Enhancement #8: Avoid repainting the whole screen - Unagi Compositing Manager - mini-dweeb.org projects

Enhancement #8

Avoid repainting the whole screen

Added by Arnaud Fontaine over 8 years ago. Updated about 7 years ago.

Status:

Closed

Priority:

High

Assignee:

Arnaud Fontaine

Category:

Core

Target version:

0.2

Start date:

02/11/2010

Due date:

% Done:

100%

Description

At the moment, the whole screen is repainted each time a window is modified, which is a huge performance bottleneck. It would be better to repaint only the damaged area.

Associated revisions

Revision e1cacdd6 (diff)
Added by Arnaud Fontaine about 7 years ago

Repaint only the damaged area, not the whole screen (closes #8).

This obviously improves dramatically the performances. For example, results
for displaying a single window before:

Painting time in ms (#1): 785, min=785, max=785, average=785 (/- 0.0)
Painting time in ms (#2): 1938, min=785, max=1938, average=1361 (/- 576.7)
Painting time in ms (#3): 1734, min=785, max=1938, average=1485 (/- 502.7)
Painting time in ms (#4): 900, min=785, max=1938, average=1339 (/- 503.6)

And now:

Painting time in ms (#1): 103, min=103, max=103, average=103 (/- 0.0)
Painting time in ms (#2): 127, min=103, max=127, average=115 (/- 12.0)
Painting time in ms (#3): 654, min=103, max=654, average=294 (/- 254.5)
Painting time in ms (#4): 421, min=103, max=654, average=326 (/- 227.2)
Painting time in ms (#5): 76, min=76, max=654, average=276 (+/- 226.3)

There may be still a few remaining glitches to fix though due to the fact that
we clip the region to be painted according to the damaged area, thus some code
may have been working wrongly in the past.