varLib: don't build empty HVAR or gvar tables
Fixes https://github.com/fonttools/fonttools/issues/1670
diff --git a/Lib/fontTools/varLib/__init__.py b/Lib/fontTools/varLib/__init__.py
index b428aeb..87bca8a 100644
--- a/Lib/fontTools/varLib/__init__.py
+++ b/Lib/fontTools/varLib/__init__.py
@@ -311,15 +311,13 @@
log.info("Generating gvar")
assert "gvar" not in font
- gvar = font["gvar"] = newTable('gvar')
- gvar.version = 1
- gvar.reserved = 0
- gvar.variations = {}
glyf = font['glyf']
# use hhea.ascent of base master as default vertical origin when vmtx is missing
defaultVerticalOrigin = font['hhea'].ascent
+
+ variations = {}
for glyph in font.getGlyphOrder():
isComposite = glyf[glyph].isComposite()
@@ -339,7 +337,6 @@
del allControls
# Update gvar
- gvar.variations[glyph] = []
deltas = model.getDeltas(allCoords)
supports = model.supports
assert len(deltas) == len(supports)
@@ -378,7 +375,14 @@
if optimized_len < unoptimized_len:
var = var_opt
- gvar.variations[glyph].append(var)
+ variations.setdefault(glyph, []).append(var)
+
+ if variations:
+ gvar = font["gvar"] = newTable('gvar')
+ gvar.version = 1
+ gvar.reserved = 0
+ gvar.variations = variations
+
def _remove_TTHinting(font):
for tag in ("cvar", "cvt ", "fpgm", "prep"):
@@ -482,10 +486,6 @@
tableTag = tableFields.tableTag
assert tableTag not in font
log.info("Generating " + tableTag)
- VHVAR = newTable(tableTag)
- tableClass = getattr(ot, tableTag)
- vhvar = VHVAR.table = tableClass()
- vhvar.Version = 0x00010000
glyphOrder = font.getGlyphOrder()
@@ -505,7 +505,15 @@
masterModel, master_ttfs, axisTags, glyphOrder, advMetricses,
vOrigMetricses)
+ if not metricsStore.VarRegionList.Region: # VarStore is empty
+ return
+
+ VHVAR = newTable(tableTag)
+ tableClass = getattr(ot, tableTag)
+ vhvar = VHVAR.table = tableClass()
+ vhvar.Version = 0x00010000
vhvar.VarStore = metricsStore
+
if advanceMapping is None:
setattr(vhvar, tableFields.advMapping, None)
else:
@@ -516,7 +524,7 @@
setattr(vhvar, tableFields.sb2, None)
font[tableTag] = VHVAR
- return
+
def _get_advance_metrics(font, masterModel, master_ttfs,
axisTags, glyphOrder, advMetricses, vOrigMetricses=None):
