add --no-auto-use-my-metrics to disable setting USE_MY_METRICS in ufo2ft

Requires googlefonts/ufo2ft#741

Lib/fontmake/__main__.py

@@ -504,6 +504,12 @@ def main(args=None):
         "in the UFO lib. You can use an ellipsis --filter='...' to keep the "
         "latter and insert additional --filter(s), either before or after it.",
     )
+    contourGroup.add_argument(
+        "--no-auto-use-my-metrics",
+        dest="auto_use_my_metrics",
+        action="store_false",
+        help="Don't automatically set USE_MY_METRICS glyf component flags (0x0200)."
+    )
 
     layoutGroup = parser.add_argument_group(title="Handling of OpenType Layout")
     layoutGroup.add_argument(

Lib/fontmake/font_project.py

@@ -312,6 +312,7 @@ def _build_interpolatable_masters(
         fea_include_dir=None,
         flatten_components=False,
         filters=None,
+        auto_use_my_metrics=True,
         **kwargs,
     ):
         if ttf:
@@ -325,6 +326,7 @@ def _build_interpolatable_masters(
                 feaIncludeDir=fea_include_dir,
                 filters=filters,
                 flattenComponents=flatten_components,
+                autoUseMyMetrics=auto_use_my_metrics,
                 inplace=True,
             )
         else:
@@ -369,6 +371,7 @@ def build_variable_fonts(
         fea_include_dir=None,
         flatten_components=False,
         filters=None,
+        auto_use_my_metrics=True,
         **kwargs,
     ):
         """Build OpenType variable fonts from masters in a designspace."""
@@ -430,6 +433,7 @@ def build_variable_fonts(
                 filters=filters,
                 inplace=True,
                 variableFontNames=list(vf_name_to_output_path),
+                autoUseMyMetrics=auto_use_my_metrics,
             )
         else:
             fonts = ufo2ft.compileVariableCFF2s(
@@ -461,6 +465,7 @@ def _iter_compile(self, ufos, ttf=False, debugFeatureFile=None, **kwargs):
                 "cubicConversionError",
                 "reverseDirection",
                 "flattenComponents",
+                "autoUseMyMetrics",
             ):
                 options.pop(key, None)
             compile_func, fmt = ufo2ft.compileOTF, "OTF"
@@ -507,6 +512,7 @@ def save_otfs(
         filters=None,
         generate_GDEF=True,
         fea_include_dir=None,
+        auto_use_my_metrics=True,
     ):
         """Build OpenType binaries from UFOs.
 
@@ -562,6 +568,8 @@ def save_otfs(
                 pre-filters or post-filters, called before or after the default
                 filters. The default filters are format specific and some can
                 be disabled with other arguments.
+            auto_use_my_metrics: whether to automatically set USE_MY_METRICS glyf
+                component flags (0x0200). Not needed unless the font has hinted metrics.
         """  # noqa: B950
         assert not (output_path and output_dir), "mutually exclusive args"
 
@@ -615,6 +623,7 @@ def save_otfs(
             subroutinizer=subroutinizer,
             flattenComponents=flatten_components,
             filters=filters,
+            autoUseMyMetrics=auto_use_my_metrics,
             inplace=True,  # avoid extra copy
         )