[otlLib] Move building of MarkLigPos from feaLib to otlLib

Lib/fontTools/feaLib/builder.py

@@ -984,7 +984,6 @@ class MarkLigPosBuilder(LookupBuilder):
 
     def build(self):
         markClasses = self.buildMarkClasses_(self.marks)
-        markClassList = sorted(markClasses.keys(), key=markClasses.get)
         marks = {mark: (markClasses[mc], anchor)
                  for mark, (mc, anchor) in self.marks.items()}
         ligs = {}
@@ -992,16 +991,8 @@ class MarkLigPosBuilder(LookupBuilder):
             ligs[lig] = []
             for c in components:
                 ligs[lig].append({markClasses[mc]: a for mc, a in c.items()})
-
+        subtables = otl.buildMarkLigPos(marks, ligs, self.glyphMap)
-        st = otTables.MarkLigPos()
+        return self.buildLookup_(subtables)
-        st.Format = 1
-        st.MarkCoverage = otl.buildCoverage(marks, self.glyphMap)
-        st.MarkArray = otl.buildMarkArray(marks, self.glyphMap)
-        st.ClassCount = max([mc for mc, _ in marks.values()]) + 1
-        st.LigatureCoverage = otl.buildCoverage(ligs, self.glyphMap)
-        st.LigatureArray = \
-            otl.buildLigatureArray(ligs, st.ClassCount, self.glyphMap)
-        return self.buildLookup_([st])
 
 
 class MarkMarkPosBuilder(LookupBuilder):

Lib/fontTools/otlLib/builder.py

@@ -211,7 +211,7 @@ def buildMarkArray(marks, glyphMap):
 def buildMarkBasePos(marks, bases, glyphMap):
     """Build a list of MarkBasePos subtables.
 
-    a1, a2, a3, a4 = buildAnchor(500, 100), ...
+    a1, a2, a3, a4, a5 = buildAnchor(500, 100), ...
     marks = {"acute": (0, a1), "grave": (0, a1), "cedilla": (1, a2)}
     bases = {"a": {0: a3, 1: a5}, "b": {0: a4, 1: a5}}
     """
@@ -232,7 +232,7 @@ def buildMarkBasePos(marks, bases, glyphMap):
 def buildMarkBasePosSubtable(marks, bases, glyphMap):
     """Build a single MarkBasePos subtable.
 
-    a1, a2, a3, a4 = buildAnchor(500, 100), ...
+    a1, a2, a3, a4, a5 = buildAnchor(500, 100), ...
     marks = {"acute": (0, a1), "grave": (0, a1), "cedilla": (1, a2)}
     bases = {"a": {0: a3, 1: a5}, "b": {0: a4, 1: a5}}
     """
@@ -246,6 +246,37 @@ def buildMarkBasePosSubtable(marks, bases, glyphMap):
     return self
 
 
+def buildMarkLigPos(marks, ligs, glyphMap):
+    """Build a list of MarkLigPos subtables.
+
+    a1, a2, a3, a4, a5 = buildAnchor(500, 100), ...
+    marks = {"acute": (0, a1), "grave": (0, a1), "cedilla": (1, a2)}
+    ligs = {"f_i": [{0: a3, 1: a5},  {0: a4, 1: a5}], "c_t": [{...}, {...}]}
+    """
+    # TODO: Consider splitting into multiple subtables to save space,
+    # as with MarkBasePos, this would be a trade-off that would need
+    # profiling. And, depending on how typical fonts are structured,
+    # it might not be worth doing at all.
+    return [buildMarkLigPosSubtable(marks, ligs, glyphMap)]
+
+
+def buildMarkLigPosSubtable(marks, ligs, glyphMap):
+    """Build a single MarkLigPos subtable.
+
+    a1, a2, a3, a4, a5 = buildAnchor(500, 100), ...
+    marks = {"acute": (0, a1), "grave": (0, a1), "cedilla": (1, a2)}
+    ligs = {"f_i": [{0: a3, 1: a5},  {0: a4, 1: a5}], "c_t": [{...}, {...}]}
+    """
+    self = ot.MarkLigPos()
+    self.Format = 1
+    self.MarkCoverage = buildCoverage(marks, glyphMap)
+    self.MarkArray = buildMarkArray(marks, glyphMap)
+    self.ClassCount = max([mc for mc, _ in marks.values()]) + 1
+    self.LigatureCoverage = buildCoverage(ligs, glyphMap)
+    self.LigatureArray = buildLigatureArray(ligs, self.ClassCount, glyphMap)
+    return self
+
+
 def buildMarkRecord(classID, anchor):
     assert isinstance(classID, int)
     assert isinstance(anchor, ot.Anchor)

