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mutter/clutter/clutter-main.c

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/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Authored By Matthew Allum <mallum@openedhand.com>
*
* Copyright (C) 2006 OpenedHand
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:clutter-main
* @short_description: Various 'global' clutter functions.
*
* Functions to retrieve various global Clutter resources and other utility
* functions for mainloops, events and threads
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdlib.h>
#include "clutter-event.h"
#include "clutter-backend.h"
#include "clutter-main.h"
#include "clutter-feature.h"
#include "clutter-actor.h"
#include "clutter-stage.h"
#include "clutter-private.h"
#include "clutter-debug.h"
#include "clutter-version.h" /* For flavour define */
#include "clutter-frame-source.h"
#include "cogl/cogl.h"
/* main context */
static ClutterMainContext *ClutterCntx = NULL;
/* main lock and locking/unlocking functions */
static GMutex *clutter_threads_mutex = NULL;
static GCallback clutter_threads_lock = NULL;
static GCallback clutter_threads_unlock = NULL;
static gboolean clutter_is_initialized = FALSE;
static gboolean clutter_show_fps = FALSE;
static gboolean clutter_fatal_warnings = FALSE;
static guint clutter_default_fps = 60;
static guint clutter_main_loop_level = 0;
static GSList *main_loops = NULL;
guint clutter_debug_flags = 0; /* global clutter debug flag */
#ifdef CLUTTER_ENABLE_DEBUG
static const GDebugKey clutter_debug_keys[] = {
{ "misc", CLUTTER_DEBUG_MISC },
{ "actor", CLUTTER_DEBUG_ACTOR },
{ "texture", CLUTTER_DEBUG_TEXTURE },
{ "event", CLUTTER_DEBUG_EVENT },
{ "paint", CLUTTER_DEBUG_PAINT },
{ "gl", CLUTTER_DEBUG_GL },
{ "alpha", CLUTTER_DEBUG_ALPHA },
{ "behaviour", CLUTTER_DEBUG_BEHAVIOUR },
{ "pango", CLUTTER_DEBUG_PANGO },
{ "backend", CLUTTER_DEBUG_BACKEND },
{ "scheduler", CLUTTER_DEBUG_SCHEDULER },
{ "script", CLUTTER_DEBUG_SCRIPT },
{ "shader", CLUTTER_DEBUG_SHADER },
{ "multistage", CLUTTER_DEBUG_MULTISTAGE },
};
#endif /* CLUTTER_ENABLE_DEBUG */
/**
* clutter_get_show_fps:
*
* Returns whether Clutter should print out the frames per second on the
* console. You can enable this setting either using the
* <literal>CLUTTER_SHOW_FPS</literal> environment variable or passing
* the <literal>--clutter-show-fps</literal> command line argument. *
*
* Return value: %TRUE if Clutter should show the FPS.
*
* Since: 0.4
*/
gboolean
clutter_get_show_fps (void)
{
return clutter_show_fps;
}
static inline void
clutter_maybe_setup_viewport (ClutterStage *stage)
{
if (CLUTTER_PRIVATE_FLAGS (stage) & CLUTTER_ACTOR_SYNC_MATRICES)
{
ClutterPerspective perspective;
guint width, height;
clutter_actor_get_size (CLUTTER_ACTOR (stage), &width, &height);
clutter_stage_get_perspectivex (stage, &perspective);
CLUTTER_NOTE (PAINT, "Setting up the viewport");
cogl_setup_viewport (width, height,
perspective.fovy,
perspective.aspect,
perspective.z_near,
perspective.z_far);
CLUTTER_UNSET_PRIVATE_FLAGS (stage, CLUTTER_ACTOR_SYNC_MATRICES);
}
}
/**
* clutter_redraw:
*
* Forces a redraw of the entire stage. Applications should never use this
* function, but queue a redraw using clutter_actor_queue_redraw().
*/
void
clutter_redraw (ClutterStage *stage)
{
ClutterMainContext *ctx;
static GTimer *timer = NULL;
static guint timer_n_frames = 0;
ctx = clutter_context_get_default ();
CLUTTER_TIMESTAMP (SCHEDULER, "Redraw start for stage:%p", stage);
CLUTTER_NOTE (PAINT, " Redraw enter for stage:%p", stage);
CLUTTER_NOTE (MULTISTAGE, "Redraw called for stage:%p", stage);
_clutter_backend_ensure_context (ctx->backend, stage);
/* Setup FPS count - not currently across *all* stages rather than per */
if (G_UNLIKELY (clutter_get_show_fps ()))
{
if (!timer)
timer = g_timer_new ();
}
/* The code below can't go in stage paint as base actor_paint
* will get called before it (and break picking, etc)
*/
clutter_maybe_setup_viewport (stage);
/* Call through to the actual backend to do the painting down from
* the stage. It will likely need to swap buffers, vblank sync etc
* which will be windowing system dependant.
*/
_clutter_backend_redraw (ctx->backend, stage);
/* Complete FPS info */
if (G_UNLIKELY (clutter_get_show_fps ()))
{
timer_n_frames++;
if (g_timer_elapsed (timer, NULL) >= 1.0)
{
g_print ("*** FPS: %i ***\n", timer_n_frames);
timer_n_frames = 0;
g_timer_start (timer);
}
}
CLUTTER_NOTE (PAINT, " Redraw leave for stage:%p", stage);
CLUTTER_TIMESTAMP (SCHEDULER, "Redraw finish for stage:%p", stage);
}
/**
* clutter_set_motion_events_enabled:
* @enable: %TRUE to enable per-actor motion events
*
* Sets whether per-actor motion events should be enabled or not (the
* default is to enable them).
*
* If @enable is %FALSE the following events will not work:
* <itemizedlist>
* <listitem><para>ClutterActor::motion-event, unless on the
* #ClutterStage</para></listitem>
* <listitem><para>ClutterActor::enter-event</para></listitem>
* <listitem><para>ClutterActor::leave-event</para></listitem>
* </itemizedlist>
*
* Since: 0.6
*/
void
clutter_set_motion_events_enabled (gboolean enable)
{
ClutterMainContext *context = clutter_context_get_default ();
context->motion_events_per_actor = enable;
}
/**
* clutter_get_motion_events_enabled:
*
* Gets whether the per-actor motion events are enabled.
