New issue
Advanced search Search tips

Issue 748733 link

Starred by 1 user

Issue metadata

Status: Archived
Owner:
Closed: Aug 2017
EstimatedDays: ----
NextAction: ----
OS: Chrome
Pri: 2
Type: Bug



Sign in to add a comment

Improve pointer prediction for short trajectories

Project Member Reported by kaznacheev@chromium.org, Jul 25 2017

Issue description

Currently FastInkPoints::Predict method always uses 4 points
to compute velocity/acceleration/jerk. If fewer points are
avaialble, the oldest point is cloned. This results in suboptimal
prediction.

For example, if there are just 2 points: (0,0),(1,1), the 
prediction will be based on the 4 points (0,0),(0,0),(0,0),(1,1) 
and the straightforward computation will produce non-zero acceleration
and jerk (which is clearly not a good prediction).

Expected:
If there are just 2 points, predicted acceleration is zero.
If there are just 3 points, predicted jerk is zero.

 
Project Member

Comment 1 by bugdroid1@chromium.org, Jul 27 2017

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/28cc3784cd55890ef97c757a90c1d91e07734576

commit 28cc3784cd55890ef97c757a90c1d91e07734576
Author: Vladislav Kaznacheev <kaznacheev@google.com>
Date: Thu Jul 27 23:53:06 2017

Better pointer prediction for short trajectories

When there are only source 2 points available,
predict zero acceleration.

When there are only source 3 points available,
predict zero jerk.

Bug:  748733 
Change-Id: I6bbedc1479618b6719b63667160f4a82effbbd0c
Reviewed-on: https://chromium-review.googlesource.com/585172
Reviewed-by: David Reveman <reveman@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: Vladislav Kaznacheev <kaznacheev@chromium.org>
Cr-Commit-Position: refs/heads/master@{#490138}
[modify] https://crrev.com/28cc3784cd55890ef97c757a90c1d91e07734576/ash/fast_ink/fast_ink_points.cc
[modify] https://crrev.com/28cc3784cd55890ef97c757a90c1d91e07734576/ash/fast_ink/fast_ink_points_unittest.cc

Project Member

Comment 2 by bugdroid1@chromium.org, Aug 3 2017

Labels: merge-merged-3163
The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/be815b504eabb1a0809229aeb672a73b3ec11620

commit be815b504eabb1a0809229aeb672a73b3ec11620
Author: Vladislav Kaznacheev <kaznacheev@google.com>
Date: Thu Aug 03 00:55:41 2017

Better pointer prediction for short trajectories

When there are only source 2 points available,
predict zero acceleration.

When there are only source 3 points available,
predict zero jerk.

TBR=kaznacheev@google.com

(cherry picked from commit 28cc3784cd55890ef97c757a90c1d91e07734576)

Bug:  748733 
Change-Id: I6bbedc1479618b6719b63667160f4a82effbbd0c
Reviewed-on: https://chromium-review.googlesource.com/585172
Reviewed-by: David Reveman <reveman@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: Vladislav Kaznacheev <kaznacheev@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#490138}
Reviewed-on: https://chromium-review.googlesource.com/599447
Reviewed-by: Vladislav Kaznacheev <kaznacheev@chromium.org>
Cr-Commit-Position: refs/branch-heads/3163@{#258}
Cr-Branched-From: ff259bab28b35d242e10186cd63af7ed404fae0d-refs/heads/master@{#488528}
[modify] https://crrev.com/be815b504eabb1a0809229aeb672a73b3ec11620/ash/fast_ink/fast_ink_points.cc
[modify] https://crrev.com/be815b504eabb1a0809229aeb672a73b3ec11620/ash/fast_ink/fast_ink_points_unittest.cc

Status: Fixed (was: Assigned)

Comment 4 by dchan@chromium.org, Jan 22 2018

Status: Archived (was: Fixed)

Sign in to add a comment