Merge pull request #4691 from googlefonts/colrv1

[instancer] support partial instancing for COLRv1

src/OT/Color/COLR/COLR.hh

@@ -269,8 +269,18 @@ struct Variable
     if (c->plan->all_axes_pinned)
       return_trace (true);
 
-    //TODO: update varIdxBase for partial-instancing
-    return_trace (c->serializer->embed (varIdxBase));
+    VarIdx new_varidx;
+    new_varidx = varIdxBase;
+    if (varIdxBase != VarIdx::NO_VARIATION)
+    {
+      hb_pair_t<unsigned, int> *new_varidx_delta;
+      if (!c->plan->colrv1_variation_idx_delta_map.has (varIdxBase, &new_varidx_delta))
+        return_trace (false);
+
+      new_varidx = hb_first (*new_varidx_delta);
+    }
+
+    return_trace (c->serializer->embed (new_varidx));
   }
 
   bool sanitize (hb_sanitize_context_t *c) const
@@ -1993,6 +2003,76 @@ struct LayerList : Array32OfOffset32To<Paint>
   }
 };
 
+struct delta_set_index_map_subset_plan_t
+{
+  unsigned get_inner_bit_count () const { return inner_bit_count; }
+  unsigned get_width ()           const { return ((outer_bit_count + inner_bit_count + 7) / 8); }
+  hb_array_t<const uint32_t> get_output_map () const { return output_map.as_array (); }
+
+  delta_set_index_map_subset_plan_t (const hb_map_t &new_deltaset_idx_varidx_map)
+  {
+    map_count = 0;
+    outer_bit_count = 0;
+    inner_bit_count = 1;
+    output_map.init ();
+
+    /* search backwards */
+    unsigned count = new_deltaset_idx_varidx_map.get_population ();
+    if (!count) return;
+
+    unsigned last_idx = (unsigned)-1;
+    unsigned last_varidx = (unsigned)-1;
+
+    for (unsigned i = count; i; i--)
+    {
+      unsigned delta_set_idx = i - 1;
+      unsigned var_idx = new_deltaset_idx_varidx_map.get (delta_set_idx);
+      if (i == count)
+      {
+        last_idx = delta_set_idx;
+        last_varidx = var_idx;
+        continue;
+      }
+      if (var_idx != last_varidx)
+        break;
+      last_idx = delta_set_idx;
+    }
+
+    map_count = last_idx + 1;
+  }
+
+  bool remap (const hb_map_t &new_deltaset_idx_varidx_map)
+  {
+    /* recalculate bit_count */
+    outer_bit_count = 1;
+    inner_bit_count = 1;
+
+    if (unlikely (!output_map.resize (map_count, false))) return false;
+
+    for (unsigned idx = 0; idx < map_count; idx++)
+    {
+      uint32_t *var_idx;
+      if (!new_deltaset_idx_varidx_map.has (idx, &var_idx)) return false;
+      output_map.arrayZ[idx] = *var_idx;
+
+      unsigned outer = (*var_idx) >> 16;
+      unsigned bit_count = (outer == 0) ? 1 : hb_bit_storage (outer);
+      outer_bit_count = hb_max (bit_count, outer_bit_count);
+      
+      unsigned inner = (*var_idx) & 0xFFFF;
+      bit_count = (inner == 0) ? 1 : hb_bit_storage (inner);
+      inner_bit_count = hb_max (bit_count, inner_bit_count);
+    }
+    return true;
+  }
+
+  private:
+  unsigned map_count;
+  unsigned outer_bit_count;
+  unsigned inner_bit_count;
+  hb_vector_t<uint32_t> output_map;
+};
+
 struct COLR
 {
   static constexpr hb_tag_t tableTag = HB_OT_TAG_COLR;
@@ -2055,6 +2135,12 @@ struct COLR
     const ItemVariationStore &get_var_store () const
     { return colr->get_var_store (); }
 
+    bool has_delta_set_index_map () const
+    { return colr->has_delta_set_index_map (); }
+
+    const DeltaSetIndexMap &get_delta_set_index_map () const
+    { return colr->get_delta_set_index_map (); }
+
     private:
     hb_blob_ptr_t<COLR> colr;
   };
@@ -2141,6 +2227,9 @@ struct COLR
   bool has_delta_set_index_map () const
   { return version >= 1 && varIdxMap != 0; }
 
