inter/misc/glyphs-scripts/fixup-vertical-metrics.py
2019-03-30 17:03:54 -07:00

110 lines
3.7 KiB
Python

#MenuTitle: Fixup Vertical Metrics
# -*- coding: utf-8 -*-
font = Glyphs.font
caps = set(font.classes['Uppercase'].code.strip().split(' '))
lowercase = set(font.classes['Lowercase'].code.strip().split(' '))
print(font)
mainMaxDescent = 0
mainMaxDescentGlyph = ""
maxDescent = 0
mainMaxAscent = 0
mainMaxAscentGlyph = ""
maxAscent = 0
typoAscender = 0
typoDescender = 0
for master in font.masters:
ta = max(master.ascender, master.capHeight)
if typoAscender == 0:
typoAscender = ta
elif typoAscender != ta:
raise Error('ascender or capHeight varies with masters; vertical metrics must be same in all masters')
td = master.descender
if typoDescender == 0:
typoDescender = td
elif typoDescender != td:
raise Error('descender or capHeight varies with masters; vertical metrics must be same in all masters')
for glyph in font.glyphs:
if not glyph.export:
continue
layer = glyph.layers[master.id]
# get descender of current layer
descent = layer.bounds.origin.y
# get ascender of current layer
ascent = layer.bounds.size.height + descent
# if descent/ascent of current layer is greater than previous max descents/ascents, update the max descent/ascent
if descent <= maxDescent:
maxDescent = descent
maxDescentGlyph = glyph.name
if ascent >= maxAscent:
maxAscent = ascent
maxAscentGlyph = glyph.name
# get descender of current layer
descent = layer.bounds.origin.y
# get ascender of current layer (total height of layer, subtracting value of descender)
ascent = layer.bounds.size.height + descent
# get maximums of only letters in list vars, for typo and hhea values
if glyph.name in caps and ascent >= mainMaxAscent:
mainMaxAscent = ascent
mainMaxAscentGlyph = glyph.name
if glyph.name in lowercase and descent <= mainMaxDescent:
# if descent/ascent of current layer is greater than previous max descents/ascents, update the max descent/ascent
mainMaxDescent = descent
mainMaxDescentGlyph = glyph.name
# check values for sanity
# print(maxDescentGlyph, maxDescent, maxAscentGlyph, maxAscent)
# make lineGap so that the total of `ascent + descent + lineGap` equals 120% of UPM size
# UPM = font.upm
# totalSize = maxAscent + abs(maxDescent)
# lineGap = int((UPM * 1.2)) - totalSize
# print(UPM, UPM * 1.2, totalSize, lineGap)
## use highest/lowest points to set custom parameters for winAscent and winDescent
## following vertical metric schema from https://github.com/googlefonts/gf-docs/tree/master/VerticalMetrics
font.customParameters["Use Typo Metrics"] = True
# ascenderDelta = max(abs(typoAscender), abs(mainMaxAscent)) - min(abs(typoAscender), abs(mainMaxAscent))
descenderDelta = max(typoDescender, mainMaxDescent) - min(typoDescender, mainMaxDescent)
if descenderDelta == 0:
print('descenderDelta is zero -- no change')
else:
print('descenderDelta:', descenderDelta)
for master in font.masters:
# Win Ascent/Descent = Font bbox yMax/yMin
master.customParameters["winAscent"] = maxAscent
master.customParameters["winDescent"] = abs(maxDescent)
# no/zero line gap
# if "typoLineGap" in master.customParameters:
# del master.customParameters["typoLineGap"]
# if "hheaLineGap" in master.customParameters:
# del master.customParameters["hheaLineGap"]
master.customParameters["typoLineGap"] = 0
master.customParameters["hheaLineGap"] = 0
master.customParameters["typoDescender"] = typoDescender - descenderDelta
master.customParameters["hheaDescender"] = typoDescender - descenderDelta
master.customParameters["typoAscender"] = typoAscender + descenderDelta
master.customParameters["hheaAscender"] = typoAscender + descenderDelta