Support narrow/halfwidth forms as the context

This patch includes narrow/halfwidth forms as the context of kerning,
as long as the target glyph is fullwidth.

Fixes issue #38.

east_asian_spacing/config.py

@@ -23,6 +23,12 @@ def __init__(self):
         self.cjk_colon_semicolon = {0xFF1A, 0xFF1B}
         self.cjk_exclam_question = {0xFF01, 0xFF1F}
 
+        # Narrow/Halfwidth forms do not have internal spacings,
+        # but they can appear in the context.
+        # E.g., full-closing should kern if followed by a narrow-closing.
+        self.narrow_opening = {0x28, 0x5B, 0xFF62}
+        self.narrow_closing = {0x29, 0x5D, 0xFF63}
+
         # Skip adding the features to fonts with monospace ASCII.
         self.skip_monospace_ascii = False
         # Determines the applicability by computing ink bounds.

east_asian_spacing/spacing.py

@@ -47,6 +47,11 @@ def __init__(self,
         self.middle = middle if middle is not None else GlyphDataList()
         self.space = space if space is not None else GlyphDataList()
 
+        # Not-applicable left and right. They are not kerned, but they can
+        # appear in the context.
+        self.na_left = GlyphDataList()
+        self.na_right = GlyphDataList()
+
         self._add_glyphs_count = 0
         # For checking purposes. Because this class keeps glyph IDs, using the
         # same instance for different fonts may lead to unexpected behaviors,
@@ -84,6 +89,8 @@ def assert_glyphs_are_disjoint(self):
         assert self.middle.isdisjoint(self.right)
         assert self.middle.isdisjoint(self.space)
         assert self.right.isdisjoint(self.space)
+        assert self.left.isdisjoint(self.na_left)
+        assert self.right.isdisjoint(self.na_right)
 
     def _to_str(self, glyph_ids=False):
         name_and_glyph_data_lists = self._name_and_glyph_data_lists
@@ -148,6 +155,8 @@ def unite(self, other):
         self.middle |= other.middle
         self.right |= other.right
         self.space |= other.space
+        self.na_left |= other.na_left
+        self.na_right |= other.na_right
         self._all_glyphs |= other._all_glyphs
 
     def add_by_ink_part(self, glyphs: Iterable[GlyphData], font):
@@ -163,16 +172,11 @@ def add_by_ink_part(self, glyphs: Iterable[GlyphData], font):
 
     def ifilter_fullwidth(self, font: Font):
         em = font.fullwidth_advance
-        self.left.ifilter_advance(em)
-        self.right.ifilter_advance(em)
+        self.left.ifilter_advance(em, self.na_left)
+        self.right.ifilter_advance(em, self.na_right)
         self.middle.ifilter_advance(em)
         self.space.ifilter_advance(em)
 
-    def ifilter_ink_part(self):
-        self.left.ifilter_ink_part(InkPart.LEFT)
-        self.right.ifilter_ink_part(InkPart.RIGHT)
-        self.middle.ifilter_ink_part(InkPart.MIDDLE)
-
     async def add_glyphs(self, font, config):
         self.assert_font(font)
         config = config.for_font(font)
@@ -196,20 +200,23 @@ async def add_glyphs(self, font, config):
 
     class _ShapeHelper(object):
 
-        def __init__(self, glyph_sets: 'GlyphSets', font, log_name=None):
+        def __init__(self, glyph_sets: 'GlyphSets', font: Font, log_name=None):
             self._font = font
             self._all_glyphs = glyph_sets._all_glyphs
             self._log_name = log_name
 
