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

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
  )