Fix the misplacement of rasterized object in DrawingArea in the vectorized backends
#30171
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…orrection for rasterized content
DrawingArea in the vectorized backends
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Hi all, just a gentle follow-up on this PR. I'd appreciate any feedback when time permits. Let me know if there's anything I can improve or clarify. Thanks! |
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Thanks for the feedback! I think we can test this using image comparison—by generating a target image and validating output against it. On a related note, I'm not entirely confident that my current method for checking whether the renderer is a vectorized backend is the most robust or appropriate approach. I'd really appreciate any input or suggestions on improving that part of the implementation. |
| while type(actual_renderer).__name__ == 'MixedModeRenderer': | ||
| actual_renderer = getattr(actual_renderer, '_renderer', actual_renderer) | ||
| renderer_name = type(actual_renderer).__name__ |
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This approach feels quite hacky. The functionality should live in a method MxedModeRenderer.is_vector_renderer(). Possibly that function should be made a core feature Renderer so that the whole _is_vector_renderer can go away. Though I'm not sure whether there are implications for third party renders. @anntzer what do you as a backend implementer think?
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I suspect whether the backend has vector output is not actually the right test here; indeed, mplcairo doesn't exhibit the #28549 bug even for vector output. Rather, the bug likely resides either in backend_{pdf,ps,svg}, or, more likely (just my guess), in MixedModeRenderer. |
PR summary
This PR is trying to fix a bug when rendering rasterized Artists in
DrawingArea, they will be misplaced in the vectorized backend. closes #28549The fix is done by enforcing correct DPI transformation during rasterization, specifically in the vectorized backends
There is no API change or documentation change associated with this PR.
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