static inline void
edges_start_or_continue (cairo_bo_edge_t *left,
cairo_bo_edge_t *right,
int top,
cairo_polygon_t *polygon)
{
assert (right->deferred.other == NULL);
if (left->deferred.other == right)
return;
if (left->deferred.other != NULL) {
if (right != NULL && edges_colinear (left->deferred.other, right)) {
cairo_bo_edge_t *old = left->deferred.other;
/* continuation on right, extend right to cover both */
assert (old->deferred.other == NULL);
assert (old->edge.line.p2.y > old->edge.line.p1.y);
if (old->edge.line.p1.y < right->edge.line.p1.y)
right->edge.line.p1 = old->edge.line.p1;
if (old->edge.line.p2.y > right->edge.line.p2.y)
right->edge.line.p2 = old->edge.line.p2;
left->deferred.other = right;
return;
}
edges_end (left, top, polygon);
}
if (right != NULL && ! edges_colinear (left, right)) {
left->deferred.top = top;
left->deferred.other = right;
}
}
static inline void
_cairo_bo_edge_start_or_continue (cairo_bo_edge_t *left,
cairo_bo_edge_t *right,
int top,
cairo_polygon_t *polygon)
{
if (left->deferred.right == right)
return;
if (left->deferred.right != NULL) {
if (right != NULL && edges_colinear (left->deferred.right, right))
{
/* continuation on right, so just swap edges */
left->deferred.right = right;
return;
}
_cairo_bo_edge_end (left, top, polygon);
}
if (right != NULL && ! edges_colinear (left, right)) {
left->deferred.top = top;
left->deferred.right = right;
}
}
static inline void
_active_edges_to_polygon (cairo_bo_edge_t *left,
int32_t top,
cairo_fill_rule_t fill_rule,
cairo_polygon_t *polygon)
{
cairo_bo_edge_t *right;
unsigned int mask;
if (fill_rule == CAIRO_FILL_RULE_WINDING)
mask = ~0;
else
mask = 1;
while (left != NULL) {
int in_out = left->edge.dir;
right = left->next;
if (left->deferred.right == NULL) {
while (right != NULL && right->deferred.right == NULL)
right = right->next;
if (right != NULL && edges_colinear (left, right)) {
/* continuation on left */
left->deferred = right->deferred;
right->deferred.right = NULL;
}
}
right = left->next;
while (right != NULL) {
if (right->deferred.right != NULL)
_cairo_bo_edge_end (right, top, polygon);
in_out += right->edge.dir;
if ((in_out & mask) == 0) {
/* skip co-linear edges */
if (right->next == NULL || !edges_colinear (right, right->next))
break;
}
right = right->next;
}
_cairo_bo_edge_start_or_continue (left, right, top, polygon);
left = right;
if (left != NULL)
left = left->next;
}
}
static inline void
active_edges (cairo_bo_edge_t *left,
int32_t top,
cairo_polygon_t *polygon)
{
cairo_bo_edge_t *right;
int winding[2] = {0, 0};
/* Yes, this is naive. Consider this a placeholder. */
while (left != NULL) {
assert (is_zero (winding));
do {
winding[left->a_or_b] += left->edge.dir;
if (! is_zero (winding))
break;
if unlikely ((left->deferred.other))
edges_end (left, top, polygon);
left = left->next;
if (! left)
return;
} while (1);
right = left->next;
do {
if unlikely ((right->deferred.other))
edges_end (right, top, polygon);
winding[right->a_or_b] += right->edge.dir;
if (is_zero (winding)) {
if (right->next == NULL ||
! edges_colinear (right, right->next))
break;
}
right = right->next;
} while (1);
edges_start_or_continue (left, right, top, polygon);
left = right->next;
}
}