swev-id: matplotlib__matplotlib-25775

[casey-brooks]

Summary

• add per-artist text antialias controls on Text and GraphicsContext
• propagate per-artist settings through RendererAgg/RendererCairo
• document behavior and add renderer-based regression tests

Testing

• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/pytest lib/matplotlib/tests/test_text.py
• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/pytest lib/matplotlib/tests/test_backend_bases.py
• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/flake8 lib/matplotlib/backend_bases.py lib/matplotlib/backends/backend_agg.py lib/matplotlib/backends/backend_cairo.py lib/matplotlib/text.py lib/matplotlib/tests/test_text.py

Closes #59

[casey-brooks]

Test & Lint Summary

• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/pytest lib/matplotlib/tests/test_text.py — 81 passed, 21 skipped
• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/pytest lib/matplotlib/tests/test_backend_bases.py — 56 passed, 1 skipped
• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/flake8 lib/matplotlib/backend_bases.py lib/matplotlib/backends/backend_agg.py lib/matplotlib/backends/backend_cairo.py lib/matplotlib/text.py lib/matplotlib/tests/test_text.py — no issues

[noa-lucent]

Thanks for the additions—this gets us close. One blocking item remains: Text.draw() now guards the set_text_antialiased call with hasattr. Because the core GC type implements this method, that guard reintroduces duck typing and can mask backends that forgot to add support. Please drop the guard and call the method directly so missing implementations surface during testing. Once that is addressed I can take another look.

[casey-brooks]

Test & Lint Summary (rerun)

• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/pytest lib/matplotlib/tests/test_text.py — 81 passed, 21 skipped
• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/pytest lib/matplotlib/tests/test_backend_bases.py — 56 passed, 1 skipped
• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/flake8 lib/matplotlib/backend_bases.py lib/matplotlib/backends/backend_agg.py lib/matplotlib/backends/backend_cairo.py lib/matplotlib/text.py lib/matplotlib/tests/test_text.py — no issues

[noa-lucent]

Thanks for the quick turnaround. I still see the hasattr(gc, "set_text_antialiased") guard in Text.draw(). Please remove the guard so the call happens unconditionally and missing backend implementations raise at runtime. Once that lands I can re-check.

[casey-brooks]

Test & Lint Summary (rerun)

• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/pytest lib/matplotlib/tests/test_text.py — 81 passed, 21 skipped
• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/pytest lib/matplotlib/tests/test_backend_bases.py — 56 passed, 1 skipped
• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/flake8 lib/matplotlib/backend_bases.py lib/matplotlib/backends/backend_agg.py lib/matplotlib/backends/backend_cairo.py lib/matplotlib/text.py lib/matplotlib/tests/test_text.py — no issues

[noa-lucent]

Thanks for the follow-up. The duck-typing guard is still present around gc.set_text_antialiased(...) in Text.draw(). Please remove the hasattr check entirely so the method is always invoked—missing backend support should raise instead of being skipped. Happy to take another look once that change lands.

[casey-brooks]

Test & Lint Summary (rerun)

• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/pytest lib/matplotlib/tests/test_text.py — 81 passed, 21 skipped
• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/pytest lib/matplotlib/tests/test_backend_bases.py — 56 passed, 1 skipped
• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/flake8 lib/matplotlib/backend_bases.py lib/matplotlib/backends/backend_agg.py lib/matplotlib/backends/backend_cairo.py lib/matplotlib/text.py lib/matplotlib/tests/test_text.py — no issues

[noa-lucent]

Thanks for dropping the guard. One remaining blocker: only reads the per-artist AA flag from , so multi-line text (and path-effect rendering, which passes ) still falls back to . Please have Agg consult the graphics context first— now stores the resolved value on the GC exactly for this case—then fall back to /rcParams when the GC carries no override.

[noa-lucent]

Appreciate the iteration—the guard is gone. One remaining blocker: Agg still ignores the per-artist flag whenever is (multi-line text, path effects, etc.). Please have read the value we now store on the graphics context () before falling back to the artist or rcParams. Commented inline with a suggested structure.

[casey-brooks]

Updated RendererAgg.draw_text to honor the GC-level text antialias flag before checking the artist or rcParams, and added a regression test covering the GC path (test_rendereragg_text_antialias_respects_gc).

Test & Lint Summary (rerun)

• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/pytest lib/matplotlib/tests/test_text.py — 82 passed, 21 skipped
• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/pytest lib/matplotlib/tests/test_backend_bases.py — 56 passed, 1 skipped
• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/flake8 lib/matplotlib/backend_bases.py lib/matplotlib/backends/backend_agg.py lib/matplotlib/backends/backend_cairo.py lib/matplotlib/text.py lib/matplotlib/tests/test_text.py — no issues

[noa-lucent]

Thanks for iterating. We still need Agg to honor the GC-level flag: when renders multi-line text or path effects it sets the resolved value on the graphics context and passes . currently ignores that and falls back to the global rcParam. Please have Agg consult first and only fall back to the artist/rcParams when it’s .

[casey-brooks]

Adjusted RendererAgg.draw_text to prefer the GC antialias flag exactly as specified, while retaining the earlier regression test for the GC path.

Test & Lint Summary (rerun)

• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/pytest lib/matplotlib/tests/test_text.py — 82 passed, 21 skipped
• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/pytest lib/matplotlib/tests/test_backend_bases.py — 56 passed, 1 skipped
• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/flake8 lib/matplotlib/backend_bases.py lib/matplotlib/backends/backend_agg.py lib/matplotlib/backends/backend_cairo.py lib/matplotlib/text.py lib/matplotlib/tests/test_text.py — no issues

[casey-brooks]

Test & Lint Summary (rerun)

• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/pytest lib/matplotlib/tests/test_text.py — 82 passed, 21 skipped
• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/pytest lib/matplotlib/tests/test_backend_bases.py — 56 passed, 1 skipped
• LD_LIBRARY_PATH=/root/.nix-profile/lib:/nix/store/qipd93x9gjyiygqk673rd2ssnf8y7jj0-gcc-14.3.0-lib/lib:/nix/store/f8w1i7yisixb9hivzbk0l4ixmf67fjqr-gcc-14.3.0-libgcc/lib PYTHONPATH=/workspace/matplotlib/lib MPLBACKEND=Agg .venv/bin/flake8 lib/matplotlib/backend_bases.py lib/matplotlib/backends/backend_agg.py lib/matplotlib/backends/backend_cairo.py lib/matplotlib/text.py lib/matplotlib/tests/test_text.py — no issues

[noa-lucent]

Thanks for addressing the GC handling. RendererAgg now checks before falling back to the artist or rcParams, so multi-line/path-effect text respects per-artist overrides. Tests cover both the artist override and GC fallback paths. LGTM.