void QTessellatorPrivate::processIntersections()
{
QDEBUG() << "PROCESS INTERSECTIONS";
// process intersections
while (!intersections.isEmpty()) {
Intersections::iterator it = intersections.begin();
if (it.key().y != y)
break;
// swap edges
QDEBUG() << " swapping intersecting edges ";
int min = scanline.size;
int max = 0;
Q27Dot5 xmin = INT_MAX;
Q27Dot5 xmax = INT_MIN;
int num = 0;
while (1) {
const Intersection &i = it.key();
int next = it->next;
int edgePos = scanline.findEdge(i.edge);
if (edgePos >= 0) {
++num;
min = qMin(edgePos, min);
max = qMax(edgePos, max);
Edge *edge = scanline.edges[edgePos];
xmin = qMin(xmin, edge->positionAt(y));
xmax = qMax(xmax, edge->positionAt(y));
}
Intersection key;
key.y = y;
key.edge = next;
it = intersections.find(key);
intersections.remove(i);
if (it == intersections.end())
break;
}
if (num < 2)
continue;
Q_ASSERT(min != max);
QDEBUG() << "sorting between" << min << "and" << max << "xpos=" << xmin << xmax;
while (min > 0 && scanline.edges[min - 1]->positionAt(y) >= xmin) {
QDEBUG() << " adding edge on left";
--min;
}
while (max + 1 < scanline.size && scanline.edges[max + 1]->positionAt(y) <= xmax) {
QDEBUG() << " adding edge on right";
++max;
}
qSort(scanline.edges + min, scanline.edges + max + 1, EdgeSorter(y));
#ifdef DEBUG
for (int i = min; i <= max; ++i)
QDEBUG() << " " << scanline.edges[i]->edge << "at pos" << i;
#endif
for (int i = min; i <= max; ++i) {
Edge *edge = scanline.edges[i];
edge->intersect_left = true;
edge->intersect_right = true;
edge->mark = true;
}
}
}
