mutter/cogl/cogl-clip-state.c
Neil Roberts 0c8eb904c0 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

352 lines
9.3 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/>.
*
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include <math.h>
#include <glib.h>
#include "cogl.h"
#include "cogl-clip-stack.h"
#include "cogl-clip-state.h"
#include "cogl-context.h"
#include "cogl-internal.h"
#include "cogl-framebuffer-private.h"
#include "cogl-journal-private.h"
#include "cogl-util.h"
#include "cogl-matrix-private.h"
void
cogl_clip_push_window_rectangle (int x_offset,
int y_offset,
int width,
int height)
{
CoglFramebuffer *framebuffer;
CoglClipState *clip_state;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
/* We don't log clip stack changes in the journal so we must flush
* it before making modifications */
_cogl_journal_flush ();
framebuffer = _cogl_get_framebuffer ();
clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
clip_state->stacks->data =
_cogl_clip_stack_push_window_rectangle (clip_state->stacks->data,
x_offset, y_offset,
width, height);
}
/* XXX: This is deprecated API */
void
cogl_clip_push_window_rect (float x_offset,
float y_offset,
float width,
float height)
{
cogl_clip_push_window_rectangle (x_offset, y_offset, width, height);
}
/* Try to push a rectangle given in object coordinates as a rectangle in window
* coordinates instead of object coordinates */
static gboolean
try_pushing_rect_as_window_rect (float x_1,
float y_1,
float x_2,
float y_2)
{
CoglMatrix matrix;
CoglMatrix matrix_p;
float v[4];
cogl_get_modelview_matrix (&matrix);
/* If the modelview meets these constraints then a transformed rectangle
* should still be a rectangle when it reaches screen coordinates.
*
* FIXME: we are are making certain assumptions about the projection
* matrix a.t.m and should really be looking at the combined modelview
* and projection matrix.
* FIXME: we don't consider rotations that are a multiple of 90 degrees
* which could be quite common.
*/
if (matrix.xy != 0 || matrix.xz != 0 ||
matrix.yx != 0 || matrix.yz != 0 ||
matrix.zx != 0 || matrix.zy != 0)
return FALSE;
cogl_get_projection_matrix (&matrix_p);
cogl_get_viewport (v);
_cogl_transform_point (&matrix, &matrix_p, v, &x_1, &y_1);
_cogl_transform_point (&matrix, &matrix_p, v, &x_2, &y_2);
/* Consider that the modelview matrix may flip the rectangle
* along the x or y axis... */
#define SWAP(A,B) do { float tmp = B; B = A; A = tmp; } while (0)
if (x_1 > x_2)
SWAP (x_1, x_2);
if (y_1 > y_2)
SWAP (y_1, y_2);
#undef SWAP
cogl_clip_push_window_rectangle (COGL_UTIL_NEARBYINT (x_1),
COGL_UTIL_NEARBYINT (y_1),
COGL_UTIL_NEARBYINT (x_2 - x_1),
COGL_UTIL_NEARBYINT (y_2 - y_1));
return TRUE;
}
void
cogl_clip_push_rectangle (float x_1,
float y_1,
float x_2,
float y_2)
{
CoglFramebuffer *framebuffer;
CoglClipState *clip_state;
CoglMatrix modelview_matrix;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
/* We don't log clip stack changes in the journal so we must flush
* it before making modifications */
_cogl_journal_flush ();
/* Try and catch window space rectangles so we can redirect to
* cogl_clip_push_window_rect which will use scissoring. */
if (try_pushing_rect_as_window_rect (x_1, y_1, x_2, y_2))
return;
framebuffer = _cogl_get_framebuffer ();
clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
cogl_get_modelview_matrix (&modelview_matrix);
clip_state->stacks->data =
_cogl_clip_stack_push_rectangle (clip_state->stacks->data,
x_1, y_1, x_2, y_2,
&modelview_matrix);
}
/* XXX: Deprecated API */
void
cogl_clip_push (float x_offset,
float y_offset,
float width,
float height)
{
cogl_clip_push_rectangle (x_offset,
y_offset,
x_offset + width,
y_offset + height);
}
void
cogl_clip_push_from_path_preserve (void)
{
CoglFramebuffer *framebuffer;
CoglClipState *clip_state;
CoglMatrix modelview_matrix;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
