Use JSON format UFOs for intermediaries, fixes googlefonts#731

Lib/gftools/builder/__init__.py

@@ -99,11 +99,11 @@ def glyphs_to_ufo(self, source):
         FontProject().run_from_glyphs(
             str(source.resolve()),
             **{
-                "format": ["ufo"],
                 "output": ["ufo"],
                 "output_dir": directory,
                 "master_dir": directory,
                 "designspace_path": output,
+                "ufo_structure": "json"
             },
         )
         return source.with_suffix(".designspace").name

Lib/gftools/builder/file.py

@@ -6,6 +6,8 @@
 from fontTools.designspaceLib import InstanceDescriptor
 from glyphsLib.builder import UFOBuilder
 
+from gftools.utils import open_ufo
+
 
 @dataclass
 class File:
@@ -35,7 +37,7 @@ def is_glyphs(self):
 
     @property
     def is_ufo(self):
-        return self.extension == "ufo"
+        return self.extension == "ufo" or ".ufo.json" in self.path
 
     @property
     def is_designspace(self):
@@ -79,7 +81,7 @@ def family_name(self):
         elif self.designspace.sources[0].familyName:
             return self.designspace.sources[0].familyName
         else:
-            self.designspace.loadSourceFonts(ufoLib2.Font.open)
+            self.designspace.loadSourceFonts(open_ufo)
             self.designspace.sources[0].font.info.familyName
         return name
 

Lib/gftools/builder/operations/addSubset.py

@@ -10,7 +10,7 @@
 
 class AddSubset(OperationBase):
     description = "Add a subset from another font"
-    rule = "gftools-add-ds-subsets -y $yaml -o $out $in"
+    rule = "gftools-add-ds-subsets -j -y $yaml -o $out $in"
 
     def validate(self):
         # Ensure there is a new name

Lib/gftools/builder/operations/instantiateUfo.py

@@ -46,12 +46,13 @@ def targets(self):
         assert instance is not None
         assert instance.filename is not None
         # if self.first_source.is_glyphs:
-        return [ File(str(self.instance_dir / os.path.basename(instance.filename))) ]
+        return [ File(str(self.instance_dir / (os.path.basename(instance.filename)+".json"))) ]
         # return [ File(instance.filename) ]
 
     @property
     def variables(self):
         vars = super().variables
+        vars["fontmake_args"] += " --ufo-structure=json "
         if self.first_source.is_glyphs:
             vars["fontmake_args"] += f"--instance-dir {escape_path(str(self.instance_dir))}"
         else:

Lib/gftools/builder/recipeproviders/noto.py

@@ -218,7 +218,7 @@ def build_a_static(self, source, instance, output):
                     "operation": "instantiateUfo",
                     "instance_name": instance.name,
                     "target": "full-designspace/instance_ufos/"
-                    + os.path.basename(instance.filename),
+                    + os.path.basename(instance.filename)+".json",
                 },
                 {"operation": "buildTTF" if output == "ttf" else "buildOTF"},
             ]

Lib/gftools/scripts/add_ds_subsets.py

@@ -78,6 +78,9 @@ def main(args=None):
     parser.add_argument("--file", "-f", help="Source file within GitHub repository")
     parser.add_argument("--name", "-n", help="Name of subset to use from glyphset")
     parser.add_argument("--codepoints", "-c", help="Range of codepoints to subset")
+    parser.add_argument(
+        "--json", "-j", action="store_true", help="Use JSON structured UFOs"
+    )
 
     parser.add_argument("--output", "-o", help="Output designspace file")
 
@@ -122,7 +125,7 @@ def main(args=None):
                     }
                 )
     SubsetMerger(
-        args.input, args.output, subsets, googlefonts=args.googlefonts
+        args.input, args.output, subsets, googlefonts=args.googlefonts, json=args.json
     ).add_subsets()
 
 

