mutter/clutter/clutter-backend.c
Emmanuele Bassi e3259435f2 2.0: Remove all Since: annotations
We're starting from scratch.
2013-04-05 18:48:01 +01:00

1150 lines
32 KiB
C

/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Authored By:
* Matthew Allum <mallum@openedhand.com>
* Emmanuele Bassi <ebassi@linux.intel.com>
*
* Copyright (C) 2006, 2007, 2008 OpenedHand Ltd
* Copyright (C) 2009, 2010 Intel Corp
*
* 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, see <http://www.gnu.org/licenses/>.
*/
/**
* SECTION:clutter-backend
* @short_description: Backend abstraction
*
* Clutter can be compiled against different backends. Each backend
* has to implement a set of functions, in order to be used by Clutter.
*
* #ClutterBackend is the base class abstracting the various implementation;
* it provides a basic API to query the backend for generic information
* and settings.
*
* #ClutterBackend is available since Clutter 0.4
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#define CLUTTER_ENABLE_EXPERIMENTAL_API
#include "clutter-backend-private.h"
#include "clutter-debug.h"
#include "clutter-event-private.h"
#include "clutter-marshal.h"
#include "clutter-private.h"
#include "clutter-profile.h"
#include "clutter-stage-manager-private.h"
#include "clutter-stage-private.h"
#include "clutter-stage-window.h"
#include "clutter-version.h"
#ifdef HAVE_CLUTTER_WAYLAND_COMPOSITOR
#include "wayland/clutter-wayland-compositor.h"
#endif /* HAVE_CLUTTER_WAYLAND_COMPOSITOR */
#include <cogl/cogl.h>
#ifdef CLUTTER_INPUT_X11
#include "x11/clutter-backend-x11.h"
#endif
#ifdef CLUTTER_INPUT_WIN32
#include "win32/clutter-backend-win32.h"
#endif
#ifdef CLUTTER_INPUT_OSX
#include "osx/clutter-backend-osx.h"
#endif
#ifdef CLUTTER_INPUT_GDK
#include "gdk/clutter-backend-gdk.h"
#endif
#ifdef CLUTTER_INPUT_EVDEV
#include "evdev/clutter-device-manager-evdev.h"
#endif
#ifdef CLUTTER_INPUT_TSLIB
/* XXX - should probably warn, here */
#include "tslib/clutter-event-tslib.h"
#endif
#ifdef CLUTTER_INPUT_WAYLAND
#include "wayland/clutter-device-manager-wayland.h"
#endif
#ifdef HAVE_CLUTTER_WAYLAND_COMPOSITOR
#include <cogl/cogl-wayland-server.h>
#include <wayland-server.h>
#include "wayland/clutter-wayland-compositor.h"
#endif
G_DEFINE_ABSTRACT_TYPE (ClutterBackend, clutter_backend, G_TYPE_OBJECT);
#define DEFAULT_FONT_NAME "Sans 10"
#define CLUTTER_BACKEND_GET_PRIVATE(obj) \
(G_TYPE_INSTANCE_GET_PRIVATE ((obj), CLUTTER_TYPE_BACKEND, ClutterBackendPrivate))
struct _ClutterBackendPrivate
{
cairo_font_options_t *font_options;
gfloat units_per_em;
gint32 units_serial;
GList *event_translators;
};
enum
{
RESOLUTION_CHANGED,
FONT_CHANGED,
SETTINGS_CHANGED,
LAST_SIGNAL
};
static guint backend_signals[LAST_SIGNAL] = { 0, };
/* Global for being able to specify a compositor side wayland display
* pointer before clutter initialization */
#ifdef HAVE_CLUTTER_WAYLAND_COMPOSITOR
static struct wl_display *_wayland_compositor_display;
#endif
static void
clutter_backend_dispose (GObject *gobject)
{
ClutterBackendPrivate *priv = CLUTTER_BACKEND (gobject)->priv;
/* clear the events still in the queue of the main context */
_clutter_clear_events_queue ();
/* remove all event translators */
if (priv->event_translators != NULL)
{
g_list_free (priv->event_translators);
priv->event_translators = NULL;
}
G_OBJECT_CLASS (clutter_backend_parent_class)->dispose (gobject);
}
static void
clutter_backend_finalize (GObject *gobject)
{
ClutterBackend *backend = CLUTTER_BACKEND (gobject);
g_source_destroy (backend->cogl_source);
clutter_backend_set_font_options (backend, NULL);