+  const DeltaSetIndexMap &get_delta_set_index_map () const
+  { return (version == 0 || varIdxMap == 0) ? Null (DeltaSetIndexMap) : this+varIdxMap; }
+
   const ItemVariationStore &get_var_store () const
   { return (version == 0 || varStore == 0) ? Null (ItemVariationStore) : this+varStore; }
 
@@ -2219,6 +2308,88 @@ struct COLR
     return record;
   }
 
+  bool downgrade_to_V0 (const hb_set_t &glyphset) const
+  {
+    //no more COLRv1 glyphs, downgrade to version 0
+    for (const BaseGlyphPaintRecord& _ : get_baseglyphList ())
+      if (glyphset.has (_.glyphId))
+        return false;
+
+    return true;
+  }
+
+  bool subset_varstore (hb_subset_context_t *c,
+                        COLR* out /* OUT */) const
+  {
+    TRACE_SUBSET (this);
+    if (!varStore || c->plan->all_axes_pinned ||
+        !c->plan->colrv1_variation_idx_delta_map)
+      return_trace (true);
+
+    const ItemVariationStore& var_store = this+varStore;
+    if (c->plan->normalized_coords)
+    {
+      item_variations_t item_vars;
+      /* turn off varstore optimization when varIdxMap is null, so we maintain
+       * original var_idx sequence */
+      bool optimize = (varIdxMap != 0) ? true : false;
+      if (!item_vars.instantiate (var_store, c->plan,
+                                  optimize, /* optimization */
+                                  optimize, /* use_no_variation_idx = false */
+                                  c->plan->colrv1_varstore_inner_maps.as_array ()))
+        return_trace (false);
+
+      if (!out->varStore.serialize_serialize (c->serializer,
+                                              item_vars.has_long_word (),
+                                              c->plan->axis_tags,
+                                              item_vars.get_region_list (),
+                                              item_vars.get_vardata_encodings ()))
+        return_trace (false);
+
+      /* if varstore is optimized, update colrv1_new_deltaset_idx_varidx_map in
+       * subset plan */
+      if (optimize)
+      {
+        const hb_map_t &varidx_map = item_vars.get_varidx_map ();
+        for (auto _ : c->plan->colrv1_new_deltaset_idx_varidx_map.iter_ref ())
+        {
+          uint32_t varidx = _.second;
+          uint32_t *new_varidx;
+          if (varidx_map.has (varidx, &new_varidx))
+            _.second = *new_varidx;
+          else
+            _.second = VarIdx::NO_VARIATION;
+        }
+      }
+    }
+    else
+    {
+      if (unlikely (!out->varStore.serialize_serialize (c->serializer,
+                                                        &var_store,
+                                                        c->plan->colrv1_varstore_inner_maps.as_array ())))
+        return_trace (false);
+    }
+
+    return_trace (true);
+  }
+
+  bool subset_delta_set_index_map (hb_subset_context_t *c,
+                                   COLR* out /* OUT */) const
+  {
+    TRACE_SUBSET (this);
+    if (!varIdxMap || c->plan->all_axes_pinned ||
+        !c->plan->colrv1_new_deltaset_idx_varidx_map)
+      return_trace (true);
+
+    const hb_map_t &deltaset_idx_varidx_map = c->plan->colrv1_new_deltaset_idx_varidx_map;
+    delta_set_index_map_subset_plan_t index_map_plan (deltaset_idx_varidx_map);
+
+    if (unlikely (!index_map_plan.remap (deltaset_idx_varidx_map)))
+      return_trace (false);
+
+    return_trace (out->varIdxMap.serialize_serialize (c->serializer, index_map_plan));
+  }
+
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
@@ -2287,34 +2458,28 @@ struct COLR
     auto *colr_prime = c->serializer->start_embed<COLR> ();
     if (unlikely (!c->serializer->extend_min (colr_prime)))  return_trace (false);
 
-    if (version == 0)
-    return_trace (colr_prime->serialize_V0 (c->serializer, version, base_it, layer_it));
+    if (version == 0 || downgrade_to_V0 (glyphset))
+    return_trace (colr_prime->serialize_V0 (c->serializer, 0, base_it, layer_it));
 
-    auto snap = c->serializer->snapshot ();
+    //start version 1
     if (!c->serializer->allocate_size<void> (5 * HBUINT32::static_size)) return_trace (false);
+    if (!colr_prime->serialize_V0 (c->serializer, version, base_it, layer_it)) return_trace (false);
+
+    /* subset ItemVariationStore first, cause varidx_map needs to be updated
+     * after instancing */
+    if (!subset_varstore (c, colr_prime)) return_trace (false);
 
