[cantarell-fonts] Make use of new ufo2ft and fontTools APIs

[Nikolaus Waxweiler <nwaxweiler src gnome org>]

commit 64b909ca931bb031b3229b6c9de01e0e665191d2
Author: Nikolaus Waxweiler <madigens gmail com>
Date:   Mon May 13 21:36:40 2019 +0100

    Make use of new ufo2ft and fontTools APIs

 scripts/instantiator.py       |  6 ++----
 scripts/make-variable-font.py | 24 ++++--------------------
 2 files changed, 6 insertions(+), 24 deletions(-)
---
diff --git a/scripts/instantiator.py b/scripts/instantiator.py
index a989c1c4..f5e9f485 100644
--- a/scripts/instantiator.py
+++ b/scripts/instantiator.py
@@ -66,12 +66,10 @@ class Instantiator:
                 "Can't generate UFOs from this designspace: no default font."
             )
 
+        designspace.loadSourceFonts(ufoLib2.Font.open)
+
         glyph_names: Set[str] = set()
         for source in designspace.sources:
-            if source.font is None:
-                if not Path(source.path).exists():
-                    raise ValueError(f"Source at path '{source.path}' not found.")
-                source.font = ufoLib2.Font.open(source.path, lazy=False)
             glyph_names.update(source.font.keys())
 
         # Construct Variators
diff --git a/scripts/make-variable-font.py b/scripts/make-variable-font.py
index 046f9f0a..e31cba32 100644
--- a/scripts/make-variable-font.py
+++ b/scripts/make-variable-font.py
@@ -32,32 +32,16 @@ output_path = args.output_path.resolve()
 
 # 1. Load Designspace and filter out instances that are marked as non-exportable.
 designspace = fontTools.designspaceLib.DesignSpaceDocument.fromfile(designspace_path)
-for source in designspace.sources:
-    source.font = ufoLib2.Font.open(designspace_path.parent / source.filename)
-
-    # 1.5. Apply ufo2ft filters to masters before compiling them -- in ufo2ft up to and
-    # including 2.8.0, filters were applied in compileInterpolatableOTFsFromDS, but not
-    # compileInterpolatableTTFsFromDS. Do it manually to be sure...
-    pre_filter, post_filter = ufo2ft.filters.loadFilters(source.font)
-    for pf in pre_filter:
-        pf(font=source.font)
-    for pf in post_filter:
-        pf(font=source.font)
-
-    # ... and then delete the key so they aren't re-applied.
-    del source.font.lib["com.github.googlei18n.ufo2ft.filters"]
+designspace.loadSourceFonts(ufoLib2.Font.open)
 
 designspace.instances = [
     s for s in designspace.instances if s.lib.get("com.schriftgestaltung.export", True)
 ]
 
-# 2. Compile interpolatable master TTFs.
-ufo2ft.compileInterpolatableTTFsFromDS(designspace, inplace=True)
-
-# 3. Combine masters into a variable TTF.
-varfont, _, _ = fontTools.varLib.build(designspace)
+# 2. Compile variable TTF from the masters.
+varfont = ufo2ft.compileVariableTTF(designspace, inplace=True)
 
-# 4. Generate STAT table.
+# 3. Generate STAT table.
 stylespace = statmake.classes.Stylespace.from_file(stylespace_path)
 statmake.lib.apply_stylespace_to_variable_font(stylespace, varfont, {})