G_OBJECT_CLASS (clutter_backend_parent_class)->finalize (gobject);
}
static gfloat
get_units_per_em (ClutterBackend *backend,
PangoFontDescription *font_desc)
{
gfloat units_per_em = -1.0;
gboolean free_font_desc = FALSE;
gdouble dpi;
dpi = clutter_backend_get_resolution (backend);
if (font_desc == NULL)
{
ClutterSettings *settings;
gchar *font_name = NULL;
settings = clutter_settings_get_default ();
g_object_get (settings, "font-name", &font_name, NULL);
if (G_LIKELY (font_name != NULL && *font_name != '\0'))
{
font_desc = pango_font_description_from_string (font_name);
free_font_desc = TRUE;
g_free (font_name);
}
}
if (font_desc != NULL)
{
gdouble font_size = 0;
gint pango_size;
gboolean is_absolute;
pango_size = pango_font_description_get_size (font_desc);
is_absolute = pango_font_description_get_size_is_absolute (font_desc);
/* "absolute" means "device units" (usually, pixels); otherwise,
* it means logical units (points)
*/
if (is_absolute)
font_size = (gdouble) pango_size / PANGO_SCALE;
else
font_size = dpi * ((gdouble) pango_size / PANGO_SCALE) / 72.0f;
/* 10 points at 96 DPI is 13.3 pixels */
units_per_em = (1.2f * font_size) * dpi / 96.0f;
}
else
units_per_em = -1.0f;
if (free_font_desc)
pango_font_description_free (font_desc);
return units_per_em;
}
static void
clutter_backend_real_resolution_changed (ClutterBackend *backend)
{
ClutterBackendPrivate *priv = backend->priv;
ClutterMainContext *context;
ClutterSettings *settings;
gdouble resolution;
gint dpi;
settings = clutter_settings_get_default ();
g_object_get (settings, "font-dpi", &dpi, NULL);
if (dpi < 0)
resolution = 96.0;
else
resolution = dpi / 1024.0;
context = _clutter_context_get_default ();
if (context->font_map != NULL)
cogl_pango_font_map_set_resolution (context->font_map, resolution);
priv->units_per_em = get_units_per_em (backend, NULL);
priv->units_serial += 1;
CLUTTER_NOTE (BACKEND, "Units per em: %.2f", priv->units_per_em);
}
static void
clutter_backend_real_font_changed (ClutterBackend *backend)
{
ClutterBackendPrivate *priv = backend->priv;
priv->units_per_em = get_units_per_em (backend, NULL);
priv->units_serial += 1;
CLUTTER_NOTE (BACKEND, "Units per em: %.2f", priv->units_per_em);
}
static gboolean
clutter_backend_real_create_context (ClutterBackend *backend,
GError **error)
{
ClutterBackendClass *klass;
CoglSwapChain *swap_chain;
GError *internal_error;
if (backend->cogl_context != NULL)
return TRUE;
klass = CLUTTER_BACKEND_GET_CLASS (backend);
swap_chain = NULL;
internal_error = NULL;
CLUTTER_NOTE (BACKEND, "Creating Cogl renderer");
if (klass->get_renderer != NULL)
backend->cogl_renderer = klass->get_renderer (backend, &internal_error);
else
backend->cogl_renderer = cogl_renderer_new ();
if (backend->cogl_renderer == NULL)
goto error;
#ifdef HAVE_CLUTTER_WAYLAND_COMPOSITOR
/* If the application is trying to act as a Wayland compositor then
it needs to have an EGL-based renderer backend */
if (_wayland_compositor_display)
cogl_renderer_add_constraint (backend->cogl_renderer,
COGL_RENDERER_CONSTRAINT_USES_EGL);
#endif
CLUTTER_NOTE (BACKEND, "Connecting the renderer");
if (!cogl_renderer_connect (backend->cogl_renderer, &internal_error))
goto error;
CLUTTER_NOTE (BACKEND, "Creating Cogl swap chain");
swap_chain = cogl_swap_chain_new ();
CLUTTER_NOTE (BACKEND, "Creating Cogl display");
if (klass->get_display != NULL)
{
backend->cogl_display = klass->get_display (backend,
backend->cogl_renderer,
swap_chain,
&internal_error);
}
else
{
CoglOnscreenTemplate *tmpl;
gboolean res;
tmpl = cogl_onscreen_template_new (swap_chain);
/* XXX: I have some doubts that this is a good design.
