Bug 72351

Summary: x11-backend with pixman renderer does not repaint on Expose
Product: Wayland Reporter: Pekka Paalanen <ppaalanen>
Component: westonAssignee: Wayland bug list <wayland-bugs>
Status: VERIFIED FIXED QA Contact:
Severity: minor    
Priority: medium    
Version: unspecified   
Hardware: Other   
OS: All   
Whiteboard:
i915 platform: i915 features:

Description Pekka Paalanen 2013-12-05 13:07:11 UTC 
I'm running X without a compositing manager. When I run Weston's x11-backend with the pixman renderer, the weston window does not repaint on Expose events. For example, visit a different virtual desktop and return, and Weston's window contains garbage. Forcing Weston to repaint by other means, like moving a window inside weston, fixes the damage.

This is Daniel's analysis:
- the x11/pixman thing only happens if you aren't also using an x11 compositing manager
- and it's not handling the Expose events, needs to force a redraw when that happens; atm it does queue an output repaint, but with an empty region, so nothing actually gets re-rendered
Comment 1 Kristian Høgsberg 2013-12-05 20:31:11 UTC 
commit a98c2e17fd35e70bf50cdfac5a884aa639b99a92
Author: Kristian Høgsberg <krh@bitplanet.net>
Date:   Thu Dec 5 12:30:37 2013 -0800

    compositor-x11: Damage output when we receive expose events for the window
    
    The gl renderer typically repaints everything since we don't have
    EGL_buffer_age under X, but the pixman renderer carefully only repaints
    damaged regions.  So to actually repaint anything with the pixman
    renderer, we need to damage the output.
    
    https://bugs.freedesktop.org/show_bug.cgi?id=72351
Comment 2 Pekka Paalanen 2013-12-09 11:07:20 UTC 
The fix works nicely, thanks!

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