From fb44727401d36adc14615deda91574a6e7ec2cd6 Mon Sep 17 00:00:00 2001
From: Qunxin Liu <qxliu@google.com>
Date: Mon, 7 Aug 2023 09:44:41 -0700
Subject: [PATCH] [instancer] add instantiate () for gvar

---
 src/hb-ot-var-common.hh     | 11 ++++++++---
 src/hb-ot-var-gvar-table.hh | 22 ++++++++++++++++++++++
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/src/hb-ot-var-common.hh b/src/hb-ot-var-common.hh
index ae1f3785b..e1de07901 100644
--- a/src/hb-ot-var-common.hh
+++ b/src/hb-ot-var-common.hh
@@ -1088,7 +1088,7 @@ struct TupleVariationData
     void merge_tuple_variations ()
     {
       hb_vector_t<tuple_delta_t> new_vars;
-      hb_hashmap_t<hb_hashmap_t<hb_tag_t, Triple>, unsigned> m;
+      hb_hashmap_t<const hb_hashmap_t<hb_tag_t, Triple>*, unsigned> m;
       unsigned i = 0;
       for (const tuple_delta_t& var : tuple_vars)
       {
@@ -1096,14 +1096,14 @@ struct TupleVariationData
         if (var.axis_tuples.is_empty ()) continue;
 
         unsigned *idx;
-        if (m.has (var.axis_tuples, &idx))
+        if (m.has (&(var.axis_tuples), &idx))
         {
           new_vars[*idx] += var;
         }
         else
         {
           new_vars.push (var);
-          m.set (var.axis_tuples, i);
+          m.set (&(var.axis_tuples), i);
           i++;
         }
       }
@@ -1256,6 +1256,11 @@ struct TupleVariationData
     {
       if (!tuple_vars) return true;
       change_tuple_variations_axis_limits (normalized_axes_location, axes_triple_distances);
+      /* compute inferred deltas only for gvar */
+      if (contour_points)
+        if (!calc_inferred_deltas (*contour_points))
+          return false;
+
       merge_tuple_variations ();
       return !tuple_vars.in_error ();
     }
diff --git a/src/hb-ot-var-gvar-table.hh b/src/hb-ot-var-gvar-table.hh
index 5b9e64243..3f9e10612 100644
--- a/src/hb-ot-var-gvar-table.hh
+++ b/src/hb-ot-var-gvar-table.hh
@@ -378,9 +378,31 @@ struct gvar
                                                        (char *) glyph_var_data_offsets));
   }
 
+  bool instantiate (hb_subset_context_t *c) const
+  {
+    TRACE_SUBSET (this);
+    glyph_variations_t glyph_vars;
+    if (!decompile_glyph_variations (c->plan, glyph_vars))
+      return_trace (false);
+
+    if (!glyph_vars.instantiate (c->plan)) return_trace (false);
+    if (!glyph_vars.compile_bytes (c->plan->axes_index_map, c->plan->axes_old_index_tag_map))
+      return_trace (false);
+
+    unsigned axis_count = c->plan->axes_index_map.get_population ();
+    unsigned num_glyphs = c->plan->num_output_glyphs ();
+    auto it = hb_iter (c->plan->new_to_old_gid_list);
+    return_trace (serialize (c->serializer, glyph_vars, it, axis_count, num_glyphs));
+  }
+
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
+    if (c->plan->all_axes_pinned)
+      return_trace (false);
+
+    if (c->plan->normalized_coords)
+      return_trace (instantiate (c));
 
     unsigned glyph_count = version.to_int () ? c->plan->source->get_num_glyphs () : 0;