cogl-pixel-buffer: add a pixel buffer object class

This subclass of CoglBuffer aims at wrapping PBOs or other system
surfaces like DRM buffer objects. Two constructors are available:

cogl_pixel_buffer_new() with a size when you only care about the size of
the buffer (such a buffer can be used to store several texture data such
as the three planes of a I420 frame).

cogl_pixel_buffer_new_full() is more a 1:1 mapping between the data and
an underlying surface, with the possibility of having access to a low
level memory buffer that may have a stride.

cogl/cogl-pixel-buffer-private.h

@@ -0,0 +1,72 @@
+/*
+ * 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, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Authors:
+ *   Damien Lespiau <damien.lespiau@intel.com>
+ */
+
+#ifndef __COGL_PIXEL_BUFFER_PRIVATE_H__
+#define __COGL_PIXEL_BUFFER_PRIVATE_H__
+
+#include "cogl-handle.h"
+#include "cogl-buffer-private.h"
+
+#include <glib.h>
+
+G_BEGIN_DECLS
+
+#define COGL_PIXEL_BUFFER(buffer)     ((CoglPixelBuffer *)(buffer))
+
+#define COGL_PIXEL_BUFFER_SET_FLAG(buffer, flag) \
+  ((buffer)->flags |= (COGL_PIXEL_BUFFER_FLAG_ ## flag))
+
+#define COGL_PIXEL_BUFFER_CLEAR_FLAG(buffer, flag) \
+  ((buffer)->flags &= ~(COGL_PIXEL_BUFFER_FLAG_ ## flag))
+
+#define COGL_PIXEL_BUFFER_FLAG_IS_SET(buffer, flag) \
+  ((buffer)->flags & (COGL_PIXEL_BUFFER_FLAG_ ## flag))
+
+typedef enum _CoglPixelBufferFlags
+{
+  COGL_PIXEL_BUFFER_FLAG_NONE = 0,
+  COGL_PIXEL_BUFFER_FLAG_STORE_CREATED = 1 << 0,
+} CoglPixelBufferFlags;
+
+typedef struct _CoglPixelBuffer
+{
+  CoglBuffer            _parent;
+
+  CoglPixelBufferFlags  flags;
+
+  GLenum                gl_target;
+  CoglPixelFormat       format;
+  guint                 width;
+  guint                 height;
+  guint                 stride;
+
+} CoglPixelBuffer;
+
+GQuark    _cogl_handle_pixel_buffer_get_type    (void);
+
+G_END_DECLS
+
+#endif /* __COGL_PIXEL_BUFFER_PRIVATE_H__ */