[feaLib] Parse ValueRecord format C

However, not sure how to build the otTables object graph for emitting
GPOS tables with device values; the current code thus silently strips
off any device values. Left a TODO comment for implementing this.

Lib/fontTools/feaLib/ast.py

@@ -197,12 +197,13 @@ class SubstitutionRule(Statement):
 
 
 class ValueRecord(Statement):
-    def __init__(self, location, xPlacement, yPlacement, xAdvance, yAdvance):
+    def __init__(self, location, xPlacement, yPlacement, xAdvance, yAdvance,
+                 xPlaDevice, yPlaDevice, xAdvDevice, yAdvDevice):
         Statement.__init__(self, location)
         self.xPlacement, self.yPlacement = (xPlacement, yPlacement)
         self.xAdvance, self.yAdvance = (xAdvance, yAdvance)
-        self.xPlaDevice, self.yPlaDevice = (0, 0)
+        self.xPlaDevice, self.yPlaDevice = (xPlaDevice, yPlaDevice)
-        self.xAdvDevice, self.yAdvDevice = (0, 0)
+        self.xAdvDevice, self.yAdvDevice = (xAdvDevice, yAdvDevice)
 
     def __eq__(self, other):
         return (self.xPlacement == other.xPlacement and

Lib/fontTools/feaLib/builder.py

@@ -327,14 +327,20 @@ def makeOpenTypeValueRecord(v):
         vr.XAdvance = v.xAdvance
     if v.yAdvance:
         vr.YAdvance = v.yAdvance
-    if v.xPlaDevice:
+
-        vr.XPlaDevice = v.xPlaDevice
+    # TODO: Implement the following. Not sure how, though.
-    if v.yPlaDevice:
+    # The commented-out lines did not work; the problem is that we need to
-        vr.YPlaDevice = v.yPlaDevice
+    # construct a Device table with an array of delta values.
-    if v.xAdvDevice:
+    # if v.xPlaDevice:
-        vr.XAdvDevice = v.xAdvDevice
+    #    vr.XPlaDevice = otTables.XPlaDevice()
-    if v.yAdvDevice:
+    #    vr.XPlaDevice.value = v.xPlaDevice
-        vr.YAdvDevice = v.yAdvDevice
+    # if v.yPlaDevice:
+    #     vr.YPlaDevice = v.yPlaDevice
+    # if v.xAdvDevice:
+    #     vr.XAdvDevice = v.xAdvDevice
+    # if v.yAdvDevice:
+    #    vr.YAdvDevice = v.yAdvDevice
+
     vrMask = 0
     for mask, name, _, _ in otBase.valueRecordFormat:
         if getattr(vr, name, 0) != 0:

Lib/fontTools/feaLib/parser.py

@@ -332,9 +332,9 @@ class Parser(object):
         if self.next_token_type_ is Lexer.NUMBER:
             number, location = self.expect_number_(), self.cur_token_location_
             if vertical:
-                val = ast.ValueRecord(location, 0, 0, 0, number)
+                val = ast.ValueRecord(location, 0, 0, 0, number, 0, 0, 0, 0)
             else:
-                val = ast.ValueRecord(location, 0, 0, number, 0)
+                val = ast.ValueRecord(location, 0, 0, number, 0, 0, 0, 0, 0)
             return val
         self.expect_symbol_("<")
         location = self.cur_token_location_
@@ -351,9 +351,16 @@ class Parser(object):
             xPlacement, yPlacement, xAdvance, yAdvance = (
                 self.expect_number_(), self.expect_number_(),
                 self.expect_number_(), self.expect_number_())
+        if self.next_token_type_ is Lexer.NUMBER:
+            xPlaDevice, yPlaDevice, xAdvDevice, yAdvDevice = (
+                self.expect_number_(), self.expect_number_(),
+                self.expect_number_(), self.expect_number_())
+        else:
+            xPlaDevice, yPlaDevice, xAdvDevice, yAdvDevice = (0, 0, 0, 0)
         self.expect_symbol_(">")
         return ast.ValueRecord(
-            location, xPlacement, yPlacement, xAdvance, yAdvance)
+            location, xPlacement, yPlacement, xAdvance, yAdvance,
+            xPlaDevice, yPlaDevice, xAdvDevice, yAdvDevice)
 
     def parse_valuerecord_definition_(self, vertical):
         assert self.is_cur_keyword_("valueRecordDef")

Lib/fontTools/feaLib/parser_test.py

@@ -444,6 +444,10 @@ class ParserTest(unittest.TestCase):
         self.assertEqual(value.yPlacement, 0)
         self.assertEqual(value.xAdvance, 123)
         self.assertEqual(value.yAdvance, 0)
+        self.assertEqual(value.xPlaDevice, 0)
+        self.assertEqual(value.yPlaDevice, 0)
+        self.assertEqual(value.xAdvDevice, 0)
+        self.assertEqual(value.yAdvDevice, 0)
 
     def test_valuerecord_format_a_vertical(self):
         doc = self.parse("feature vkrn {valueRecordDef 123 foo;} vkrn;")
@@ -452,6 +456,10 @@ class ParserTest(unittest.TestCase):
         self.assertEqual(value.yPlacement, 0)
         self.assertEqual(value.xAdvance, 0)
         self.assertEqual(value.yAdvance, 123)
+        self.assertEqual(value.xPlaDevice, 0)
+        self.assertEqual(value.yPlaDevice, 0)
+        self.assertEqual(value.xAdvDevice, 0)
+        self.assertEqual(value.yAdvDevice, 0)
 
     def test_valuerecord_format_b(self):
         doc = self.parse("feature liga {valueRecordDef <1 2 3 4> foo;} liga;")
@@ -460,6 +468,23 @@ class ParserTest(unittest.TestCase):
         self.assertEqual(value.yPlacement, 2)
         self.assertEqual(value.xAdvance, 3)
         self.assertEqual(value.yAdvance, 4)
+        self.assertEqual(value.xPlaDevice, 0)
+        self.assertEqual(value.yPlaDevice, 0)
+        self.assertEqual(value.xAdvDevice, 0)
+        self.assertEqual(value.yAdvDevice, 0)
+
+    def test_valuerecord_format_c(self):
+        doc = self.parse(
+            "feature liga {valueRecordDef <1 2 3 4 5 6 7 8> foo;} liga;")
+        value = doc.statements[0].statements[0].value
+        self.assertEqual(value.xPlacement, 1)
+        self.assertEqual(value.yPlacement, 2)
+        self.assertEqual(value.xAdvance, 3)
+        self.assertEqual(value.yAdvance, 4)
+        self.assertEqual(value.xPlaDevice, 5)
+        self.assertEqual(value.yPlaDevice, 6)
+        self.assertEqual(value.xAdvDevice, 7)
+        self.assertEqual(value.yAdvDevice, 8)
 
     def test_valuerecord_named(self):
         doc = self.parse("valueRecordDef <1 2 3 4> foo;"

Lib/fontTools/feaLib/testdata/GPOS_1.fea

@@ -4,8 +4,8 @@ languagesystem DFLT dflt;
 
 feature kern {
     position [one two three] <-80 0 -160 0>;
-    position A <1 2 3 4>;
+    position A <1 2 3 4 5 6 7 8>;
-    position B <1 2 3 4>;
+    position B <1 2 3 4 5 6 7 8>;
     position four 400;
     position five <-80 0 -160 0>;
     position six -200;