mutter/src/compositor/region-utils.h

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/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/*
* Utilities for region manipulation
*
* Copyright (C) 2010 Red Hat, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __META_REGION_UTILS_H__
#define __META_REGION_UTILS_H__
#include <clutter/clutter.h>
#include <cairo.h>
#include <glib.h>
/**
* MetaRegionIterator:
* @region: region being iterated
* @rectangle: current rectangle
* @line_start: whether the current rectangle starts a horizontal band
* @line_end: whether the current rectangle ends a horizontal band
*
* cairo_region_t is a yx banded region; sometimes its useful to iterate through
* such a region treating the start and end of each horizontal band in a distinct
* fashion.
*
* Usage:
*
* MetaRegionIterator iter;
* for (meta_region_iterator_init (&iter, region);
* !meta_region_iterator_at_end (&iter);
* meta_region_iterator_next (&iter))
* {
* [ Use iter.rectangle, iter.line_start, iter.line_end ]
* }
*/
typedef struct _MetaRegionIterator MetaRegionIterator;
struct _MetaRegionIterator {
cairo_region_t *region;
cairo_rectangle_int_t rectangle;
gboolean line_start;
gboolean line_end;
int i;
/*< private >*/
int n_rectangles;
cairo_rectangle_int_t next_rectangle;
};
typedef struct _MetaRegionBuilder MetaRegionBuilder;
#define META_REGION_BUILDER_MAX_LEVELS 16
struct _MetaRegionBuilder {
/* To merge regions in binary tree order, we need to keep track of
* the regions that we've already merged together at different
* levels of the tree. We fill in an array in the pattern:
*
* |a |
* |b |a |
* |c | |ab |
* |d |c |ab |
* |e | | |abcd|
*/
cairo_region_t *levels[META_REGION_BUILDER_MAX_LEVELS];
int n_levels;
};
void meta_region_builder_init (MetaRegionBuilder *builder);
void meta_region_builder_add_rectangle (MetaRegionBuilder *builder,
int x,
int y,
int width,
int height);
cairo_region_t * meta_region_builder_finish (MetaRegionBuilder *builder);
void meta_region_iterator_init (MetaRegionIterator *iter,
cairo_region_t *region);
gboolean meta_region_iterator_at_end (MetaRegionIterator *iter);
void meta_region_iterator_next (MetaRegionIterator *iter);
cairo_region_t *meta_make_border_region (cairo_region_t *region,
int x_amount,
int y_amount,
gboolean flip);
#endif /* __META_REGION_UTILS_H__ */