*
* Return value: %TRUE if the motion events are enabled
*
* Since: 0.6
*/
gboolean
clutter_get_motion_events_enabled (void)
{
ClutterMainContext *context = clutter_context_get_default ();
return context->motion_events_per_actor;
}
ClutterActor *
_clutter_do_pick (ClutterStage *stage,
gint x,
gint y,
ClutterPickMode mode)
{
ClutterMainContext *context;
guchar pixel[4];
GLint viewport[4];
ClutterColor white = { 0xff, 0xff, 0xff, 0xff };
guint32 id;
gint r,g,b;
context = clutter_context_get_default ();
_clutter_backend_ensure_context (context->backend, stage);
/* needed for when a context switch happens */
clutter_maybe_setup_viewport (stage);
cogl_paint_init (&white);
/* Disable dithering (if any) when doing the painting in pick mode */
glDisable (GL_DITHER);
/* Render the entire scence in pick mode - just single colored silhouette's
* are drawn offscreen (as we never swap buffers)
*/
context->pick_mode = mode;
clutter_actor_paint (CLUTTER_ACTOR (stage));
context->pick_mode = CLUTTER_PICK_NONE;
/* Calls should work under both GL and GLES, note GLES needs RGBA */
glGetIntegerv(GL_VIEWPORT, viewport);
/* Below to be safe, particularly on GL ES. an EGL wait call or full
* could be nicer.
*/
glFinish();
/* glEnable (GL_DITHER); we never enabled this originally, so its
probably not safe to then enable it */
glReadPixels (x, viewport[3] - y -1, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, pixel);
if (pixel[0] == 0xff && pixel[1] == 0xff && pixel[2] == 0xff)
return CLUTTER_ACTOR (stage);
cogl_get_bitmasks (&r, &g, &b, NULL);
/* Decode color back into an ID, taking into account fb depth */
id = pixel[2]>>(8-b) | pixel[1]<<b>>(8-g) | pixel[0]<<(g+b)>>(8-r);
return clutter_get_actor_by_gid (id);
}
static void
clutter_context_free (ClutterMainContext *context)
{
/* this will take care of destroying the stage */
g_object_unref (context->backend);
context->backend = NULL;
clutter_id_pool_free (context->id_pool);
context->id_pool = NULL;
/* XXX: The cleaning up of the event queue should be moved here from
the backend base class. */
g_free (context);
}
/**
* clutter_main_quit:
*
* Terminates the Clutter mainloop.
*/
void
clutter_main_quit (void)
{
g_return_if_fail (main_loops != NULL);
g_main_loop_quit (main_loops->data);
}
/**
* clutter_main_level:
*
* Retrieves the depth of the Clutter mainloop.
*
* Return value: The level of the mainloop.
*/
gint
clutter_main_level (void)
{
return clutter_main_loop_level;
}
/**
* clutter_main:
*
* Starts the Clutter mainloop.
*/
void
clutter_main (void)
{
ClutterMainContext *context = CLUTTER_CONTEXT ();
GMainLoop *loop;
if (!clutter_is_initialized)
{
g_warning ("Called clutter_main() but Clutter wasn't initialised. "
"You must call clutter_init() first.");
return;
}
CLUTTER_MARK ();
clutter_main_loop_level++;
loop = g_main_loop_new (NULL, TRUE);
main_loops = g_slist_prepend (main_loops, loop);
#ifdef HAVE_CLUTTER_FRUITY_FOO
clutter_fruity_main ();
#else
if (g_main_loop_is_running (main_loops->data))
{
clutter_threads_leave ();
g_main_loop_run (loop);
clutter_threads_enter ();
}
#endif
main_loops = g_slist_remove (main_loops, loop);
g_main_loop_unref (loop);
clutter_main_loop_level--;
if (clutter_main_loop_level == 0)
{
clutter_context_free (context);
}
CLUTTER_MARK ();
}
static void
clutter_threads_impl_lock (void)
{
if (clutter_threads_mutex)
g_mutex_lock (clutter_threads_mutex);
}
static void
clutter_threads_impl_unlock (void)
{
if (clutter_threads_mutex)
g_mutex_unlock (clutter_threads_mutex);
}
/**
* clutter_threads_init:
*
* Initialises the Clutter threading mechanism, so that Clutter API can be
* called by multiple threads, using clutter_threads_enter() and
* clutter_threads_leave() to mark the critical sections.
*
* You must call g_thread_init() before this function.
*
* This function must be called before clutter_init().
*
* Since: 0.4
*/
void
clutter_threads_init (void)
{
if (!g_thread_supported ())
g_error ("g_thread_init() must be called before clutter_threads_init()");
clutter_threads_mutex = g_mutex_new ();
if (!clutter_threads_lock)
clutter_threads_lock = clutter_threads_impl_lock;
if (!clutter_threads_unlock)
clutter_threads_unlock = clutter_threads_impl_unlock;
}
/**
* clutter_threads_set_lock_functions:
* @enter_fn: function called when aquiring the Clutter main lock
* @leave_fn: function called when releasing the Clutter main lock
*
* Allows the application to replace the standard method that
* Clutter uses to protect its data structures. Normally, Clutter
* creates a single #GMutex that is locked by clutter_threads_enter(),
* and released by clutter_threads_leave(); using this function an
* application provides, instead, a function @enter_fn that is
* called by clutter_threads_enter() and a function @leave_fn that is
* called by clutter_threads_leave().
*
* The functions must provide at least same locking functionality
* as the default implementation, but can also do extra application
* specific processing.
*
* As an example, consider an application that has its own recursive
* lock that when held, holds the Clutter lock as well. When Clutter
* unlocks the Clutter lock when entering a recursive main loop, the
* application must temporarily release its lock as well.
*
* Most threaded Clutter apps won't need to use this method.
*
* This method must be called before clutter_threads_init(), and cannot
* be called multiple times.
*
* Since: 0.4
*/
void
clutter_threads_set_lock_functions (GCallback enter_fn,
GCallback leave_fn)
{
g_return_if_fail (clutter_threads_lock == NULL &&
clutter_threads_unlock == NULL);
clutter_threads_lock = enter_fn;
clutter_threads_unlock = leave_fn;
}
typedef struct
{
GSourceFunc func;
gpointer data;
GDestroyNotify notify;
} ClutterThreadsDispatch;
static gboolean
clutter_threads_dispatch (gpointer data)
{
ClutterThreadsDispatch *dispatch = data;
gboolean ret = FALSE;
clutter_threads_enter ();
if (!g_source_is_destroyed (g_main_current_source ()))
ret = dispatch->func (dispatch->data);
clutter_threads_leave ();
return ret;
}
static void
clutter_threads_dispatch_free (gpointer data)
{
ClutterThreadsDispatch *dispatch = data;
/* XXX - we cannot hold the thread lock here because the main loop
* might destroy a source while still in the dispatcher function; so
* knowing whether the lock is being held or not is not known a priori.