*
* Conceptually should we be able to check an onscreen_template
* without more details about the CoglDisplay configuration?
*/
res = cogl_renderer_check_onscreen_template (backend->cogl_renderer,
tmpl,
&internal_error);
if (!res)
goto error;
backend->cogl_display = cogl_display_new (backend->cogl_renderer, tmpl);
/* the display owns the template */
cogl_object_unref (tmpl);
}
if (backend->cogl_display == NULL)
goto error;
#ifdef HAVE_CLUTTER_WAYLAND_COMPOSITOR
cogl_wayland_display_set_compositor_display (backend->cogl_display,
_wayland_compositor_display);
#endif
CLUTTER_NOTE (BACKEND, "Setting up the display");
if (!cogl_display_setup (backend->cogl_display, &internal_error))
goto error;
CLUTTER_NOTE (BACKEND, "Creating the Cogl context");
backend->cogl_context = cogl_context_new (backend->cogl_display, &internal_error);
if (backend->cogl_context == NULL)
goto error;
backend->cogl_source = cogl_glib_source_new (backend->cogl_context,
G_PRIORITY_DEFAULT);
g_source_attach (backend->cogl_source, NULL);
/* the display owns the renderer and the swap chain */
cogl_object_unref (backend->cogl_renderer);
cogl_object_unref (swap_chain);
return TRUE;
error:
if (backend->cogl_display != NULL)
{
cogl_object_unref (backend->cogl_display);
backend->cogl_display = NULL;
}
if (backend->cogl_renderer != NULL)
{
cogl_object_unref (backend->cogl_renderer);
backend->cogl_renderer = NULL;
}
if (swap_chain != NULL)
cogl_object_unref (swap_chain);
if (internal_error != NULL)
g_propagate_error (error, internal_error);
else
g_set_error_literal (error, CLUTTER_INIT_ERROR,
CLUTTER_INIT_ERROR_BACKEND,
_("Unable to initialize the Clutter backend"));
return FALSE;
}
static void
clutter_backend_real_ensure_context (ClutterBackend *backend,
ClutterStage *stage)
{
ClutterStageWindow *stage_impl;
CoglFramebuffer *framebuffer;
if (stage == NULL)
return;
stage_impl = _clutter_stage_get_window (stage);
if (stage_impl == NULL)
return;
framebuffer = _clutter_stage_window_get_active_framebuffer (stage_impl);
if (framebuffer == NULL)
return;
cogl_set_framebuffer (framebuffer);
}
static ClutterFeatureFlags
clutter_backend_real_get_features (ClutterBackend *backend)
{
ClutterFeatureFlags flags = 0;
if (cogl_clutter_winsys_has_feature (COGL_WINSYS_FEATURE_MULTIPLE_ONSCREEN))
{
CLUTTER_NOTE (BACKEND, "Cogl supports multiple onscreen framebuffers");
flags |= CLUTTER_FEATURE_STAGE_MULTIPLE;
}
else
{
CLUTTER_NOTE (BACKEND, "Cogl only supports one onscreen framebuffer");
flags |= CLUTTER_FEATURE_STAGE_STATIC;
}
if (cogl_clutter_winsys_has_feature (COGL_WINSYS_FEATURE_SWAP_THROTTLE))
{
CLUTTER_NOTE (BACKEND, "Cogl supports swap buffers throttling");
