[morx] Preliminary code for writing AATLookups

Needs more work.

Lib/fontTools/misc/testTools.py

@@ -37,6 +37,7 @@ def parseXML(xmlSnippet):
 class FakeFont:
     def __init__(self, glyphs):
         self.glyphOrder_ = glyphs
+        self.reverseGlyphOrderDict_ = {g:i for i,g in enumerate(glyphs)}
         self.lazy = False
         self.tables = {}
 
@@ -50,7 +51,7 @@ class FakeFont:
         return self.tables.get(tag, default)
 
     def getGlyphID(self, name):
-        return self.glyphOrder_.index(name)
+        return self.reverseGlyphOrderDict_[name]
 
     def getGlyphName(self, glyphID):
         if glyphID < len(self.glyphOrder_):
@@ -61,6 +62,9 @@ class FakeFont:
     def getGlyphOrder(self):
         return self.glyphOrder_
 
+    def getReverseGlyphMap(self):
+        return self.reverseGlyphOrderDict_
+
 
 class TestXMLReader_(object):
     def __init__(self):

Lib/fontTools/ttLib/tables/otConverters.py

@@ -566,6 +566,36 @@ class AATLookup(BaseConverter):
 		return {font.getGlyphName(k):font.getGlyphName(v)
 		        for k, v in mapping.items() if k != v}
 
+	def write(self, writer, font, tableDict, value, repeatIndex=None):
+		glyphMap = font.getReverseGlyphMap()
+		binSrchHeaderSize = 10
+		formatSizes = {6: binSrchHeaderSize + len(value) * 4}
+		if glyphMap.keys() == value.keys():
+			formatSizes[0] = len(value) * 2
+		# TODO: Also implement format 2, 4, and 8.
+		bestFormat = min(formatSizes, key=formatSizes.get)
+		writeMethod = getattr(self, 'writeFormat%d' % bestFormat)
+		writer.writeUShort(bestFormat)
+		writeMethod(writer, font, value)
+
+	def writeFormat0(self, writer, font, value):
+		for glyph in font.getGlyphOrder():
+			writer.writeUShort(font.getGlyphID(value[glyph]))
+
+	def writeFormat6(self, writer, font, value):
+		writer.writeUShort(2)  # unit size
+		writer.writeUShort(len(value))  # nUnits
+		# TODO: The following three are not correct yet.
+		writer.writeUShort(int.bit_length(len(value)))  # searchRange
+		writer.writeUShort(int.bit_length(len(value)))  # entrySelector
+		writer.writeUShort(int.bit_length(len(value)))  # rangeShift
+		table = [(font.getGlyphID(key), font.getGlyphID(value))
+		         for key, value in value.items()]
+		table.sort()
+		for key, value in table:
+			writer.writeUShort(key)
+			writer.writeUShort(value)
+
 	def readFormat0(self, reader, numGlyphs):
 		data = reader.readUShortArray(numGlyphs)
 		return {k:v for (k,v) in enumerate(data)}

Tests/ttLib/tables/otConverters_test.py

@@ -250,6 +250,29 @@ class AATLookupTest(unittest.TestCase):
             "unsupported lookup format: 9",
             self.converter.read, reader, self.font, None)
 
+    def test_writeFormat0(self):
+        writer = OTTableWriter()
+        font = FakeFont(".notdef A B C".split())
+        self.converter.write(writer, font, {}, {
+            ".notdef": ".notdef",
+            "A": "C",
+            "B": "C",
+            "C": "A"
+        })
+        self.assertEqual(writer.getData(), deHexStr("0000 0000 0003 0003 0001"))
+
+    def test_writeFormat6(self):
+        writer = OTTableWriter()
+        font = FakeFont(".notdef A B C".split())
+        self.converter.write(writer, font, {}, {
+            "A": "C",
+            "C": "B"
+        })
+        # TODO: The binSrchHeader entries have the wrong values.
+        self.assertEqual(writer.getData(),
+                         deHexStr("0006 0002 0002 0002 0002 0002 "
+                                  "0001 0003 0003 0002"))
+
     def test_xmlRead(self):
         value = self.converter.xmlRead({}, [
             ("Substitution", {"in": "A", "out": "A.alt"}, []),