Not clearing the contents of a RenderWindow after Display

[workmad3]

The code required to check which pixels have changed is more inefficient than brute force pixel pushing with todays hardware, yes. Especially when doing such an 'optimisation' will frequently require you to do things like get the rendered image from the hardware which is hugely inefficient in todays rendering pipelines as copying data to and from the graphics hardware is frequently a bottleneck. If a software renderer is introduced into the SFML library, then I'd expect issues like this to start appearing (or for laurent to implement it in such a way that redrawing things that haven't changed become a no-op if possible

[Laurent]

The Display() function means "display what you have rendered since last call". So if you don't draw anything between two calls of Display(), the second call won't show anything.

I agree with workmad3, there's really no point doing that. If you come back one day in big trouble because of this particular thing, ok, but right now there's no point trying to do such things.

SFML is designed for fast real-time graphics, which means we shouldn't have to care about optimizing static stuff.

[Kernelpanic]

Okay, for the moment I manage the redrawing with a few pointers.
Thank you! Nice Forum!