CODEWITHSUNDEEP
c++qtqmlqtquick2qt-quick
Thelastpolaris
Thelastpolaris

Reputation: 351

High-DPI scaling of QQuickItem-derived class

I use QtQuickControls 2 together with QQuickItem-derived class in my app. After I set AA_EnableHighDpiScaling attribute and all QQuickControls 2 components look correctly on my smartphone but object of my custom class is scaled incorrectly. Here is the app without HighDpi scaling with minimum zoom(the way it is meant to work):

Correct display of QQuickItem

And here is the one with scaling with minimum zoom:

Incorrect display of QQuickItem

It seems that on the second screen the object is scaled too much and I can see square pixels of all textures that I draw with QPixmap or QImage. However, the images that I load from external memory and nodes like QSGGeometryNode look correct. Can I switch off scaling for just one particular QQuickItem? If no, what should I set to render it correctly?

Also, when I try to set opacity on QQuickItem with a lot of QSGOpacityNodes in scene graph node tree I get segmentation fault. What can cause this?

Upvotes: 4

Views: 548

Answers (1)

Thelastpolaris
Thelastpolaris

Reputation: 351

So I solved this problem by dividing the size of QSGTexture by QQuickWindow::effectiveDevicePixelRatio() and also multiplying the size of the image from which texture is created by this ratio. If you are drawing the text using on QImage you should also multiply your font's size by this ratio. The same thing should be done with geometrical shapes and QPixmap::scaled().

Upvotes: 2

Related Questions