mutter/clutter/cogl/cogl/cogl-offscreen.h
Robert Bragg 43efab46bc Intial Re-layout of the Cogl source code and introduction of a Cogl Winsys
As part of an incremental process to have Cogl be a standalone project we
want to re-consider how we organise the Cogl source code.

Currently this is the structure I'm aiming for:
cogl/
    cogl/
	<put common source here>
	winsys/
	   cogl-glx.c
	   cogl-wgl.c
	driver/
	    gl/
	    gles/
	os/ ?
    utils/
	cogl-fixed
	cogl-matrix-stack?
        cogl-journal?
        cogl-primitives?
    pango/

The new winsys component is a starting point for migrating window system
code (i.e.  x11,glx,wgl,osx,egl etc) from Clutter to Cogl.

The utils/ and pango/ directories aren't added by this commit, but they are
noted because I plan to add them soon.

Overview of the planned structure:

* The winsys/ API is the API that binds OpenGL to a specific window system,
  be that X11 or win32 etc.  Example are glx, wgl and egl. Much of the logic
  under clutter/{glx,osx,win32 etc} should migrate here.

* Note there is also the idea of a winsys-base that may represent a window
  system for which there are multiple winsys APIs.  An example of this is
  x11, since glx and egl may both be used with x11.  (currently only Clutter
  has the idea of a winsys-base)

* The driver/ represents a specific varient of OpenGL. Currently we have "gl"
  representing OpenGL 1.4-2.1 (mostly fixed function) and "gles" representing
  GLES 1.1 (fixed funciton) and 2.0 (fully shader based)

* Everything under cogl/ should fundamentally be supporting access to the
  GPU.  Essentially Cogl's most basic requirement is to provide a nice GPU
  Graphics API and drawing a line between this and the utility functionality
  we add to support Clutter should help keep this lean and maintainable.

* Code under utils/ as suggested builds on cogl/ adding more convenient
  APIs or mechanism to optimize special cases. Broadly speaking you can
  compare cogl/ to OpenGL and utils/ to GLU.

* clutter/pango will be moved to clutter/cogl/pango

How some of the internal configure.ac/pkg-config terminology has changed:
backendextra -> CLUTTER_WINSYS_BASE # e.g. "x11"
backendextralib -> CLUTTER_WINSYS_BASE_LIB # e.g. "x11/libclutter-x11.la"
clutterbackend -> {CLUTTER,COGL}_WINSYS # e.g. "glx"
CLUTTER_FLAVOUR -> {CLUTTER,COGL}_WINSYS
clutterbackendlib -> CLUTTER_WINSYS_LIB
CLUTTER_COGL -> COGL_DRIVER # e.g. "gl"

Note: The CLUTTER_FLAVOUR and CLUTTER_COGL defines are kept for apps

As the first thing to take advantage of the new winsys component in Cogl;
cogl_get_proc_address() has been moved from cogl/{gl,gles}/cogl.c into
cogl/common/cogl.c and this common implementation first trys
_cogl_winsys_get_proc_address() but if that fails then it falls back to
gmodule.
2009-10-16 18:58:50 +01:00

97 lines
3.0 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2007,2008,2009 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.
*/
#if !defined(__COGL_H_INSIDE__) && !defined(CLUTTER_COMPILATION)
#error "Only <cogl/cogl.h> can be included directly."
#endif
#ifndef __COGL_OFFSCREEN_H__
#define __COGL_OFFSCREEN_H__
#include <cogl/cogl-types.h>
G_BEGIN_DECLS
/**
* SECTION:cogl-offscreen
* @short_description: Fuctions for creating and manipulating offscreen
* frame buffer objects
*
* Cogl allows creating and operating on offscreen render targets.
*/
/* Offscreen api */
/**
* cogl_offscreen_new_to_texture:
* @handle: A CoglHandle for a Cogl texture
*
* This creates an offscreen buffer object using the given texture as the
* primary color buffer. It doesn't just initialize the contents of the
* offscreen buffer with the texture; they are tightly bound so that
* drawing to the offscreen buffer effectivly updates the contents of the
* given texture. You don't need to destroy the offscreen buffer before
* you can use the texture again.
*
* Note: This does not work with sliced Cogl textures.
*
* Returns: a #CoglHandle for the new offscreen buffer or %COGL_INVALID_HANDLE
* if it wasn't possible to create the buffer.
*/
CoglHandle cogl_offscreen_new_to_texture (CoglHandle handle);
/**
* cogl_offscreen_ref:
* @handle: A CoglHandle for an offscreen buffer
*
* Increments the reference count on the offscreen buffer.
*
* Returns: For convenience it returns the given CoglHandle
*/
CoglHandle cogl_offscreen_ref (CoglHandle handle);
/**
* cogl_is_offscreen:
* @handle: A CoglHandle for an offscreen buffer
*
* Gets whether the given handle references an existing offscreen buffer
* object.
*
* Returns: %TRUE if the handle references an offscreen buffer,
* %FALSE otherwise
*/
gboolean cogl_is_offscreen (CoglHandle handle);
/**
* cogl_offscreen_unref:
* @handle: A CoglHandle for an offscreen buffer
*
* Decreases the reference count for the offscreen buffer and frees it when
* the count reaches 0.
*/
void cogl_offscreen_unref (CoglHandle handle);
G_END_DECLS
#endif /* __COGL_OFFSCREEN_H__ */