Bug 410158

Im having difficulties reproducing this behaviour. all brushes react in the same speed.

Could you share a preset (either by name, or attaching if its a custom) you know its best to show this?

I can confirm this on my master build. Not only the curves are affected, but any slider throughout the brush settings I tested can produce severe slowdown, increasingly so the longer I keep dragging the slider. Maybe it's something to do with signal compressors?

Almost any brush preset and engine I tested was affected and I was able to provoke 10+ seconds freezes with a Filter Engine brush. However, the Clone Engine wasn't affected (at least not noticeably), which might be because it doesn't create a preview.

In the Brush Tip section I noticed that while moving the sliders with Predefined and Text tips causes the lag, for Auto tips the brush preview only updates once I let go of the slider.

Should I create a separate bug report for the described problems?

 Version: 4.3.0-prealpha (git 600ee12)
 Languages: en_US
 Hidpi: true

Qt

  Version (compiled): 5.13.0
  Version (loaded): 5.13.0

OS Information

  Build ABI: x86_64-little_endian-lp64
  Build CPU: x86_64
  CPU: x86_64
  Kernel Type: linux
  Kernel Version: 5.2.2-1-MANJARO
  Pretty Productname: Manjaro Linux
  Product Type: manjaro
  Product Version: unknown


Hardware Information

  GPU Acceleration: auto
  Memory: 15950 Mb
  Number of Cores: 8
  Swap Location: /tmp

Created attachment 121721 [details]
Brush preset examples for brush editor lag

I attach three brush presets and a .gih brush tip (which is used by two of them) as examples.

It does seem that updating the brush stroke preview is a significant factor in the lag. A complex .gih brush and many control parameters being active leads to more lag.

I've tried these with a recent 4.3.0 pre-alpha portable .zip on Windows 10 and the lag is much smaller than with an appimage on Linux.

On Linux, the difference between 4.2.3 and 4.3.0 is severe.

I can confirm the issue on Linux. I think the issues Manuel noted are related, so no new bug report is needed.

Weird... I've started bisecting, and after a couple of hours, suddenly I cannot reproduce the issue anymore :-(

I can confirm the issue and I think enabling pattern gives a good probability to reproduce the issue. My wild guess would be that the brush preview that gets generated is the reason for this lag.

Note: This does not happen in the recent 4.2.6 appimage formal release but it still happens in the latest 4.3.0 pre-alpha appimage (git aa34d6d).

Ahab: can you please check if there is a difference now between Krita Next (unstable/master) and Krita Plus (stable, should be the same as formal release + a few more commits)? It sounds weird to me since I was working on curves recently and I don't remember any commits that went into the release but weren't on master, too.

In any case, I believe this bug should be solved in this MR: https://invent.kde.org/kde/krita/merge_requests/121

Krita Stable 4.2.6 appimage #491 Sep 11 (git f86e9ee) does not show lag on curve or slider adjustment.

Krita Next/Nightly 4.3.0 pre-alpha appimage #619 Sep 11 (git aa34d6d) shows lag of about 5 seconds on curve and slider adjustment.

The 4.2.6 beta-1 that I've had since it was released does not show lag.

(This seems strange.)

Git commit 542da22bbbdcdb68e015bdb3b47e3f46c83c6214 by Agata Cacko.
Committed on 13/09/2019 at 23:23.
Pushed by tymond into branch 'master'.

Fix curve changing with sensors w/ Use Same Curve

Before this commit, curve would change semi-randomly in some cases
if you change from some specific sensors to some other specific sensors
(having a complex curve and clicking randomly should show a bug though)
when "Share curve across all settings" is selected.
This commit fixes that behaviour.
Related: bug 383909

M  +3    -3    libs/global/kis_signal_compressor.h
M  +18   -1    libs/ui/widgets/kis_curve_widget.cpp
M  +17   -0    libs/ui/widgets/kis_curve_widget.h
M  +6    -2    libs/ui/widgets/kis_curve_widget_p.h
M  +4    -0    plugins/paintops/libpaintop/kis_auto_brush_widget.cpp
M  +27   -22   plugins/paintops/libpaintop/kis_curve_option.cpp
M  +6    -2    plugins/paintops/libpaintop/kis_curve_option.h
M  +35   -15   plugins/paintops/libpaintop/kis_curve_option_widget.cpp
M  +5    -2    plugins/paintops/libpaintop/kis_curve_option_widget.h

https://invent.kde.org/kde/krita/commit/542da22bbbdcdb68e015bdb3b47e3f46c83c6214

Still happens. (Win7) It's more like flickering now, like the frame is dropping.

Git commit a2a86bd9a7c0c595fa6f7e6a7bcfb44144c00e4c by Agata Cacko.
Committed on 14/09/2019 at 15:25.
Pushed by tymond into branch 'krita/4.2'.

