Only decompose glyphs with reflected components (#171)

Instead of decomposing a component if any scaling is happening, only decompose a component if xScale < 0 or yScale < 0 (that is, if it is mirrored on the x or y axis). Removes yAxisIsNonTrivial which was set for all italic instances and would cause all composed glyphs to be decomposed.

Closes #169

2 files changed, 88 insertions, 93 deletions

diff --git a/misc/fontbuild b/misc/fontbuild
index 1d4a8d801..075886a7e 100755
--- a/misc/fontbuild
+++ b/misc/fontbuild
@@ -58,26 +58,22 @@ def fatal(msg):
 
 
 
-def composedGlyphIsNonTrivial(g, yAxisIsNonTrivial=False):
-  # A non-trivial glyph is one that is composed from either multiple
-  # components or that uses component transformations.
-  # If yAxisIsNonTrivial is true, then any transformation over the Y axis
-  # is be considered non-trivial.
+def composedGlyphIsNonTrivial(g):
+  # A non-trivial glyph is one that uses reflecting component transformations.
   if g.components and len(g.components) > 0:
-    if len(g.components) > 1:
-      return True
     for c in g.components:
       # has non-trivial transformation? (i.e. scaled)
       # Example of optimally trivial transformation:
       #   (1, 0, 0, 1, 0, 0)  no scale or offset
       # Example of scaled transformation matrix:
       #   (-1.0, 0, 0.3311, 1, 1464.0, 0)  flipped x axis, sheered and offset
-      # 
-      xScale, xyScale, yxScale, yScale, xOffset, yOffset = c.transformation
-      if xScale != 1 or xyScale != 0 or yxScale != 0 or yScale != 1:
-        return True
-      if yAxisIsNonTrivial and yOffset != 0:
+      #
+      xScale = c.transformation[0]
+      yScale = c.transformation[3]
+      # If glyph is reflected along x or y axes, it won't slant well.
+      if xScale < 0 or yScale < 0:
         return True
+
   return False
 
 
@@ -157,7 +153,7 @@ class VarFontProject(FontProject):
     **kwargs
   ):
     """Build OpenType binaries with interpolatable outlines."""
-    # We decompose any glyph with two or more components to make sure
+    # We decompose any glyph with reflected components to make sure
     # that fontTools varLib is able to produce properly-slanting interpolation.
 
     self._load_designspace_sources(designspace)
@@ -179,12 +175,11 @@ class VarFontProject(FontProject):
         ufo.info.openTypeNamePreferredFamilyName =\
           ufo.info.openTypeNamePreferredFamilyName.replace('Inter', self.familyName)
       updateFontVersion(ufo)
-      isItalic = ufo.info.italicAngle != 0
       ufoname = basename(ufo.path)
-      
+
       for g in ufo:
         directives = findGlyphDirectives(g)
-        if g.components and composedGlyphIsNonTrivial(g, yAxisIsNonTrivial=isItalic):
+        if g.components and composedGlyphIsNonTrivial(g):
           decomposeGlyphs.add(g.name)
         if 'removeoverlap' in directives:
           if g.components and len(g.components) > 0:
@@ -247,7 +242,7 @@ def updateFontVersion(font, dummy=False):
 
 
 # setFontInfo patches font.info
-# 
+#
 def setFontInfo(font, weight):
   #
   # For UFO3 names, see
@@ -487,7 +482,7 @@ class Main(object):
     if outfilename is None or outfilename == '':
       outfilename = os.path.splitext(basename(args.srcfile))[0] + '.otf'
       log.info('setting --output %r' % outfilename)
-    
+
     # build formats list from filename extension
     formats = []
     # for outfilename in args.outputs:
@@ -550,7 +545,7 @@ class Main(object):
       success = False
       if len(otssan_res) == 0:
         otssan_res = 'error'
-    
+
     if success:
       os.unlink(tmpfile)
     else:
@@ -732,7 +727,7 @@ class Main(object):
       else:
         # name "Black" => "black"
         source.name = source.styleName.lower().replace(' ', '')
-      
+
       source.path = ufo_path
       weight = int(source.location['Weight'])
 
