mutter/clutter/clutter-feature.c
Emmanuele Bassi d2bb57c3b2 Emit a critical warning if features are not initialized
If you forgot to call clutter_init() then you currently end up with a
warning saying that the stage cannot be initialized because the backend
does not support multiple stages. Clearly not useful.

We can catch some of the missing initialization in the features API,
since we will likely end up asking for a feature at some point.
2010-03-18 14:15:33 +00:00

163 lines
3.9 KiB
C

/*
* 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, see <http://www.gnu.org/licenses/>.
*
*
*/
/**
* SECTION:clutter-feature
* @short_description: Run-time detection of Clutter features
*
* Parts of Clutter depend on the underlying platform, including the
* capabilities of the backend used and the OpenGL features exposed through the
* Clutter and COGL API.
*
* It is possible to ask whether Clutter has support for specific features at
* run-time.
*
* See also cogl_get_features() and #CoglFeatureFlags
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include "clutter-feature.h"
#include "clutter-main.h"
#include "clutter-private.h"
#include "clutter-debug.h"
#include "cogl/cogl.h"
typedef struct ClutterFeatures
{
ClutterFeatureFlags flags;
guint features_set : 1;
} ClutterFeatures;
static ClutterFeatures* __features = NULL;
ClutterFeatureFlags
_clutter_features_from_cogl (guint cogl_flags)
{
ClutterFeatureFlags clutter_flags = 0;
if (cogl_flags & COGL_FEATURE_TEXTURE_NPOT)
clutter_flags |= CLUTTER_FEATURE_TEXTURE_NPOT;
if (cogl_flags & COGL_FEATURE_TEXTURE_YUV)
clutter_flags |= CLUTTER_FEATURE_TEXTURE_YUV;
if (cogl_flags & COGL_FEATURE_TEXTURE_READ_PIXELS)
clutter_flags |= CLUTTER_FEATURE_TEXTURE_READ_PIXELS;
if (cogl_flags & COGL_FEATURE_SHADERS_GLSL)
clutter_flags |= CLUTTER_FEATURE_SHADERS_GLSL;
if (cogl_flags & COGL_FEATURE_OFFSCREEN)
clutter_flags |= CLUTTER_FEATURE_OFFSCREEN;
return clutter_flags;
}
gboolean
_clutter_feature_init (GError **error)
{
ClutterMainContext *context;
CLUTTER_NOTE (MISC, "checking features");
if (!__features)
{
CLUTTER_NOTE (MISC, "allocating features data");
__features = g_new0 (ClutterFeatures, 1);
__features->features_set = FALSE; /* don't rely on zero-ing */
}
if (__features->features_set)
return TRUE;
context = _clutter_context_get_default ();
/* makes sure we have a GL context; if we have, this is a no-op */
if (!_clutter_backend_create_context (context->backend, error))
return FALSE;
__features->flags = (_clutter_features_from_cogl (cogl_get_features ())
| _clutter_backend_get_features (context->backend));
__features->features_set = TRUE;
CLUTTER_NOTE (MISC, "features checked");
return TRUE;
}
/**
* clutter_feature_available:
* @feature: a #ClutterFeatureFlags
*
* Checks whether @feature is available. @feature can be a logical
* OR of #ClutterFeatureFlags.
*
* Return value: %TRUE if a feature is available
*
* Since: 0.1.1
*/
gboolean
clutter_feature_available (ClutterFeatureFlags feature)
{
if (G_UNLIKELY (!__features))
{
g_critical ("Unable to check features. Have you initialized Clutter?");
return FALSE;
}
return (__features->flags & feature);
}
/**
* clutter_feature_get_all:
*
* Returns all the supported features.
*
* Return value: a logical OR of all the supported features.
*
* Since: 0.1.1
*/
ClutterFeatureFlags
clutter_feature_get_all (void)
{
if (G_UNLIKELY (!__features))
{
g_critical ("Unable to check features. Have you initialized Clutter?");
return FALSE;
}
return __features->flags;
}