*
* see bug: http://bugzilla.gnome.org/show_bug.cgi?id=459555
*/
if (dispatch->notify)
dispatch->notify (dispatch->data);
g_slice_free (ClutterThreadsDispatch, dispatch);
}
/**
* clutter_threads_add_idle_full:
* @priority: the priority of the timeout source. Typically this will be in the
* range between #G_PRIORITY_DEFAULT_IDLE and #G_PRIORITY_HIGH_IDLE
* @func: function to call
* @data: data to pass to the function
* @notify: functio to call when the idle source is removed
*
* Adds a function to be called whenever there are no higher priority
* events pending. If the function returns %FALSE it is automatically
* removed from the list of event sources and will not be called again.
*
* This variant of g_idle_add_full() calls @function with the Clutter lock
* held. It can be thought of a MT-safe version for Clutter actors for the
* following use case, where you have to worry about idle_callback()
* running in thread A and accessing @self after it has been finalized
* in thread B:
*
* <informalexample><programlisting>
* static gboolean
* idle_callback (gpointer data)
* {
* // clutter_threads_enter(); would be needed for g_idle_add()
*
* SomeActor *self = data;
* /<!-- -->* do stuff with self *<!-- -->/
*
* self->idle_id = 0;
*
* // clutter_threads_leave(); would be needed for g_idle_add()
* return FALSE;
* }
* static void
* some_actor_do_stuff_later (SomeActor *self)
* {
* self->idle_id = clutter_threads_add_idle (idle_callback, self)
* // using g_idle_add() here would require thread protection in the callback
* }
*
* static void
* some_actor_finalize (GObject *object)
* {
* SomeActor *self = SOME_ACTOR (object);
* if (self->idle_id)
* g_source_remove (self->idle_id);
* G_OBJECT_CLASS (parent_class)->finalize (object);
* }
* </programlisting></informalexample>
*
* Return value: the ID (greater than 0) of the event source.
*
* Since: 0.4
*/
guint
clutter_threads_add_idle_full (gint priority,
GSourceFunc func,
gpointer data,
GDestroyNotify notify)
{
ClutterThreadsDispatch *dispatch;
g_return_val_if_fail (func != NULL, 0);
dispatch = g_slice_new (ClutterThreadsDispatch);
dispatch->func = func;
dispatch->data = data;
dispatch->notify = notify;
return g_idle_add_full (priority,
clutter_threads_dispatch, dispatch,
clutter_threads_dispatch_free);
}
/**
* clutter_threads_add_idle:
* @func: function to call
* @data: data to pass to the function
*
* Simple wrapper around clutter_threads_add_idle_full()
*
* Return value: the ID (greater than 0) of the event source.
*
* Since: 0.4
*/
guint
clutter_threads_add_idle (GSourceFunc func,
gpointer data)
{
g_return_val_if_fail (func != NULL, 0);
return clutter_threads_add_idle_full (G_PRIORITY_DEFAULT_IDLE,
func, data,
NULL);
}
/**
* clutter_threads_add_timeout_full:
* @priority: the priority of the timeout source. Typically this will be in the
* range between #G_PRIORITY_DEFAULT and #G_PRIORITY_HIGH.
* @interval: the time between calls to the function, in milliseconds
* @func: function to call
* @data: data to pass to the function
* @notify: function to call when the timeout source is removed
*
* Sets a function to be called at regular intervals holding the Clutter lock,
* with the given priority. The function is called repeatedly until it
* returns %FALSE, at which point the timeout is automatically destroyed
* and the function will not be called again. The @notify function is
* called when the timeout is destroyed. The first call to the
* function will be at the end of the first @interval.
*
* Note that timeout functions may be delayed, due to the processing of other
* event sources. Thus they should not be relied on for precise timing.
* After each call to the timeout function, the time of the next
* timeout is recalculated based on the current time and the given interval
* (it does not try to 'catch up' time lost in delays).
*
* This variant of g_timeout_add_full() can be thought of a MT-safe version
* for Clutter actors. See also clutter_threads_add_idle_full().
*
* Return value: the ID (greater than 0) of the event source.
*
* Since: 0.4
*/
guint
clutter_threads_add_timeout_full (gint priority,
guint interval,
GSourceFunc func,
gpointer data,
GDestroyNotify notify)
{
ClutterThreadsDispatch *dispatch;
g_return_val_if_fail (func != NULL, 0);
dispatch = g_slice_new (ClutterThreadsDispatch);
dispatch->func = func;
dispatch->data = data;
dispatch->notify = notify;
return g_timeout_add_full (priority,
interval,
clutter_threads_dispatch, dispatch,
clutter_threads_dispatch_free);
}
/**
* clutter_threads_add_timeout:
* @interval: the time between calls to the function, in milliseconds
* @func: function to call
* @data: data to pass to the function
*
* Simple wrapper around clutter_threads_add_timeout_full().
*
* Return value: the ID (greater than 0) of the event source.
*
* Since: 0.4
*/
guint
clutter_threads_add_timeout (guint interval,
GSourceFunc func,
gpointer data)
{
g_return_val_if_fail (func != NULL, 0);
return clutter_threads_add_timeout_full (G_PRIORITY_DEFAULT,
interval,
func, data,
NULL);
}
/**
* clutter_threads_add_frame_source_full:
* @priority: the priority of the frame source. Typically this will be in the
* range between #G_PRIORITY_DEFAULT and #G_PRIORITY_HIGH.
* @interval: the time between calls to the function, in milliseconds
* @func: function to call
* @data: data to pass to the function
* @notify: function to call when the timeout source is removed
*
* Sets a function to be called at regular intervals holding the Clutter lock,
* with the given priority. The function is called repeatedly until it
* returns %FALSE, at which point the timeout is automatically destroyed
* and the function will not be called again. The @notify function is
* called when the timeout is destroyed. The first call to the
* function will be at the end of the first @interval.
