[subset] GPOS Lookup Type 2: PairPos

src/hb-ot-layout-gpos-table.hh

@@ -558,7 +558,7 @@ struct SinglePosFormat1
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
+    const hb_set_t &glyphset = *c->plan->glyphset ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     auto it =
@@ -647,7 +647,7 @@ struct SinglePosFormat2
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
+    const hb_set_t &glyphset = *c->plan->glyphset ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     unsigned sub_length = valueFormat.get_len ();
@@ -761,6 +761,18 @@ struct PairValueRecord
 {
   friend struct PairSet;
 
+  bool serialize (hb_serialize_context_t *c,
+                  unsigned size,
+                  const hb_map_t &glyph_map) const
+  {
+    TRACE_SERIALIZE (this);
+    auto *out = c->start_embed (*this);
+    if (unlikely (!c->extend_min (out))) return_trace (false);
+    
+    out->secondGlyph = glyph_map[secondGlyph];
+    return_trace (c->copy (values, size));
+  }
+
   protected:
   HBGlyphID	secondGlyph;		/* GlyphID of second glyph in the
 					 * pair--first glyph is listed in the
@@ -846,6 +858,37 @@ struct PairSet
     return_trace (false);
   }
 
+  bool subset (hb_subset_context_t *c,
+               const ValueFormat valueFormats[2]) const
+  {
+    TRACE_SUBSET (this);
+    auto snap = c->serializer->snapshot ();
+
+    auto *out = c->serializer->start_embed (*this);
+    if (unlikely (!c->serializer->extend_min (out))) return_trace (false);
+    out->len = 0;
+
+    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_map_t &glyph_map = *c->plan->glyph_map;
+
+    unsigned len1 = valueFormats[0].get_size ();
+    unsigned len2 = valueFormats[1].get_size ();
+    unsigned record_size = HBUINT16::static_size + len1 + len2;
+
+    const PairValueRecord *record = &firstPairValueRecord;
+    unsigned count = len, num = 0;
+    for (unsigned i = 0; i < count; i++)
+    {
+      if (!glyphset.has (record->secondGlyph)) continue;
+      if (record->serialize (c->serializer, record_size, glyph_map)) num++;
+      record = &StructAtOffset<const PairValueRecord> (record, record_size);
+    }
+
+    out->len = num;
+    if (!num) c->serializer->revert (snap);
+    return_trace (num);
+  }
+
   struct sanitize_closure_t
   {
     const void *base;
@@ -919,8 +962,43 @@ struct PairPosFormat1
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    // TODO(subset)
-    return_trace (false);
+
+    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_map_t &glyph_map = *c->plan->glyph_map;
+
+    auto *out = c->serializer->start_embed (*this);
+    if (unlikely (!c->serializer->extend_min (out))) return_trace (false);
+    out->format = format;
+    out->valueFormat[0] = valueFormat[0];
+    out->valueFormat[1] = valueFormat[1];
+
+    hb_sorted_vector_t<hb_codepoint_t> new_coverage;
+
+    + hb_zip (this+coverage, pairSet)
+    | hb_filter (glyphset, hb_first)
+    | hb_filter ([this, c, out] (const OffsetTo<PairSet>& _)
+		 {
+		   auto *o = out->pairSet.serialize_append (c->serializer);
+		   if (unlikely (!o)) return false;
+		   auto snap = c->serializer->snapshot ();
+		   bool ret = o->serialize_subset (c, _, this, out, valueFormat);
+		   if (!ret)
+		   {
+		     out->pairSet.pop ();
+		     c->serializer->revert (snap);
+		   }
+		   return ret;
+		 },
+		 hb_second)
+    | hb_map (hb_first)
+    | hb_map (glyph_map)
+    | hb_sink (new_coverage)
+    ;
+
+    out->coverage.serialize (c->serializer, out)
+		 .serialize (c->serializer, new_coverage.iter ());
+
+    return_trace (bool (new_coverage));
   }
 
   bool sanitize (hb_sanitize_context_t *c) const
@@ -1011,8 +1089,49 @@ struct PairPosFormat2
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    // TODO(subset)
-    return_trace (false);
+    auto *out = c->serializer->start_embed (*this);
+    if (unlikely (!c->serializer->extend_min (out))) return_trace (false);
+    out->format = format;
+    out->valueFormat1 = valueFormat1;
+    out->valueFormat2 = valueFormat2;
+
+    hb_map_t klass1_map;
+    out->classDef1.serialize_subset (c, classDef1, this, out, &klass1_map);
+    out->class1Count = klass1_map.get_population ();
+
+    hb_map_t klass2_map;
+    out->classDef2.serialize_subset (c, classDef2, this, out, &klass2_map);
+    out->class2Count = klass2_map.get_population ();
+
+    unsigned record_len = valueFormat1.get_len () + valueFormat2.get_len ();
+
+    + hb_range ((unsigned) class1Count)
+    | hb_filter (klass1_map)
+    | hb_apply ([&] (const unsigned class1_idx)
+                {
+                  + hb_range ((unsigned) class2Count)
+                  | hb_filter (klass2_map)
+                  | hb_apply ([&] (const unsigned class2_idx)
+                              {
+                                unsigned idx = (class1_idx * (unsigned) class2Count + class2_idx) * record_len;
+                                for (unsigned i = 0; i < record_len; i++)
+                                  c->serializer->copy (values[idx+i]);
+                              })
+                  ;
+                })
+    ;
+
+    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_map_t &glyph_map = *c->plan->glyph_map;
+
+    auto it =
+    + hb_iter (this+coverage)
+    | hb_filter (glyphset)
+    | hb_map_retains_sorting (glyph_map)
+    ;
+
+    out->coverage.serialize (c->serializer, out).serialize (c->serializer, it);
+    return_trace (out->class1Count && out->class2Count && bool (it));
   }
 
   bool sanitize (hb_sanitize_context_t *c) const

test/subset/data/Makefile.am

@@ -14,6 +14,7 @@ EXTRA_DIST += \
 	expected/cff-japanese \
 	expected/layout \
 	expected/layout.gpos \
+	expected/layout.gpos2 \
 	expected/layout.gpos3 \
 	expected/layout.gsub6 \
 	expected/cmap14 \

test/subset/data/Makefile.sources

@@ -6,6 +6,7 @@ TESTS = \
 	tests/cff-japanese.tests \
 	tests/layout.tests \
 	tests/layout.gpos.tests \
+	tests/layout.gpos2.tests \
 	tests/layout.gpos3.tests \
 	tests/layout.gsub6.tests \
 	tests/cmap14.tests \

test/subset/data/tests/layout.gpos2.tests

@@ -0,0 +1,12 @@
+FONTS:
+gpos2_1_font7.otf
+gpos2_2_font5.otf
+
+PROFILES:
+keep-layout.txt
+keep-layout-retain-gids.txt
+
+SUBSETS:
+!#
+!#%
+*