If the design space file uses an <axes> element, use this to define the axis map, and preserve the axis order.

Lib/fontTools/varLib/__init__.py

@@ -29,6 +29,7 @@ from fontTools.ttLib.tables._g_v_a_r import TupleVariation
 from fontTools.ttLib.tables import otTables as ot
 from fontTools.varLib import builder, designspace, models
 from fontTools.varLib.merger import VariationMerger
+import collections
 import warnings
 import os.path
 import logging
@@ -59,7 +60,9 @@ def _add_fvar(font, axes, instances, axis_map):
 	font['fvar'] = fvar = newTable('fvar')
 	nameTable = font['name']
 
-	for iden in sorted(axes.keys(), key=lambda k: axis_map[k][0]):
+	for iden in axis_map.keys():
+		if not axes.has_key(iden):
+			continue
 		axis = Axis()
 		axis.axisTag = Tag(axis_map[iden][0])
 		axis.minValue, axis.defaultValue, axis.maxValue = axes[iden]
@@ -265,7 +268,7 @@ def build(designspace_filename, master_finder=lambda s:s, axisMap=None):
 	(axis-tag, axis-name).
 	"""
 
-	masters, instances = designspace.load(designspace_filename)
+	masters, instances, axisMapDS = designspace.load(designspace_filename)
 	base_idx = None
 	for i,m in enumerate(masters):
 		if 'info' in m and m['info']['copy']:
@@ -281,18 +284,14 @@ def build(designspace_filename, master_finder=lambda s:s, axisMap=None):
 	master_ttfs = [master_finder(os.path.join(basedir, m['filename'])) for m in masters]
 	master_fonts = [TTFont(ttf_path) for ttf_path in master_ttfs]
 
-	standard_axis_map = {
-		'weight':  ('wght', 'Weight'),
-		'width':   ('wdth', 'Width'),
-		'slant':   ('slnt', 'Slant'),
-		'optical': ('opsz', 'Optical Size'),
-		'custom':  ('xxxx', 'Custom'),
-	}
-
-	axis_map = standard_axis_map
 	if axisMap:
-		axis_map = axis_map.copy()
+		axis_map = designspace.standard_axis_map.copy()
 		axis_map.update(axisMap)
+	elif axisMapDS:
+		axis_map = axisMapDS
+	else:
+		axis_map = designspace.standard_axis_map
+	
 
 	# TODO: For weight & width, use OS/2 values and setup 'avar' mapping.
 

Lib/fontTools/varLib/designspace.py

@@ -1,5 +1,6 @@
 """Rudimentary support for loading MutatorMath .designspace files."""
 from __future__ import print_function, division, absolute_import
+import collections
 from fontTools.misc.py23 import *
 try:
 	import xml.etree.cElementTree as ET
@@ -8,6 +9,14 @@ except ImportError:
 
 __all__ = ['load', 'loads']
 
+standard_axis_map = collections.OrderedDict(
+	[['weight', ('wght', 'Weight')],
+	['width', ('wdth', 'Width')],
+	['slant', ('slnt', 'Slant')],
+	['optical', ('opsz', 'Optical Size')],
+	['custom',('xxxx', 'Custom')]]
+	)
+
 def _xmlParseLocation(et):
 	loc = {}
 	for dim in et.find('location'):
@@ -32,8 +41,24 @@ def _loadItem(et):
 	return item
 
 def _load(et):
-	masters = []
 	ds = et.getroot()
+	
+	axisMap = collections.OrderedDict()
+	axesET = ds.find('axes')
+	if axesET:
+		axisList = axesET.findall('axis')
+		for axisET in axisList:
+			axisName = axisET.attrib["name"]
+			labelET = axisET.find('labelname')
+			if (None == labelET):
+				# If the designpsace file axes is a std axes, the label name may be omitted.
+				tag, label = standard_axis_map[axisName]
+			else:
+				label = labelET.text
+				tag = axisET.attrib["tag"]
+			axisMap[axisName] = (tag,  label)
+
+	masters = []
 	for et in ds.find('sources'):
 		masters.append(_loadItem(et))
 
@@ -41,7 +66,7 @@ def _load(et):
 	for et in ds.find('instances'):
 		instances.append(_loadItem(et))
 
-	return masters, instances
+	return masters, instances, axisMap
 
 def load(filename):
 	"""Load designspace from a file name or object.  Returns two items:

Lib/fontTools/varLib/interpolate_layout.py

@@ -12,7 +12,7 @@ import os.path
 
 def interpolate_layout(designspace_filename, loc, finder):
 
-	masters, instances = designspace.load(designspace_filename)
+	masters, instances, axisMap = designspace.load(designspace_filename)
 	base_idx = None
 	for i,m in enumerate(masters):
 		if 'info' in m and m['info']['copy']: