RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-07-27 15:57:35 +00:00
Code Issues Activity Actions

LibGUI+WindowServer: Improve window resizing performance

Browse source 
The old `GUI::Window` resizing behavior created a new backing store for
each resize event (i.e. every visible window size). This caused a lot of
trashing and on my machine, caused up to 25% of CPU time spent in
creating new backing stores.

The new behavior is a bit more sensible:

  * If the window size is shrinking, the backing store is already large
    enough to contain the entire window - so we don't create a new one.

  * If the window size is growing, as soon as the backing store can no
    longer contain the window, it is inflated with a large margin (of an
    arbitrary chosen 64 pixels) in both directions to accommodate some
    leeway in resizing before an even larger backing store is required.

  * When the user stops resizing the window, the backing store is
    resized to the exact dimensions of the window.

For me, this brings the CPU time for creating backing stores down to 0%.
This commit is contained in:
Jelle Raaijmakers 2023-01-11 21:46:14 +01:00 • committed by Andreas Kling
parent 45e85d20b6
commit 634d1e0197
8 changed files with 73 additions and 39 deletions
Download patch file Download diff file Expand all files Collapse all files

13
Userland/Services/WindowServer/Compositor.cpp
View file

@ -386,6 +386,10 @@ void Compositor::compose()
});
}
auto update_window_rect = window_rect.intersected(rect);
if (update_window_rect.is_empty())
return;
auto clear_window_rect = [&](const Gfx::IntRect& clear_rect) {
auto fill_color = wm.palette().window();
if (!window.is_opaque())
@ -394,7 +398,7 @@ void Compositor::compose()
};
if (!backing_store) {
clear_window_rect(window_rect.intersected(rect));
clear_window_rect(update_window_rect);
return;
}
@ -407,7 +411,7 @@ void Compositor::compose()
// it was previously, and fill the rest of the window with its
// background color.
Gfx::IntRect backing_rect;
backing_rect.set_size(backing_store->size());
backing_rect.set_size(window.backing_store_visible_size());
switch (WindowManager::the().resize_direction_of_window(window)) {
case ResizeDirection::None:
case ResizeDirection::Right:
@ -434,8 +438,7 @@ void Compositor::compose()
break;
}
Gfx::IntRect dirty_rect_in_backing_coordinates = rect.intersected(window_rect)
.intersected(backing_rect)
Gfx::IntRect dirty_rect_in_backing_coordinates = update_window_rect.intersected(backing_rect)
.translated(-backing_rect.location());
if (!dirty_rect_in_backing_coordinates.is_empty()) {
@ -459,7 +462,7 @@ void Compositor::compose()
}
}
for (auto background_rect : window_rect.shatter(backing_rect))
for (auto background_rect : update_window_rect.shatter(backing_rect))
clear_window_rect(background_rect);
};