@@ -840,11 +835,11 @@ class Main(object):
       # clear anchors
       for g in font:
         g.clearAnchors()
-      
+
       # update font info
       weight = instance_weight[basename(font.path)]
       setFontInfo(font, weight)
-      
+
       font.save()
 
 
@@ -875,7 +870,7 @@ class Main(object):
 
     argparser.add_argument('files', metavar='<file>', nargs='+',
       help='Font files')
-    
+
     args = argparser.parse_args(argv)
     q = Queue()
 
diff --git a/src/Inter.glyphs b/src/Inter.glyphs
index f0e3be58c..4ad966191 100644
--- a/src/Inter.glyphs
+++ b/src/Inter.glyphs
@@ -1,5 +1,5 @@
 {
-.appVersion = "1240";
+.appVersion = "1247";
 classes = (
 {
 automatic = 1;
@@ -26013,7 +26013,7 @@ userData = {
 },
 {
 glyphname = Idieresis;
-lastChange = "2019-02-04 01:15:21 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -26091,7 +26091,7 @@ transform = "{1, 0, 0, 1, -564, 64}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = Idieresis;
@@ -26105,7 +26105,7 @@ userData = {
 },
 {
 glyphname = Idieresisacute;
-lastChange = "2019-03-30 20:56:26 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -26239,7 +26239,7 @@ transform = "{1, 0, 0, 1, 866, 0}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = Idieresis;
@@ -26251,7 +26251,7 @@ interface.gridadjust.original = "{'width': 1018, 'leftMargin': 28, 'rightMargin'
 },
 {
 glyphname = Istroke;
-lastChange = "2018-12-31 21:21:37 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -26329,7 +26329,7 @@ transform = "{1, 0, 0, 1, -220, 64}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 unicode = 0197;
@@ -26342,7 +26342,7 @@ interface.gridadjust.original = "{'width': 938, 'leftMargin': 27, 'rightMargin':
 },
 {
 glyphname = Itildebelow;
-lastChange = "2018-12-31 21:21:37 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -26420,7 +26420,7 @@ transform = "{1, 0, 0, 1, 1376, 0}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = B;
@@ -26435,7 +26435,7 @@ interface.gridadjust.original = "{'width': 1011, 'leftMargin': -13, 'rightMargin
 },
 {
 glyphname = Igrave;
-lastChange = "2019-01-01 00:04:58 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -26513,7 +26513,7 @@ transform = "{1, 0, 0, 1, -392, 512}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = B;
@@ -26522,7 +26522,7 @@ unicode = 00CC;
 },
 {
 glyphname = Iacute;
-lastChange = "2019-02-10 19:23:45 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -26600,7 +26600,7 @@ transform = "{1, 0, 0, 1, -258, 512}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = B;
@@ -26609,7 +26609,7 @@ unicode = 00CD;
 },
 {
 glyphname = Icircumflex;
-lastChange = "2019-02-04 01:15:21 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -26687,7 +26687,7 @@ transform = "{1, 0, 0, 1, -156, 512}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = Idieresis;
@@ -26797,7 +26797,7 @@ unicode = 0128;
 },
 {
 glyphname = Imacron;
-lastChange = "2019-02-04 01:15:21 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -26875,7 +26875,7 @@ transform = "{1, 0, 0, 1, 26, 512}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = Idieresis;
@@ -26884,7 +26884,7 @@ unicode = 012A;
 },
 {
 glyphname = Ibreve;
-lastChange = "2019-02-04 01:15:21 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -26962,7 +26962,7 @@ transform = "{1, 0, 0, 1, -148, 512}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = Idieresis;
@@ -27070,7 +27070,7 @@ unicode = 012E;
 },
 {
 glyphname = Idotaccent;
