mutter/cogl/cogl-clip-stack.h
Neil Roberts f15b47cc03 cogl-clip-stack: Don't allocate a separate struct for CoglClipStack
Instead of having a separate CoglHandle for CoglClipStack the code is
now expected to directly hold a pointer to the top entry on the
stack. The empty stack is then the NULL pointer. This saves an
allocation when we want to copy the stack because we can just take a
reference on a stack entry. The idea is that this will make it
possible to store the clip stack in the journal without any extra
allocations.

The _cogl_get_clip_stack and set functions now take a CoglClipStack
pointer instead of a handle so it would no longer make sense to make
them public. However I think the only reason we would have wanted that
in the first place would be to save the clip state between switching
FBOs and that is no longer necessary.
2010-11-04 18:08:27 +00:00

70 lines
2.5 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
/* The clip stack works like a GSList where only a pointer to the top
of the stack is stored. The empty clip stack is represented simply
by the NULL pointer. When an entry is added to or removed from the
stack the new top of the stack is returned. When an entry is pushed
a new clip stack entry is created which effectively takes ownership
of the reference on the old entry. Therefore unrefing the top entry
effectively loses ownership of all entries in the stack */
typedef struct _CoglClipStack CoglClipStack;
CoglClipStack *
_cogl_clip_stack_push_window_rectangle (CoglClipStack *stack,
int x_offset,
int y_offset,
int width,
int height);
CoglClipStack *
_cogl_clip_stack_push_rectangle (CoglClipStack *stack,
float x_1,
float y_1,
float x_2,
float y_2,
const CoglMatrix *modelview_matrix);
CoglClipStack *
_cogl_clip_stack_push_from_path (CoglClipStack *stack,
CoglPath *path,
const CoglMatrix *modelview_matrix);
CoglClipStack *
_cogl_clip_stack_pop (CoglClipStack *stack);
void
_cogl_clip_stack_flush (CoglClipStack *stack,
gboolean *stencil_used_p);
CoglClipStack *
_cogl_clip_stack_ref (CoglClipStack *stack);
void
_cogl_clip_stack_unref (CoglClipStack *stack);
#endif /* __COGL_CLIP_STACK_H */