     ItemVarStoreInstancer instancer (varStore ? &(this+varStore) : nullptr,
 	                         varIdxMap ? &(this+varIdxMap) : nullptr,
 	                         c->plan->normalized_coords.as_array ());
 
     if (!colr_prime->baseGlyphList.serialize_subset (c, baseGlyphList, this, instancer))
-    {
-      if (c->serializer->in_error ()) return_trace (false);
-      //no more COLRv1 glyphs: downgrade to version 0
-      c->serializer->revert (snap);
-      return_trace (colr_prime->serialize_V0 (c->serializer, 0, base_it, layer_it));
-    }
-
-    if (!colr_prime->serialize_V0 (c->serializer, version, base_it, layer_it)) return_trace (false);
+      return_trace (false);
 
     colr_prime->layerList.serialize_subset (c, layerList, this, instancer);
     colr_prime->clipList.serialize_subset (c, clipList, this, instancer);
-    if (!varStore || c->plan->all_axes_pinned)
-      return_trace (true);
 
-    colr_prime->varIdxMap.serialize_copy (c->serializer, varIdxMap, this);
-    colr_prime->varStore.serialize_copy (c->serializer, varStore, this);
-    return_trace (true);
+    return_trace (subset_delta_set_index_map (c, colr_prime));
   }
 
   const Paint *get_base_glyph_paint (hb_codepoint_t glyph) const

src/hb-subset-plan-member-list.hh

@@ -104,6 +104,10 @@ HB_SUBSET_PLAN_MEMBER (hb_map_t, colrv1_layers)
 HB_SUBSET_PLAN_MEMBER (hb_map_t, colr_palettes)
 //colrv1 varstore retained varidx mapping
 HB_SUBSET_PLAN_MEMBER (hb_vector_t<hb_inc_bimap_t>, colrv1_varstore_inner_maps)
+//colrv1 retained varidx -> (new varidx, delta) mapping
+HB_SUBSET_PLAN_MEMBER (mutable hb_hashmap_t E(<unsigned, hb_pair_t E(<unsigned, int>)>), colrv1_variation_idx_delta_map)
+//colrv1 retained new delta set index -> new varidx mapping
+HB_SUBSET_PLAN_MEMBER (hb_map_t, colrv1_new_deltaset_idx_varidx_map)
 
 //Old layout item variation index -> (New varidx, delta) mapping
 HB_SUBSET_PLAN_MEMBER (mutable hb_hashmap_t E(<unsigned, hb_pair_t E(<unsigned, int>)>), layout_variation_idx_delta_map)

src/hb-subset-plan.cc

@@ -513,6 +513,30 @@ _cmap_closure (hb_face_t	   *face,
   cmap.table->closure_glyphs (unicodes, glyphset);
 }
 
+static void
+_remap_colrv1_delta_set_index_indices (const OT::DeltaSetIndexMap &index_map,
+                                       const hb_set_t &delta_set_idxes,
+                                       hb_hashmap_t<unsigned, hb_pair_t<unsigned, int>> &variation_idx_delta_map, /* IN/OUT */
+                                       hb_map_t &new_deltaset_idx_varidx_map /* OUT */)
+{
+  if (!index_map.get_map_count ())
+    return;
+
+  hb_hashmap_t<unsigned, hb_pair_t<unsigned, int>> delta_set_idx_delta_map;
+  unsigned new_delta_set_idx = 0;
+  for (unsigned delta_set_idx : delta_set_idxes)
+  {
+    unsigned var_idx = index_map.map (delta_set_idx);
+    hb_pair_t<unsigned, int> *new_varidx_delta;
+    if (!variation_idx_delta_map.has (var_idx, &new_varidx_delta)) continue;
+
+    new_deltaset_idx_varidx_map.set (new_delta_set_idx, hb_first (*new_varidx_delta));
+    delta_set_idx_delta_map.set (delta_set_idx, hb_pair_t<unsigned, int> (new_delta_set_idx, hb_second (*new_varidx_delta)));
+    new_delta_set_idx++;
+  }
+  variation_idx_delta_map = std::move (delta_set_idx_delta_map);
+}
+
 static void _colr_closure (hb_subset_plan_t* plan,
                            hb_set_t *glyphs_colred)
 {
@@ -535,10 +559,36 @@ static void _colr_closure (hb_subset_plan_t* plan,
   _remap_indexes (&layer_indices, &plan->colrv1_layers);
   _remap_palette_indexes (&palette_indices, &plan->colr_palettes);
 
