PR summary

Some time ago, I came across https://github.com/unicode-org/last-resort-font. Through some charmap magic, the "High Efficiency" font from this project is able to provide a glyph for every Unicode codepoint while only being about 550K. (The expanded version in that repo in 8.6MB.)

This is a proof-of-concept for applying this font as final fallback at (almost) all times. I have added an rcParam to turn it off, mostly for one test to work, but we may not want to use that. I'm also not sure if it's been inserted in the best place. We may instead want to insert the glyph at the point where we have none, so that we can warn about it too.

These glyphs show a representative character from the Unicode block, a square frame, and if large enough, the block name and code point range:

import matplotlib.pyplot as plt

text = '\N{Bengali Digit Zero}\N{Hiragana Letter A}\ufdd0'
sizes = [
    (0.90, 6),
    (0.85, 8),
    (0.80, 10),
    (0.75, 12),
    (0.70, 16),
    (0.63, 20),
    (0.55, 24),
    (0.45, 32),
    (0.30, 48),
    (0.10, 64),
]

fig = plt.figure()
for y, size in sizes:
    fig.text(0.01, y, f'{size}pt: {text}', fontsize=size)
plt.show()

PR checklist

• [n/a] "closes #0000" is in the body of the PR description to link the related issue
• new and changed code is tested
• Plotting related features are demonstrated in an example
• New Features and API Changes are noted with a directive and release note
• Documentation complies with general and docstring guidelines