Yes, it's just rendering into the texture redraws the entire window and you never really need to worry about redrawing only the parts of the screen that changed. But I think GGP was actually talking about redrawing the window every frame even if nothing's changed at all, which is indeed inefficent (though not necessarily "horribly").
GGP is me, and yes that’s what I meant. Under no circumstance would zed actually be drawing 120 frames each second, right? That would be 100x more energy usage than would actually be required, and so I think “horribly” is accurate.
> Under no circumstance would zed actually be drawing 120 frames each second, right?
It does this when scrolling for sure. That's a trivial case where 120 FPS is required on a 120Hz display.
It also does this even when nothing on the screen is changing, but only for about 1 second after the last user input. This is explained in a blog post[0].
Now this does cause more power usage, because when Zed does not do this, the display can actually downclock to save power. But downclocking like that increases latency, which is why they prevent it from happening in the middle of user input (but still allow it to happen betwen each burst of input).