Lib/fontTools/otlLib/builder_test.py

@@ -632,6 +632,100 @@ class BuilderTest(unittest.TestCase):
     def test_buildMarkGlyphSetsDef_None(self):
         self.assertIsNone(builder.buildMarkGlyphSetsDef(None, self.GLYPHMAP))
 
+    def test_buildMarkLigPosSubtable(self):
+        anchor = builder.buildAnchor
+        marks = {
+            "acute": (0, anchor(300, 700)),
+            "cedilla": (1, anchor(300, -100)),
+            "grave": (0, anchor(300, 700))
+        }
+        bases = {
+            "f_i": [{}, {0: anchor(200, 400)}],  # nothing on f; only 1 on i
+            "c_t": [
+                {0: anchor(500, 600), 1: anchor(500, -20)},   # c
+                {0: anchor(1300, 800), 1: anchor(1300, -20)}  # t
+            ]
+        }
+        table = builder.buildMarkLigPosSubtable(marks, bases, self.GLYPHMAP)
+        self.maxDiff = None
+        self.assertEqual(getXML(table.toXML),
+                         '<MarkLigPos Format="1">'
+                         '  <MarkCoverage>'
+                         '    <Glyph value="grave"/>'
+                         '    <Glyph value="acute"/>'
+                         '    <Glyph value="cedilla"/>'
+                         '  </MarkCoverage>'
+                         '  <LigatureCoverage>'
+                         '    <Glyph value="f_i"/>'
+                         '    <Glyph value="c_t"/>'
+                         '  </LigatureCoverage>'
+                         '  <!-- ClassCount=2 -->'
+                         '  <MarkArray>'
+                         '    <!-- MarkCount=3 -->'
+                         '    <MarkRecord index="0">'
+                         '      <Class value="0"/>'
+                         '      <MarkAnchor Format="1">'
+                         '        <XCoordinate value="300"/>'
+                         '        <YCoordinate value="700"/>'
+                         '      </MarkAnchor>'
+                         '    </MarkRecord>'
+                         '    <MarkRecord index="1">'
+                         '      <Class value="0"/>'
+                         '      <MarkAnchor Format="1">'
+                         '        <XCoordinate value="300"/>'
+                         '        <YCoordinate value="700"/>'
+                         '      </MarkAnchor>'
+                         '    </MarkRecord>'
+                         '    <MarkRecord index="2">'
+                         '      <Class value="1"/>'
+                         '      <MarkAnchor Format="1">'
+                         '        <XCoordinate value="300"/>'
+                         '        <YCoordinate value="-100"/>'
+                         '      </MarkAnchor>'
+                         '    </MarkRecord>'
+                         '  </MarkArray>'
+                         '  <LigatureArray>'
+                         '    <!-- LigatureCount=2 -->'
+                         '    <LigatureAttach index="0">'
+                         '      <!-- ComponentCount=2 -->'
+                         '      <ComponentRecord index="0">'
+                         '        <LigatureAnchor index="0" empty="1"/>'
+                         '        <LigatureAnchor index="1" empty="1"/>'
+                         '      </ComponentRecord>'
+                         '      <ComponentRecord index="1">'
+                         '        <LigatureAnchor index="0" Format="1">'
+                         '          <XCoordinate value="200"/>'
+                         '          <YCoordinate value="400"/>'
+                         '        </LigatureAnchor>'
+                         '        <LigatureAnchor index="1" empty="1"/>'
+                         '      </ComponentRecord>'
+                         '    </LigatureAttach>'
+                         '    <LigatureAttach index="1">'
+                         '      <!-- ComponentCount=2 -->'
+                         '      <ComponentRecord index="0">'
+                         '        <LigatureAnchor index="0" Format="1">'
+                         '          <XCoordinate value="500"/>'
+                         '          <YCoordinate value="600"/>'
+                         '        </LigatureAnchor>'
+                         '        <LigatureAnchor index="1" Format="1">'
+                         '          <XCoordinate value="500"/>'
+                         '          <YCoordinate value="-20"/>'
+                         '        </LigatureAnchor>'
+                         '      </ComponentRecord>'
+                         '      <ComponentRecord index="1">'
+                         '        <LigatureAnchor index="0" Format="1">'
+                         '          <XCoordinate value="1300"/>'
+                         '          <YCoordinate value="800"/>'
+                         '        </LigatureAnchor>'
+                         '        <LigatureAnchor index="1" Format="1">'
+                         '          <XCoordinate value="1300"/>'
+                         '          <YCoordinate value="-20"/>'
+                         '        </LigatureAnchor>'
+                         '      </ComponentRecord>'
+                         '    </LigatureAttach>'
+                         '  </LigatureArray>'
+                         '</MarkLigPos>')
+
     def test_buildMarkRecord(self):
         rec = builder.buildMarkRecord(17, builder.buildAnchor(500, -20))
         self.assertEqual(getXML(rec.toXML),