[cffLib] Add CFF<->CFF2 convertors that work on otFont

Lib/fontTools/cffLib/CFF2ToCFF.py

@@ -14,7 +14,7 @@ __all__ = ["convertCFF2ToCFF", "main"]
 log = logging.getLogger("fontTools.cffLib")
 
 
-def convertCFF2ToCFF(cff, otFont):
+def _convertCFF2ToCFF(cff, otFont):
     """Converts this object from CFF2 format to CFF format. This conversion
     is done 'in-place'. The conversion cannot be reversed.
 
@@ -79,6 +79,14 @@ def convertCFF2ToCFF(cff, otFont):
             cs.program.insert(0, width - private.nominalWidthX)
 
 
+def convertCFF2ToCFF(font):
+    cff = font["CFF2"].cff
+    _convertCFF2ToCFF(cff, font)
+    del font["CFF2"]
+    table = font["CFF "] = newTable("CFF ")
+    table.cff = cff
+
+
 def main(args=None):
     """Convert CFF OTF font to CFF2 OTF font"""
     if args is None:
@@ -136,13 +144,8 @@ def main(args=None):
     )
 
     font = TTFont(infile, recalcTimestamp=options.recalc_timestamp, recalcBBoxes=False)
-    cff = font["CFF2"].cff
 
-    cff.convertCFF2ToCFF(font)
+    convertCFF2ToCFF(font)
-
-    del font["CFF2"]
-    table = font["CFF "] = newTable("CFF ")
-    table.cff = cff
 
     log.info(
         "Saving %s",

Lib/fontTools/cffLib/CFFToCFF2.py

@@ -21,7 +21,7 @@ __all__ = ["convertCFFToCFF2", "main"]
 log = logging.getLogger("fontTools.cffLib")
 
 
-def convertCFFToCFF2(cff, otFont):
+def _convertCFFToCFF2(cff, otFont):
     """Converts this object from CFF format to CFF2 format. This conversion
     is done 'in-place'. The conversion cannot be reversed.
 
@@ -113,6 +113,14 @@ def convertCFFToCFF2(cff, otFont):
     cff.decompile(file, otFont, isCFF2=True)
 
 
+def convertCFFToCFF2(font):
+    cff = font["CFF "].cff
+    del font["CFF "]
+    _convertCFFToCFF2(cff, font)
+    table = font["CFF2"] = newTable("CFF2")
+    table.cff = cff
+
+
 def main(args=None):
     """Convert CFF OTF font to CFF2 OTF font"""
     if args is None:
@@ -170,13 +178,8 @@ def main(args=None):
     )
 
     font = TTFont(infile, recalcTimestamp=options.recalc_timestamp, recalcBBoxes=False)
-    cff = font["CFF "].cff
-    del font["CFF "]
 
-    cff.convertCFFToCFF2(font)
+    convertCFFToCFF2(font)
-
-    table = font["CFF2"] = newTable("CFF2")
-    table.cff = cff
 
     log.info(
         "Saving %s",

Lib/fontTools/cffLib/__init__.py

@@ -386,14 +386,14 @@ class CFFFontSet(object):
             self.minor = int(attrs["value"])
 
     def convertCFFToCFF2(self, otFont):
-        from .CFFToCFF2 import convertCFFToCFF2
+        from .CFFToCFF2 import _convertCFFToCFF2
 
-        convertCFFToCFF2(self, otFont)
+        _convertCFFToCFF2(self, otFont)
 
     def convertCFF2ToCFF(self, otFont):
-        from .CFF2ToCFF import convertCFF2ToCFF
+        from .CFF2ToCFF import _convertCFF2ToCFF
 
-        convertCFF2ToCFF(self, otFont)
+        _convertCFF2ToCFF(self, otFont)
 
     def desubroutinize(self):
         for fontName in self.fontNames:

Lib/fontTools/varLib/__init__.py

@@ -845,9 +845,10 @@ def _add_CFF2(varFont, model, master_fonts):
 
     glyphOrder = varFont.getGlyphOrder()
     if "CFF2" not in varFont:
-        from .cff import convertCFFtoCFF2
+        from fontTools.cffLib.CFFToCFF2 import convertCFFToCFF2
+
+        convertCFFToCFF2(varFont)
 
-        convertCFFtoCFF2(varFont)
     ordered_fonts_list = model.reorderMasters(master_fonts, model.reverseMapping)
     # re-ordering the master list simplifies building the CFF2 data item lists.
     merge_region_fonts(varFont, model, ordered_fonts_list, glyphOrder)

Lib/fontTools/varLib/cff.py

@@ -13,7 +13,6 @@ from fontTools.cffLib import (
 )
 from io import BytesIO
 from fontTools.cffLib.specializer import specializeCommands, commandsToProgram
-from fontTools.cffLib.CFFToCFF2 import convertCFFToCFF2 as lib_convertCFFToCFF2
 from fontTools.ttLib import newTable
 from fontTools import varLib
 from fontTools.varLib.models import allEqual
@@ -50,16 +49,6 @@ def addCFFVarStore(varFont, varModel, varDataList, masterSupports):
                 fontDict.Private.vstore = topDict.VarStore
 
 
-def convertCFFtoCFF2(varFont):
-    # Convert base font to a single master CFF2 font.
-    cffTable = varFont["CFF "]
-    lib_convertCFFToCFF2(cffTable.cff, varFont)
-    newCFF2 = newTable("CFF2")
-    newCFF2.cff = cffTable.cff
-    varFont["CFF2"] = newCFF2
-    del varFont["CFF "]
-
-
 def conv_to_int(num):
     if isinstance(num, float) and num.is_integer():
         return int(num)

Lib/fontTools/varLib/instancer/__init__.py

@@ -601,10 +601,9 @@ def instantiateCFF2(
     varStore = topDict.VarStore.otVarStore
     if not varStore:
         if downgrade:
-            table = varfont["CFF "] = newTable("CFF ")
+            from fontTools.cffLib.CFF2ToCFF import convertCFF2ToCFF
-            table.cff = cff
+
-            cff.convertCFF2ToCFF(varfont)
+            convertCFF2ToCFF(varfont)
-            del varfont["CFF2"]
         return
 
     cff.desubroutinize()
@@ -821,10 +820,9 @@ def instantiateCFF2(
             del private.vstore
 
         if downgrade:
-            table = varfont["CFF "] = newTable("CFF ")
+            from fontTools.cffLib.CFF2ToCFF import convertCFF2ToCFF
-            table.cff = cff
+
-            cff.convertCFF2ToCFF(varfont)
+            convertCFF2ToCFF(varfont)
-            del varfont["CFF2"]
 
 
 def _instantiateGvarGlyph(

Tests/fontBuilder/fontBuilder_test.py

@@ -330,9 +330,9 @@ def test_build_cff_to_cff2(tmpdir):
     }
     fb.setupCFF("TestFont", {}, charStrings, {})
 
-    from fontTools.varLib.cff import convertCFFtoCFF2
+    from fontTools.cffLib.CFFToCFF2 import convertCFFToCFF2
 
-    convertCFFtoCFF2(fb.font)
+    convertCFFToCFF2(fb.font)
 
 
 def test_setupNameTable_no_mac():