Move the private Backend API to a separate header.
This also allows us to finally move the class vtable and instance
structure to a separate file and plug the visibility hole that left
the Backend class bare for everyone to poke into.
In 4ee05f8e21 the namespace for the clutter keysym macros were
changed to CLUTTER_KEY_* but the win32 events backend was still
referring to the old names.
This uses actor paint volumes to perform culling during
clutter_actor_paint.
When performing a clipped redraw (because only a few localized actors
changed) then as we traverse the scenegraph painting the actors we can
now ignore actors that don't intersect the clip region. Early testing
shows this can have a big performance benefit; e.g. 100% fps improvement
for test-state with culling enabled and we hope that there are even much
more compelling examples than that in the real world,
Most Clutter applications are 2Dish interfaces and have quite a lot of
actors that get continuously painted when anything is animated. The
dynamic actors are often localized to an area of user focus though so
with culling we can completely avoid painting any of the static actors
outside the current clip region.
Obviously the cost of culling has to be offset against the cost of
painting to determine if it's a win, but our (limited) testing suggests
it should be a win for most applications.
Note: we hope we will be able to also bring another performance bump
from culling with another iteration - hopefully in the 1.6 cycle - to
avoid doing the culling in screen space and instead do it in the stage's
model space. This will hopefully let us minimize the cost of
transforming the actor volumes for culling.
This is a fairly extensive second pass at exposing paint volumes for
actors.
The API has changed to allow clutter_actor_get_paint_volume to fail
since there are times - such as when an actor isn't a descendent of the
stage - when the volume can't be determined. Another example is when
something has connected to the "paint" signal of the actor and we simply
have no way of knowing what might be drawn in that handler.
The API has also be changed to return a const ClutterPaintVolume pointer
(transfer none) so we can avoid having to dynamically allocate the
volumes in the most common/performance critical code paths. Profiling was
showing the slice allocation of volumes taking about 1% of an apps time,
for some fairly basic tests. Most volumes can now simply be allocated on
the stack; for clutter_actor_get_paint_volume we return a pointer to
&priv->paint_volume and if we need a more dynamic allocation there is
now a _clutter_stage_paint_volume_stack_allocate() mechanism which lets
us allocate data which expires at the start of the next frame.
The API has been extended to make it easier to implement
get_paint_volume for containers by using
clutter_actor_get_transformed_paint_volume and
clutter_paint_volume_union. The first allows you to query the paint
volume of a child but transformed into parent actor coordinates. The
second lets you combine volumes together so you can union all the
volumes for a container's children and report that as the container's
own volume.
The representation of paint volumes has been updated to consider that
2D actors are the most common.
The effect apis, clutter-texture and clutter-group have been update
accordingly.
*** WARNING: THIS COMMIT CHANGES THE BUILD ***
Do not recurse into the backend directories to build private, internal
libraries.
We only recurse from clutter/ into the cogl sub-directory; from there,
we don't recurse any further. All the backend-specific code in Cogl and
Clutter is compiled conditionally depending on the macros defined by the
configure script.
We still recurse from the top-level directory into doc, clutter and
tests, because gtk-doc and tests do not deal nicely with non-recursive
layouts.
This change makes Clutter compile slightly faster, and cleans up the
build system, especially when dealing with introspection data.
Ideally, we also want to make Cogl part of the top-level build, so that
we can finally drop the sed trick to change the shared library from the
GIR before compiling it.
Currently disabled:
‣ OSX backend
‣ Fruity backend
Currently enabled but untested:
‣ EGL backend
‣ Windows backend
When building actor relative transforms, instead of using the matrix
stack to combine transformations and making assumptions about what is
currently on the stack we now just explicitly initialize an identity
matrix and apply transforms to that.
This removes the full_vertex_t typedef for internal transformation code
and we just use ClutterVertex.
ClutterStage now implements apply_transform like any other actor now
and the code we had in _cogl_setup_viewport has been moved to the
stage's apply_transform instead.
ClutterStage now tracks an explicit projection matrix and viewport
geometry. The projection matrix is derived from the perspective whenever
that changes, and the viewport is updated when the stage gets a new
allocation. The SYNC_MATRICES mechanism has been removed in favour of
_clutter_stage_dirty_viewport/projection() APIs that get used when
switching between multiple stages to ensure cogl has the latest
information about the onscreen framebuffer.