*
* This function is similar to clutter_threads_add_timeout_full except
* that it will try to compensate for delays. For example, if @func
* takes half the interval time to execute then the function will be
* called again half the interval time after it finished. In contrast
* clutter_threads_add_timeout_full would not fire until a full
* interval after the function completes so the delay between calls
* would be @interval * 1.5. This function does not however try to
* invoke the function multiple times to catch up missing frames if
* @func takes more than @interval ms to execute.
*
* Return value: the ID (greater than 0) of the event source.
*
* Since: 0.8
*/
guint
clutter_threads_add_frame_source_full (gint priority,
guint interval,
GSourceFunc func,
gpointer data,
GDestroyNotify notify)
{
ClutterThreadsDispatch *dispatch;
g_return_val_if_fail (func != NULL, 0);
dispatch = g_slice_new (ClutterThreadsDispatch);
dispatch->func = func;
dispatch->data = data;
dispatch->notify = notify;
return clutter_frame_source_add_full (priority,
interval,
clutter_threads_dispatch, dispatch,
clutter_threads_dispatch_free);
}
/**
* clutter_threads_add_frame_source:
* @interval: the time between calls to the function, in milliseconds
* @func: function to call
* @data: data to pass to the function
*
* Simple wrapper around clutter_threads_add_frame_source_full().
*
* Return value: the ID (greater than 0) of the event source.
*
* Since: 0.8
*/
guint
clutter_threads_add_frame_source (guint interval,
GSourceFunc func,
gpointer data)
{
g_return_val_if_fail (func != NULL, 0);
return clutter_threads_add_frame_source_full (G_PRIORITY_DEFAULT,
interval,
func, data,
NULL);
}
/**
* clutter_threads_enter:
*
* Locks the Clutter thread lock.
*
* Since: 0.4
*/
void
clutter_threads_enter (void)
{
if (clutter_threads_lock)
(* clutter_threads_lock) ();
}
/**
* clutter_threads_leave:
*
* Unlocks the Clutter thread lock.
*
* Since: 0.4
*/
void
clutter_threads_leave (void)
{
if (clutter_threads_unlock)
(* clutter_threads_unlock) ();
}
/**
* clutter_get_debug_enabled:
*
* Check if clutter has debugging turned on.
*
* Return value: TRUE if debugging is turned on, FALSE otherwise.
*/
gboolean
clutter_get_debug_enabled (void)
{
#ifdef CLUTTER_ENABLE_DEBUG
return clutter_debug_flags != 0;
#else
return FALSE;
#endif
}
ClutterMainContext *
clutter_context_get_default (void)
{
if (G_UNLIKELY(!ClutterCntx))
{
ClutterMainContext *ctx;
ctx = g_new0 (ClutterMainContext, 1);
ctx->backend = g_object_new (_clutter_backend_impl_get_type (), NULL);
ctx->is_initialized = FALSE;
ctx->motion_events_per_actor = TRUE;
#ifdef CLUTTER_ENABLE_DEBUG
ctx->timer = g_timer_new ();
g_timer_start (ctx->timer);
#endif
ClutterCntx = ctx;
}
return ClutterCntx;
}
/**
* clutter_get_timestamp:
*
* Returns the approximate number of microseconds passed since clutter was
* intialised.
*
* Return value: Number of microseconds since clutter_init() was called.
*/
gulong
clutter_get_timestamp (void)
{
#ifdef CLUTTER_ENABLE_DEBUG
ClutterMainContext *ctx;
gdouble seconds;
ctx = clutter_context_get_default ();
/* FIXME: may need a custom timer for embedded setups */
seconds = g_timer_elapsed (ctx->timer, NULL);
return (gulong)(seconds / 1.0e-6);
#else
return 0;
#endif
}
#ifdef CLUTTER_ENABLE_DEBUG
static gboolean
clutter_arg_debug_cb (const char *key,
const char *value,
gpointer user_data)
{
clutter_debug_flags |=
g_parse_debug_string (value,
clutter_debug_keys,
G_N_ELEMENTS (clutter_debug_keys));
return TRUE;
}
static gboolean
clutter_arg_no_debug_cb (const char *key,
const char *value,
gpointer user_data)
{
clutter_debug_flags &=
~g_parse_debug_string (value,
clutter_debug_keys,
G_N_ELEMENTS (clutter_debug_keys));
return TRUE;
}
#endif /* CLUTTER_ENABLE_DEBUG */
static GOptionEntry clutter_args[] = {
{ "clutter-show-fps", 0, 0, G_OPTION_ARG_NONE, &clutter_show_fps,
"Show frames per second", NULL },
{ "clutter-default-fps", 0, 0, G_OPTION_ARG_INT, &clutter_default_fps,
"Default frame rate", "FPS" },
{ "g-fatal-warnings", 0, 0, G_OPTION_ARG_NONE, &clutter_fatal_warnings,
"Make all warnings fatal", NULL },
#ifdef CLUTTER_ENABLE_DEBUG
{ "clutter-debug", 0, 0, G_OPTION_ARG_CALLBACK, clutter_arg_debug_cb,
"Clutter debugging flags to set", "FLAGS" },
{ "clutter-no-debug", 0, 0, G_OPTION_ARG_CALLBACK, clutter_arg_no_debug_cb,
"Clutter debugging flags to unset", "FLAGS" },
#endif /* CLUTTER_ENABLE_DEBUG */
{ NULL, },
};
/* pre_parse_hook: initialise variables depending on environment
* variables; these variables might be overridden by the command
* line arguments that are going to be parsed after.
