UPM 2048 and opsz axis (#462)

- UPM is adjusted to 2048
- Additional opsz VF axis (multi master) added which will eventually replace the separate Display family
- New tooling that uses fontmake instead of Inter's own fontbuild toolchain. (The old toolchain is still supported, i.e. `make -f Makefile_v1.make ...`)

misc/glyphs-scripts/generate-opsz-layers.py

@@ -0,0 +1,71 @@
+#MenuTitle: Generate opsz brace layers
+# -*- coding: utf-8 -*-
+import GlyphsApp
+import copy
+
+Font = Glyphs.font
+selectedLayers = Font.selectedLayers
+
+# Glyphs.font.selection - selected glyphs in "Font" tab
+# Glyphs.font.selectedFontMaster
+
+def build_axis_coordinates(g, master):
+  coordinates = {}
+  for i in range(len(g.parent.axes)):
+    axis = g.parent.axes[i]
+    if axis.axisTag == "opsz":
+      coordinates[axis.axisId] = 72
+    else:
+      coordinates[axis.axisId] = master.axes[i]
+  return coordinates
+
+
+def process_glyph(g, axes):
+  print("processing glyph %r" % g.name)
+
+  existing_opsz_layers = {}
+  for layer in g.layers:
+    # print("- %s (%r) %r" % (
+    #   layer.name, layer.associatedMasterId, layer.attributes['coordinates']))
+    if layer.attributes['coordinates']:
+      existing_opsz_layers[layer.associatedMasterId] = layer
+  # print("existing_opsz_layers %r" % existing_opsz_layers)
+
+  for master in g.parent.masters:
+    if master.name.startswith("Regular"):
+      # Regular uses dedicated master for opsz
+      continue
+    layer = g.layers[master.id]
+    # print("%s" % layer.name)
+    if master.id in existing_opsz_layers:
+      print("skip layer %s with existing opsz brace layer" % layer.name)
+      continue
+
+    newLayer = layer.copy()
+    # Note: "same name" matters for designspace generation!
+    newLayer.name = "opsz"
+    newLayer.associatedMasterId = master.id
+    newLayer.attributes['coordinates'] = build_axis_coordinates(g, master)
+    g.layers.append(newLayer)
+    print("layer.guides %r" % layer.guides)
+    print("created layer %s (copy of %r)" % (newLayer.name, layer.name))
+
+
+if Glyphs.font and Glyphs.font.selectedLayers:
+  try:
+    Glyphs.font.disableUpdateInterface()
+    glyphs = set([l.parent for l in Glyphs.font.selectedLayers])
+    print(glyphs)
+    axes = {}
+    for i in range(len(Glyphs.font.axes)):
+      axis = Glyphs.font.axes[i]
+      axes[axis.axisTag] = {"index":i, "axis":axis}
+      # print("%r => %r" % (axis.axisTag, axis.axisId))
+    for g in glyphs:
+      try:
+        g.beginUndo()
+        process_glyph(g, axes)
+      finally:
+        g.endUndo()
+  finally:
+    Glyphs.font.enableUpdateInterface()