Commit eae4561929 tried to clean how it checks for the private actor
flags. However the check for the 'IN_DESTRUCTION' flag in the Win32
backend got inverted so it would always clear the current
context. This was causing _cogl_check_driver_valid to fail later and
then the realize would get stuck in a infinite loop.
It's possible that a single WM_MOUSEWHEEL event can arrive with a
scroll amount greater than WHEEL_DELTA. Previously it would accumulate
these amounts but it would still only emit a single event per
message. For example, if a message arrived that is worth two
WHEEL_DELTAs then it would emit one event and leave scroll_pos as
+WHEEL_DELTA. If the wheel is then scrolled in the opposite direction
then wheel delta would end up as zero and the scroll event would get
lost.
This patch fixes it so that it always emits enough events to put
scroll_pos back to less than WHEEL_DELTA.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2135
Previously the window procedure for the stage window would always
create a ClutterEvent struct for every message and then pass that on
to message_translate to fill in the details. message_translate could
return FALSE to abandon the event. Instead of this, message_translate
now creates and queues the event itself whenever it sees a message
that could translate to an event. The function now returns void. This
has a number of advantages:
* It saves redundantly allocating events for messages that Clutter
doesn't care about.
* A single message can now easily be translated into multiple events.
* There were some messages that were handled and did not fill in the
event struct but did not cause the function to return FALSE. I think
this would end up with a CLUTTER_NOTHING event being emitted.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2135
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
The DeviceManager class should be abstract in Clutter, and implemented
by each backend, as different backends will have different ways to
detect, initialize and list devices; the X11 backend alone has *two*
ways of dealing with devices.
This commit makes DeviceManager an abstract class and delegates the
device initialization and enumeration to per-backend sub-classes.
The responsible for creating the device manager is, obviously, the
backend singleton.
The X11 and Win32 backends have been updated to the new layout; the
Win32 backend has been updated blindly, so it might require additional
testing.
The Win32 backend now implements the create_context method which
creates a context and binds it to a 1x1 invisible window. That way
there will always be a context bound and the features can be retrieved
without creating the default stage. This reflects the changes in
1c6ffc8..b245d55 to the GLX backend.
Mostly lifted from the core pointer and keyboard X11 backend support.
The win32 backend registers two devices (a core pointer and a core
keyboard) and assigns them to the event structure when doing the
translation from native events to Clutter events.
Thanks to: Samuel Degrande <Samuel.Degrande@lifl.fr> for testing this
patch.
The win32 backend now handles the WM_SETCURSOR message and sets a
fully transparent cursor if the cursor-visible property has been
cleared on the stage. The icon is stored in the library via a resource
file. The instance handle for the DLL is needed to load the resource
so there is now a DllMain function to grab the handle.
As part of an incremental process to have Cogl be a standalone project we
want to re-consider how we organise the Cogl source code.
Currently this is the structure I'm aiming for:
cogl/
cogl/
<put common source here>
winsys/
cogl-glx.c
cogl-wgl.c
driver/
gl/
gles/
os/ ?
utils/
cogl-fixed
cogl-matrix-stack?
cogl-journal?
cogl-primitives?
pango/
The new winsys component is a starting point for migrating window system
code (i.e. x11,glx,wgl,osx,egl etc) from Clutter to Cogl.
The utils/ and pango/ directories aren't added by this commit, but they are
noted because I plan to add them soon.
Overview of the planned structure:
* The winsys/ API is the API that binds OpenGL to a specific window system,
be that X11 or win32 etc. Example are glx, wgl and egl. Much of the logic
under clutter/{glx,osx,win32 etc} should migrate here.
* Note there is also the idea of a winsys-base that may represent a window
system for which there are multiple winsys APIs. An example of this is
x11, since glx and egl may both be used with x11. (currently only Clutter
has the idea of a winsys-base)
* The driver/ represents a specific varient of OpenGL. Currently we have "gl"
representing OpenGL 1.4-2.1 (mostly fixed function) and "gles" representing
GLES 1.1 (fixed funciton) and 2.0 (fully shader based)
* Everything under cogl/ should fundamentally be supporting access to the
GPU. Essentially Cogl's most basic requirement is to provide a nice GPU
Graphics API and drawing a line between this and the utility functionality
we add to support Clutter should help keep this lean and maintainable.
* Code under utils/ as suggested builds on cogl/ adding more convenient
APIs or mechanism to optimize special cases. Broadly speaking you can
compare cogl/ to OpenGL and utils/ to GLU.
