/*
* Construct a fan around the midpoint using the vertices from pen between
* inpt and outpt.
*/
static void
add_fan (struct stroker *stroker,
const cairo_slope_t *in_vector,
const cairo_slope_t *out_vector,
const cairo_point_t *midpt,
cairo_bool_t clockwise,
struct stroke_contour *c)
{
cairo_pen_t *pen = &stroker->pen;
int start, stop;
if (stroker->has_bounds &&
! _cairo_box_contains_point (&stroker->bounds, midpt))
return;
assert (stroker->pen.num_vertices);
if (clockwise) {
_cairo_pen_find_active_cw_vertices (pen,
in_vector, out_vector,
&start, &stop);
while (start != stop) {
cairo_point_t p = *midpt;
translate_point (&p, &pen->vertices[start].point);
contour_add_point (stroker, c, &p);
if (++start == pen->num_vertices)
start = 0;
}
} else {
_cairo_pen_find_active_ccw_vertices (pen,
in_vector, out_vector,
&start, &stop);
while (start != stop) {
cairo_point_t p = *midpt;
translate_point (&p, &pen->vertices[start].point);
contour_add_point (stroker, c, &p);
if (start-- == 0)
start += pen->num_vertices;
}
}
}
/*
* Construct a fan around the midpoint using the vertices from pen between
* inpt and outpt.
*/
static cairo_status_t
_tessellate_fan (cairo_stroker_t *stroker,
const cairo_slope_t *in_vector,
const cairo_slope_t *out_vector,
const cairo_point_t *midpt,
const cairo_point_t *inpt,
const cairo_point_t *outpt,
cairo_bool_t clockwise)
{
cairo_point_t stack_points[64], *points = stack_points;
cairo_pen_t *pen = &stroker->pen;
int start, stop, num_points = 0;
cairo_status_t status;
if (stroker->has_bounds &&
! _cairo_box_contains_point (&stroker->bounds, midpt))
goto BEVEL;
assert (stroker->pen.num_vertices);
if (clockwise) {
_cairo_pen_find_active_ccw_vertices (pen,
in_vector, out_vector,
&start, &stop);
if (stroker->add_external_edge) {
cairo_point_t last;
last = *inpt;
while (start != stop) {
cairo_point_t p = *midpt;
_translate_point (&p, &pen->vertices[start].point);
status = stroker->add_external_edge (stroker->closure,
&last, &p);
if (unlikely (status))
return status;
last = p;
if (start-- == 0)
start += pen->num_vertices;
}
status = stroker->add_external_edge (stroker->closure,
&last, outpt);
} else {
if (start == stop)
goto BEVEL;
num_points = stop - start;
if (num_points < 0)
num_points += pen->num_vertices;
num_points += 2;
if (num_points > ARRAY_LENGTH(stack_points)) {
points = _cairo_malloc_ab (num_points, sizeof (cairo_point_t));
if (unlikely (points == NULL))
return _cairo_error (CAIRO_STATUS_NO_MEMORY);
}
points[0] = *inpt;
num_points = 1;
while (start != stop) {
points[num_points] = *midpt;
_translate_point (&points[num_points], &pen->vertices[start].point);
num_points++;
if (start-- == 0)
start += pen->num_vertices;
}
points[num_points++] = *outpt;
}
} else {
_cairo_pen_find_active_cw_vertices (pen,
in_vector, out_vector,
&start, &stop);
if (stroker->add_external_edge) {
cairo_point_t last;
last = *inpt;
while (start != stop) {
cairo_point_t p = *midpt;
_translate_point (&p, &pen->vertices[start].point);
status = stroker->add_external_edge (stroker->closure,
&p, &last);
if (unlikely (status))
return status;
last = p;
if (++start == pen->num_vertices)
start = 0;
}
status = stroker->add_external_edge (stroker->closure,
outpt, &last);
} else {
if (start == stop)
goto BEVEL;
num_points = stop - start;
if (num_points < 0)
num_points += pen->num_vertices;
num_points += 2;
if (num_points > ARRAY_LENGTH(stack_points)) {
points = _cairo_malloc_ab (num_points, sizeof (cairo_point_t));
if (unlikely (points == NULL))
return _cairo_error (CAIRO_STATUS_NO_MEMORY);
}
points[0] = *inpt;
num_points = 1;
while (start != stop) {
points[num_points] = *midpt;
_translate_point (&points[num_points], &pen->vertices[start].point);
num_points++;
if (++start == pen->num_vertices)
start = 0;
}
points[num_points++] = *outpt;
}
}
if (num_points) {
status = stroker->add_triangle_fan (stroker->closure,
midpt, points, num_points);
}
if (points != stack_points)
free (points);
return status;
BEVEL:
/* Ensure a leak free connection... */
if (stroker->add_external_edge != NULL) {
if (clockwise)
return stroker->add_external_edge (stroker->closure, inpt, outpt);
else
return stroker->add_external_edge (stroker->closure, outpt, inpt);
} else {
stack_points[0] = *midpt;
stack_points[1] = *inpt;
stack_points[2] = *outpt;
return stroker->add_triangle (stroker->closure, stack_points);
}
}