-lastChange = "2019-02-04 01:15:21 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -27148,7 +27148,7 @@ transform = "{1, 0, 0, 1, 182, 512}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = B;
@@ -27157,7 +27157,7 @@ unicode = 0130;
 },
 {
 glyphname = Icaron;
-lastChange = "2019-02-04 01:15:21 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -27235,7 +27235,7 @@ transform = "{1, 0, 0, 1, -152, 512}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = B;
@@ -27244,7 +27244,7 @@ unicode = 01CF;
 },
 {
 glyphname = Idblgrave;
-lastChange = "2019-02-10 19:12:05 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -27322,7 +27322,7 @@ transform = "{1, 0, 0, 1, 1206, 512}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = Idieresis;
@@ -27331,7 +27331,7 @@ unicode = 0208;
 },
 {
 glyphname = Iinvertedbreve;
-lastChange = "2018-12-31 21:21:37 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -27409,7 +27409,7 @@ transform = "{1, 0, 0, 1, 1180, 612}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = Idieresis;
@@ -27418,7 +27418,7 @@ unicode = 020A;
 },
 {
 glyphname = Ihookabove;
-lastChange = "2018-12-31 21:21:37 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -27496,7 +27496,7 @@ transform = "{1, 0, 0, 1, 1144, 572}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = B;
@@ -27505,7 +27505,7 @@ unicode = 1EC8;
 },
 {
 glyphname = Idotbelow;
-lastChange = "2019-02-02 20:28:22 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -27583,7 +27583,7 @@ transform = "{1, 0, 0, 1, 1120, 0}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = B;
@@ -27592,7 +27592,7 @@ unicode = 1ECA;
 },
 {
 glyphname = Iota;
-lastChange = "2018-12-31 21:21:37 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -27646,7 +27646,7 @@ name = I;
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = B;
@@ -27753,7 +27753,7 @@ unicode = 038A;
 },
 {
 glyphname = Iotadieresis;
-lastChange = "2018-12-31 21:21:37 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -27807,7 +27807,7 @@ name = Idieresis;
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = Idieresis;
@@ -28614,7 +28614,7 @@ unicode = 1F3F;
 },
 {
 glyphname = uni1FD8;
-lastChange = "2019-02-04 01:15:21 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -28692,7 +28692,7 @@ transform = "{1, 0, 0, 1, -148, 512}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = Idieresis;
@@ -28701,7 +28701,7 @@ unicode = 1FD8;
 },
 {
 glyphname = uni1FD9;
-lastChange = "2019-02-04 01:15:21 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -28779,7 +28779,7 @@ transform = "{1, 0, 0, 1, 26, 512}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = Idieresis;
@@ -28988,7 +28988,7 @@ unicode = 1FDB;
 },
 {
 glyphname = afii10055;
-lastChange = "2018-12-31 21:21:37 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -29042,7 +29042,7 @@ name = I;
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = B;
@@ -29051,7 +29051,7 @@ unicode = 0406;
 },
 {
 glyphname = afii10056;
-lastChange = "2019-01-01 00:18:52 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -29129,7 +29129,7 @@ transform = "{1, 0, 0, 1, -488, 512}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = Idieresis;
@@ -38019,7 +38019,7 @@ interface.gridadjust.original = "{'width': 2010, 'leftMargin': 241, 'rightMargin
 },
 {
 glyphname = uni040D;
-lastChange = "2019-01-23 15:58:06 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -38093,11 +38093,11 @@ name = afii10026;
 },
 {
 name = grave;
-transform = "{1, 0, 0, 1, 334, 512}";
+transform = "{1, 0, 0, 1, 340, 512}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 2170;
