[varc] Use a varStore cache

src/OT/Var/VARC/VARC.cc

@@ -134,7 +134,8 @@ VarComponent::get_path_at (hb_font_t *font,
 			   hb_ubytes_t total_record,
 			   hb_set_t *visited,
 			   signed *edges_left,
-			   signed depth_left) const
+			   signed depth_left,
+			   VarRegionList::cache_t *cache) const
 {
   auto &VARC = *font->face->table.VARC;
   const unsigned char *end = total_record.arrayZ + total_record.length;
@@ -206,7 +207,7 @@ VarComponent::get_path_at (hb_font_t *font,
     uint32_t axisValuesVarIdx;
     READ_UINT32VAR (axisValuesVarIdx);
     if (show && coords && !axisValues.in_error ())
-      varStore.get_delta (axisValuesVarIdx, coords, axisValues.as_array ());
+      varStore.get_delta (axisValuesVarIdx, coords, axisValues.as_array (), cache);
   }
 
   auto component_coords = coords;
@@ -269,7 +270,7 @@ VarComponent::get_path_at (hb_font_t *font,
 	  transformValues[numTransformValues++] = transform.name;
     PROCESS_TRANSFORM_COMPONENTS;
 #undef PROCESS_TRANSFORM_COMPONENT
-    varStore.get_delta (transformVarIdx, coords, hb_array (transformValues, numTransformValues));
+    varStore.get_delta (transformVarIdx, coords, hb_array (transformValues, numTransformValues), cache);
     numTransformValues = 0;
 #define PROCESS_TRANSFORM_COMPONENT(type, flag, name) \
 	if (flags & (unsigned) flags_t::flag) \

src/OT/Var/VARC/VARC.hh

@@ -49,7 +49,8 @@ struct VarComponent
 	       hb_ubytes_t record,
 	       hb_set_t *visited,
 	       signed *edges_left,
-	       signed depth_left) const;
+	       signed depth_left,
+	       VarRegionList::cache_t *cache = nullptr) const;
 };
 
 struct VarCompositeGlyph
@@ -62,7 +63,8 @@ struct VarCompositeGlyph
 	       hb_ubytes_t record,
 	       hb_set_t *visited,
 	       signed *edges_left,
-	       signed depth_left)
+	       signed depth_left,
+	       VarRegionList::cache_t *cache = nullptr)
   {
     while (record)
     {
@@ -70,7 +72,7 @@ struct VarCompositeGlyph
       record = comp.get_path_at (font, glyph,
 				 draw_session, coords,
 				 record,
-				 visited, edges_left, depth_left);
+				 visited, edges_left, depth_left, cache);
     }
   }
 };
@@ -126,11 +128,16 @@ struct VARC
       return true;
     visited->add (glyph);
 
+    VarRegionList::cache_t *cache = (this+varStore).create_cache ();
+
     hb_ubytes_t record = (this+glyphRecords)[idx];
     VarCompositeGlyph::get_path_at (font, glyph,
 				    draw_session, coords,
 				    record,
-				    visited, edges_left, depth_left);
+				    visited, edges_left, depth_left,
+				    cache);
+
+    (this+varStore).destroy_cache (cache);
 
     visited->del (glyph);