diff options
Diffstat (limited to 'examples/widgets/graphicsview/diagramscene/arrow.cpp')
| -rw-r--r-- | examples/widgets/graphicsview/diagramscene/arrow.cpp | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/examples/widgets/graphicsview/diagramscene/arrow.cpp b/examples/widgets/graphicsview/diagramscene/arrow.cpp index 012b9ea2ed..ae7fa7af90 100644 --- a/examples/widgets/graphicsview/diagramscene/arrow.cpp +++ b/examples/widgets/graphicsview/diagramscene/arrow.cpp @@ -51,7 +51,7 @@ #include "arrow.h" -#include <math.h> +#include <cmath> #include <QPen> #include <QPainter> @@ -132,9 +132,7 @@ void Arrow::paint(QPainter *painter, const QStyleOptionGraphicsItem *, setLine(QLineF(intersectPoint, myStartItem->pos())); //! [5] //! [6] - double angle = ::acos(line().dx() / line().length()); - if (line().dy() >= 0) - angle = (Pi * 2) - angle; + double angle = std::atan2(-line().dy(), line().dx()); QPointF arrowP1 = line().p1() + QPointF(sin(angle + Pi / 3) * arrowSize, cos(angle + Pi / 3) * arrowSize); |