mutter/clutter/clutter/clutter-backend.c
2021-09-20 16:37:37 +00:00

885 lines
24 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
*/
#include "clutter-build-config.h"
#include "clutter-backend-private.h"
#include "clutter-debug.h"
#include "clutter-event-private.h"
#include "clutter-marshal.h"
#include "clutter-mutter.h"
#include "clutter-private.h"
#include "clutter-stage-manager-private.h"
#include "clutter-stage-private.h"
#include "clutter-stage-window.h"
#include <cogl/cogl.h>
#define DEFAULT_FONT_NAME "Sans 10"
enum
{
RESOLUTION_CHANGED,
FONT_CHANGED,
SETTINGS_CHANGED,
LAST_SIGNAL
};
G_DEFINE_ABSTRACT_TYPE (ClutterBackend, clutter_backend, G_TYPE_OBJECT)
static guint backend_signals[LAST_SIGNAL] = { 0, };
static void
clutter_backend_dispose (GObject *gobject)
{
ClutterBackend *backend = CLUTTER_BACKEND (gobject);
/* clear the events still in the queue of the main context */
_clutter_clear_events_queue ();
g_clear_object (&backend->dummy_onscreen);
if (backend->stage_window)
{
g_object_remove_weak_pointer (G_OBJECT (backend->stage_window),
(gpointer *) &backend->stage_window);
backend->stage_window = NULL;
}
g_clear_pointer (&backend->cogl_source, g_source_destroy);
g_clear_pointer (&backend->font_name, g_free);
g_clear_pointer (&backend->font_options, cairo_font_options_destroy);
g_clear_object (&backend->input_method);
G_OBJECT_CLASS (clutter_backend_parent_class)->dispose (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)
{
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);
backend->units_per_em = get_units_per_em (backend, NULL);
backend->units_serial += 1;
CLUTTER_NOTE (BACKEND, "Units per em: %.2f", backend->units_per_em);
}
static void
clutter_backend_real_font_changed (ClutterBackend *backend)
{
backend->units_per_em = get_units_per_em (backend, NULL);
backend->units_serial += 1;
CLUTTER_NOTE (BACKEND, "Units per em: %.2f", backend->units_per_em);
}
static gboolean
clutter_backend_do_real_create_context (ClutterBackend *backend,
CoglDriver driver_id,
GError **error)
{
ClutterBackendClass *klass;
CoglSwapChain *swap_chain;
klass = CLUTTER_BACKEND_GET_CLASS (backend);
swap_chain = NULL;
CLUTTER_NOTE (BACKEND, "Creating Cogl renderer");
backend->cogl_renderer = klass->get_renderer (backend, error);
if (backend->cogl_renderer == NULL)
goto error;
CLUTTER_NOTE (BACKEND, "Connecting the renderer");
cogl_renderer_set_driver (backend->cogl_renderer, driver_id);
if (!cogl_renderer_connect (backend->cogl_renderer, 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,
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,
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;
CLUTTER_NOTE (BACKEND, "Setting up the display");
if (!cogl_display_setup (backend->cogl_display, error))
goto error;
CLUTTER_NOTE (BACKEND, "Creating the Cogl context");
backend->cogl_context = cogl_context_new (backend->cogl_display, error);
if (backend->cogl_context == NULL)
goto error;
/* 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);
return FALSE;
}
static const struct {
const char *driver_name;
const char *driver_desc;
CoglDriver driver_id;
} all_known_drivers[] = {
{ "gl3", "OpenGL 3.2 core profile", COGL_DRIVER_GL3 },
{ "gl", "OpenGL legacy profile", COGL_DRIVER_GL },
{ "gles2", "OpenGL ES 2.0", COGL_DRIVER_GLES2 },
{ "any", "Default Cogl driver", COGL_DRIVER_ANY },
};
static const char *allowed_drivers;
static gboolean
clutter_backend_real_create_context (ClutterBackend *backend,
GError **error)
{
GError *internal_error = NULL;
const char *drivers_list;
char **known_drivers;
gboolean allow_any;
int i;
if (backend->cogl_context != NULL)
return TRUE;
if (allowed_drivers == NULL)
allowed_drivers = CLUTTER_DRIVERS;
