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/* cairo - a vector graphics library with display and print output
*
* Copyright © 2002 University of Southern California
*
* This library is free software; you can redistribute it and/or
* modify it either under the terms of the GNU Lesser General Public
* License version 2.1 as published by the Free Software Foundation
* (the "LGPL") or, at your option, under the terms of the Mozilla
* Public License Version 1.1 (the "MPL"). If you do not alter this
* notice, a recipient may use your version of this file under either
* the MPL or the LGPL.
*
* You should have received a copy of the LGPL along with this library
* in the file COPYING-LGPL-2.1; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
* You should have received a copy of the MPL along with this library
* in the file COPYING-MPL-1.1
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
* OF ANY KIND, either express or implied. See the LGPL or the MPL for
* the specific language governing rights and limitations.
*
* The Original Code is the cairo graphics library.
*
* The Initial Developer of the Original Code is University of Southern
* California.
*
* Contributor(s):
* Carl D. Worth <cworth@cworth.org>
*/
#include "cairoint.h"
void
_cairo_polygon_init (cairo_polygon_t *polygon)
{
polygon->status = CAIRO_STATUS_SUCCESS;
polygon->num_edges = 0;
polygon->edges = polygon->edges_embedded;
polygon->edges_size = ARRAY_LENGTH (polygon->edges_embedded);
polygon->has_current_point = FALSE;
}
void
_cairo_polygon_fini (cairo_polygon_t *polygon)
{
if (polygon->edges != polygon->edges_embedded)
free (polygon->edges);
}
/* make room for at least one more edge */
static cairo_bool_t
_cairo_polygon_grow (cairo_polygon_t *polygon)
{
cairo_edge_t *new_edges;
int old_size = polygon->edges_size;
int new_size = 4 * old_size;
if (polygon->edges == polygon->edges_embedded) {
new_edges = _cairo_malloc_ab (new_size, sizeof (cairo_edge_t));
if (new_edges != NULL)
memcpy (new_edges, polygon->edges, old_size * sizeof (cairo_edge_t));
} else {
new_edges = _cairo_realloc_ab (polygon->edges,
new_size, sizeof (cairo_edge_t));
}
if (unlikely (new_edges == NULL)) {
polygon->status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
return FALSE;
}
polygon->edges = new_edges;
polygon->edges_size = new_size;
return TRUE;
}
void
_cairo_polygon_add_edge (cairo_polygon_t *polygon,
const cairo_point_t *p1,
const cairo_point_t *p2,
int dir)
{
cairo_edge_t *edge;
/* drop horizontal edges */
if (p1->y == p2->y)
return;
if (polygon->num_edges == polygon->edges_size) {
if (! _cairo_polygon_grow (polygon))
return;
}
edge = &polygon->edges[polygon->num_edges++];
if (p1->y < p2->y) {
edge->edge.p1 = *p1;
edge->edge.p2 = *p2;
edge->dir = dir;
} else {
edge->edge.p1 = *p2;
edge->edge.p2 = *p1;
edge->dir = -dir;
}
}
void
_cairo_polygon_move_to (cairo_polygon_t *polygon,
const cairo_point_t *point)
{
if (! polygon->has_current_point)
polygon->first_point = *point;
polygon->current_point = *point;
polygon->has_current_point = TRUE;
}
void
_cairo_polygon_line_to (cairo_polygon_t *polygon,
const cairo_point_t *point)
{
if (polygon->has_current_point)
_cairo_polygon_add_edge (polygon, &polygon->current_point, point, 1);
_cairo_polygon_move_to (polygon, point);
}
void
_cairo_polygon_close (cairo_polygon_t *polygon)
{
if (polygon->has_current_point) {
_cairo_polygon_add_edge (polygon,
&polygon->current_point,
&polygon->first_point,
1);
polygon->has_current_point = FALSE;
}
}
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