         async def shape(self,
                         unicodes,
                         language=None,
+                        fullwidth=True,
                         temporary=False) -> GlyphDataList:
             font = self._font
             text = ''.join(chr(c) for c in unicodes)
             # Unified code points (e.g., U+2018-201D) in most fonts are Latin glyphs.
+            features = []
             # Enable "fwid" feature to get fullwidth glyphs.
-            features = ['fwid', 'vert'] if font.is_vertical else ['fwid']
+            if fullwidth: features.append('fwid')
+            if font.is_vertical: features.append('vert')
             shaper = Shaper(font,
                             language=language,
                             script='hani',
@@ -259,24 +266,32 @@ async def ensure_fullwidth_advance(font: Font, config: Config) -> bool:
         return False
 
     async def get_opening_closing(self, font, config):
-        opening = config.cjk_opening | config.quotes_opening
-        closing = config.cjk_closing | config.quotes_closing
+        cjk_opening = config.cjk_opening | config.quotes_opening
+        cjk_closing = config.cjk_closing | config.quotes_closing
         shaper = GlyphSets._ShapeHelper(self, font, log_name='opening_closing')
         left, right, middle, space = await asyncio.gather(
-            shaper.shape(closing), shaper.shape(opening),
+            shaper.shape(cjk_closing), shaper.shape(cjk_opening),
             shaper.shape(config.cjk_middle),
             shaper.shape(config.fullwidth_space))
         trio = GlyphSets(left, right, middle, space)
         if font.is_vertical:
             # Left/right in vertical should apply only if they have `vert` glyphs.
             # YuGothic/UDGothic doesn't have 'vert' glyphs for U+2018/201C/301A/301B.
             horizontal = await self._shape(font.horizontal_font,
-                                           opening | closing)
+                                           cjk_opening | cjk_closing)
             trio.left -= horizontal
             trio.right -= horizontal
+        else:
+            assert not trio.na_left
+            assert not trio.na_right
+            trio.na_left, trio.na_right = await asyncio.gather(
+                shaper.shape(config.narrow_closing, fullwidth=False),
+                shaper.shape(config.narrow_opening, fullwidth=False))
         trio.assert_glyphs_are_disjoint()
         if config.use_ink_bounds:
-            trio.ifilter_ink_part()
+            trio.left.ifilter_ink_part(InkPart.LEFT, self.na_left)
+            trio.right.ifilter_ink_part(InkPart.RIGHT, self.na_right)
+            trio.middle.ifilter_ink_part(InkPart.MIDDLE)
         return trio
 
     async def get_period_comma(self, font, config):
@@ -297,7 +312,9 @@ async def get_period_comma(self, font, config):
                 zht.clear()
         trio = GlyphSets(ja, None, zht)
         if config.use_ink_bounds:
-            trio.ifilter_ink_part()
+            trio.left.ifilter_ink_part(InkPart.LEFT)
+            trio.right.ifilter_ink_part(InkPart.RIGHT)
+            trio.middle.ifilter_ink_part(InkPart.MIDDLE)
         trio.assert_glyphs_are_disjoint()
         return trio
 
@@ -418,10 +435,13 @@ def add_from_cache(self, font, glyphs: GlyphDataList) -> GlyphDataList:
 
     class PosValues(object):
 
-        def __init__(self, font: Font, trio) -> None:
-            self.left, self.right, self.middle, self.space = (
+        def __init__(self, font: Font, glyph_sets: 'GlyphSets') -> None:
+            glyph_sets.assert_glyphs_are_disjoint()
+            self.left, self.right, self.middle, self.space, self.na_left, self.na_right = (
                 tuple(font.glyph_names(sorted(glyphs.glyph_id_set)))
-                for glyphs in trio._glyph_data_lists)
+                for glyphs in (glyph_sets.left, glyph_sets.right,
+                               glyph_sets.middle, glyph_sets.space,
+                               glyph_sets.na_left, glyph_sets.na_right))
 
             em = font.fullwidth_advance
             # When `em` is an odd number, ceil the advance. To do this, use
@@ -545,7 +565,7 @@ def _build_single_pos_lookup(
         return lookup
 
     def _build_chws_lookup(self, font: Font, lookups: List[otTables.Lookup],
-                           pos) -> List[int]:
+                           pos: 'GlyphSets.PosValues') -> List[int]:
         self.assert_font(font)
         lookup_indices = []
 