flags |= CLUTTER_FEATURE_SYNC_TO_VBLANK;
}
else
CLUTTER_NOTE (BACKEND, "Cogl doesn't support swap buffers throttling");
if (cogl_clutter_winsys_has_feature (COGL_WINSYS_FEATURE_SWAP_BUFFERS_EVENT))
{
CLUTTER_NOTE (BACKEND, "Cogl supports swap buffers complete events");
flags |= CLUTTER_FEATURE_SWAP_EVENTS;
}
return flags;
}
static ClutterStageWindow *
clutter_backend_real_create_stage (ClutterBackend *backend,
ClutterStage *wrapper,
GError **error)
{
ClutterBackendClass *klass;
if (!clutter_feature_available (CLUTTER_FEATURE_STAGE_MULTIPLE))
{
ClutterStageManager *manager = clutter_stage_manager_get_default ();
if (clutter_stage_manager_get_default_stage (manager) != NULL)
{
g_set_error (error, CLUTTER_INIT_ERROR,
CLUTTER_INIT_ERROR_BACKEND,
_("The backend of type '%s' does not support "
"creating multiple stages"),
G_OBJECT_TYPE_NAME (backend));
return NULL;
}
}
klass = CLUTTER_BACKEND_GET_CLASS (backend);
g_assert (klass->stage_window_type != G_TYPE_INVALID);
return g_object_new (klass->stage_window_type,
"backend", backend,
"wrapper", wrapper,
NULL);
}
static void
clutter_backend_real_init_events (ClutterBackend *backend)
{
const char *input_backend = NULL;
input_backend = g_getenv ("CLUTTER_INPUT_BACKEND");
if (input_backend != NULL)
input_backend = g_intern_string (input_backend);
#ifdef CLUTTER_INPUT_OSX
if (clutter_check_windowing_backend (CLUTTER_WINDOWING_OSX) &&
(input_backend == NULL || input_backend == I_(CLUTTER_INPUT_OSX)))
{
_clutter_backend_osx_events_init (backend);
}
else
#endif
#ifdef CLUTTER_INPUT_WIN32
if (clutter_check_windowing_backend (CLUTTER_WINDOWING_WIN32) &&
(input_backend == NULL || input_backend == I_(CLUTTER_INPUT_WIN32)))
{
_clutter_backend_win32_events_init (backend);
}
else
#endif
#ifdef CLUTTER_INPUT_X11
if (clutter_check_windowing_backend (CLUTTER_WINDOWING_X11) &&
(input_backend == NULL || input_backend == I_(CLUTTER_INPUT_X11)))
{
_clutter_backend_x11_events_init (backend);
}
else
#endif
#ifdef CLUTTER_INPUT_GDK
if (clutter_check_windowing_backend (CLUTTER_WINDOWING_GDK) &&
(input_backend == NULL || input_backend == I_(CLUTTER_INPUT_GDK)))
{
_clutter_backend_gdk_events_init (backend);
}
else
#endif
#ifdef CLUTTER_INPUT_EVDEV
/* Evdev can be used regardless of the windowing system */
if (input_backend != NULL &&
strcmp (input_backend, CLUTTER_INPUT_EVDEV) == 0)
{
_clutter_events_evdev_init (backend);
}
else
#endif
#ifdef CLUTTER_INPUT_TSLIB
/* Tslib can be used regardless of the windowing system */
if (input_backend != NULL &&
strcmp (input_backend, CLUTTER_INPUT_TSLIB) == 0)
{
_clutter_events_tslib_init (backend);
}
else
