Mir

Hardware cursor is always slightly ahead of the composited image

Bug #1274408 reported by Daniel van Vugt on 2014-01-30
10
This bug affects 2 people
Affects Status Importance Assigned to Milestone
Mir
Fix Released
Low
Daniel van Vugt
mir (Ubuntu)
Undecided
Unassigned

Bug Description

The hardware cursor is always slightly ahead of the composited image. This is a common problem you'll see on the Ubuntu desktop too.

However in Mir we have the possibility of fixing it all in a single project... The issue is that we update the hardware cursor position immediately in the same thread as the Android input logic that controls it. But it takes several context switches and a buffer flip or two before a corresponding change in the client surface can appear on screen.

Even worse, there still seems to be some (less) visible lag between the hardware cursor position and the shell (which is in the same process). I can see some lag when dragging windows around with Alt+left-button.

Related branches

Daniel van Vugt (vanvugt) wrote :

Linked two related branches. This bug would be close enough to resolved if they both landed but we can do more later to further reduce lag end-to-end.

description: updated
tags: added: performance
PS Jenkins bot (ps-jenkins) wrote :

Fix committed into lp:mir at revision None, scheduled for release in mir, milestone 0.11.0

Changed in mir:
status: Triaged → Fix Committed
Daniel van Vugt (vanvugt) wrote :

Actually, close enough. It's only the compositor/system shell that has a chance of keeping up with the hardware cursor and the attached mesa-double branch resolves that sufficiently.

Changed in mir:
status: Fix Committed → Triaged
status: Triaged → Fix Committed
milestone: none → 0.11.0
assignee: nobody → Daniel van Vugt (vanvugt)
Launchpad Janitor (janitor) wrote :
Download full text (3.2 KiB)

This bug was fixed in the package mir - 0.11.0+15.04.20150209.1-0ubuntu1

---------------
mir (0.11.0+15.04.20150209.1-0ubuntu1) vivid; urgency=medium

  [ Daniel van Vugt ]
  * New upstream release 0.11.0 (https://launchpad.net/mir/+milestone/0.11.0)
    - Enhancements:
      . Lots more major plumbing in the Android code, on the path to
        supporting external displays.
      . Add support for clang 3.6.
      . Major redesign of server classes in mir::shell,scene and friends
        (still in progress).
      . Added client API for creating dialogs and tooltips.
      . Added new surface states: mir_surface_state_hidden and
        mir_surface_state_horizmaximized.
      . Performance: Use optimally efficient fragment shading when possible.
      . Performance: (Desktop) Composite using double buffering instead of
        triple to reduce visible lag.
      . mir_proving_server: Can now resize windows from any edge or corner
        using the existing Alt+middlebuttondrag.
      . mir_proving_server: Added some demo custom shaders (negative and
        high contrast modes: Super+N/C).
      . mir_proving_server: Can now close clients politely via Alt+F4.
      . Added MirPointerInputEvent (part of the new input API, the old
        MirMotionEvent is still supported also for now).
    - ABI summary: Servers need rebuilding, but clients do not;
      . Mirclient ABI unchanged at 8
      . Mircommon ABI unchanged at 3
      . Mirplatform ABI bumped to 6
      . Mirserver ABI bumped to 29
    - Bug fixes:
      . [regression] mir_demo_server exits immediately with boost
        bad_any_cast exception (LP: #1414630)
      . need way to position menus and tooltips (relative positioning to
        parent) (LP: #1324101)
      . GLibMainLoopTest failure seen in CI (LP: #1413748)
      . Clang builds fail in CI (LP: #1416317)
      . segfault in mir::compositor::GLProgramFamily::Shader::init()
        (LP: #1416482)
      . GLRenderer: The default fragment shader is sub-optimal for alpha=1.0
        (LP: #1350674)
      . mesa::DisplayBuffer::post_update is triple buffered - more laggy than
        it needs to be (LP: #1350725)
      . Cannot connect to nested server when started from a differen vt
        (LP: #1379266)
      . [testfail] AsioMainLoopAlarmTest fails in CI (LP: #1392256)
      . Compositor report inconsistently reports frame time during bypass,
        and render time otherwise (LP: #1408906)
      . [regression] mir_demo_client_fingerpaint doesn't paint anything any
        more (with the mouse) (LP: #1413139)
      . Hardware cursor is always slightly ahead of the composited image
        (LP: #1274408)
      . integration tests are outputting (too many) DisplayServer log
        messages (LP: #1408231)
      . [regression] deploy-and-test.sh doesn't work any more (unless you
        have umockdev installed already) (LP: #1413479)
      . Color Inverse on display. Toggle Negative Image (LP: #1400580)
      . mir-ubuntu-vivid-armhf-ci fails consistently (LP: #1407863)
      . Double-buffered surfaces may lag or freeze if event driven and not
        constantly redrawing (LP: #1395581)
      . Pointer motion and crossing events...

Read more...

Changed in mir (Ubuntu):
status: New → Fix Released
Changed in mir:
status: Fix Committed → Fix Released
PS Jenkins bot (ps-jenkins) wrote :

Fix committed into lp:mir at revision 2673, scheduled for release in mir, milestone 0.14.0

Changed in mir:
status: Fix Released → Fix Committed
Changed in mir:
status: Fix Committed → Fix Released
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