#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);
}
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 (new_edges == NULL) {
polygon->status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
return FALSE;
}
polygon->edges = new_edges;
polygon->edges_size = new_size;
return TRUE;
}
static void
_cairo_polygon_add_edge (cairo_polygon_t *polygon,
const cairo_point_t *p1,
const cairo_point_t *p2)
{
cairo_edge_t *edge;
if (p1->y == p2->y)
goto DONE;
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->clockWise = 1;
} else {
edge->edge.p1 = *p2;
edge->edge.p2 = *p1;
edge->clockWise = 0;
}
DONE:
_cairo_polygon_move_to (polygon, p2);
}
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);
else
_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);
polygon->has_current_point = FALSE;
}
}