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Add check: Grade axis doesn't have any reflow

See original GitHub issue

Observed behaviour

The grade (GRAD) axis should not change any advanceWidth or kerning data across its design space.

Expected behaviour

We should have a FB check for that.

Resources and exact process needed to replicate

@madig wrote this script for @chrissimpkins to report advance width issues. Kerning is a good 2nd step after this check ships.

# flake8: noqa

from pathlib import Path

from ufoLib2 import Font


TARGET_DIR = Path("source/")
DEFAULT = {
    "Family-opsz17-wght380-GRAD-50.ufo": "Family-opsz17-wght380-GRAD0.ufo",
    "Family-opsz17-wght380-GRAD200.ufo": "Family-opsz17-wght380-GRAD0.ufo",
    "Family-opsz18-wght380-GRAD-50.ufo": "Family-opsz18-wght380-GRAD0.ufo",
    "Family-opsz18-wght380-GRAD200.ufo": "Family-opsz18-wght380-GRAD0.ufo",
    "FamilyItalic-opsz17-wght380-GRAD-50.ufo": "FamilyItalic-opsz17-wght380-GRAD0.ufo",
    "FamilyItalic-opsz17-wght380-GRAD200.ufo": "FamilyItalic-opsz17-wght380-GRAD0.ufo",
    "FamilyItalic-opsz18-wght380-GRAD-50.ufo": "FamilyItalic-opsz18-wght380-GRAD0.ufo",
    "FamilyItalic-opsz18-wght380-GRAD200.ufo": "FamilyItalic-opsz18-wght380-GRAD0.ufo",
}

comparison_ufos = {}

for ufo_path, comparison_ufo_path in DEFAULT.items():
    ufo = Font.open(TARGET_DIR / ufo_path)
    if comparison_ufo_path in comparison_ufos:
        comparison_ufo = comparison_ufos[comparison_ufo_path]
    else:
        comparison_ufo = Font.open(TARGET_DIR / comparison_ufo_path)
        comparison_ufos[comparison_ufo_path] = comparison_ufo

    mismatches = [
        glyph.name for glyph in ufo if glyph.width != comparison_ufo[glyph.name].width
    ]
    if mismatches:
        print(f"UFO {ufo_path} width mismatches compared to {comparison_ufo_path}:")
        print("\n".join(f"  {x}" for x in mismatches))

Issue Analytics

State:
Created 3 years ago
Comments:19 (18 by maintainers)

Top GitHub Comments

3reactions

anthrotypecommented, Mar 5, 2021

i checked varLib.iup code, and the last four phantom points are treated specially (see iup_delta and iup_contour functions), in the sense that if deltas are None, they will be always inferred as (0, 0). so I think you’re safe to ignore IUP for those 4

2reactions

m4rc1ecommented, Mar 5, 2021

@kontur https://github.com/google/fonts/blob/main/axisregistry/grade.textproto