@@ -554,7 +574,7 @@ def _build_chws_lookup(self, font: Font, lookups: List[otTables.Lookup],
         pair_pos_builder = PairPosBuilder(ttfont, None)
         pair_pos_builder.addClassPair(
             None, pos.left, pos.left_value,
-            pos.left + pos.right + pos.middle + pos.space, None)
+            pos.left + pos.right + pos.middle + pos.space + pos.na_left, None)
         lookup = pair_pos_builder.build()
         assert lookup
         lookup_indices.append(len(lookups))
@@ -569,8 +589,9 @@ def _build_chws_lookup(self, font: Font, lookups: List[otTables.Lookup],
 
         chain_context_pos_builder = ChainContextPosBuilder(ttfont, None)
         chain_context_pos_builder.rules.append(
-            ChainContextualRule([pos.right + pos.middle + pos.space],
-                                [pos.right], [], [[single_pos_lookup]]))
+            ChainContextualRule(
+                [pos.right + pos.middle + pos.space + pos.na_right],
+                [pos.right], [], [[single_pos_lookup]]))
         lookup = chain_context_pos_builder.build()
         assert lookup
         lookup_indices.append(len(lookups))

references/BIZ-UDGothicR.ttc-0.G_P_O_S_.ttx.diff

@@ -1,6 +1,6 @@
 @@
 +<?xml version="1.0" encoding="UTF-8"?>
-+<ttFont ttLibVersion="4.26">
++<ttFont ttLibVersion="4.28">
 +
 +  <GPOS>
 +    <Version value="0x00010000"/>
@@ -147,6 +147,8 @@
 +          <ClassDef1>
 +          </ClassDef1>
 +          <ClassDef2>
++            <ClassDef glyph="bracketright" class="1"/>
++            <ClassDef glyph="parenright" class="1"/>
 +            <ClassDef glyph="quotedblleft" class="1"/>
 +            <ClassDef glyph="quotedblright" class="1"/>
 +            <ClassDef glyph="quoteleft" class="1"/>
@@ -185,6 +187,7 @@
 +            <ClassDef glyph="uniFF5D" class="1"/>
 +            <ClassDef glyph="uniFF5F" class="1"/>
 +            <ClassDef glyph="uniFF60" class="1"/>
++            <ClassDef glyph="uniFF63" class="1"/>
 +          </ClassDef2>
 +          <!-- Class1Count=1 -->
 +          <!-- Class2Count=2 -->
@@ -231,6 +234,8 @@
 +        <ChainContextPos index="0" Format="3">
 +          <!-- BacktrackGlyphCount=1 -->
 +          <BacktrackCoverage index="0">
++            <Glyph value="parenleft"/>
++            <Glyph value="bracketleft"/>
 +            <Glyph value="uni3000"/>
 +            <Glyph value="uni30FB"/>
 +            <Glyph value="uniFF1A"/>
@@ -250,6 +255,7 @@
 +            <Glyph value="uni3018"/>
 +            <Glyph value="uni3016"/>
 +            <Glyph value="uni301D"/>
++            <Glyph value="uniFF62"/>
 +          </BacktrackCoverage>
 +          <!-- InputGlyphCount=1 -->
 +          <InputCoverage index="0">

references/BIZ-UDGothicR.ttc-glyphs

@@ -44,8 +44,14 @@
 # 0 U+301B 〛
 # 0 U+301E 〞
 # 0 U+301A 〚
+# 10 U+0028 (
+# 11 U+0029 )
+# 61 U+005B [
+# 63 U+005D ]
 # 105 U+FF1F ？
 # 106 U+FF01 ！
+# 12419 U+FF62 ｢
+# 12420 U+FF63 ｣
 # vertical.left
 11951 # U+3001 、
 11952 # U+3002 。