allow_any = strstr (allowed_drivers, "*") != NULL;
drivers_list = g_getenv ("CLUTTER_DRIVER");
if (drivers_list == NULL)
drivers_list = allowed_drivers;
known_drivers = g_strsplit (drivers_list, ",", 0);
for (i = 0; backend->cogl_context == NULL && known_drivers[i] != NULL; i++)
{
const char *driver_name = known_drivers[i];
gboolean is_any = g_str_equal (driver_name, "*");
int j;
for (j = 0; j < G_N_ELEMENTS (all_known_drivers); j++)
{
if (!allow_any && !is_any && !strstr (driver_name, all_known_drivers[j].driver_name))
continue;
if ((allow_any && is_any) ||
(is_any && strstr (allowed_drivers, all_known_drivers[j].driver_name)) ||
g_str_equal (all_known_drivers[j].driver_name, driver_name))
{
CLUTTER_NOTE (BACKEND, "Checking for the %s driver", all_known_drivers[j].driver_desc);
if (clutter_backend_do_real_create_context (backend, all_known_drivers[j].driver_id, &internal_error))
break;
if (internal_error)
{
CLUTTER_NOTE (BACKEND, "Unable to use the %s driver: %s",
all_known_drivers[j].driver_desc,
internal_error->message);
g_clear_error (&internal_error);
}
}
}
}
g_strfreev (known_drivers);
if (backend->cogl_context == NULL)
{
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: no available drivers found.");
return FALSE;
}
backend->cogl_source = cogl_glib_source_new (backend->cogl_context, G_PRIORITY_DEFAULT);
g_source_attach (backend->cogl_source, NULL);
return TRUE;
}
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_BUFFERS_EVENT))
{
CLUTTER_NOTE (BACKEND, "Cogl supports swap buffers complete events");
flags |= CLUTTER_FEATURE_SWAP_EVENTS;
}
return flags;
}
static ClutterBackend * (* custom_backend_func) (void);
void
clutter_set_custom_backend_func (ClutterBackend *(* func) (void))
{
custom_backend_func = func;
}
ClutterBackend *
_clutter_create_backend (void)
{
ClutterBackend *retval;
g_return_val_if_fail (custom_backend_func, NULL);
retval = custom_backend_func ();
if (!retval)
g_error ("Failed to create custom backend.");
return retval;
}
static void
clutter_backend_class_init (ClutterBackendClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->dispose = clutter_backend_dispose;
/**
* 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.
*
* Since: 1.0
*/
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, NULL,
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.
*
* Since: 1.0
*/
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, NULL,
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.
*
* Since: 1.4
*/
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, NULL,
G_TYPE_NONE, 0);
klass->resolution_changed = clutter_backend_real_resolution_changed;
klass->font_changed = clutter_backend_real_font_changed;
klass->create_context = clutter_backend_real_create_context;
klass->get_features = clutter_backend_real_get_features;
}
static void
clutter_backend_init (ClutterBackend *self)
{
self->units_per_em = -1.0;
self->units_serial = 1;
self->dummy_onscreen = NULL;
self->fallback_resource_scale = 1.f;
}
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));
backend->stage_window = stage_window;
g_object_add_weak_pointer (G_OBJECT (backend->stage_window),
(gpointer *) &backend->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);
}
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;
}
gfloat
_clutter_backend_get_units_per_em (ClutterBackend *backend,
PangoFontDescription *font_desc)
{
/* recompute for the font description, but do not cache the result */
if (font_desc != NULL)
return get_units_per_em (backend, font_desc);
if (backend->units_per_em < 0)
backend->units_per_em = get_units_per_em (backend, NULL);
return backend->units_per_em;
}
/**
* 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.