-  if (!colr.has_var_store ()) return;
-  
-  unsigned subtable_count = colr.get_var_store ().get_sub_table_count ();
+  if (!colr.has_var_store () || !variation_indices) return;
+
+  const OT::ItemVariationStore &var_store = colr.get_var_store ();
+  // generated inner_maps is used by ItemVariationStore serialize(), which is subset only
+  unsigned subtable_count = var_store.get_sub_table_count ();
   _generate_varstore_inner_maps (variation_indices, subtable_count, plan->colrv1_varstore_inner_maps);
+
+  /* colr variation indices mapping during planning phase:
+   * generate colrv1_variation_idx_delta_map. When delta set index map is not
+   * included, it's a mapping from varIdx-> (new varIdx,delta). Otherwise, it's
+   * a mapping from old delta set idx-> (new delta set idx, delta). Mapping
+   * delta set indices is the same as gid mapping.
+   * Besides, we need to generate a delta set idx-> new var_idx map for updating
+   * delta set index map if exists. This map will be updated again after
+   * instancing. */
+  if (!plan->all_axes_pinned)
+  {
+    _remap_variation_indices (var_store,
+                              variation_indices,
+                              plan->normalized_coords,
+                              false, /* no need to calculate delta for COLR during planning */
+                              plan->all_axes_pinned,
+                              plan->colrv1_variation_idx_delta_map);
+
+    if (colr.has_delta_set_index_map ())
+      _remap_colrv1_delta_set_index_indices (colr.get_delta_set_index_map (),
+                                             delta_set_indices,
+                                             plan->colrv1_variation_idx_delta_map,
+                                             plan->colrv1_new_deltaset_idx_varidx_map);
+  }
 }
 
 static inline void

test/subset/data/Makefile.am

@@ -51,7 +51,7 @@ EXTRA_DIST += \
 	expected/colr \
 	expected/colr_glyphs \
 	expected/colrv1 \
-	expected/colrv1_copy_varstore \
+	expected/colrv1_subset_varstore \
 	expected/colr_with_components \
 	expected/cbdt \
 	expected/variable \
@@ -72,9 +72,19 @@ EXTRA_DIST += \
 	expected/post_apply_mvar_delta \
 	expected/apply_cvar_delta \
 	expected/collect_name_ids \
-	expected/instantiate_colrv1 \
 	expected/instantiate_cff2_update_metrics \
 	expected/layout.empty_ligature_offset \
+	expected/instantiate_base \
+	expected/instantiate_colrv1 \
+	expected/glyf_partial_instancing \
+	expected/feature_variations_partial_instance \
+	expected/update_def_wght \
+	expected/mvar_partial_instance \
+	expected/value_format_partial_instance \
+	expected/gdef_partial_instance \
+	expected/feature_variation_instance_collect_lookups \
+	expected/sync_vmetrics \
+	expected/empty_region_vardata \
 	fonts \
 	profiles \
 	$(NULL)

test/subset/data/Makefile.sources

@@ -11,7 +11,7 @@ TESTS = \
 	tests/colr.tests \
 	tests/colr_glyphs.tests \
 	tests/colrv1.tests \
-	tests/colrv1_copy_varstore.tests \
+	tests/colrv1_subset_varstore.tests \
 	tests/colr_with_components.tests \
 	tests/full-font.tests \
 	tests/glyf_bug_3131.tests \
@@ -63,9 +63,19 @@ TESTS = \
 	tests/post_apply_mvar_delta.tests \
 	tests/apply_cvar_delta.tests \
 	tests/collect_name_ids.tests \
-	tests/instantiate_colrv1.tests \
 	tests/instantiate_cff2_update_metrics.tests \
 	tests/layout.empty_ligature_offset.tests \
+	tests/instantiate_base.tests \
+	tests/instantiate_colrv1.tests \
+	tests/glyf_partial_instancing.tests \
+	tests/feature_variations_partial_instance.tests \
+	tests/update_def_wght.tests \
+	tests/mvar_partial_instance.tests \
+	tests/value_format_partial_instance.tests \
+	tests/gdef_partial_instance.tests \
+	tests/feature_variation_instance_collect_lookups.tests \
+	tests/sync_vmetrics.tests \
+	tests/empty_region_vardata.tests \
 	$(NULL)
 
 # TODO: re-enable once colrv1 subsetting is stabilized.