/* We don't log clip stack changes in the journal so we must flush
* it before making modifications */
_cogl_journal_flush ();
framebuffer = _cogl_get_framebuffer ();
clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
cogl_get_modelview_matrix (&modelview_matrix);
clip_state->stacks->data =
_cogl_clip_stack_push_from_path (clip_state->stacks->data, cogl_get_path (),
&modelview_matrix);
}
void
cogl_clip_push_from_path (void)
{
cogl_clip_push_from_path_preserve ();
cogl_path_new ();
}
static void
_cogl_clip_pop_real (CoglClipState *clip_state)
{
/* We don't log clip stack changes in the journal so we must flush
* it before making modifications */
_cogl_journal_flush ();
clip_state->stacks->data = _cogl_clip_stack_pop (clip_state->stacks->data);
}
void
cogl_clip_pop (void)
{
CoglFramebuffer *framebuffer;
CoglClipState *clip_state;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
framebuffer = _cogl_get_framebuffer ();
clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
_cogl_clip_pop_real (clip_state);
}
void
_cogl_clip_state_flush (CoglClipState *clip_state)
{
/* Flush the topmost stack. The clip stack code will bail out early
if this is already flushed */
_cogl_clip_stack_flush (clip_state->stacks->data);
}
/* XXX: This should never have been made public API! */
void
cogl_clip_ensure (void)
{
CoglClipState *clip_state;
clip_state = _cogl_framebuffer_get_clip_state (_cogl_get_framebuffer ());
_cogl_clip_state_flush (clip_state);
}
static void
_cogl_clip_stack_save_real (CoglClipState *clip_state)
{
/* We don't log clip stack changes in the journal so we must flush
* it before making modifications */
_cogl_journal_flush ();
clip_state->stacks = g_slist_prepend (clip_state->stacks, NULL);
}
void
cogl_clip_stack_save (void)
{
CoglFramebuffer *framebuffer;
CoglClipState *clip_state;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
framebuffer = _cogl_get_framebuffer ();
clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
_cogl_clip_stack_save_real (clip_state);
}
static void
_cogl_clip_stack_restore_real (CoglClipState *clip_state)
{
CoglHandle stack;
g_return_if_fail (clip_state->stacks != NULL);
/* We don't log clip stack changes in the journal so we must flush
* it before making modifications */
_cogl_journal_flush ();
stack = clip_state->stacks->data;
_cogl_clip_stack_unref (stack);
/* Revert to an old stack */
clip_state->stacks = g_slist_delete_link (clip_state->stacks,
clip_state->stacks);
}
void
cogl_clip_stack_restore (void)
{
CoglFramebuffer *framebuffer;
CoglClipState *clip_state;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
framebuffer = _cogl_get_framebuffer ();
clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
_cogl_clip_stack_restore_real (clip_state);
}
void
_cogl_clip_state_init (CoglClipState *clip_state)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
clip_state->stacks = NULL;
/* Add an intial stack */
_cogl_clip_stack_save_real (clip_state);
}
void
_cogl_clip_state_destroy (CoglClipState *clip_state)
{
/* Destroy all of the stacks */
while (clip_state->stacks)
_cogl_clip_stack_restore_real (clip_state);
}
CoglClipStack *
_cogl_get_clip_stack (void)
{
CoglFramebuffer *framebuffer;
CoglClipState *clip_state;
_COGL_GET_CONTEXT (ctx, COGL_INVALID_HANDLE);
framebuffer = _cogl_get_framebuffer ();
clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
return clip_state->stacks->data;
}
void
_cogl_set_clip_stack (CoglClipStack *stack)
{
CoglFramebuffer *framebuffer;
CoglClipState *clip_state;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
framebuffer = _cogl_get_framebuffer ();
clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
/* Replace the top of the stack of stacks */
_cogl_clip_stack_ref (stack);
_cogl_clip_stack_unref (clip_state->stacks->data);
clip_state->stacks->data = stack;
}