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mutter-performance-source/cogl/winsys/cogl-texture-pixmap-x11.h
Robert Bragg df21e20f65 Adds CoglError api
Although we use GLib internally in Cogl we would rather not leak GLib
api through Cogl's own api, except through explicitly namespaced
cogl_glib_ / cogl_gtype_ feature apis.

One of the benefits we see to not leaking GLib through Cogl's public API
is that documentation for Cogl won't need to first introduce the Glib
API to newcomers, thus hopefully lowering the barrier to learning Cogl.

This patch provides a Cogl specific typedef for reporting runtime errors
which by no coincidence matches the typedef for GError exactly.  If Cogl
is built with --enable-glib (default) then developers can even safely
assume that a CoglError is a GError under the hood.

This patch also enforces a consistent policy for when NULL is passed as
an error argument and an error is thrown. In this case we log the error
and abort the application, instead of silently ignoring it. In common
cases where nothing has been implemented to handle a particular error
and/or where applications are just printing the error and aborting
themselves then this saves some typing. This also seems more consistent
with language based exceptions which usually cause a program to abort if
they are not explicitly caught (which passing a non-NULL error signifies
in this case)

Since this policy for NULL error pointers is stricter than the standard
GError convention, there is a clear note in the documentation to warn
developers that are used to using the GError api.

Reviewed-by: Neil Roberts <neil@linux.intel.com>

(cherry picked from commit b068d5ea09ab32c37e8c965fc8582c85d1b2db46)

Note: Since we can't change the Cogl 1.x api the patch was changed to
not rename _error_quark() functions to be _error_domain() functions and
although it's a bit ugly, instead of providing our own CoglError type
that's compatible with GError we simply #define CoglError to GError
unless Cogl is built with glib disabled.

Note: this patch does technically introduce an API break since it drops
the cogl_error_get_type() symbol generated by glib-mkenum (Since the
CoglError enum was replaced by a CoglSystemError enum) but for now we
are assuming that this will not affect anyone currently using the Cogl
API. If this does turn out to be a problem in practice then we would be
able to fix this my manually copying an implementation of
cogl_error_get_type() generated by glib-mkenum into a compatibility
source file and we could also define the original COGL_ERROR_ enums for
compatibility too.

Note: another minor concern with cherry-picking this patch to the 1.14
branch is that an api scanner would be lead to believe that some APIs
have changed, and for example the gobject-introspection parser which
understands the semantics of GError will not understand the semantics of
CoglError. We expect most people that have tried to use
gobject-introspection with Cogl already understand though that it is not
well suited to generating bindings of the Cogl api anyway and we aren't
aware or anyone depending on such bindings for apis involving GErrors.
(GnomeShell only makes very-very minimal use of Cogl via the gjs
bindings for the cogl_rectangle and cogl_color apis.)

The main reason we have cherry-picked this patch to the 1.14 branch
even given the above concerns is that without it it would become very
awkward for us to cherry-pick other beneficial patches from master.
2013-01-22 17:47:39 +00:00

