Fix a bug in the initialization (and debug-output) of BSP trees

On a horizontal split the current rectangle is split along the y-axis,
creating two children with the dimensions [x, y, width, height / 2]
and [x, y + height / 2, width, height / 2] respectively. When the
BSP tree is initialized, the type of the root node is set to
"Horizontal". However, the offset of the root node is wrongly
initialized with a split along the x-axis instead of the y-axis.
This leads to wrong behavior on QGraphicsScenes with a non square
aspect ratio. E.g on a QGraphicsScene with an apsect ratio favoring
the y-axis, every item between yItem = sceneWidth/2 and
yItem = sceneHeight/2 will be added to the wrong leaf.

[ChangeLog][QWidgets][QGraphicsScene] Fixed a bug in the initialization
of BSP trees to increase the performance of QGraphicsScenes with non
quadratic scene rectangles.

Fixes: QTBUG-87174
Pick-to: 5.15
Change-Id: I360033e94e22eb961f820278993754d10bfc1e45
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

0 files changed, 0 insertions, 0 deletions