references/BIZ-UDGothicR.ttc.tables.diff

@@ -2,7 +2,7 @@
  Font 0: "BIZ UDGothic" "Regular" PS="BIZ-UDGothic"
  Font 1: "BIZ UDPGothic" "Regular" PS="BIZ-UDPGothic"
  Tag  Size      
-+GPOS        648 [0]
++GPOS        672 [0]
  GSUB     43,556 [0]
  GSUB     45,586 [1]
  OS/2         96 [0]
@@ -14,7 +14,7 @@
 -Data: 5,027,902
 -Gap: 650
 -Tables: 24
-+Total: 5,029,202
-+Data: 5,028,550
++Total: 5,029,226
++Data: 5,028,574
 +Gap: 652
 +Tables: 25

references/NotoSansCJK-Bold.ttc-0.G_P_O_S_.ttx.diff

@@ -710,6 +710,8 @@
 +          <ClassDef1>
 +          </ClassDef1>
 +          <ClassDef2>
++            <ClassDef glyph="cid00010" class="1"/>
++            <ClassDef glyph="cid00062" class="1"/>
 +            <ClassDef glyph="cid01396" class="1"/>
 +            <ClassDef glyph="cid01397" class="1"/>
 +            <ClassDef glyph="cid01398" class="1"/>
@@ -747,6 +749,7 @@
 +            <ClassDef glyph="cid59139" class="1"/>
 +            <ClassDef glyph="cid59140" class="1"/>
 +            <ClassDef glyph="cid59141" class="1"/>
++            <ClassDef glyph="cid59144" class="1"/>
 +            <ClassDef glyph="cid63145" class="1"/>
 +            <ClassDef glyph="cid63146" class="1"/>
 +            <ClassDef glyph="cid63147" class="1"/>
@@ -806,6 +809,8 @@
 +        <ChainContextPos index="0" Format="3">
 +          <!-- BacktrackGlyphCount=1 -->
 +          <BacktrackCoverage index="0">
++            <Glyph value="cid00009"/>
++            <Glyph value="cid00060"/>
 +            <Glyph value="cid01396"/>
 +            <Glyph value="cid01404"/>
 +            <Glyph value="cid01406"/>
@@ -824,6 +829,7 @@
 +            <Glyph value="cid59105"/>
 +            <Glyph value="cid59137"/>
 +            <Glyph value="cid59140"/>
++            <Glyph value="cid59143"/>
 +            <Glyph value="cid63145"/>
 +            <Glyph value="cid63146"/>
 +            <Glyph value="cid63148"/>

references/NotoSansCJK-Bold.ttc-1.G_P_O_S_.ttx.diff

@@ -710,6 +710,8 @@
 +          <ClassDef1>
 +          </ClassDef1>
 +          <ClassDef2>
++            <ClassDef glyph="cid00010" class="1"/>
++            <ClassDef glyph="cid00062" class="1"/>
 +            <ClassDef glyph="cid01396" class="1"/>
 +            <ClassDef glyph="cid01397" class="1"/>
 +            <ClassDef glyph="cid01398" class="1"/>
@@ -747,6 +749,7 @@
 +            <ClassDef glyph="cid59139" class="1"/>
 +            <ClassDef glyph="cid59140" class="1"/>
 +            <ClassDef glyph="cid59141" class="1"/>
++            <ClassDef glyph="cid59144" class="1"/>
 +            <ClassDef glyph="cid63145" class="1"/>
 +            <ClassDef glyph="cid63146" class="1"/>
 +            <ClassDef glyph="cid63147" class="1"/>
@@ -806,6 +809,8 @@
 +        <ChainContextPos index="0" Format="3">
 +          <!-- BacktrackGlyphCount=1 -->
 +          <BacktrackCoverage index="0">
++            <Glyph value="cid00009"/>
++            <Glyph value="cid00060"/>
 +            <Glyph value="cid01396"/>
 +            <Glyph value="cid01404"/>
 +            <Glyph value="cid01406"/>
@@ -824,6 +829,7 @@
 +            <Glyph value="cid59105"/>
 +            <Glyph value="cid59137"/>
 +            <Glyph value="cid59140"/>
++            <Glyph value="cid59143"/>
 +            <Glyph value="cid63145"/>
 +            <Glyph value="cid63146"/>
 +            <Glyph value="cid63148"/>

