mutter/cogl/cogl-clip-stack.h
Neil Roberts 30c4678ff4 cogl: Implement retained clip stacks
This adds three new internal API functions which can be used to retain
the clip stack state and restore it later:

 _cogl_get_clip_stack
 _cogl_set_clip_stack
 _cogl_clip_stack_copy

The functions are currently internal and not yet used but we may want
to make them public in future to replace the cogl_clip_stack_save()
and cogl_clip_stack_restore() APIs.

The get function just returns the handle to the clip stack at the top
of the stack of stacks and the set function just replaces it.

The copy function makes a cheap copy of an existing stack by taking a
reference to the top stack entry. This ends up working like a deep
copy because there is no way to modify entries of a stack but it
doesn't actually copy the data.
2010-04-15 14:51:01 +01:00

76 lines
2.4 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2007,2008,2009,2010 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_CLIP_STACK_H
#define __COGL_CLIP_STACK_H
CoglHandle
_cogl_clip_stack_new (void);
void
_cogl_clip_stack_push_window_rectangle (CoglHandle handle,
int x_offset,
int y_offset,
int width,
int height);
void
_cogl_clip_stack_push_rectangle (CoglHandle handle,
float x_1,
float y_1,
float x_2,
float y_2,
const CoglMatrix *modelview_matrix);
void
_cogl_clip_stack_push_from_path (CoglHandle handle,
CoglHandle path,
const CoglMatrix *modelview_matrix);
void
_cogl_clip_stack_pop (CoglHandle handle);
void
_cogl_clip_stack_flush (CoglHandle handle,
gboolean *stencil_used_p);
/* TODO: we may want to make this function public because it can be
* used to implement a better API than cogl_clip_stack_save() and
* cogl_clip_stack_restore().
*/
/*
* _cogl_clip_stack_copy:
* @handle: A handle to a clip stack
*
* Creates a copy of the given clip stack and returns a new handle to
* it. The data from the original stack is shared with the new stack
* so making copies is relatively cheap. Modifying the original stack
* does not affect the new stack.
*
* Return value: a new clip stack with the same data as @handle
*/
CoglHandle
_cogl_clip_stack_copy (CoglHandle handle);
#endif /* __COGL_CLIP_STACK_H */