#endif
#ifdef CLUTTER_INPUT_WAYLAND
if (clutter_check_windowing_backend (CLUTTER_WINDOWING_WAYLAND) &&
(input_backend == NULL || input_backend == I_(CLUTTER_INPUT_WAYLAND)))
{
_clutter_events_wayland_init (backend);
}
else
#endif
if (input_backend != NULL)
{
if (input_backend != I_(CLUTTER_INPUT_NULL))
g_error ("Unrecognized input backend '%s'", input_backend);
}
else
g_error ("Unknown input backend");
}
static ClutterDeviceManager *
clutter_backend_real_get_device_manager (ClutterBackend *backend)
{
if (G_UNLIKELY (backend->device_manager == NULL))
{
g_critical ("No device manager available, expect broken input");
return NULL;
}
return backend->device_manager;
}
static gboolean
clutter_backend_real_translate_event (ClutterBackend *backend,
gpointer native,
ClutterEvent *event)
{
ClutterBackendPrivate *priv = backend->priv;
GList *l;
for (l = priv->event_translators;
l != NULL;
l = l->next)
{
ClutterEventTranslator *translator = l->data;
ClutterTranslateReturn retval;
retval = _clutter_event_translator_translate_event (translator,
native,
event);
if (retval == CLUTTER_TRANSLATE_QUEUE)
return TRUE;
if (retval == CLUTTER_TRANSLATE_REMOVE)
return FALSE;
}
return FALSE;
}
static void
clutter_backend_class_init (ClutterBackendClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->dispose = clutter_backend_dispose;
gobject_class->finalize = clutter_backend_finalize;
g_type_class_add_private (gobject_class, sizeof (ClutterBackendPrivate));
klass->stage_window_type = G_TYPE_INVALID;
/**
* ClutterBackend::resolution-changed:
* @backend: the #ClutterBackend that emitted the signal
*
* The ::resolution-changed signal is emitted each time the font
* resolutions has been changed through #ClutterSettings.
*
*
*/
backend_signals[RESOLUTION_CHANGED] =
g_signal_new (I_("resolution-changed"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST,
G_STRUCT_OFFSET (ClutterBackendClass, resolution_changed),
NULL, NULL,
_clutter_marshal_VOID__VOID,
G_TYPE_NONE, 0);
/**
* ClutterBackend::font-changed:
* @backend: the #ClutterBackend that emitted the signal
*
* The ::font-changed signal is emitted each time the font options
* have been changed through #ClutterSettings.
*
*
*/
backend_signals[FONT_CHANGED] =
g_signal_new (I_("font-changed"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST,
G_STRUCT_OFFSET (ClutterBackendClass, font_changed),
NULL, NULL,
_clutter_marshal_VOID__VOID,
G_TYPE_NONE, 0);
/**
* ClutterBackend::settings-changed:
* @backend: the #ClutterBackend that emitted the signal
*
* The ::settings-changed signal is emitted each time the #ClutterSettings
* properties have been changed.