references/NotoSansCJK-Bold.ttc-2.G_P_O_S_.ttx.diff

@@ -710,6 +710,8 @@
 +          <ClassDef1>
 +          </ClassDef1>
 +          <ClassDef2>
++            <ClassDef glyph="cid00010" class="1"/>
++            <ClassDef glyph="cid00062" class="1"/>
 +            <ClassDef glyph="cid01396" class="1"/>
 +            <ClassDef glyph="cid01397" class="1"/>
 +            <ClassDef glyph="cid01398" class="1"/>
@@ -747,6 +749,7 @@
 +            <ClassDef glyph="cid59139" class="1"/>
 +            <ClassDef glyph="cid59140" class="1"/>
 +            <ClassDef glyph="cid59141" class="1"/>
++            <ClassDef glyph="cid59144" class="1"/>
 +            <ClassDef glyph="cid63145" class="1"/>
 +            <ClassDef glyph="cid63146" class="1"/>
 +            <ClassDef glyph="cid63147" class="1"/>
@@ -806,6 +809,8 @@
 +        <ChainContextPos index="0" Format="3">
 +          <!-- BacktrackGlyphCount=1 -->
 +          <BacktrackCoverage index="0">
++            <Glyph value="cid00009"/>
++            <Glyph value="cid00060"/>
 +            <Glyph value="cid01396"/>
 +            <Glyph value="cid01404"/>
 +            <Glyph value="cid01406"/>
@@ -824,6 +829,7 @@
 +            <Glyph value="cid59105"/>
 +            <Glyph value="cid59137"/>
 +            <Glyph value="cid59140"/>
++            <Glyph value="cid59143"/>
 +            <Glyph value="cid63145"/>
 +            <Glyph value="cid63146"/>
 +            <Glyph value="cid63148"/>

references/NotoSansCJK-Bold.ttc-3.G_P_O_S_.ttx.diff

@@ -710,6 +710,8 @@
 +          <ClassDef1>
 +          </ClassDef1>
 +          <ClassDef2>
++            <ClassDef glyph="cid00010" class="1"/>
++            <ClassDef glyph="cid00062" class="1"/>
 +            <ClassDef glyph="cid01396" class="1"/>
 +            <ClassDef glyph="cid01397" class="1"/>
 +            <ClassDef glyph="cid01398" class="1"/>
@@ -747,6 +749,7 @@
 +            <ClassDef glyph="cid59139" class="1"/>
 +            <ClassDef glyph="cid59140" class="1"/>
 +            <ClassDef glyph="cid59141" class="1"/>
++            <ClassDef glyph="cid59144" class="1"/>
 +            <ClassDef glyph="cid63145" class="1"/>
 +            <ClassDef glyph="cid63146" class="1"/>
 +            <ClassDef glyph="cid63147" class="1"/>
@@ -806,6 +809,8 @@
 +        <ChainContextPos index="0" Format="3">
 +          <!-- BacktrackGlyphCount=1 -->
 +          <BacktrackCoverage index="0">
++            <Glyph value="cid00009"/>
++            <Glyph value="cid00060"/>
 +            <Glyph value="cid01396"/>
 +            <Glyph value="cid01404"/>
 +            <Glyph value="cid01406"/>
@@ -824,6 +829,7 @@
 +            <Glyph value="cid59105"/>
 +            <Glyph value="cid59137"/>
 +            <Glyph value="cid59140"/>
++            <Glyph value="cid59143"/>
 +            <Glyph value="cid63145"/>
 +            <Glyph value="cid63146"/>
 +            <Glyph value="cid63148"/>