SUMMARY The size slider in the liquify section of transform tool options react very slowly to slide operation, often there is a huge cpu spike which hangs krita for 2-4 seconds. STEPS TO REPRODUCE 1. Open krita and a file 2. Activate transform tool and the liquify mode. 3. Drag the size slider to new value OBSERVED RESULT Slider takes too long to respond and there is a cpu spike while doing the slide operation EXPECTED RESULT slider should be as smooth as the shift + drag resize SOFTWARE/OS VERSIONS Operating System: Arch Linux KDE Plasma Version: 5.19.4 KDE Frameworks Version: 5.73.0 Qt Version: 5.15.0 Kernel Version: 5.7.12-arch1-1 OS Type: 64-bit Processors: 8 × Intel® Core™ i7-4790K CPU @ 4.00GHz Memory: 31.3 GiB of RAM Graphics Processor: GeForce GTX 750 Ti/PCIe/SSE2
Also see this [bug report](https://bugs.kde.org/show_bug.cgi?id=423788) which may be related
What's interesting is that the tool itself is not that much laggy at all, only the sliders are acting weird. (I've seen bug 423788 and for me even in such big size was slow but smooth; however setting that size was difficult, in the end I just entered the value directly into the field without relying on the slider).
Then it probably just needs a signal compressor.
I guess the problem happens because changing these properties trigger canvas update, therefore the layer will be recalculated, which shouldn't really happen.
Git commit 47c897453c509ab0f5189a1edffcd9b431bf1e33 by Dmitry Kazakov. Committed on 17/07/2021 at 11:41. Pushed by dkazakov into branch 'master'. Do not request transform preview update on changing liquify options These options affect the brush settings only, not what the actual visual representation is. M +7 -5 plugins/tools/tool_transform2/kis_tool_transform.cc M +1 -1 plugins/tools/tool_transform2/kis_tool_transform.h M +11 -11 plugins/tools/tool_transform2/kis_tool_transform_config_widget.cpp M +2 -2 plugins/tools/tool_transform2/kis_tool_transform_config_widget.h https://invent.kde.org/graphics/krita/commit/47c897453c509ab0f5189a1edffcd9b431bf1e33