Use fontc as alternative gftools.builder compiler

Lib/gftools/builder/operations/__init__.py

@@ -5,13 +5,25 @@
 import pkgutil
 import importlib
 import inspect
+import logging
 import sys
 from os.path import dirname
 from tempfile import NamedTemporaryFile
 
 from gftools.builder.file import File
 from gftools.utils import shell_quote
 
+log = logging.getLogger(__name__)
+
+
+# Grossness to allow class properties in Python
+class classproperty:
+    def __init__(self, func):
+        self.fget = func
+
+    def __get__(self, instance, owner):
+        return self.fget(owner)
+
 
 @dataclass
 class OperationBase:
@@ -131,9 +143,24 @@ def validate(self):
 
 
 class FontmakeOperationBase(OperationBase):
+    COMPILER_ENV_KEY = "GFTOOLS_COMPILER"
+    static = False
+    format = "ttf"
+
+    @classproperty
+    def rule(self):
+        if self.compiler == "fontmake":
+            return "fontmake --output-path $out -o $format $fontmake_type $in $args"
+        else:
+            # Construct a ninja rule which correctly builds the requested font type
+            # (Good luck with fontmake args...)
+            return "fontc -o $out $in $args"
+
     @property
     def variables(self):
         vars = defaultdict(str)
+        vars["compiler"] = self.compiler
+        vars["format"] = self.format  # buildTTF -> ttf, etc.
         for k, v in self.original.items():
             if k != "needs":
                 vars[k] = v
@@ -144,11 +171,42 @@ def variables(self):
             vars["fontmake_type"] = "-m"
         elif self.first_source.is_ufo:
             vars["fontmake_type"] = "-u"
-        if "--verbose" not in vars["fontmake_args"]:
-            vars["fontmake_args"] += " --verbose WARNING "
+        if "--verbose" not in vars["args"]:
+            vars["args"] += " --verbose WARNING "
+
+        if "--filter" in vars["args"] and self.compiler == "fontc":
+            log.warning("Cannot use --filter with fontc, dropping arguments...")
+            del vars["args"]
 
         return vars
 
+    @property
+    def compiler(self):
+        return self.original.get(
+            "compiler", os.environ.get(self.COMPILER_ENV_KEY, "fontmake")
+        )
+
+    def validate(self):
+        if self.static:
+            if not self.first_source.exists():
+                # We can't check this file (assume it was generated as part of the
+                # build), so user is on their own.
+                return
+            if (
+                self.first_source.is_glyphs
+                and len(self.first_source.gsfont.masters) > 1
+            ):
+                raise ValueError(
+                    f"Cannot build a static font from {self.first_source.path}"
+                )
+            if (
+                self.first_source.designspace
+                and len(self.first_source.designspace.sources) > 1
+            ):
+                raise ValueError(
+                    f"Cannot build a static font from {self.first_source.path}"
+                )
+
 
 known_operations = {}
 

Lib/gftools/builder/operations/buildOTF.py

@@ -3,21 +3,5 @@
 
 class BuildOTF(FontmakeOperationBase):
     description = "Build a OTF from a source file"
-    rule = "fontmake --output-path $out -o otf $fontmake_type $in $args"
-
-    def validate(self):
-        if not self.first_source.exists():
-            # We can't check this file (assume it was generated as part of the
-            # build), so user is on their own.
-            return
-        if self.first_source.is_glyphs and len(self.first_source.gsfont.masters) > 1:
-            raise ValueError(
-                f"Cannot build a static font from {self.first_source.path}"
-            )
-        if (
-            self.first_source.designspace
-            and len(self.first_source.designspace.sources) > 1
-        ):
-            raise ValueError(
-                f"Cannot build a static font from {self.first_source.path}"
-            )
+    format = "otf"
+    static = True

Lib/gftools/builder/operations/buildTTF.py

@@ -3,21 +3,5 @@
 
 class BuildTTF(FontmakeOperationBase):
     description = "Build a TTF from a source file"
-    rule = "fontmake --output-path $out -o ttf $fontmake_type $in $args"
-
-    def validate(self):
-        if not self.first_source.exists():
-            # We can't check this file (assume it was generated as part of the
-            # build), so user is on their own.
-            return
-        if self.first_source.is_glyphs and len(self.first_source.gsfont.masters) > 1:
-            raise ValueError(
-                f"Cannot build a static font from {self.first_source.path}"
-            )
-        if (
-            self.first_source.designspace
-            and len(self.first_source.designspace.sources) > 1
-        ):
-            raise ValueError(
-                f"Cannot build a static font from {self.first_source.path}"
-            )
+    static = True
+    format = "ttf"

Lib/gftools/builder/operations/buildVariable.py

@@ -3,4 +3,5 @@
 
 class BuildVariable(FontmakeOperationBase):
     description = "Build a variable font from a source file"
-    rule = "fontmake --output-path $out -o variable $fontmake_type $in $args"
+    format = "variable"
+    static = False

Lib/gftools/builder/schema.py

@@ -109,5 +109,6 @@
         Optional("extraStaticFontmakeArgs"): Str(),
         Optional("buildSmallCap"): Bool(),
         Optional("splitItalic"): Bool(),
+        Optional("localMetadata"): Any(),
     }
 )

docs/gftools-builder/README.md

@@ -204,6 +204,9 @@ The build can be customized by adding the following keys to the YAML file:
     subspace them into separate roman and italic VF files to comply with
     Google Fonts' specification. Defaults to true.
 
+-   `localMetadata`: A field that's ignored so you can put whatever you like in it.
+
+
 ## *Really* customizing the build process
 
 If the options above aren't enough for you - let's say you want to run your