static void
_cairo_polygon_add_edge (cairo_polygon_t *polygon,
const cairo_point_t *p1,
const cairo_point_t *p2,
int dir)
{
/* drop horizontal edges */
if (p1->y == p2->y)
return;
if (p1->y > p2->y) {
const cairo_point_t *t;
t = p1, p1 = p2, p2 = t;
dir = -dir;
}
if (polygon->num_limits) {
if (p2->y <= polygon->limit.p1.y)
return;
if (p1->y >= polygon->limit.p2.y)
return;
_add_clipped_edge (polygon, p1, p2, p1->y, p2->y, dir);
} else
_add_edge (polygon, p1, p2, p1->y, p2->y, dir);
}
cairo_status_t
_cairo_polygon_add_line (cairo_polygon_t *polygon,
const cairo_line_t *line,
int top, int bottom,
int dir)
{
/* drop horizontal edges */
if (line->p1.y == line->p2.y)
return CAIRO_STATUS_SUCCESS;
if (bottom <= top)
return CAIRO_STATUS_SUCCESS;
if (polygon->num_limits) {
if (line->p2.y <= polygon->limit.p1.y)
return CAIRO_STATUS_SUCCESS;
if (line->p1.y >= polygon->limit.p2.y)
return CAIRO_STATUS_SUCCESS;
_add_clipped_edge (polygon, &line->p1, &line->p2, top, bottom, dir);
} else
_add_edge (polygon, &line->p1, &line->p2, top, bottom, dir);
return polygon->status;
}
static void
_add_edge (struct reduce *r,
const cairo_point_t *p1,
const cairo_point_t *p2)
{
int top, bottom;
int top_y, bot_y;
int n;
if (p1->y < p2->y) {
top = p1->y;
bottom = p2->y;
} else {
top = p2->y;
bottom = p1->y;
}
if (bottom < r->limit.p1.y || top > r->limit.p2.y)
return;
if (p1->x > p2->x) {
const cairo_point_t *t = p1;
p1 = p2;
p2 = t;
}
if (p2->x <= r->limit.p1.x || p1->x >= r->limit.p2.x)
return;
for (n = 0; n < r->clip->num_boxes; n++) {
const cairo_box_t *limits = &r->clip->boxes[n];
if (bottom < limits->p1.y || top > limits->p2.y)
continue;
if (p2->x <= limits->p1.x || p1->x >= limits->p2.x)
continue;
if (p1->x >= limits->p1.x && p2->x <= limits->p1.x) {
top_y = top;
bot_y = bottom;
} else {
int p1_y, p2_y;
p1_y = _cairo_edge_compute_intersection_y_for_x (p1, p2,
limits->p1.x);
p2_y = _cairo_edge_compute_intersection_y_for_x (p1, p2,
limits->p2.x);
if (p1_y < p2_y) {
top_y = p1_y;
bot_y = p2_y;
} else {
top_y = p2_y;
bot_y = p1_y;
}
if (top_y < top)
top_y = top;
if (bot_y > bottom)
bot_y = bottom;
}
if (top_y < limits->p1.y)
top_y = limits->p1.y;
if (bot_y > limits->p2.y)
bot_y = limits->p2.y;
if (bot_y > top_y)
_add_clipped_edge (r, p1, p2, top_y, bot_y);
}
}