<![CDATA[drawing dense items in graphics scene]]>i have a lot of coordinates like these: (-0.45, -3.1), (-0.14, -1.8) etc. and i need to draw polygons using these.
as you can see the values are so close to each other that when i draw the items now, they overlap, and look very small in the center of the view.
how can i draw so that all drawn items occupy all visible area of the view? should i do something like multiplying the values of coordinates? or what?

thanks.

]]>https://forum.qt.io/topic/89421/drawing-dense-items-in-graphics-sceneRSS for NodeFri, 23 Oct 2026 16:25:12 GMTSat, 31 Mar 2018 18:55:32 GMT60<![CDATA[Reply to drawing dense items in graphics scene on Sun, 01 Apr 2018 06:53:25 GMT]]>@user4592357
Why don't you put your QGraphicsScene to QGraphicsView by
void QGraphicsView::setScene(QGraphicsScene *scene)
and use
void QGraphicsView::scale(qreal sx, qreal sy) ?
You may also use mousewheel to zoom in/out.
See this

]]>https://forum.qt.io/post/450631https://forum.qt.io/post/450631Sun, 01 Apr 2018 06:53:25 GMT<![CDATA[Reply to drawing dense items in graphics scene on Sat, 31 Mar 2018 20:56:22 GMT]]>Hi,

Frome QGraphicsView's documentation:

QGraphicsView can be used to visualize a whole scene, or only parts of it. The visualized area is by default detected
automatically when the view is displayed for the first time (by calling QGraphicsScene::itemsBoundingRect()). To
set the visualized area rectangle yourself, you can call setSceneRect(). This will adjust the scroll bars' ranges 
appropriately. Note that although the scene supports a virtually unlimited size, the range of the scroll bars will 
never exceed the range of an integer (INT_MIN, INT_MAX).
]]>https://forum.qt.io/post/450603https://forum.qt.io/post/450603Sat, 31 Mar 2018 20:56:22 GMT