Fix curve changing with sensors w/ Use Same Curve

Before this commit, curve would change semi-randomly in some cases
if you change from some specific sensors to some other specific sensors
(having a complex curve and clicking randomly should show a bug though)
when "Share curve across all settings" is selected.
This commit fixes that behaviour.
Related: bug 383909

M  +3    -3    libs/global/kis_signal_compressor.h
M  +18   -1    libs/ui/widgets/kis_curve_widget.cpp
M  +17   -0    libs/ui/widgets/kis_curve_widget.h
M  +6    -2    libs/ui/widgets/kis_curve_widget_p.h
M  +4    -0    plugins/paintops/libpaintop/kis_auto_brush_widget.cpp
M  +27   -22   plugins/paintops/libpaintop/kis_curve_option.cpp
M  +6    -2    plugins/paintops/libpaintop/kis_curve_option.h
M  +35   -15   plugins/paintops/libpaintop/kis_curve_option_widget.cpp
M  +5    -2    plugins/paintops/libpaintop/kis_curve_option_widget.h

https://invent.kde.org/kde/krita/commit/a2a86bd9a7c0c595fa6f7e6a7bcfb44144c00e4c

Krita 4.3.0 pre-alpha #622 Sep14 (git 68fe323) does not show lag when dragging a point on an adjustment curve.
It does show lag when dragging a slider. This is not too bad on a simple brush preset but can be significant on a complicated brush preset, e.g one with a pattern set active and more parameters active.
However, you can click on the slider instead of dragging it to set a value and the response to point clicks on the sliders is good. From the point of view of practical use, it seems much better and almost fully solved. 

This bug was reported against the 4.3.0 pre-alpha at a time when 4.2.3 was the formal release and 4.2.3 did not have the bug.
I've just noticed (because I've only just checked) that 4.2.4, 4.2.5, 4.2.6 beta-1 (and 4.2.6) appimages do not show the bug. It seems to have been present only in the 4.3.0 pre-alphas.

Bugs are in both 4.2.6, 4.3.0 pre-alphas here. It's slightly better in 4.3.0 pre-alphas than 4.2.6. 

It doesn't happen when I'm dragging the silders in 'Brush Tip', but happens with any other sliders in other options.

I finished bisecting when the slowdown first started, the result is:

commit bbc0f80732afbf0cb36ccdf5fd6b672dd15712a6
Author: Dmitry Kazakov <dimula73@gmail.com>
Date:   Fri Jul 12 20:02:22 2019 +0300

    Refactor signal compressor to have better timing properties
    
    * before: emits signals with time range [1.0...2.0] * interval
    * after: emits signals with time range [0.5...1.5] * interval
    
    Bascially, now it handles it much better when interval is around
    10-20 ms. With the old version it caused KisCanvas2 to drop frames
    and look ugly when the user pans the canvas.
    
    CCBUG:409460

Git commit fef9ff850aa25ba67cceafac60cf99cd7b79f6e1 by Dmitry Kazakov.
Committed on 16/09/2019 at 14:37.
Pushed by dkazakov into branch 'master'.

Fix freezes when changing brush properties/curves

This patch basically makes brush preview to be calculated asynchronously
in a separate worker thread and update preview only on a completion-signal
arrival.

WARNING: this patch can theoretically cause a bug, which will make
         the strokes on canvas be painted in extremely small size
         (< 25px). If it happens, then originalPresetSize recovering
         should be restored.

M  +1    -1    libs/image/brushengine/kis_paintop_config_widget.cpp
M  +1    -1    libs/image/brushengine/kis_paintop_preset.cpp
M  +1    -1    libs/ui/widgets/kis_paintop_presets_popup.cpp
M  +63   -27   libs/ui/widgets/kis_preset_live_preview_view.cpp
M  +8    -1    libs/ui/widgets/kis_preset_live_preview_view.h

https://invent.kde.org/kde/krita/commit/fef9ff850aa25ba67cceafac60cf99cd7b79f6e1

It's reduced but still there... (git 02bdc53)

With both the 4.3.0-prealpha (git 71126cc) appimage and the 4.3.0-prealpha (git 02bdc53) portable .zip, I find the sliders and the curves have no lag even if I activate lots of parameters and control inputs and share the curve across settings.

(My PC and graphics card are not particularly modern or powerful.)

Git commit 61462209126d6b70195da80f94893faa4cfb5943 by Dmitry Kazakov.
Committed on 21/09/2019 at 10:02.
Pushed by dkazakov into branch 'krita/4.2'.

Fix freezes when changing brush properties/curves

This patch basically makes brush preview to be calculated asynchronously
in a separate worker thread and update preview only on a completion-signal
arrival.

WARNING: this patch can theoretically cause a bug, which will make
         the strokes on canvas be painted in extremely small size
         (< 25px). If it happens, then originalPresetSize recovering
         should be restored.

M  +1    -1    libs/image/brushengine/kis_paintop_config_widget.cpp
M  +1    -1    libs/image/brushengine/kis_paintop_preset.cpp
M  +1    -1    libs/ui/widgets/kis_paintop_presets_popup.cpp
M  +63   -27   libs/ui/widgets/kis_preset_live_preview_view.cpp
M  +8    -1    libs/ui/widgets/kis_preset_live_preview_view.h

https://invent.kde.org/kde/krita/commit/61462209126d6b70195da80f94893faa4cfb5943