*/
static gboolean
pre_parse_hook (GOptionContext *context,
GOptionGroup *group,
gpointer data,
GError **error)
{
ClutterMainContext *clutter_context;
ClutterBackend *backend;
const char *env_string;
if (clutter_is_initialized)
return TRUE;
clutter_context = clutter_context_get_default ();
clutter_context->font_map = PANGO_FT2_FONT_MAP (pango_ft2_font_map_new ());
pango_ft2_font_map_set_resolution (clutter_context->font_map, 96.0, 96.0);
clutter_context->id_pool = clutter_id_pool_new (256);
backend = clutter_context->backend;
g_assert (CLUTTER_IS_BACKEND (backend));
#ifdef CLUTTER_ENABLE_DEBUG
env_string = g_getenv ("CLUTTER_DEBUG");
if (env_string != NULL)
{
clutter_debug_flags =
g_parse_debug_string (env_string,
clutter_debug_keys,
G_N_ELEMENTS (clutter_debug_keys));
env_string = NULL;
}
#endif /* CLUTTER_ENABLE_DEBUG */
env_string = g_getenv ("CLUTTER_SHOW_FPS");
if (env_string)
clutter_show_fps = TRUE;
env_string = g_getenv ("CLUTTER_DEFAULT_FPS");
if (env_string)
{
gint default_fps = g_ascii_strtoll (env_string, NULL, 10);
clutter_default_fps = CLAMP (default_fps, 1, 1000);
}
if (CLUTTER_BACKEND_GET_CLASS (backend)->pre_parse)
return CLUTTER_BACKEND_GET_CLASS (backend)->pre_parse (backend, error);
return TRUE;
}
/* post_parse_hook: initialise the context and data structures
* and opens the X display
*/
static gboolean
post_parse_hook (GOptionContext *context,
GOptionGroup *group,
gpointer data,
GError **error)
{
ClutterMainContext *clutter_context;
ClutterBackend *backend;
gboolean retval = FALSE;
if (clutter_is_initialized)
return TRUE;
clutter_context = clutter_context_get_default ();
backend = clutter_context->backend;
g_assert (CLUTTER_IS_BACKEND (backend));
if (clutter_fatal_warnings)
{
GLogLevelFlags fatal_mask;
fatal_mask = g_log_set_always_fatal (G_LOG_FATAL_MASK);
fatal_mask |= G_LOG_LEVEL_WARNING | G_LOG_LEVEL_CRITICAL;
g_log_set_always_fatal (fatal_mask);
}
clutter_context->frame_rate = clutter_default_fps;
if (CLUTTER_BACKEND_GET_CLASS (backend)->post_parse)
retval = CLUTTER_BACKEND_GET_CLASS (backend)->post_parse (backend, error);
else
retval = TRUE;
clutter_is_initialized = retval;
return retval;
}
/**
* clutter_get_option_group:
*
* Returns a #GOptionGroup for the command line arguments recognized
* by Clutter. You should add this group to your #GOptionContext with
* g_option_context_add_group(), if you are using g_option_context_parse()
* to parse your commandline arguments.
*
* Return value: a GOptionGroup for the commandline arguments
* recognized by Clutter
*
* Since: 0.2
*/
GOptionGroup *
clutter_get_option_group (void)
{
ClutterMainContext *context;
GOptionGroup *group;
context = clutter_context_get_default ();
group = g_option_group_new ("clutter",
"Clutter Options",
"Show Clutter Options",
NULL,
NULL);
g_option_group_set_parse_hooks (group, pre_parse_hook, post_parse_hook);
g_option_group_add_entries (group, clutter_args);
/* add backend-specific options */
_clutter_backend_add_options (context->backend, group);
return group;
}
GQuark
clutter_init_error_quark (void)
{
return g_quark_from_static_string ("clutter-init-error-quark");
}
/**
* clutter_init_with_args:
* @argc: a pointer to the number of command line arguments
* @argv: a pointer to the array of comman line arguments
* @parameter_string: a string which is displayed in the
* first line of <option>--help</option> output, after
* <literal><replaceable>programname</replaceable> [OPTION...]</literal>
* @entries: a %NULL terminated array of #GOptionEntry<!-- -->s
* describing the options of your program
* @translation_domain: a translation domain to use for translating
* the <option>--help</option> output for the options in @entries
* with gettext(), or %NULL
* @error: a return location for a #GError
*
* This function does the same work as clutter_init(). Additionally,
* it allows you to add your own command line options, and it
* automatically generates nicely formatted <option>--help</option>
* output. Note that your program will be terminated after writing
* out the help output. Also note that, in case of error, the
* error message will be placed inside @error instead of being
* printed on the display.
*
* Return value: %CLUTTER_INIT_SUCCESS if Clutter has been successfully
* initialised, or other values or #ClutterInitError in case of
* error.
*
* Since: 0.2
*/
ClutterInitError
clutter_init_with_args (int *argc,
char ***argv,
char *parameter_string,
GOptionEntry *entries,
char *translation_domain,
GError **error)
{
ClutterMainContext *clutter_context;
GOptionContext *context;
GOptionGroup *group;
gboolean res;
ClutterActor *stage;
if (clutter_is_initialized)
return CLUTTER_INIT_SUCCESS;
clutter_base_init ();
if (argc && *argc > 0 && *argv)
g_set_prgname ((*argv)[0]);
group = clutter_get_option_group ();
context = g_option_context_new (parameter_string);
g_option_context_add_group (context, group);
if (entries)
g_option_context_add_main_entries (context, entries, translation_domain);
res = g_option_context_parse (context, argc, argv, error);
g_option_context_free (context);
/* if res is FALSE, the error is filled for
* us by g_option_context_parse()
*/
if (!res)
return CLUTTER_INIT_ERROR_INTERNAL;
clutter_context = clutter_context_get_default ();
stage = clutter_stage_get_default ();
if (!stage)
{
g_set_error (error, CLUTTER_INIT_ERROR,
CLUTTER_INIT_ERROR_INTERNAL,
"Unable to create the default stage");
return CLUTTER_INIT_ERROR_INTERNAL;
}
_clutter_backend_init_events (clutter_context->backend);
_clutter_feature_init ();
clutter_stage_set_title (CLUTTER_STAGE (stage), g_get_prgname ());
return CLUTTER_INIT_SUCCESS;
}
static gboolean
clutter_parse_args (int *argc,
char ***argv)
{
GOptionContext *option_context;
GOptionGroup *clutter_group;
GError *error = NULL;
gboolean ret = TRUE;
if (clutter_is_initialized)
return TRUE;
option_context = g_option_context_new (NULL);
g_option_context_set_ignore_unknown_options (option_context, TRUE);
g_option_context_set_help_enabled (option_context, FALSE);
/* Initiate any command line options from the backend */
clutter_group = clutter_get_option_group ();
g_option_context_set_main_group (option_context, clutter_group);
if (!g_option_context_parse (option_context, argc, argv, &error))
{
g_warning ("%s", error->message);
g_error_free (error);
ret = FALSE;
}
g_option_context_free (option_context);
return ret;
}
/**
* clutter_init:
* @argc: The number of arguments in @argv
* @argv: A pointer to an array of arguments.
*
* It will initialise everything needed to operate with Clutter and
* parses some standard command line options. @argc and @argv are
* adjusted accordingly so your own code will never see those standard
* arguments.
*
* Return value: 1 on success, < 0 on failure.