Lib/gftools/subsetmerger.py

@@ -17,7 +17,7 @@
 from ufomerge import merge_ufos
 
 from gftools.util.styles import STYLE_NAMES
-from gftools.utils import download_file
+from gftools.utils import download_file, open_ufo
 
 logger = logging.getLogger(__name__)
 logging.basicConfig(level=logging.INFO)
@@ -92,12 +92,13 @@ def prepare_minimal_subsets(subsets):
 
 class SubsetMerger:
     def __init__(
-        self, input_ds, output_ds, subsets, googlefonts=False, cache="../subset-files"
+        self, input_ds, output_ds, subsets, googlefonts=False, cache="../subset-files", json=False
     ):
         self.input = input_ds
         self.output = output_ds
         self.subsets = prepare_minimal_subsets(subsets)
         self.googlefonts = googlefonts
+        self.json = json
         self.cache_dir = cache
         self.subset_instances = {}
 
@@ -107,13 +108,6 @@ def add_subsets(self):
         outpath = Path(self.output).parent
         added_subsets = False
         for master in ds.sources:
-            # Clone the UFO before doing anything clever with it.
-            newpath = os.path.join(outpath, os.path.basename(master.path))
-            original_ufo = ufoLib2.Font.open(master.path)
-            original_ufo.save(newpath, overwrite=True)
-
-            master.path = newpath
-
             for subset in self.subsets:
                 added_subsets |= self.add_subset(ds, master, subset)
         if not added_subsets:
@@ -137,7 +131,7 @@ def add_subset(self, ds, ds_source, subset):
             return False
 
         # Open it up and send it to ufomerge, using the options supplied.
-        target_ufo = ufoLib2.Font.open(ds_source.path)
+        target_ufo = open_ufo(ds_source.path)
         existing_handling = "skip"
         if subset.get("force"):
             existing_handling = "replace"
@@ -152,7 +146,14 @@ def add_subset(self, ds, ds_source, subset):
             existing_handling=existing_handling,
             layout_handling=layout_handling,
         )
-        target_ufo.save(ds_source.path, overwrite=True)
+        if self.json:
+            if not ds_source.path.endswith(".json"):
+                ds_source.path += ".json"
+                if ds_source.filename:
+                    ds_source.filename += ".json"
+                target_ufo.json_dump(open(ds_source.path+".json", "wb"))
+        else:
+            target_ufo.save(ds_source.path, overwrite=True)
         return True
 
     def obtain_upstream(self, upstream, location):
@@ -187,7 +188,7 @@ def obtain_upstream(self, upstream, location):
         source_ds = DesignSpaceDocument.fromfile(path)
         source_ufo = self.find_source_for_location(source_ds, location, font_name)
         if source_ufo:
-            return ufoLib2.Font.open(source_ufo.path)
+            return open_ufo(source_ufo.path)
         return None
 
     def glyphs_to_ufo(self, source, directory=None):

Lib/gftools/utils.py

@@ -19,6 +19,7 @@
 import sys
 import os
 import shutil
+import ufoLib2
 import unicodedata
 from unidecode import unidecode
 from collections import namedtuple
@@ -536,3 +537,12 @@ def primary_script(ttFont, ignore_latin=True):
     most_common = script_count.most_common(1)
     if most_common:
         return most_common[0][0]
+
+
+def open_ufo(path):
+    if os.path.isdir(path):
+        return ufoLib2.Font.open(path)
+    elif path.endswith(".json"):
+        return ufoLib2.Font.json_load(open(path, "rb"))
+    else:  # Maybe a .ufoz
+        return ufoLib2.Font.open(path)

pyproject.toml

@@ -45,7 +45,7 @@ dependencies = [
   'vttlib',
   'pygit2',
   'strictyaml',
-  'fontmake>=3.3.0',
+  'fontmake[json]>=3.3.0',
   'skia-pathops',
   'statmake',
   'PyYAML',