RoboFont Metrics Math

metric-math.py

from glyphConstruction import *
from mojo.UI import CurrentWindow

"""
RoboFont Script
- Type: Metrics
- Purpose: Fix metrics of selected glyphs according to a formula.
- Specifications:
    - Uses RoboFont GlyphConstruction syntax to change metrics of glyphs.
- Publish Date: 18 April 2021
- Author: Bahman Eslami
- License: MIT

For the following example, main reference glyphs for applying the metrics math are:
    H, O
Select the glyphs you want to update their metrics and run the script.
"""

metrics_formula = """
>U = ^ H, H
>P = ^ H, O/2
"""

cw = CurrentWindow().doodleWindowName
f = CurrentFont()
selection = []
if cw == 'FontWindow':
    f = CurrentFont()
    s = f.templateSelectedGlyphNames
    for gn in s:
        selection.append(gn)
elif cw == 'GlyphWindow':
    g = CurrentGlyph()
    if g is not None:
        selection.append(g.name)

constructions = ParseGlyphConstructionListFromString(metrics_formula)
for c in constructions:
    gn = c.split('=')[0].strip()[1:]
    if gn in selection:
        cg = GlyphConstructionBuilder(c, f)
        g = f[cg.name]
        g.prepareUndo("Metric Math")
        g.leftMargin = cg.leftMargin
        g.width = cg.width
        g.changed()
        g.performUndo()