migrations/egui
1
0
Fork 0
mirror of https://github.com/emilk/egui.git synced 2026-06-26 22:53:14 -04:00
Code Activity

Implement efficent scrolling of large content (#457)

Browse Source
This commit is contained in:
Emil Ernerfeldt
2021-06-03 18:48:45 +02:00
committed by GitHub
parent 2cdd90b111
commit 6468b2b84e
6 changed files with 209 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
README.md
View File

@@ -263,9 +263,9 @@ For "atomic" widgets (e.g. a button) `egui` knows the size before showing it, so
#### CPU usage
Since an immediate mode GUI does a full layout each frame, the layout code needs to be quick. If you have a very complex GUI this can tax the CPU. In particular, having a very large UI in a scroll area (with very long scrollback) can be slow, as the content needs to be layed out each frame.
If you design the GUI with this in mind and refrain from huge scroll areas then the performance hit is generally pretty small. For most cases you can expect `egui` to take up 1-2 ms per frame, but `egui` still has a lot of room for optimization (it's not something I've focused on yet). You can also set up `egui` to only repaint when there is interaction (e.g. mouse movement).
If you design the GUI with this in mind and refrain from huge scroll areas (or only lay out the part that is in view) then the performance hit is generally pretty small. For most cases you can expect `egui` to take up 1-2 ms per frame, but `egui` still has a lot of room for optimization (it's not something I've focused on yet). You can also set up `egui` to only repaint when there is interaction (e.g. mouse movement).
If your GUI is highly interactive, then immediate mode may actually be more performant compared to retained mode. Go to any web page and resize the browser window, and you'll notice that the browser is very slow to do the layout and eats a lot of CPU doing it. Resize a window in `egui` by contrast, and you'll get smooth 60 FPS for no extra CPU cost.
If your GUI is highly interactive, then immediate mode may actually be more performant compared to retained mode. Go to any web page and resize the browser window, and you'll notice that the browser is very slow to do the layout and eats a lot of CPU doing it. Resize a window in `egui` by contrast, and you'll get smooth 60 FPS at no extra CPU cost.
#### IDs