// Return the X projections of the edges that overlap y1,y2.
void ExclusionPolygon::computeEdgeIntersections(float y1, float y2, Vector<ExclusionInterval>& result) const
{
Vector<ExclusionPolygon::EdgeInterval> overlappingEdges;
m_edgeTree.allOverlaps(ExclusionPolygon::EdgeInterval(y1, y2, 0), overlappingEdges);
EdgeIntersection intersection;
for (unsigned i = 0; i < overlappingEdges.size(); i++) {
const ExclusionPolygonEdge *edge = static_cast<ExclusionPolygonEdge*>(overlappingEdges[i].data());
float x1;
float x2;
if (edge->minY() < y1) {
computeXIntersection(edge, y1, intersection);
x1 = intersection.point.x();
} else
x1 = (edge->vertex1().y() < edge->vertex2().y()) ? edge->vertex1().x() : edge->vertex2().x();
if (edge->maxY() > y2) {
computeXIntersection(edge, y2, intersection);
x2 = intersection.point.x();
} else
x2 = (edge->vertex1().y() > edge->vertex2().y()) ? edge->vertex1().x() : edge->vertex2().x();
if (x1 > x2)
std::swap(x1, x2);
if (x2 > x1)
result.append(ExclusionInterval(x1, x2));
}
sortExclusionIntervals(result);
}
static void computeOverlappingEdgeXProjections(const FloatPolygon& polygon, float y1, float y2, Vector<ExclusionInterval>& result)
{
Vector<const FloatPolygonEdge*> edges;
if (!polygon.overlappingEdges(y1, y2, edges))
return;
EdgeIntersection intersection;
for (unsigned i = 0; i < edges.size(); ++i) {
const FloatPolygonEdge *edge = edges[i];
float x1;
float x2;
if (edge->minY() < y1) {
computeXIntersection(edge, y1, intersection);
x1 = intersection.point.x();
} else
x1 = (edge->vertex1().y() < edge->vertex2().y()) ? edge->vertex1().x() : edge->vertex2().x();
if (edge->maxY() > y2) {
computeXIntersection(edge, y2, intersection);
x2 = intersection.point.x();
} else
x2 = (edge->vertex1().y() > edge->vertex2().y()) ? edge->vertex1().x() : edge->vertex2().x();
if (x1 > x2)
std::swap(x1, x2);
if (x2 > x1)
result.append(ExclusionInterval(x1, x2));
}
sortExclusionIntervals(result);
}
