mutter/clutter/cogl/cogl/cogl-clip-stack.h
Neil Roberts 60de7939ee cogl: Move the clip stack dirtiness to the context rather than the FB
Previously we tracked whether the clip stack needs flushing as part of
the CoglClipState which is part of the CoglFramebuffer state. This is
a bit odd because most of the clipping state (such as the clip planes
and the scissor) are part of the GL context's state rather than the
framebuffer. We were marking the clip state on the framebuffer dirty
every time we change the framebuffer anyway so it seems to make more
sense to have the dirtiness be part of the global context.

Instead of a just a single boolean to record whether the state needs
flushing, the CoglContext now holds a reference to the clip stack that
was flushed. That way we can flush arbitrary stack states and if it
happens to be the same as the state already flushed then Cogl will do
nothing. This will be useful if we log the clip stack in the journal
because then we will need to flush unrelated clip stack states for
each batch.
2010-11-04 18:08:27 +00:00

72 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
/* 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);
CoglClipStack *
_cogl_clip_stack_ref (CoglClipStack *stack);
void
_cogl_clip_stack_unref (CoglClipStack *stack);
void
_cogl_clip_stack_dirty (void);
#endif /* __COGL_CLIP_STACK_H */