+width = 2176;
 }
 );
 leftKerningGroup = B;
@@ -38106,7 +38106,7 @@ unicode = 040D;
 },
 {
 glyphname = afii10027;
-lastChange = "2019-02-04 01:15:21 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -38180,11 +38180,11 @@ name = afii10026;
 },
 {
 name = breve;
-transform = "{1, 0, 0, 1, 578, 512}";
+transform = "{1, 0, 0, 1, 584, 512}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 2170;
+width = 2176;
 }
 );
 leftKerningGroup = B;
@@ -38193,7 +38193,7 @@ unicode = 0419;
 },
 {
 glyphname = Imacroncyrillic;
-lastChange = "2019-02-04 01:15:21 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -38267,11 +38267,11 @@ name = afii10026;
 },
 {
 name = macron;
-transform = "{1, 0, 0, 1, 752, 512}";
+transform = "{1, 0, 0, 1, 758, 512}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 2170;
+width = 2176;
 }
 );
 leftKerningGroup = B;
@@ -38280,7 +38280,7 @@ unicode = 04E2;
 },
 {
 glyphname = Idieresiscyrillic;
-lastChange = "2019-02-04 01:15:21 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -38354,11 +38354,11 @@ name = afii10026;
 },
 {
 name = casedieresis.cn;
-transform = "{1, 0, 0, 1, 162, 64}";
+transform = "{1, 0, 0, 1, 168, 64}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 2170;
+width = 2176;
 }
 );
 leftKerningGroup = B;
@@ -38367,7 +38367,7 @@ unicode = 04E4;
 },
 {
 glyphname = uni048A;
-lastChange = "2019-02-04 01:15:21 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -38463,15 +38463,15 @@ name = afii10026;
 },
 {
 name = breve;
-transform = "{1, 0, 0, 1, 578, 512}";
+transform = "{1, 0, 0, 1, 584, 512}";
 },
 {
 name = cyrillictail.cn;
-transform = "{1, 0, 0, 1, 1512, -100}";
+transform = "{1, 0, 0, 1, 1518, -100}";
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 2170;
+width = 2176;
 }
 );
 leftKerningGroup = B;
@@ -80416,7 +80416,7 @@ interface.gridadjust.original = "{'width': 989, 'leftMargin': 315, 'rightMargin'
 },
 {
 glyphname = fdotaccent;
-lastChange = "2019-02-04 01:15:21 +0000";
+lastChange = "2019-07-18 20:42:52 +0000";
 layers = (
 {
 components = (
@@ -80438,11 +80438,11 @@ name = f;
 },
 {
 name = dotaccent;
-transform = "{1, 0, 0, 1, 240, 512}";
+transform = "{1, 0, 0, 1, 216, 512}";
 }
 );
 layerId = "5C20EF92-B63D-42A8-8878-93C2863E0093";
-width = 1156;
+width = 1132;
 },
 {
 components = (
@@ -80464,11 +80464,11 @@ name = f;
 },
 {
 name = dotaccent;
-transform = "{1, 0, 0, 1, 326, 512}";
+transform = "{1, 0, 0, 1, 302, 512}";
 }
 );
 layerId = "D0EC06BF-13F9-4C88-A6F5-B8203AF6C77E";
-width = 1156;
+width = 1134;
 },
 {
 components = (
@@ -94300,7 +94300,7 @@ unicode = E05C;
 },
 {
 glyphname = uni04CF;
-lastChange = "2018-12-31 21:21:38 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -94354,7 +94354,7 @@ name = I;
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = B;
@@ -307433,7 +307433,7 @@ unicode = 04BE;
 },
 {
 glyphname = palochkacyrillic;
-lastChange = "2018-12-31 21:21:38 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -307487,7 +307487,7 @@ name = I;
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 leftKerningGroup = B;
@@ -326060,7 +326060,7 @@ interface.gridadjust.original = "{'width': 1282, 'leftMargin': 138, 'rightMargin
 {
 color = (227,245,235,1);
 glyphname = romanone;
-lastChange = "2018-12-31 21:21:38 +0000";
+lastChange = "2019-07-18 20:40:07 +0000";
 layers = (
 {
 components = (
@@ -326114,7 +326114,7 @@ name = I;
 }
 );
 layerId = "200BE2C5-40F6-4CF4-AF4F-A33C0CC0964F";
-width = 700;
+width = 704;
 }
 );
 unicode = 2160;