GeezerVison

PR Summary

First commit:

Switch from a hand-written glyph outline decomposer to FreeType's one.

Instead of walking through FT_Outline ourselves, use FreeType's
FT_Outline_Decompose to decompose glyphs into paths.

Fixes incorrect positioning of first and last control points of certain
contours; compare e.g.

from pylab import *
from matplotlib.textpath import TextPath
from matplotlib.patches import PathPatch

rcParams["mathtext.fontset"] = "stixsans"
path = TextPath((0, 0), r"$\delta$", size=72)
plot(*path.vertices.T, ".-", lw=.5)
gca().add_patch(PathPatch(path, alpha=.5))
gca().set(aspect="equal")
show()

before and after the patch (before the patch, the inner loop was not
properly closed). (Technically, I believe the earlier bug affected
start/end-of-contours that are implicitly created per the ttf format at
the midpoint between two conic control points.)

before:

after:

A few SVG files need to be updated too.

Second commit:

Stop using ttconv for pdf.

Quite a bit of work goes into reproducing quirks of the old ttconv code
in order not to update baseline images, but this can easily be dropped
once the new baseline images system goes in.

figure_align_label.pdf gets modified because of tiny differences in
outline extraction (due to the ttconv emulation); there's already the
svg test that tests the fixed-dpi case so I feel OK deleting it.

This also fixes ttc subsetting for pdf output (cf. changes in
test_font_manager.py).

(PostScript is not done yet, but it's basically the same idea, it's just the header that's different.)

Fixes #17197. I'll skip adding a new font for the test, because in essence we're "just" relying on FreeType handing us the right outlines.

PR Checklist

• Has Pytest style unit tests
• Code is Flake 8 compliant
• New features are documented, with examples if plot related
• Documentation is sphinx and numpydoc compliant
• Added an entry to doc/users/next_whats_new/ if major new feature (follow instructions in README.rst there)
• Documented in doc/api/next_api_changes/* if API changed in a backward-incompatible way