*
*
*/
backend_signals[SETTINGS_CHANGED] =
g_signal_new (I_("settings-changed"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST,
G_STRUCT_OFFSET (ClutterBackendClass, settings_changed),
NULL, NULL,
_clutter_marshal_VOID__VOID,
G_TYPE_NONE, 0);
klass->resolution_changed = clutter_backend_real_resolution_changed;
klass->font_changed = clutter_backend_real_font_changed;
klass->init_events = clutter_backend_real_init_events;
klass->get_device_manager = clutter_backend_real_get_device_manager;
klass->translate_event = clutter_backend_real_translate_event;
klass->create_context = clutter_backend_real_create_context;
klass->ensure_context = clutter_backend_real_ensure_context;
klass->get_features = clutter_backend_real_get_features;
klass->create_stage = clutter_backend_real_create_stage;
}
static void
clutter_backend_init (ClutterBackend *backend)
{
ClutterBackendPrivate *priv;
priv = backend->priv = CLUTTER_BACKEND_GET_PRIVATE (backend);
priv->units_per_em = -1.0;
priv->units_serial = 1;
}
void
_clutter_backend_add_options (ClutterBackend *backend,
GOptionGroup *group)
{
ClutterBackendClass *klass;
g_assert (CLUTTER_IS_BACKEND (backend));
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (klass->add_options)
klass->add_options (backend, group);
}
gboolean
_clutter_backend_pre_parse (ClutterBackend *backend,
GError **error)
{
ClutterBackendClass *klass;
g_assert (CLUTTER_IS_BACKEND (backend));
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (klass->pre_parse)
return klass->pre_parse (backend, error);
return TRUE;
}
gboolean
_clutter_backend_post_parse (ClutterBackend *backend,
GError **error)
{
ClutterBackendClass *klass;
g_assert (CLUTTER_IS_BACKEND (backend));
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (klass->post_parse)
return klass->post_parse (backend, error);
return TRUE;
}
ClutterStageWindow *
_clutter_backend_create_stage (ClutterBackend *backend,
ClutterStage *wrapper,
GError **error)
{
ClutterBackendClass *klass;
ClutterStageWindow *stage_window;
g_assert (CLUTTER_IS_BACKEND (backend));
g_assert (CLUTTER_IS_STAGE (wrapper));
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (klass->create_stage != NULL)
stage_window = klass->create_stage (backend, wrapper, error);
else
stage_window = NULL;
if (stage_window == NULL)
return NULL;
g_assert (CLUTTER_IS_STAGE_WINDOW (stage_window));
return stage_window;
}
gboolean
_clutter_backend_create_context (ClutterBackend *backend,
GError **error)
{
ClutterBackendClass *klass;
klass = CLUTTER_BACKEND_GET_CLASS (backend);
return klass->create_context (backend, error);
}
void
_clutter_backend_ensure_context_internal (ClutterBackend *backend,
ClutterStage *stage)
{
ClutterBackendClass *klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (G_LIKELY (klass->ensure_context))
klass->ensure_context (backend, stage);
}
void
_clutter_backend_ensure_context (ClutterBackend *backend,
ClutterStage *stage)
{
static ClutterStage *current_context_stage = NULL;
g_assert (CLUTTER_IS_BACKEND (backend));
g_assert (CLUTTER_IS_STAGE (stage));
if (current_context_stage != stage || !CLUTTER_ACTOR_IS_REALIZED (stage))
{
ClutterStage *new_stage = NULL;
if (!CLUTTER_ACTOR_IS_REALIZED (stage))
{
new_stage = NULL;
CLUTTER_NOTE (BACKEND,
"Stage [%p] is not realized, unsetting the stage",
stage);
}
else
{
new_stage = stage;
CLUTTER_NOTE (BACKEND,
"Setting the new stage [%p]",
new_stage);
}
/* XXX: Until Cogl becomes fully responsible for backend windows
* Clutter need to manually keep it informed of the current window size
*
* NB: This must be done after we ensure_context above because Cogl
* always assumes there is a current GL context.
*/
if (new_stage != NULL)
{
float width, height;
_clutter_backend_ensure_context_internal (backend, new_stage);
clutter_actor_get_size (CLUTTER_ACTOR (stage), &width, &height);
cogl_onscreen_clutter_backend_set_size (width, height);
/* Eventually we will have a separate CoglFramebuffer for
* each stage and each one will track private projection
* matrix and viewport state, but until then we need to make
* sure we update the projection and viewport whenever we
* switch between stages.
*
* This dirty mechanism will ensure they are asserted before
* the next paint...
*/
_clutter_stage_dirty_viewport (stage);
_clutter_stage_dirty_projection (stage);
}
/* FIXME: With a NULL stage and thus no active context it may make more
* sense to clean the context but then re call with the default stage
* so at least there is some kind of context in place (as to avoid
* potential issue of GL calls with no context).