* clutter/pango will be moved to clutter/cogl/pango
How some of the internal configure.ac/pkg-config terminology has changed:
backendextra -> CLUTTER_WINSYS_BASE # e.g. "x11"
backendextralib -> CLUTTER_WINSYS_BASE_LIB # e.g. "x11/libclutter-x11.la"
clutterbackend -> {CLUTTER,COGL}_WINSYS # e.g. "glx"
CLUTTER_FLAVOUR -> {CLUTTER,COGL}_WINSYS
clutterbackendlib -> CLUTTER_WINSYS_LIB
CLUTTER_COGL -> COGL_DRIVER # e.g. "gl"
Note: The CLUTTER_FLAVOUR and CLUTTER_COGL defines are kept for apps
As the first thing to take advantage of the new winsys component in Cogl;
cogl_get_proc_address() has been moved from cogl/{gl,gles}/cogl.c into
cogl/common/cogl.c and this common implementation first trys
_cogl_winsys_get_proc_address() but if that fails then it falls back to
gmodule.
This makes clutter_stage_win32_show/hide be implementations of
ClutterStageWindowIface rather than overriding the methods in
ClutterActor. This reflects the changes in e4ff24bc for the X11
backend.
This function should only need to be called in exceptional circumstances
since Cogl can normally determine internally when a flush is necessary.
As an optimization Cogl drawing functions may batch up primitives
internally, so if you are trying to use raw GL outside of Cogl you stand a
better chance of being successful if you ask Cogl to flush any batched
geometry before making your state changes.
cogl_flush() ensures that the underlying driver is issued all the commands
necessary to draw the batched primitives. It provides no guarantees about
when the driver will complete the rendering.
This provides no guarantees about the GL state upon returning and to avoid
confusing Cogl you should aim to restore any changes you make before
resuming use of Cogl.
If you are making state changes with the intention of affecting Cogl drawing
primitives you are 100% on your own since you stand a good chance of
conflicting with Cogl internals. For example clutter-gst which currently
uses direct GL calls to bind ARBfp programs will very likely break when Cogl
starts to use ARBfb programs internally for the material API, but for now it
can use cogl_flush() to at least ensure that the ARBfp program isn't applied
to additional primitives.
This does not provide a robust generalized solution supporting safe use of
raw GL, its use is very much discouraged.
Previously the journal was always flushed at the end of
_cogl_rectangles_with_multitexture_coords, (i.e. the end of any
cogl_rectangle* calls) but now we have broadened the potential for batching
geometry. In ideal circumstances we will only flush once per scene.
In summary the journal works like this:
When you use any of the cogl_rectangle* APIs then nothing is emitted to the
GPU at this point, we just log one or more quads into the journal. A
journal entry consists of the quad coordinates, an associated material
reference, and a modelview matrix. Ideally the journal only gets flushed
once at the end of a scene, but in fact there are things to consider that
may cause unwanted flushing, including:
- modifying materials mid-scene
This is because each quad in the journal has an associated material
reference (i.e. not copy), so if you try and modify a material that is
already referenced in the journal we force a flush first)
NOTE: For now this means you should avoid using cogl_set_source_color()
since that currently uses a single shared material. Later we
should change it to use a pool of materials that is recycled
when the journal is flushed.
- modifying any state that isn't currently logged, such as depth, fog and
backface culling enables.
The first thing that happens when flushing, is to upload all the vertex data
associated with the journal into a single VBO.
We then go through a process of splitting up the journal into batches that
have compatible state so they can be emitted to the GPU together. This is
currently broken up into 3 levels so we can stagger the state changes:
1) we break the journal up according to changes in the number of material layers
associated with logged quads. The number of layers in a material determines
the stride of the associated vertices, so we have to update our vertex
array offsets at this level. (i.e. calling gl{Vertex,Color},Pointer etc)
2) we further split batches up according to material compatability. (e.g.
materials with different textures) We flush material state at this level.
3) Finally we split batches up according to modelview changes. At this level
we update the modelview matrix and actually emit the actual draw command.
This commit is largely about putting the initial design in-place; this will be
followed by other changes that take advantage of the extended batching.
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.
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>
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.
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.
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
Bug 1138 - No trackable "mapped" state
* Add a VISIBLE flag tracking application programmer's
expected showing-state for the actor, allowing us to
always ensure we keep what the app wants while tracking
internal implementation state separately.
* Make MAPPED reflect whether the actor will be painted;
add notification on a ClutterActor::mapped property.
Keep MAPPED state updated as the actor is shown,
ancestors are shown, actor is reparented, etc.
