Port hmtx table from numpy to array module

Lib/fontTools/ttLib/tables/_h_m_t_x.py

@@ -1,6 +1,6 @@
 import sys
 import DefaultTable
-import numpy
+import array
 from fontTools import ttLib
 from fontTools.misc.textTools import safeEval
 import warnings
@@ -14,37 +14,31 @@ class table__h_m_t_x(DefaultTable.DefaultTable):
 	numberOfMetricsName = 'numberOfHMetrics'
 	
 	def decompile(self, data, ttFont):
+		numGlyphs = ttFont['maxp'].numGlyphs
 		numberOfMetrics = int(getattr(ttFont[self.headerTag], self.numberOfMetricsName))
-		metrics = numpy.fromstring(data[:4 * numberOfMetrics], 
-				numpy.int16)
+		if numberOfMetrics > numGlyphs:
+			numberOfMetrics = numGlyphs # We warn later.
+		# Note: advanceWidth is unsigned, but we read/write as signed.
+		metrics = array.array("h", data[:4 * numberOfMetrics])
 		if sys.byteorder <> "big":
-			metrics = metrics.byteswap()
-		metrics.shape = (numberOfMetrics, 2)
+			metrics.byteswap()
 		data = data[4 * numberOfMetrics:]
-		numberOfSideBearings = ttFont['maxp'].numGlyphs - numberOfMetrics
-		numberOfSideBearings = int(numberOfSideBearings)
-		if numberOfSideBearings:
-			assert numberOfSideBearings > 0, "bad hmtx/vmtx table"
-			lastAdvance = metrics[-1][0]
-			advances = numpy.array([lastAdvance] * numberOfSideBearings, 
-					numpy.int16)
-			sideBearings = numpy.fromstring(data[:2 * numberOfSideBearings], 
-					numpy.int16)
-			if sys.byteorder <> "big":
-				sideBearings = sideBearings.byteswap()
-			data = data[2 * numberOfSideBearings:]
-			if len(advances) and len(sideBearings):
-				additionalMetrics = numpy.array([advances, sideBearings], numpy.int16)
-				metrics = numpy.concatenate((metrics, numpy.transpose(additionalMetrics)))
-			else:
-				warnings.warn('Unable to include additional metrics')
+		numberOfSideBearings = numGlyphs - numberOfMetrics
+		sideBearings = array.array("h", data[:2 * numberOfSideBearings])
+		data = data[2 * numberOfSideBearings:]
+
+		if sys.byteorder <> "big":
+			sideBearings.byteswap()
 		if data:
 			sys.stderr.write("too much data for hmtx/vmtx table\n")
-		metrics = metrics.tolist()
 		self.metrics = {}
-		for i in range(len(metrics)):
+		for i in range(numberOfMetrics):
 			glyphName = ttFont.getGlyphName(i)
-			self.metrics[glyphName] = metrics[i]
+			self.metrics[glyphName] = list(metrics[i*2:i*2+2])
+		lastAdvance = metrics[-2]
+		for i in range(numberOfSideBearings):
+			glyphName = ttFont.getGlyphName(i + numberOfMetrics)
+			self.metrics[glyphName] = [lastAdvance, sideBearings[i]]
 	
 	def compile(self, ttFont):
 		metrics = []
@@ -53,24 +47,25 @@ class table__h_m_t_x(DefaultTable.DefaultTable):
 		lastAdvance = metrics[-1][0]
 		lastIndex = len(metrics)
 		while metrics[lastIndex-2][0] == lastAdvance:
-			lastIndex = lastIndex - 1
+			lastIndex -= 1
 			if lastIndex <= 1:
 				# all advances are equal
 				lastIndex = 1
 				break
 		additionalMetrics = metrics[lastIndex:]
-		additionalMetrics = map(lambda (advance, sb): sb, additionalMetrics)
+		additionalMetrics = [sb for advance, sb in additionalMetrics]
 		metrics = metrics[:lastIndex]
 		setattr(ttFont[self.headerTag], self.numberOfMetricsName, len(metrics))
 		
-		metrics = numpy.array(metrics, numpy.int16)
+		metrics = sum(metrics,[])
+		metrics = array.array("h", metrics)
 		if sys.byteorder <> "big":
-			metrics = metrics.byteswap()
+			metrics.byteswap()
 		data = metrics.tostring()
 		
-		additionalMetrics = numpy.array(additionalMetrics, numpy.int16)
+		additionalMetrics = array.array("h", additionalMetrics)
 		if sys.byteorder <> "big":
-			additionalMetrics = additionalMetrics.byteswap()
+			additionalMetrics.byteswap()
 		data = data + additionalMetrics.tostring()
 		return data