*
* Since: 0.4
*/
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.
*
* Since: 0.4
*/
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.
*
* Since: 0.8
*/
void
clutter_backend_set_font_options (ClutterBackend *backend,
const cairo_font_options_t *options)
{
g_return_if_fail (CLUTTER_IS_BACKEND (backend));
if (backend->font_options != options)
{
if (backend->font_options)
cairo_font_options_destroy (backend->font_options);
if (options)
backend->font_options = cairo_font_options_copy (options);
else
backend->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
*
* Since: 0.8
*/
const cairo_font_options_t *
clutter_backend_get_font_options (ClutterBackend *backend)
{
g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), NULL);
if (G_LIKELY (backend->font_options))
return backend->font_options;
backend->font_options = cairo_font_options_create ();
cairo_font_options_set_hint_style (backend->font_options, CAIRO_HINT_STYLE_NONE);
cairo_font_options_set_subpixel_order (backend->font_options, CAIRO_SUBPIXEL_ORDER_DEFAULT);
cairo_font_options_set_antialias (backend->font_options, CAIRO_ANTIALIAS_DEFAULT);
g_signal_emit (backend, backend_signals[FONT_CHANGED], 0);
return backend->font_options;
}
gint32
_clutter_backend_get_units_serial (ClutterBackend *backend)
{
return backend->units_serial;
}
gboolean
_clutter_backend_translate_event (ClutterBackend *backend,
gpointer native,
ClutterEvent *event)
{
return CLUTTER_BACKEND_GET_CLASS (backend)->translate_event (backend,
native,
event);
}
/**
* clutter_backend_get_cogl_context: (skip)
* @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.
*
* Since CoglContext is itself experimental API this API should
* be considered experimental too.
*
* 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.
*
* Return value: (transfer none): The #CoglContext associated with @backend.
*
* Since: 1.8
* Stability: unstable
*/
CoglContext *
clutter_backend_get_cogl_context (ClutterBackend *backend)
{
return backend->cogl_context;
}
void
clutter_set_allowed_drivers (const char *drivers)
{
if (_clutter_context_is_initialized ())
{
g_warning ("Clutter has already been initialized.\n");
return;
}
allowed_drivers = g_strdup (drivers);
}
/**
* clutter_backend_get_input_method:
* @backend: the #CLutterBackend
*
* Returns the input method used by Clutter
*
* Returns: (transfer none): the input method
**/
ClutterInputMethod *
clutter_backend_get_input_method (ClutterBackend *backend)
{
return backend->input_method;
}
/**
* clutter_backend_set_input_method:
* @backend: the #ClutterBackend
* @method: the input method
*
* Sets the input method to be used by Clutter
**/
void
clutter_backend_set_input_method (ClutterBackend *backend,
ClutterInputMethod *method)
{
g_set_object (&backend->input_method, method);
}
ClutterStageWindow *
clutter_backend_get_stage_window (ClutterBackend *backend)
{
return backend->stage_window;
}
/**
* clutter_backend_get_default_seat:
* @backend: the #ClutterBackend
*
* Returns the default seat
*
* Returns: (transfer none): the default seat
**/
ClutterSeat *
clutter_backend_get_default_seat (ClutterBackend *backend)
{
g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), NULL);
return CLUTTER_BACKEND_GET_CLASS (backend)->get_default_seat (backend);
}
void
clutter_backend_set_fallback_resource_scale (ClutterBackend *backend,
float fallback_resource_scale)
{
backend->fallback_resource_scale = fallback_resource_scale;
}
float
clutter_backend_get_fallback_resource_scale (ClutterBackend *backend)
{
return backend->fallback_resource_scale;
}
gboolean
clutter_backend_is_display_server (ClutterBackend *backend)
{
return CLUTTER_BACKEND_GET_CLASS (backend)->is_display_server (backend);
}
void
clutter_backend_destroy (ClutterBackend *backend)
{
g_object_run_dispose (G_OBJECT (backend));
g_object_unref (backend);
}