*/
ClutterInitError
clutter_init (int *argc,
char ***argv)
{
ClutterMainContext *context;
ClutterActor *stage;
if (clutter_is_initialized)
return CLUTTER_INIT_SUCCESS;
clutter_base_init ();
if (argc && *argc > 0 && *argv)
g_set_prgname ((*argv)[0]);
/* parse_args will trigger backend creation and things like
* DISPLAY connection etc.
*/
if (clutter_parse_args (argc, argv) == FALSE)
{
CLUTTER_NOTE (MISC, "failed to parse arguments.");
return CLUTTER_INIT_ERROR_INTERNAL;
}
/* Note, creates backend if not already existing (though parse args will
* have likely created it)
*/
context = clutter_context_get_default ();
/* Stage will give us a GL Context etc */
stage = clutter_stage_get_default ();
if (!stage)
{
g_critical ("Unable to create the default stage");
return CLUTTER_INIT_ERROR_INTERNAL;
}
/* Initiate event collection */
_clutter_backend_init_events (context->backend);
/* finally features - will call to backend and cogl */
_clutter_feature_init ();
clutter_stage_set_title (CLUTTER_STAGE (stage), g_get_prgname ());
return CLUTTER_INIT_SUCCESS;
}
gboolean
_clutter_boolean_handled_accumulator (GSignalInvocationHint *ihint,
GValue *return_accu,
const GValue *handler_return,
gpointer dummy)
{
gboolean continue_emission;
gboolean signal_handled;
signal_handled = g_value_get_boolean (handler_return);
g_value_set_boolean (return_accu, signal_handled);
continue_emission = !signal_handled;
return continue_emission;
}
static void
event_click_count_generate (ClutterEvent *event)
{
/* multiple button click detection */
static gint click_count = 0;
static gint previous_x = -1;
static gint previous_y = -1;
static guint32 previous_time = 0;
static gint previous_button_number = -1;
ClutterBackend *backend;
guint double_click_time;
guint double_click_distance;
backend = clutter_context_get_default ()->backend;
double_click_distance = clutter_backend_get_double_click_distance (backend);
double_click_time = clutter_backend_get_double_click_time (backend);
switch (event->type)
{
case CLUTTER_BUTTON_PRESS:
case CLUTTER_SCROLL:
/* check if we are in time and within distance to increment an
* existing click count
*/
if (event->button.time < previous_time + double_click_time &&
(ABS (event->button.x - previous_x) <= double_click_distance) &&
(ABS (event->button.y - previous_y) <= double_click_distance)
&& event->button.button == previous_button_number)
{
click_count ++;
}
else /* start a new click count*/
{
click_count=1;
previous_button_number = event->button.button;
}
/* store time and position for this click for comparison with
* next event
*/
previous_time = event->button.time;
previous_x = event->button.x;
previous_y = event->button.y;
/* fallthrough */
case CLUTTER_BUTTON_RELEASE:
event->button.click_count=click_count;
break;
default:
g_assert (NULL);
}
}
static inline void
emit_event (ClutterEvent *event,
gboolean is_key_event)
{
#define MAX_EVENT_DEPTH 512
static ClutterActor **event_tree = NULL;
static gboolean lock = FALSE;
ClutterActor *actor;
gint i = 0, n_tree_events = 0;
if (!event->any.source)
{
g_warning ("No event source set, discarding event");
return;
}
/* reentrancy check */
if (lock != FALSE)
return;
lock = TRUE;
/* Sorry Mr Bassi. */
if (G_UNLIKELY (event_tree == NULL))
event_tree = g_new0 (ClutterActor *, MAX_EVENT_DEPTH);
actor = event->any.source;
/* Build 'tree' of emitters for the event */
while (actor && n_tree_events < MAX_EVENT_DEPTH)
{
ClutterActor *parent;
parent = clutter_actor_get_parent (actor);
if (clutter_actor_get_reactive (actor) ||
parent == NULL || /* stage gets all events */
is_key_event) /* keyboard events are always emitted */
{
event_tree[n_tree_events++] = g_object_ref (actor);
}
actor = parent;
}
/* Capture */
for (i = n_tree_events-1; i >= 0; i--)
if (clutter_actor_event (event_tree[i], event, TRUE))
goto done;
/* Bubble */
for (i = 0; i < n_tree_events; i++)
if (clutter_actor_event (event_tree[i], event, FALSE))
goto done;
done:
for (i = 0; i < n_tree_events; i++)
g_object_unref (event_tree[i]);
lock = FALSE;
#undef MAX_EVENT_DEPTH
}
static inline void
emit_pointer_event (ClutterEvent *event)
{
/* Using the global variable directly, since it has to be initialized
* at this point
*/
ClutterMainContext *context = ClutterCntx;
if (G_UNLIKELY (context->pointer_grab_actor != NULL))
clutter_actor_event (context->pointer_grab_actor, event, FALSE);
else
emit_event (event, FALSE);
}
static inline void
emit_keyboard_event (ClutterEvent *event)
{
ClutterMainContext *context = ClutterCntx;
if (G_UNLIKELY (context->keyboard_grab_actor != NULL))
clutter_actor_event (context->keyboard_grab_actor, event, FALSE);
else
emit_event (event, TRUE);
}
static void
unset_motion_last_actor (ClutterActor *actor)
{
ClutterMainContext *context = ClutterCntx;
context->motion_last_actor = NULL;
}
static inline void
generate_enter_leave_events (ClutterEvent *event)
{
ClutterMainContext *context = ClutterCntx;
ClutterActor *motion_current_actor = event->motion.source;
if (context->motion_last_actor != motion_current_actor)
{
if (motion_current_actor)
{
ClutterEvent cev;
if (context->motion_last_actor)
{
cev.crossing.type = CLUTTER_LEAVE;
cev.crossing.time = event->any.time;
cev.crossing.flags = 0;
cev.crossing.x = event->motion.x;
cev.crossing.y = event->motion.y;
cev.crossing.source = context->motion_last_actor;
cev.crossing.stage = event->any.stage;
/* unref in free */
cev.crossing.related = motion_current_actor;
g_queue_push_head (context->events_queue,
clutter_event_copy (&cev));
}
cev.crossing.type = CLUTTER_ENTER;
cev.crossing.time = event->any.time;
cev.crossing.flags = 0;
cev.crossing.x = event->motion.x;
cev.crossing.y = event->motion.y;
cev.crossing.source = motion_current_actor;
cev.crossing.stage = event->any.stage;
if (context->motion_last_actor)
cev.crossing.related = context->motion_last_actor;
else
{
/* the previous actor we were getting events from seems to have
* vanished
*/
cev.crossing.related = NULL;
}
g_queue_push_head (context->events_queue,
clutter_event_copy (&cev));
}
}
if (context->motion_last_actor &&
context->motion_last_actor != motion_current_actor)
{
g_signal_handlers_disconnect_by_func (context->motion_last_actor,
G_CALLBACK (unset_motion_last_actor),
NULL);
}
if (motion_current_actor &&
context->motion_last_actor != motion_current_actor)
{
g_signal_connect (motion_current_actor, "destroy",
G_CALLBACK (unset_motion_last_actor),
NULL);
}
context->motion_last_actor = motion_current_actor;
}
/**
* clutter_do_event
* @event: a #ClutterEvent.
*
* Processes an event. This function should never be called by applications.
*
* Since: 0.4
*/
void
clutter_do_event (ClutterEvent *event)
{
/* FIXME: This should probably be clutter_cook_event() - it would
* take a raw event from the backend and 'cook' it so its more tasty.
*
*/
ClutterMainContext *context;
ClutterBackend *backend;
ClutterActor *stage;
static gint32 motion_last_time = 0L;
context = clutter_context_get_default ();
backend = context->backend;
stage = CLUTTER_ACTOR(event->any.stage);
if (!stage)
return;
CLUTTER_TIMESTAMP (EVENT, "Event received");
switch (event->type)
{
case CLUTTER_NOTHING:
event->any.source = stage;
break;
case CLUTTER_ENTER:
case CLUTTER_LEAVE:
emit_pointer_event (event);
break;
case CLUTTER_DESTROY_NOTIFY:
case CLUTTER_DELETE:
event->any.source = stage;
/* the stage did not handle the event, so we just quit */
if (!clutter_stage_event (CLUTTER_STAGE (stage), event))
{
if (stage == clutter_stage_get_default())
clutter_main_quit ();
else
clutter_actor_destroy (stage);
}
break;
case CLUTTER_KEY_PRESS:
case CLUTTER_KEY_RELEASE:
{
ClutterActor *actor = NULL;
/* check that we're not a synthetic event with source set */
if (event->any.source == NULL)
{
actor = clutter_stage_get_key_focus (CLUTTER_STAGE (stage));
event->any.source = actor;
if (G_UNLIKELY (actor == NULL))
{
g_warning ("No key focus set, discarding");
return;
}
}
emit_keyboard_event (event);
}
break;
case CLUTTER_MOTION:
/* avoid rate throttling for synthetic motion events or if
* the per-actor events are disabled
*/
if (!(event->any.flags & CLUTTER_EVENT_FLAG_SYNTHETIC) ||
!context->motion_events_per_actor)
{
gint32 frame_rate, delta;
/* avoid issuing too many motion events, which leads to many
* redraws in pick mode (performance penalty)
*/
frame_rate = clutter_get_motion_events_frequency ();
delta = 1000 / frame_rate;
CLUTTER_NOTE (EVENT,
"skip motion event: %s (last:%d, delta:%d, time:%d)",
(event->any.time < (motion_last_time + delta) ? "yes" : "no"),
motion_last_time,
delta,
event->any.time);
if (event->any.time < (motion_last_time + delta))
break;
else
motion_last_time = event->any.time;
}
/* Only stage gets motion events if clutter_set_motion_events is TRUE,
* and the event is not a synthetic event with source set.
*/
if (!context->motion_events_per_actor &&
event->any.source == NULL)
{
/* Only stage gets motion events */
event->any.source = stage;
if (context->pointer_grab_actor != NULL)
{
clutter_actor_event (context->pointer_grab_actor, event, FALSE);
break;
}
/* Trigger handlers on stage in both capture .. */
if (!clutter_actor_event (stage, event, TRUE))
{
/* and bubbling phase */
clutter_actor_event (stage, event, FALSE);
}
break;
}
/* fallthrough */
case CLUTTER_BUTTON_PRESS:
case CLUTTER_BUTTON_RELEASE:
case CLUTTER_SCROLL:
{
ClutterActor *actor;
gint x,y;
clutter_event_get_coords (event, &x, &y);
/* Only do a pick to find the source if source is not already set
* (as it could be in a synthetic event)
*/
if (event->any.source == NULL)
{
/* Handle release off stage */
if ((x >= CLUTTER_STAGE_WIDTH () ||
y >= CLUTTER_STAGE_HEIGHT() ||
x < 0 || y < 0))
{
if (event->type == CLUTTER_BUTTON_RELEASE)
{
CLUTTER_NOTE (EVENT,"Release off stage received at %i, %i",
x, y);
event->button.source = stage;
emit_pointer_event (event);
}
break;
}
/* Map the event to a reactive actor */
actor = _clutter_do_pick (CLUTTER_STAGE (stage),
x, y,
CLUTTER_PICK_REACTIVE);
event->any.source = actor;
if (!actor)
break;
}
else
{
/* use the source already set in the synthetic event */
actor = event->any.source;
}
/* FIXME: for an optimisation should check if there are
* actually any reactive actors and avoid the pick all togeather
* (signalling just the stage). Should be big help for gles.
*/
CLUTTER_NOTE (EVENT, "Reactive event received at %i, %i - actor: %p",
x, y, actor);
if (event->type == CLUTTER_MOTION)
{
/* Generate enter leave events (if any) */
generate_enter_leave_events (event);
}
else /* (button event) */
{
/* Generate click count */
event_click_count_generate (event);
}
emit_pointer_event (event);
break;
}
case CLUTTER_STAGE_STATE:
/* fullscreen / focus - forward to stage */
event->any.source = stage;
clutter_stage_event (CLUTTER_STAGE (stage), event);
break;
case CLUTTER_CLIENT_MESSAGE:
break;
}
}
/**
* clutter_get_actor_by_gid
* @id: a #ClutterActor ID.
*
* Retrieves the #ClutterActor with @id.
*
* Return value: the actor with the passed id or %NULL. The returned
* actor does not have its reference count increased.