192 lines
5.6 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2010 Intel Corporation.
*
* 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/>.
*
*
*/
#ifndef __COGL_TEXTURE_PIXMAP_X11_H
#define __COGL_TEXTURE_PIXMAP_X11_H
#define __COGL_H_INSIDE__
#include <glib.h>
#include <cogl/cogl-context.h>
G_BEGIN_DECLS
#ifdef COGL_ENABLE_EXPERIMENTAL_API
/**
* SECTION:cogl-texture-pixmap-x11
* @short_description: Functions for creating and manipulating 2D meta
* textures derived from X11 pixmaps.
*
* These functions allow high-level meta textures (See the
* #CoglMetaTexture interface) that derive their contents from an X11
* pixmap.
*/
typedef struct _CoglTexturePixmapX11 CoglTexturePixmapX11;
#define COGL_TEXTURE_PIXMAP_X11(X) ((CoglTexturePixmapX11 *)X)
typedef enum
{
COGL_TEXTURE_PIXMAP_X11_DAMAGE_RAW_RECTANGLES,
COGL_TEXTURE_PIXMAP_X11_DAMAGE_DELTA_RECTANGLES,
COGL_TEXTURE_PIXMAP_X11_DAMAGE_BOUNDING_BOX,
COGL_TEXTURE_PIXMAP_X11_DAMAGE_NON_EMPTY
} CoglTexturePixmapX11ReportLevel;
/**
* COGL_TEXTURE_PIXMAP_X11_ERROR:
*
* #CoglError domain for texture-pixmap-x11 errors.
*
* Since: 1.10
*/
#define COGL_TEXTURE_PIXMAP_X11_ERROR (cogl_texture_pixmap_x11_error_quark ())
/**
* CoglTexturePixmapX11Error:
* @COGL_TEXTURE_PIXMAP_X11_ERROR_X11: An X11 protocol error
*
* Error codes that can be thrown when performing texture-pixmap-x11
* operations.
*
* Since: 1.10
*/
typedef enum {
COGL_TEXTURE_PIXMAP_X11_ERROR_X11,
} CoglTexturePixmapX11Error;
uint32_t cogl_texture_pixmap_x11_error_quark (void);
/**
* cogl_texture_pixmap_x11_new:
* @context: A #CoglContext
* @pixmap: A X11 pixmap ID
* @automatic_updates: Whether to automatically copy the contents of
* the pixmap to the texture.
* @error: A #CoglError for exceptions
*
* Creates a texture that contains the contents of @pixmap. If
* @automatic_updates is %TRUE then Cogl will attempt to listen for
* damage events on the pixmap and automatically update the texture
* when it changes.
*
* Return value: a new #CoglTexturePixmapX11 instance
*
* Since: 1.10
* Stability: Unstable
*/
CoglTexturePixmapX11 *
cogl_texture_pixmap_x11_new (CoglContext *context,
uint32_t pixmap,
CoglBool automatic_updates,
CoglError **error);
/**
* cogl_texture_pixmap_x11_update_area:
* @texture: A #CoglTexturePixmapX11 instance
* @x: x coordinate of the area to update
* @y: y coordinate of the area to update
* @width: width of the area to update
* @height: height of the area to update
*
* Forces an update of the given @texture so that it is refreshed with
* the contents of the pixmap that was given to
* cogl_texture_pixmap_x11_new().
*
* Since: 1.4
* Stability: Unstable
*/
void
cogl_texture_pixmap_x11_update_area (CoglTexturePixmapX11 *texture,
int x,
int y,
int width,
int height);
/**
* cogl_texture_pixmap_x11_is_using_tfp_extension:
* @texture: A #CoglTexturePixmapX11 instance
*
* Checks whether the given @texture is using the
* GLX_EXT_texture_from_pixmap or similar extension to copy the
* contents of the pixmap to the texture. This extension is usually
* implemented as zero-copy operation so it implies the updates are
* working efficiently.
*
* Return value: %TRUE if the texture is using an efficient extension
* and %FALSE otherwise
*
* Since: 1.4
* Stability: Unstable
*/
CoglBool
cogl_texture_pixmap_x11_is_using_tfp_extension (CoglTexturePixmapX11 *texture);
/**
* cogl_texture_pixmap_x11_set_damage_object:
* @texture: A #CoglTexturePixmapX11 instance
* @damage: A X11 Damage object or 0
* @report_level: The report level which describes how to interpret
* the damage events. This should match the level that the damage
* object was created with.
*
* Sets the damage object that will be used to track automatic updates
* to the @texture. Damage tracking can be disabled by passing 0 for
* @damage. Otherwise this damage will replace the one used if %TRUE
* was passed for automatic_updates to cogl_texture_pixmap_x11_new().
*
* Note that Cogl will subtract from the damage region as it processes
* damage events.
*
* Since: 1.4
* Stability: Unstable
*/
void
cogl_texture_pixmap_x11_set_damage_object (CoglTexturePixmapX11 *texture,
uint32_t damage,
CoglTexturePixmapX11ReportLevel
report_level);
/**
* cogl_is_texture_pixmap_x11:
* @object: A pointer to a #CoglObject
*
* Checks whether @object points to a #CoglTexturePixmapX11 instance.
*
* Return value: %TRUE if the object is a #CoglTexturePixmapX11, and
* %FALSE otherwise
*
* Since: 1.4
* Stability: Unstable
*/
CoglBool
cogl_is_texture_pixmap_x11 (void *object);
#endif /* COGL_ENABLE_EXPERIMENTAL_API */
G_END_DECLS
#endif /* __COGL_TEXTURE_PIXMAP_X11_H */