René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: Rendering on Wayland with fractional scaling looks bad","articleBody":"### Bug summary\n\nWhen rendering a plot on Wayland with fractional scaling turned on (e.g., 150%), the resulting plot content looks bad (i.e., jagged edges in lines and text). The UI is fine though (i.e., the toolbar looks nice and sharp).\n\n### Code for reproduction\n\n```Python\nimport matplotlib\n\nmatplotlib.use(\"qtagg\")\n\nimport matplotlib.pyplot as plt\n\nplt.plot([1, 10, -3, 17, 0, -6, 2, 12, 18, -3])\nplt.show()\n```\n\n### Actual outcome\n\n![Image](https://github.com/user-attachments/assets/ee8ae61f-ed68-4de7-bbe8-9dfa3ebeb2e4)\n\n### Expected outcome\n\nI would expect the plot to render nicely.\n\n### Additional information\n\nMaybe there is something wrong with detecting the actual DPI when fractional scaling is enabled? I also noticed that when creating the figure with 100% and then switching to 150% scaling in my desktop environment (I'm using GNOME), the figure remains sharp (i.e., plot elements are anti-aliased). It's only when I create the figure from 150% scaling that it is jagged. (I use a 4K screen with 150% fractional scaling.)\n\n### Operating system\n\nArch Linux\n\n### Matplotlib Version\n\n3.10.3\n\n### Matplotlib Backend\n\nqtagg\n\n### Python version\n\n3.13.5\n\n### Jupyter version\n\n_No response_\n\n### Installation\n\nNone","author":{"url":"https://github.com/cbrnr","@type":"Person","name":"cbrnr"},"datePublished":"2025-06-26T10:26:29.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":18},"url":"https://github.com/30218/matplotlib/issues/30218"}