Clipping region

[Tilen]

Hello,

 

does uGFX use clipping regions for redrawing screen? Or does it always redraw all children widgets if one has changed position or similar?

Thanks for answer.

[inmarket]

It uses a single rectangular clipping region. It does not use complex regions due to the (unbounded) memory requirements to support such functionality. 

What this means for redrawing is that in limited circumstances window redrawing is clipped. Outside those circumstances a bottom up redraw strategy is required. An example of when clipping optimization can be used is when a window is made invisible all underlying windows need to be redrawn bottom up but the redraws will be clipped to the area covered by window just made invisible.