*
* Since: 0.6
*/
ClutterActor*
clutter_get_actor_by_gid (guint32 id)
{
ClutterMainContext *context;
context = clutter_context_get_default ();
g_return_val_if_fail (context != NULL, NULL);
return CLUTTER_ACTOR (clutter_id_pool_lookup (context->id_pool, id));
}
void
clutter_base_init (void)
{
static gboolean initialised = FALSE;
if (!initialised)
{
GType foo; /* Quiet gcc */
initialised = TRUE;
/* initialise GLib type system */
g_type_init ();
/* CLUTTER_TYPE_ACTOR */
foo = clutter_actor_get_type ();
}
}
/**
* clutter_get_default_frame_rate:
*
* Retrieves the default frame rate used when creating #ClutterTimeline<!--
* -->s.
*
* This value is also used to compute the default frequency of motion
* events.
*
* Return value: the default frame rate
*
* Since: 0.6
*/
guint
clutter_get_default_frame_rate (void)
{
ClutterMainContext *context;
context = clutter_context_get_default ();
return context->frame_rate;
}
/**
* clutter_set_default_frame_rate:
* @frames_per_sec: the new default frame rate
*
* Sets the default frame rate to be used when creating #ClutterTimeline<!--
* -->s
*
* Since: 0.6
*/
void
clutter_set_default_frame_rate (guint frames_per_sec)
{
ClutterMainContext *context;
context = clutter_context_get_default ();
if (context->frame_rate != frames_per_sec)
context->frame_rate = frames_per_sec;
}
static void
on_pointer_grab_weak_notify (gpointer data,
GObject *where_the_object_was)
{
ClutterMainContext *context;
context = clutter_context_get_default ();
context->pointer_grab_actor = NULL;
clutter_ungrab_pointer ();
}
/**
* clutter_grab_pointer:
* @actor: a #ClutterActor
*
* Grabs pointer events, after the grab is done all pointer related events
* (press, motion, release, enter, leave and scroll) are delivered to this
* actor directly. The source set in the event will be the actor that would
* have received the event if the pointer grab was not in effect.
*
* Since: 0.6
*/
void
clutter_grab_pointer (ClutterActor *actor)
{
ClutterMainContext *context;
g_return_if_fail (actor == NULL || CLUTTER_IS_ACTOR (actor));
context = clutter_context_get_default ();
if (context->pointer_grab_actor == actor)
return;
if (context->pointer_grab_actor)
{
g_object_weak_unref (G_OBJECT (context->pointer_grab_actor),
on_pointer_grab_weak_notify,
NULL);
context->pointer_grab_actor = NULL;
}
if (actor)
{
context->pointer_grab_actor = actor;
g_object_weak_ref (G_OBJECT (actor),
on_pointer_grab_weak_notify,
NULL);
}
}
/**
* clutter_ungrab_pointer:
*
* Removes an existing grab of the pointer.
*
* Since: 0.6
*/
void
clutter_ungrab_pointer (void)
{
clutter_grab_pointer (NULL);
}
/**
* clutter_get_pointer_grab:
*
* Queries the current pointer grab of clutter.
*
* Return value: the actor currently holding the pointer grab, or NULL if there is no grab.
*
* Since: 0.6
*/
ClutterActor *
clutter_get_pointer_grab (void)
{
ClutterMainContext *context;
context = clutter_context_get_default ();
return context->pointer_grab_actor;
}
static void
on_keyboard_grab_weak_notify (gpointer data,
GObject *where_the_object_was)
{
ClutterMainContext *context;
context = clutter_context_get_default ();
context->keyboard_grab_actor = NULL;
clutter_ungrab_keyboard ();
}
/**
* clutter_grab_keyboard:
* @actor: a #ClutterActor
*
* Grabs keyboard events, after the grab is done keyboard events ("key-press-event"
* and "key-release-event") are delivered to this actor directly. The source
* set in the event will be the actor that would have received the event if the
* keyboard grab was not in effect.
*
* Since: 0.6
*/
void
clutter_grab_keyboard (ClutterActor *actor)
{
ClutterMainContext *context;
g_return_if_fail (actor == NULL || CLUTTER_IS_ACTOR (actor));
context = clutter_context_get_default ();
if (context->keyboard_grab_actor == actor)
return;
if (context->keyboard_grab_actor)
{
g_object_weak_unref (G_OBJECT (context->keyboard_grab_actor),
on_keyboard_grab_weak_notify,
NULL);
context->keyboard_grab_actor = NULL;
}
if (actor)
{
context->keyboard_grab_actor = actor;
g_object_weak_ref (G_OBJECT (actor),
on_keyboard_grab_weak_notify,
NULL);
}
}
/**
* clutter_ungrab_keyboard:
*
* Removes an existing grab of the keyboard.
*
* Since: 0.6
*/
void
clutter_ungrab_keyboard (void)
{
clutter_grab_keyboard (NULL);
}
/**
* clutter_get_keyboard_grab:
*
* Queries the current keyboard grab of clutter.
*
* Return value: the actor currently holding the keyboard grab, or NULL if there is no grab.
*
* Since: 0.6
*/
ClutterActor *
clutter_get_keyboard_grab (void)
{
ClutterMainContext *context;
context = clutter_context_get_default ();
return context->keyboard_grab_actor;
}
/**
* clutter_get_motion_events_frequency:
*
* Retrieves the number of motion events per second that are delivered
* to the stage.
*
* See clutter_set_motion_events_frequency().
*
* Return value: the number of motion events per second
*
* Since: 0.6
*/
guint
clutter_get_motion_events_frequency (void)
{
ClutterMainContext *context = clutter_context_get_default ();
if (G_LIKELY (context->motion_frequency == 0))
{
guint frequency;
frequency = clutter_default_fps / 4;
frequency = CLAMP (frequency, 20, 45);
return frequency;
}
else
return context->motion_frequency;
}
/**
* clutter_set_motion_events_frequency:
* @frequency: the number of motion events per second, or 0 for the
* default value
*
* Sets the motion events frequency. Setting this to a non-zero value
* will override the default setting, so it should be rarely used.
*
* Motion events are delivered from the default backend to the stage
* and are used to generate the enter/leave events pair. This might lead
* to a performance penalty due to the way the actors are identified.
* Using this function is possible to reduce the frequency of the motion
* events delivery to the stage.
*
* Since: 0.6
*/
void
clutter_set_motion_events_frequency (guint frequency)
{
ClutterMainContext *context = clutter_context_get_default ();
/* never allow the motion events to exceed the default frame rate */
context->motion_frequency = CLAMP (frequency, 1, clutter_default_fps);
}
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