1 files changed, 59 insertions, 0 deletions
diff --git a/Lib/fontTools/config/__init__.py b/Lib/fontTools/config/__init__.py
new file mode 100644
index 00000000..f5a62eaf
--- /dev/null
+++ b/Lib/fontTools/config/__init__.py
@@ -0,0 +1,59 @@
+"""
+Define all configuration options that can affect the working of fontTools
+modules. E.g. optimization levels of varLib IUP, otlLib GPOS compression level,
+etc. If this file gets too big, split it into smaller files per-module.
+
+An instance of the Config class can be attached to a TTFont object, so that
+the various modules can access their configuration options from it.
+"""
+from textwrap import dedent
+
+from fontTools.misc.configTools import *
+
+
+class Config(AbstractConfig):
+    options = Options()
+
+
+OPTIONS = Config.options
+
+
+Config.register_option(
+    name="fontTools.otlLib.optimize.gpos:COMPRESSION_LEVEL",
+    help=dedent(
+        """\
+        GPOS Lookup type 2 (PairPos) compression level:
+            0 = do not attempt to compact PairPos lookups;
+            1 to 8 = create at most 1 to 8 new subtables for each existing
+                subtable, provided that it would yield a 50%% file size saving;
+            9 = create as many new subtables as needed to yield a file size saving.
+        Default: 0.
+
+        This compaction aims to save file size, by splitting large class
+        kerning subtables (Format 2) that contain many zero values into
+        smaller and denser subtables. It's a trade-off between the overhead
+        of several subtables versus the sparseness of one big subtable.
+
+        See the pull request: https://github.com/fonttools/fonttools/pull/2326
+        """
+    ),
+    default=0,
+    parse=int,
+    validate=lambda v: v in range(10),
+)
+
+Config.register_option(
+    name="fontTools.ttLib.tables.otBase:USE_HARFBUZZ_REPACKER",
+    help=dedent(
+        """\
+        FontTools tries to use the HarfBuzz Repacker to serialize GPOS/GSUB tables
+        if the uharfbuzz python bindings are importable, otherwise falls back to its
+        slower, less efficient serializer. Set to False to always use the latter.
+        Set to True to explicitly request the HarfBuzz Repacker (will raise an
+        error if uharfbuzz cannot be imported).
+        """
+    ),
+    default=None,
+    parse=Option.parse_optional_bool,
+    validate=Option.validate_optional_bool,
+)