*/
current_context_stage = new_stage;
}
else
CLUTTER_NOTE (BACKEND, "Stage is the same");
}
ClutterFeatureFlags
_clutter_backend_get_features (ClutterBackend *backend)
{
ClutterBackendClass *klass;
GError *error;
g_assert (CLUTTER_IS_BACKEND (backend));
klass = CLUTTER_BACKEND_GET_CLASS (backend);
/* we need to have a context here; so we create the
* GL context first and the ask for features. if the
* context already exists this should be a no-op
*/
error = NULL;
if (klass->create_context != NULL)
{
gboolean res;
res = klass->create_context (backend, &error);
if (!res)
{
if (error)
{
g_critical ("Unable to create a context: %s", error->message);
g_error_free (error);
}
else
g_critical ("Unable to create a context: unknown error");
return 0;
}
}
if (klass->get_features)
return klass->get_features (backend);
return 0;
}
void
_clutter_backend_init_events (ClutterBackend *backend)
{
ClutterBackendClass *klass;
g_assert (CLUTTER_IS_BACKEND (backend));
klass = CLUTTER_BACKEND_GET_CLASS (backend);
klass->init_events (backend);
}
gfloat
_clutter_backend_get_units_per_em (ClutterBackend *backend,
PangoFontDescription *font_desc)
{
ClutterBackendPrivate *priv;
priv = backend->priv;
/* recompute for the font description, but do not cache the result */
if (font_desc != NULL)
return get_units_per_em (backend, font_desc);
if (priv->units_per_em < 0)
priv->units_per_em = get_units_per_em (backend, NULL);
return priv->units_per_em;
}
void
_clutter_backend_copy_event_data (ClutterBackend *backend,
const ClutterEvent *src,
ClutterEvent *dest)
{
ClutterBackendClass *klass;
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (klass->copy_event_data != NULL)
klass->copy_event_data (backend, src, dest);
}
void
_clutter_backend_free_event_data (ClutterBackend *backend,
ClutterEvent *event)
{
ClutterBackendClass *klass;
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (klass->free_event_data != NULL)
klass->free_event_data (backend, event);
}
/**
* clutter_get_default_backend:
*
* Retrieves the default #ClutterBackend used by Clutter. The
* #ClutterBackend holds backend-specific configuration options.
*
* Return value: (transfer none): the default backend. You should
* not ref or unref the returned object. Applications should rarely
* need to use this.
*
*
*/
ClutterBackend *
clutter_get_default_backend (void)
{
ClutterMainContext *clutter_context;
clutter_context = _clutter_context_get_default ();
return clutter_context->backend;
}
/**
* clutter_backend_get_resolution:
* @backend: a #ClutterBackend
*
* Gets the resolution for font handling on the screen.
*
* The resolution is a scale factor between points specified in a
* #PangoFontDescription and cairo units. The default value is 96.0,
* meaning that a 10 point font will be 13 units
* high (10 * 96. / 72. = 13.3).
*
* Clutter will set the resolution using the current backend when
* initializing; the resolution is also stored in the
* #ClutterSettings:font-dpi property.
*
* Return value: the current resolution, or -1 if no resolution
* has been set.
*
*
*/
gdouble
clutter_backend_get_resolution (ClutterBackend *backend)
{
ClutterSettings *settings;
gint resolution;
g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), -1.0);
settings = clutter_settings_get_default ();
g_object_get (settings, "font-dpi", &resolution, NULL);
if (resolution < 0)
return 96.0;
return resolution / 1024.0;
}
/**
* clutter_backend_set_font_options:
* @backend: a #ClutterBackend
* @options: Cairo font options for the backend, or %NULL
*
* Sets the new font options for @backend. The #ClutterBackend will
* copy the #cairo_font_options_t.
*
* If @options is %NULL, the first following call to
* clutter_backend_get_font_options() will return the default font
* options for @backend.
*
* This function is intended for actors creating a Pango layout
* using the PangoCairo API.
