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/*
* Copyright © 2002 University of Southern California
*
* Permission to use, copy, modify, distribute, and sell this software
* and its documentation for any purpose is hereby granted without
* fee, provided that the above copyright notice appear in all copies
* and that both that copyright notice and this permission notice
* appear in supporting documentation, and that the name of the
* University of Southern California not be used in advertising or
* publicity pertaining to distribution of the software without
* specific, written prior permission. The University of Southern
* California makes no representations about the suitability of this
* software for any purpose. It is provided "as is" without express
* or implied warranty.
*
* THE UNIVERSITY OF SOUTHERN CALIFORNIA DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL THE UNIVERSITY OF
* SOUTHERN CALIFORNIA BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
* OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Author: Carl D. Worth <cworth@isi.edu>
*/
#include <stdlib.h>
#include "cairoint.h"
#define CAIRO_POLYGON_GROWTH_INC 10
/* private functions */
static cairo_status_t
_cairo_polygon_grow_by (cairo_polygon_t *polygon, int additional);
static void
_cairo_polygon_set_last_point (cairo_polygon_t *polygon, cairo_point_t *point);
void
_cairo_polygon_init (cairo_polygon_t *polygon)
{
polygon->num_edges = 0;
polygon->edges_size = 0;
polygon->edges = NULL;
polygon->first_point_defined = 0;
polygon->last_point_defined = 0;
polygon->closed = 0;
}
void
_cairo_polygon_fini (cairo_polygon_t *polygon)
{
if (polygon->edges_size) {
free (polygon->edges);
polygon->edges = NULL;
polygon->edges_size = 0;
polygon->num_edges = 0;
}
polygon->first_point_defined = 0;
polygon->last_point_defined = 0;
polygon->closed = 0;
}
static cairo_status_t
_cairo_polygon_grow_by (cairo_polygon_t *polygon, int additional)
{
cairo_edge_t *new_edges;
int old_size = polygon->edges_size;
int new_size = polygon->num_edges + additional;
if (new_size <= polygon->edges_size) {
return CAIRO_STATUS_SUCCESS;
}
polygon->edges_size = new_size;
new_edges = realloc (polygon->edges, polygon->edges_size * sizeof (cairo_edge_t));
if (new_edges == NULL) {
polygon->edges_size = old_size;
return CAIRO_STATUS_NO_MEMORY;
}
polygon->edges = new_edges;
return CAIRO_STATUS_SUCCESS;
}
static void
_cairo_polygon_set_last_point (cairo_polygon_t *polygon, cairo_point_t *point)
{
polygon->last_point = *point;
polygon->last_point_defined = 1;
}
cairo_status_t
_cairo_polygon_add_edge (cairo_polygon_t *polygon, cairo_point_t *p1, cairo_point_t *p2)
{
cairo_status_t status;
cairo_edge_t *edge;
if (! polygon->first_point_defined) {
polygon->first_point = *p1;
polygon->first_point_defined = 1;
polygon->closed = 0;
}
/* drop horizontal edges */
if (p1->y == p2->y) {
goto DONE;
}
if (polygon->num_edges >= polygon->edges_size) {
status = _cairo_polygon_grow_by (polygon, CAIRO_POLYGON_GROWTH_INC);
if (status) {
return status;
}
}
edge = &polygon->edges[polygon->num_edges];
if (p1->y < p2->y) {
edge->edge.p1 = *p1;
edge->edge.p2 = *p2;
edge->clockWise = 1;
} else {
edge->edge.p1 = *p2;
edge->edge.p2 = *p1;
edge->clockWise = 0;
}
polygon->num_edges++;
DONE:
_cairo_polygon_set_last_point (polygon, p2);
return CAIRO_STATUS_SUCCESS;
}
cairo_status_t
_cairo_polygon_add_point (cairo_polygon_t *polygon, cairo_point_t *point)
{
cairo_status_t status = CAIRO_STATUS_SUCCESS;
if (polygon->last_point_defined) {
status = _cairo_polygon_add_edge (polygon, &polygon->last_point, point);
} else {
_cairo_polygon_set_last_point (polygon, point);
}
return status;
}
cairo_status_t
_cairo_polygon_close (cairo_polygon_t *polygon)
{
cairo_status_t status;
if (polygon->closed == 0 && polygon->last_point_defined) {
status = _cairo_polygon_add_edge (polygon, &polygon->last_point, &polygon->first_point);
if (status)
return status;
polygon->closed = 1;
polygon->first_point_defined = 0;
}
return CAIRO_STATUS_SUCCESS;
}
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