't queue a redraw and allow the backend to clear and swap
the buffers then the results will be skewed because it is not
predictable when the driver will actually render the scene.
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.
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
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 ()
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
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>
* 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
- Fix a typo in a for loop in create_label which left 'i'
uninitialised and caused a crash if you're unlucky.
- Set the CLUTTER_VBLANK=none environment variable.
- Don't quit on a keypress.
- Trailing whitespace tidy up.
Print out the cursor and selection positions in order to verify
the behaviour of the Text actor.
This is a likely candidate for a conformance test unit as well.
The picking test has two configurables: the number of actors and
the number of events per frame. It makes sense to have them as
command line options to test with multiple configurations without
having to change defines and recompile.
COGLenum, COGLint and COGLuint which were simply typedefs for GL{enum,int,uint}
have been removed from the API and replaced with specialised enum typedefs, int
and unsigned int. These were causing problems for generating bindings and also
considered poor style.
The cogl texture filter defines CGL_NEAREST and CGL_LINEAR etc are now replaced
by a namespaced typedef 'CoglTextureFilter' so they should be replaced with
COGL_TEXTURE_FILTER_NEAREST and COGL_TEXTURE_FILTER_LINEAR etc.
The shader type defines CGL_VERTEX_SHADER and CGL_FRAGMENT_SHADER are handled by
a CoglShaderType typedef and should be replaced with COGL_SHADER_TYPE_VERTEX and
COGL_SHADER_TYPE_FRAGMENT.
cogl_shader_get_parameteriv has been replaced by cogl_shader_get_type and
cogl_shader_is_compiled. More getters can be added later if desired.
With the recent change to internal floating point values, ClutterUnit
has become a redundant type, defined to be a float. All integer entry
points are being internally converted to floating point values to be
passed to the GL pipeline with the least amount of conversion.
ClutterUnit is thus exposed as just a "pixel with fractionary bits",
and not -- as users might think -- as generic, resolution and device
independent units. not that it was the case, but a definitive amount
of people was convinced it did provide this "feature", and was flummoxed
about the mere existence of this type.
So, having ClutterUnit exposed in the public API doubles the entry
points and has the following disadvantages:
- we have to maintain twice the amount of entry points in ClutterActor
- we still do an integer-to-float implicit conversion
- we introduce a weird impedance between pixels and "pixels with
fractionary bits"
- language bindings will have to choose what to bind, and resort
to manually overriding the API
+ *except* for language bindings based on GObject-Introspection, as
they cannot do manual overrides, thus will replicate the entire
set of entry points
For these reason, we should coalesces every Actor entry point for
pixels and for ClutterUnit into a single entry point taking a float,
like:
void clutter_actor_set_x (ClutterActor *self,
gfloat x);
void clutter_actor_get_size (ClutterActor *self,
gfloat *width,
gfloat *height);
gfloat clutter_actor_get_height (ClutterActor *self);
etc.
The issues I have identified are:
- we'll have a two cases of compiler warnings:
- printf() format of the return values from %d to %f
- clutter_actor_get_size() taking floats instead of unsigned ints
- we'll have a problem with varargs when passing an integer instead
of a floating point value, except on 64bit platforms where the
size of a float is the same as the size of an int
To be clear: the *intent* of the API should not change -- we still use
pixels everywhere -- but:
- we remove ambiguity in the API with regard to pixels and units
- we remove entry points we get to maintain for the whole 1.0
version of the API
- we make things simpler to bind for both manual language bindings
and automatic (gobject-introspection based) ones
- we have the simplest API possible while still exposing the
capabilities of the underlying GL implementation
There were several functions I believe no one is currently using that were
only implemented in the GL backend (cogl_offscreen_blit_region and
cogl_offscreen_blit) that have simply been removed so we have a chance to
think about design later with a real use case.
There was one nonsense function (cogl_offscreen_new_multisample) that
sounded exciting but in all cases it just returned COGL_INVALID_HANDLE
(though at least for GL it checked for multisampling support first!?)
it has also been removed.
The MASK draw buffer type has been removed. If we want to expose color
masking later then I think it at least would be nicer to have the mask be a
property that can be set on any draw buffer.
The cogl_draw_buffer and cogl_{push,pop}_draw_buffer function prototypes
have been moved up into cogl.h since they are for managing global Cogl state
and not for modifying or creating the actual offscreen buffers.
This also documents the API so for example desiphering the semantics of
cogl_offscreen_new_to_texture() should be a bit easier now.
The units in the Timeline test suite just rely on the timeline
being a timeout automatically advanced by the main loop. This
is not the case anymore, since the merge of the master-clock.
To make the test units work again we need to "emulate" the master
clock without effectively having a stage to redraw; we do this
by creating a frame source and manually advancing the timelines
we create for test purposes, using the advance_msecs() "protected"
method.