*
*
*/
void
clutter_backend_set_font_options (ClutterBackend *backend,
const cairo_font_options_t *options)
{
ClutterBackendPrivate *priv;
g_return_if_fail (CLUTTER_IS_BACKEND (backend));
priv = backend->priv;
if (priv->font_options != options)
{
if (priv->font_options)
cairo_font_options_destroy (priv->font_options);
if (options)
priv->font_options = cairo_font_options_copy (options);
else
priv->font_options = NULL;
g_signal_emit (backend, backend_signals[FONT_CHANGED], 0);
}
}
/**
* clutter_backend_get_font_options:
* @backend: a #ClutterBackend
*
* Retrieves the font options for @backend.
*
* Return value: (transfer none): the font options of the #ClutterBackend.
* The returned #cairo_font_options_t is owned by the backend and should
* not be modified or freed
*
*
*/
const cairo_font_options_t *
clutter_backend_get_font_options (ClutterBackend *backend)
{
ClutterBackendPrivate *priv;
g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), NULL);
priv = backend->priv;
if (G_LIKELY (priv->font_options))
return priv->font_options;
priv->font_options = cairo_font_options_create ();
cairo_font_options_set_hint_style (priv->font_options,
CAIRO_HINT_STYLE_NONE);
cairo_font_options_set_subpixel_order (priv->font_options,
CAIRO_SUBPIXEL_ORDER_DEFAULT);
cairo_font_options_set_antialias (priv->font_options,
CAIRO_ANTIALIAS_DEFAULT);
g_signal_emit (backend, backend_signals[FONT_CHANGED], 0);
return priv->font_options;
}
gint32
_clutter_backend_get_units_serial (ClutterBackend *backend)
{
return backend->priv->units_serial;
}
gboolean
_clutter_backend_translate_event (ClutterBackend *backend,
gpointer native,
ClutterEvent *event)
{
return CLUTTER_BACKEND_GET_CLASS (backend)->translate_event (backend,
native,
event);
}
void
_clutter_backend_add_event_translator (ClutterBackend *backend,
ClutterEventTranslator *translator)
{
ClutterBackendPrivate *priv = backend->priv;
if (g_list_find (priv->event_translators, translator) != NULL)
return;
priv->event_translators =
g_list_prepend (priv->event_translators, translator);
}
void
_clutter_backend_remove_event_translator (ClutterBackend *backend,
ClutterEventTranslator *translator)
{
ClutterBackendPrivate *priv = backend->priv;
if (g_list_find (priv->event_translators, translator) == NULL)
return;
priv->event_translators =
g_list_remove (priv->event_translators, translator);
}
/**
* clutter_backend_get_cogl_context:
* @backend: a #ClutterBackend
*
* Retrieves the #CoglContext associated with the given clutter
* @backend. A #CoglContext is required when using some of the
* experimental 2.0 Cogl API.
*
* <note>Since CoglContext is itself experimental API this API should
* be considered experimental too.</note>
*
* <note>This API is not yet supported on OSX because OSX still
* uses the stub Cogl winsys and the Clutter backend doesn't
* explicitly create a CoglContext.</note>
*
* Return value: The #CoglContext associated with @backend.
*
*
* Stability: unstable
*/
CoglContext *
clutter_backend_get_cogl_context (ClutterBackend *backend)
{
return backend->cogl_context;
}
#ifdef HAVE_CLUTTER_WAYLAND_COMPOSITOR
/**
* clutter_wayland_set_compositor_display:
* @display: A compositor side struct wl_display pointer
*
* This informs Clutter of your compositor side Wayland display
* object. This must be called before calling clutter_init().
*
*
* Stability: unstable
*/
void
clutter_wayland_set_compositor_display (void *display)
{
if (_clutter_context_is_initialized ())
{
g_warning ("%s() can only be used before calling clutter_init()",
G_STRFUNC);
return;
}
_wayland_compositor_display = display;
}
#endif