diff options
| -rw-r--r-- | src/corelib/tools/qline.cpp | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/src/corelib/tools/qline.cpp b/src/corelib/tools/qline.cpp index 9c7c243..7e3dd34 100644 --- a/src/corelib/tools/qline.cpp +++ b/src/corelib/tools/qline.cpp @@ -488,7 +488,8 @@ bool QLineF::isNull() const /*! \fn qreal QLineF::dx() const - Returns the horizontal component of the line's vector. + Returns the horizontal component of the line's vector. + Return value is positive if x2() >= x1() and negative if x2() < x1(). \sa dy(), pointAt() */ @@ -497,6 +498,7 @@ bool QLineF::isNull() const \fn qreal QLineF::dy() const Returns the vertical component of the line's vector. + Return value is positive if y2() >= y1() and negative if y2() < y1(). \sa dx(), pointAt() */ @@ -506,7 +508,8 @@ bool QLineF::isNull() const Sets the length of the line to the given \a length. QLineF will move the end point - p2() - of the line to give the line its new length. - + If the given \a length is negative the angle() is also changed. + If the line is a null line, the length will remain zero regardless of the length specified. @@ -762,7 +765,7 @@ QLineF::IntersectType QLineF::intersect(const QLineF &l, QPointF *intersectionPo \since 4.4 - Returns the angle (in degrees) from this line to the given \a + Returns the angle (in positive degrees) from this line to the given \a line, taking the direction of the lines into account. If the lines do not intersect within their range, it is the intersection point of the extended lines that serves as origin (see |