buffer: splits out GL specific code

As part of an on-going effort to be able to support non-opengl drivers
for Cogl this splits out the opengl specific code from cogl-buffer.c
into driver/gl/cogl-buffer-gl.c

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

(cherry picked from commit 4d7094a979ff2cbbe4054f4a44ca05fc41a9e447)

cogl/driver/gl/cogl-buffer-gl-private.h

@@ -0,0 +1,62 @@
+/*
+ * Cogl
+ *
+ * An object oriented GL/GLES Abstraction/Utility Layer
+ *
+ * Copyright (C) 2012 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/>.
+ *
+ *
+ *
+ * Authors:
+ *   Robert Bragg <robert@linux.intel.com>
+ */
+
+#ifndef _COGL_BUFFER_GL_PRIVATE_H_
+#define _COGL_BUFFER_GL_PRIVATE_H_
+
+#include "cogl-types.h"
+#include "cogl-context.h"
+#include "cogl-buffer.h"
+#include "cogl-buffer-private.h"
+
+void
+_cogl_buffer_gl_create (CoglBuffer *buffer);
+
+void
+_cogl_buffer_gl_destroy (CoglBuffer *buffer);
+
+void *
+_cogl_buffer_gl_map (CoglBuffer *buffer,
+                     CoglBufferAccess  access,
+                     CoglBufferMapHint hints);
+
+void
+_cogl_buffer_gl_unmap (CoglBuffer *buffer);
+
+CoglBool
+_cogl_buffer_gl_set_data (CoglBuffer *buffer,
+                          unsigned int offset,
+                          const void *data,
+                          unsigned int size);
+
+void *
+_cogl_buffer_gl_bind (CoglBuffer *buffer, CoglBufferBindTarget target);
+
+void
+_cogl_buffer_gl_unbind (CoglBuffer *buffer);
+
+#endif /* _COGL_BUFFER_GL_PRIVATE_H_ */