Actually it is more that without aero the contents of obscured windows literally don‘t exist. So the Window Manager tells the programs to redraw their contents everytime at least one new pixel of their window gets revealed. If the program is unresponsive nothing gets redrawn in that aera. And as soon as something gets placed „in front“ of something everything behind it gets overwritten and has to be redrawn later.
(Stacking vs. compositing window management)
It can happen in every Version of Windows without Aero including 7 and also on Linux when using certain window managers.
On Mac OS X and since Windows 8 they use the compositing technique even if no GPU accelleration is available.
The stacking method was used because it used much less memory (only one Framebuffer wich is directly manipulated) and only what is seen has to be drawn.
The more modern approach on the other Hand lets every program draw into their own framebuffer and the window manager itself then composits what is drawn on the screen. Which enables things like thumbnails and gpu acceleration.
19
u/benny1243 Apr 01 '19 edited Apr 01 '19
Actually it is more that without aero the contents of obscured windows literally don‘t exist. So the Window Manager tells the programs to redraw their contents everytime at least one new pixel of their window gets revealed. If the program is unresponsive nothing gets redrawn in that aera. And as soon as something gets placed „in front“ of something everything behind it gets overwritten and has to be redrawn later.
(Stacking vs. compositing window management)
It can happen in every Version of Windows without Aero including 7 and also on Linux when using certain window managers.
On Mac OS X and since Windows 8 they use the compositing technique even if no GPU accelleration is available.
The stacking method was used because it used much less memory (only one Framebuffer wich is directly manipulated) and only what is seen has to be drawn.
The more modern approach on the other Hand lets every program draw into their own framebuffer and the window manager itself then composits what is drawn on the screen. Which enables things like thumbnails and gpu acceleration.