gtk2/gdk/gdkglcontext.h
Emmanuele Bassi 22e6f37c9c GL: Split GL context creation in two phases
One of the major requests by OpenGL users has been the ability to
specify settings when creating a GL context, like the version to use
or whether the debug support should be enabled.

We have a couple of requirements in terms of API:

 • avoid, if at all possible, the "C arrays of integers with
   attribute, value pairs", which are hard to write and hard
   to bind in non-C languages.
 • allow failing in a recoverable way.
 • do not make the GL context creation API a mess of arguments.

Looking at prior art, it seems that a common pattern is to split the
construction phase in two:

 • a first phase that creates a GL context wrapper object and
   does preliminary checks on the environment.
 • a second phase that creates the backend-specific GL object.

We adopted a similar pattern:

 • gdk_window_create_gl_context() creates a GdkGLContext
 • gdk_gl_context_realize() creates the underlying resources

Calling gdk_gl_context_make_current() also realizes the context, so
simple GL users do not need to care. Advanced users will want to
call gdk_window_create_gl_context(), set up the optional requirements,
and then call gdk_gl_context_realize(). If either of these two steps
fails, it's possible to recover by changing the requirements, or simply
creating a new GdkGLContext instance.

https://bugzilla.gnome.org/show_bug.cgi?id=741946
2015-02-09 19:10:04 +00:00

68 lines
2.5 KiB
C

/* GDK - The GIMP Drawing Kit
*
* gdkglcontext.h: GL context abstraction
*
* Copyright © 2014 Emmanuele Bassi
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __GDK_GL_CONTEXT_H__
#define __GDK_GL_CONTEXT_H__
#if !defined (__GDK_H_INSIDE__) && !defined (GDK_COMPILATION)
#error "Only <gdk/gdk.h> can be included directly."
#endif
#include <gdk/gdkversionmacros.h>
#include <gdk/gdktypes.h>
G_BEGIN_DECLS
#define GDK_TYPE_GL_CONTEXT (gdk_gl_context_get_type ())
#define GDK_GL_CONTEXT(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GDK_TYPE_GL_CONTEXT, GdkGLContext))
#define GDK_IS_GL_CONTEXT(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GDK_TYPE_GL_CONTEXT))
#define GDK_GL_ERROR (gdk_gl_error_quark ())
GDK_AVAILABLE_IN_3_16
GQuark gdk_gl_error_quark (void);
GDK_AVAILABLE_IN_3_16
GType gdk_gl_context_get_type (void) G_GNUC_CONST;
GDK_AVAILABLE_IN_3_16
GdkDisplay * gdk_gl_context_get_display (GdkGLContext *context);
GDK_AVAILABLE_IN_3_16
GdkWindow * gdk_gl_context_get_window (GdkGLContext *context);
GDK_AVAILABLE_IN_3_16
GdkGLProfile gdk_gl_context_get_profile (GdkGLContext *context);
GDK_AVAILABLE_IN_3_16
GdkGLContext * gdk_gl_context_get_shared_context (GdkGLContext *context);
GDK_AVAILABLE_IN_3_16
gboolean gdk_gl_context_realize (GdkGLContext *context,
GError **error);
GDK_AVAILABLE_IN_3_16
void gdk_gl_context_make_current (GdkGLContext *context);
GDK_AVAILABLE_IN_3_16
GdkGLContext * gdk_gl_context_get_current (void);
GDK_AVAILABLE_IN_3_16
void gdk_gl_context_clear_current (void);
G_END_DECLS
#endif /* __GDK_GL_CONTEXT_H__ */