* Require a stage and realized parents to realize; this means
at realization time the correct window system and GL resources
are known. But unparented actors can no longer be realized.
* Allow children to be unrealized even if parent is realized.
Otherwise in effect either all actors or no actors are realized,
i.e. it becomes a stage-global flag.
* Allow clutter_actor_realize() to "fail" if not inside a toplevel
* Rework clutter_actor_unrealize() so internally we have
a flavor that does not mess with visibility flag
* Add _clutter_actor_rerealize() to encapsulate a somewhat
tricky operation we were doing in a couple of places
* Do not realize/unrealize children in ClutterGroup,
ClutterActor already does it
* Do not realize impl by hand in clutter_stage_show(),
since showing impl already does that
* Do not unrealize in various dispose() methods, since
ClutterActor dispose implementation already does it
and chaining up is mandatory
* ClutterTexture uses COGL while unrealizable (before it's
added to a stage). Previously this breakage was affecting
ClutterActor because we had to allow realize outside
a stage. Move the breakage to ClutterTexture, by making
ClutterTexture just use COGL while not realized.
* Unrealize before we set parent to NULL in clutter_actor_unparent().
This means unrealize() implementations can get to the stage.
Because actors need the stage in order to detach from stage.
* Update clutter-actor-invariants.txt to reflect latest changes
* Remove explicit hide/unrealize from ClutterActor::dispose since
unparent already forces those
Instead just assert that unparent() occurred and did the right thing.
* Check whether parent implements unrealize before chaining up
Needed because ClutterGroup no longer has to implement unrealize.
* Perform unrealize in the default handler for the signal.
This allows non-containers that have children to work properly,
and allows containers to override how it's done.
* Add map/unmap virtual methods and set MAPPED flag on self and
children in there. This allows subclasses to hook map/unmap.
These are not signals, because notify::mapped is better for
anything it's legitimate for a non-subclass to do.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Bug 1178 - No enter / leave events on actors when pointer leaves the
stage window
This patch causes the Win32 backend to emit CLUTTER_LEAVE events when
a WM_MOUSELEAVE event is received in the same way that f505536 does
for the X11 backend.
Windows will only send WM_MOUSELEAVE events if they are previously
requested using TrackMouseEvent so this needs to be called whenever
the mouse enters the window. There is no WM_MOUSELEAVE event but we
can detect when the mouse enters because we get a WM_MOUSEMOVE event.
window_style correction.
* clutter/win32/clutter-stage-win32.c (get_window_style): Remove
the WS_MAXIMIZEBOX style if the stage isn't resizable.
(clutter_stage_win32_set_user_resize): Queue a redraw of the
window frame when the user_resize property is changed.
* clutter/win32/clutter-event-win32.c (message_translate): Don't
update the size of the stage when handling WM_SIZE messages that
result from the stage being minimized. Thanks to Roman Yazmin.
* clutter/win32/clutter-event-win32.c (message_translate): The
coordinates in a WM_MOUSEWEEL message are given relative to the
screen so they need to be converted to client coordinates before
use. Thanks to Roman Yazmin.
* clutter/clutter-actor.c:
(clutter_actor_set_min_width),
(clutter_actor_set_min_height),
(clutter_actor_set_natural_width),
(clutter_actor_set_natural_height): Ignore any override of the
minimum and natural size of the stage on backends that only
support static stages.
* clutter/clutter-stage.c (clutter_stage_allocate): Use the
preferred size of the ClutterStage implementation instead of
the display size.
* clutter/clutter-backend.[ch]: Remove get_display_size() and
clutter_backend_get_display_size().
* clutter/eglnative/clutter-backend-egl.c:
* clutter/fruity/clutter-backend-fruity.c:
* clutter/osx/clutter-backend-osx.c:
* clutter/sdl/clutter-backend-sdl.c:
* clutter/win32/clutter-backend-win32.c:
* clutter/x11/clutter-backend-x11.c: Remove get_display_size()
implementations.
(clutter_stage_win32_realize): Use a more direct method to choose
the best pixel format instead of ChoosePixelFormat because
otherwise if the display's depth is 16 then it will prefer the
non-accelerated software implementation when the requested depth
is 24.
API. All code to do with positioning the stage has been removed so
the window is left where Windows wants to put it and it can not be
moved with clutter_actor_set_position.
* clutter/win32/clutter-stage-win32.h (ClutterStageWin32): Remove
win_xpos and win_ypos.
