QLineF::IntersectType QLineF::intersect(const QLineF &l, QPointF *intersectionPoint) const
{
// ipmlementation is based on Graphics Gems III's "Faster Line Segment Intersection"
const QPointF a = pt2 - pt1;
const QPointF b = l.pt1 - l.pt2;
const QPointF c = pt1 - l.pt1;
const qreal denominator = a.y() * b.x() - a.x() * b.y();
if (denominator == 0 || !qt_is_finite(denominator))
return NoIntersection;
const qreal reciprocal = 1 / denominator;
const qreal na = (b.y() * c.x() - b.x() * c.y()) * reciprocal;
if (intersectionPoint)
*intersectionPoint = pt1 + a * na;
if (na < 0 || na > 1)
return UnboundedIntersection;
const qreal nb = (a.x() * c.y() - a.y() * c.x()) * reciprocal;
if (nb < 0 || nb > 1)
return UnboundedIntersection;
return BoundedIntersection;
}
/*!
Returns true if the float \a {f} is a finite number.
*/
Q_CORE_EXPORT bool qIsFinite(float f) { return qt_is_finite(f); }
/*!
Returns true if the double \a {d} is a finite number.
*/
Q_CORE_EXPORT bool qIsFinite(double d) { return qt_is_finite(d); }
