SUMMARY *** If I use the v key to make lines krita randomly creates white blocks on the canvas like large merged pixels. This is very random and hard to reproduce but very annoying and it breaks the background on which the lines are painted. These random white squares can later be filled with color with the bucket fill tool. *** STEPS TO REPRODUCE 1. use the default krita startup file. 2. On the "background layer" choose a dark color and fill the background of the canvas 3. choose a brush I have tested with the "Basic-5 Size" brush and the "Basic-1 brush" 4. press the "v" key and randomly keep drawing lines. OBSERVED RESULT The lines will draw fine on the canvas but suddenly at random roughly around the endpoint a patch of white will appear on the canvas replacing the dark blue of the background with a white patch. This is very random. Sometimes undoing can exacerbate the issue. Sometimes it never happens. It is very annoying because it deletes the previously painted pixels and replaces them with these patchy white rectangles. If I further use the fill tool on this patches it replaces the white patched with the fill color. Sometimes drawing over the area where these patches appeared would change the patches slightly. I have made a video to demonstrate this problem because I am struggling to find a reliable trigger. Please view it at the below link: https://drive.google.com/file/d/1qVz-BZcLno4Y5GBnCp5DN5u_rb7y0z0f/view?usp=sharing (see ~42 secinds for the first artifact) EXPECTED RESULT The line should composite with the background correctly no random patches should appear. Krita Version: 5.0.2 Languages: en_IN, en, en, en_IN, en Hidpi: true Qt Version (compiled): 5.12.12 Version (loaded): 5.12.12 OS Information Build ABI: x86_64-little_endian-lp64 Build CPU: x86_64 CPU: x86_64 Kernel Type: linux Kernel Version: 5.4.0-96-generic Pretty Productname: Ubuntu 20.04.3 LTS Product Type: ubuntu Product Version: 20.04 Desktop: KDE OpenGL Info Vendor: "Intel" Renderer: "Mesa Intel(R) UHD Graphics 620 (KBL GT2)" Version: "4.6 (Compatibility Profile) Mesa 21.0.3" Shading language: "4.60" Requested format: QSurfaceFormat(version 3.0, options QFlags<QSurfaceFormat::FormatOption>(DeprecatedFunctions), depthBufferSize 24, redBufferSize 8, greenBufferSize 8, blueBufferSize 8, alphaBufferSize 8, stencilBufferSize 8, samples -1, swapBehavior QSurfaceFormat::DoubleBuffer, swapInterval 0, colorSpace QSurfaceFormat::DefaultColorSpace, profile QSurfaceFormat::CompatibilityProfile) Current format: QSurfaceFormat(version 4.6, options 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supportsOpenGLES: true isQtPreferOpenGLES: false useBufferInvalidation (config option): false Hardware Information GPU Acceleration: auto Memory: 7761 Mb Number of Cores: 8 Swap Location: /tmp Current Settings Current Swap Location: /tmp Current Swap Location writable: true Undo Enabled: true Undo Stack Limit: 200 Use OpenGL: true Use OpenGL Texture Buffer: true Disable Vector Optimizations: false Disable AVX Optimizations: false Canvas State: OPENGL_SUCCESS Autosave Interval: 420 Use Backup Files: true Number of Backups Kept: 1 Backup File Suffix: ~ Backup Location: Same Folder as the File Backup Location writable: false Use Win8 Pointer Input: false Use RightMiddleTabletButton Workaround: false Levels of Detail Enabled: false Use Zip64: false Display Information Number of screens: 1 Screen: 0 Name: HDMI-1 Depth: 24 Scale: 1 Resolution in pixels: 1920x1080 Manufacturer: Dell Inc. Model: DELL S2216H- Refresh Rate: 60 ADDITIONAL INFORMATION
This has nothing to do with the selected brush. I can see it happen in your video, but I cannot reproduce it myself.
Yes you are right. It has something to do with OpenGL and my hardware. I noticed if I use export DRI_PRIME=1 and use my laptop's AMD GPU it does solve the problem. On IRC someone gave me an idea that it could be OpenGL interfering and indeed it was. I wonder if it is some problem with the integrated graphics on this laptop's CPU.
I guess we can blame the display driver for this then
(In reply to Halla Rempt from comment #3) > I guess we can blame the display driver for this then Probably. Thanks for trying to reproduce. I know these types of bugs are really hard to solve. My current workaround seems to be the best option for now.