* clutter/win32/clutter-event-win32.c (message_translate): Remove
the handler for WM_MOVE because the stage no longer cares where it
is positioned.
signedness of old_xpos and old_ypos to get rid of compiler
warnings.
* clutter/win32/clutter-backend-win32.c
(clutter_backend_win32_get_features): Cast the result of
glGetString to a signed char pointer to avoid compiler warnings.
* clutter/win32/clutter-backend-win32.c: Reflect changes to the
GLX/X11 backend in revisions 2708-2709 and 2713-2715 which
simplify the backend a little.
* clutter/win32/clutter-stage-win32.c
(clutter_stage_win32_request_coords): Don't resize foreign
windows.
(clutter_stage_win32_unrealize): Don't destroy foreign windows.
(clutter_stage_win32_init): Added initialiser for is_foreign_win.
(clutter_win32_get_stage_from_window): Resort to looking in the
stage list if the window isn't the right window class so that it
can still find stages with foreign windows.
(clutter_win32_set_stage_foreign): New public function to set a
foreign window for a stage.
* clutter/win32/clutter-event-win32.c
(clutter_win32_disable_event_retrieval): New public function to
disable event retrieval.
(message_translate): Don't handle WM_SIZE or WM_MOVE for foreign
windows.
* clutter/win32/clutter-backend-win32.h (struct
_ClutterBackendWin32): Added a flag to disable event retrieval
* clutter/win32/clutter-backend-win32.c
(clutter_backend_win32_ensure_context): Update debug note to
include whether the stage is foreign or not.
subclassing code.
* clutter/win32/clutter-stage-win32.h:
* clutter/win32/clutter-stage-win32.c: Now inherits from
ClutterGroup and implements ClutterStageWindow instead of
inheriting directly from ClutterStage.
* clutter/win32/clutter-event-win32.c (message_translate): Now
takes an extra parameter to return whether DefWindowProc should be
called. This is needed to prevent the default WM_CLOSE handler
from destroying the window.
* clutter/win32/clutter-backend-win32.c
(clutter_backend_win32_dispose): Destroy all of the stages using
g_slist_foreach as per bug #871. Now also destroys the GL context.
(clutter_backend_win32_get_features): Added assertions to ensure
there is a valid GL context.
(clutter_backend_win32_ensure_context): Accepts NULL stage. Gets
implementation pointer from the stage.
* clutter/win32/clutter-backend-win32.c
(clutter_backend_win32_init): Added a call to
timeBeginPeriod. Without this the frame rates are terrible because
the glib timeouts are not accurate enough. However this requires
Glib >= 2.16.0 to take any effect because of a change in the way
g_poll is implemented. See revision 6597 of glib.
(clutter_backend_win32_finalize): Added a call to timeEndPeriod.
* configure.ac: Added -lwinmm to the library dependencies for the
Win32 backend.
* clutter/win32/clutter-win32.h:
* clutter/win32/clutter-stage-win32.h:
* clutter/win32/clutter-stage-win32.c:
* clutter/win32/clutter-event-win32.c:
* clutter/win32/clutter-backend-win32.h:
* clutter/win32/clutter-backend-win32.c:
Upgraded for multi-stage support.
* clutter/win32/clutter-stage-win32.c
(clutter_stage_win32_request_coords): Fixed so that it doesn't set
the position or size if it hasn't changed. This was causing
problems when the window was resized using the top left corner. In
that case the window receives resize and move messages separately
which caused the window to flash at a different size or position
while one message was handled before the other.
(clutter_stage_win32_realize): Added PFD_GENERIC_ACCELERATED to
the list of pixel format flags to force it to use hardware
acceleration.
2008-03-30 Neil Roberts <neil@o-hand.com>
* clutter-sections.txt: Added clutter_win32_get_stage_from_window
* clutter/win32/clutter-win32.h: Added gtk-doc documentation for
the Win32 backend section.
* clutter/win32/clutter-stage-win32.c
(clutter_win32_get_stage_window): Fixed punctuation in the
documentation.
* README: Added notes about the Win32 backend.
2008-03-26 Neil Roberts <neil@o-hand.com>
* clutter-sections.txt: Added a section for the Win32 specific
API.
* clutter-docs.sgml: Added comments about the Win32 backend.
* Makefile.am: Added bits to ignore the headers for the Win32
backend.
* clutter/win32/clutter-event-win32.c (clutter_event_check):
Removed the pointless parameter in the call to check_msg_pending.
(check_msg_pending): Fixed to use PeekMessageW instead of
PeekMessage.
