Merge pull request #3605 from harfbuzz/cache-varstore

Cache varstore
https://github.com/harfbuzz/harfbuzz/pull/3605

src/hb-ot-font.cc

@@ -110,12 +110,24 @@ hb_ot_get_glyph_h_advances (hb_font_t* font, void* font_data,
   const hb_ot_face_t *ot_face = (const hb_ot_face_t *) font_data;
   const OT::hmtx_accelerator_t &hmtx = *ot_face->hmtx;
 
+#ifndef HB_NO_VAR
+  const OT::HVARVVAR &HVAR = *hmtx.var_table;
+  const OT::VariationStore &varStore = &HVAR + HVAR.varStore;
+  OT::VariationStore::cache_t *cache = font->num_coords ? varStore.create_cache () : nullptr;
+#else
+  OT::VariationStore::cache_t *cache = nullptr;
+#endif
+
   for (unsigned int i = 0; i < count; i++)
   {
-    *first_advance = font->em_scale_x (hmtx.get_advance (*first_glyph, font));
+    *first_advance = font->em_scale_x (hmtx.get_advance (*first_glyph, font, cache));
     first_glyph = &StructAtOffsetUnaligned<hb_codepoint_t> (first_glyph, glyph_stride);
     first_advance = &StructAtOffsetUnaligned<hb_position_t> (first_advance, advance_stride);
   }
+
+#ifndef HB_NO_VAR
+  OT::VariationStore::destroy_cache (cache);
+#endif
 }
 
 #ifndef HB_NO_VERTICAL
@@ -132,12 +144,26 @@ hb_ot_get_glyph_v_advances (hb_font_t* font, void* font_data,
   const OT::vmtx_accelerator_t &vmtx = *ot_face->vmtx;
 
   if (vmtx.has_data ())
+  {
+#ifndef HB_NO_VAR
+    const OT::HVARVVAR &VVAR = *vmtx.var_table;
+    const OT::VariationStore &varStore = &VVAR + VVAR.varStore;
+    OT::VariationStore::cache_t *cache = font->num_coords ? varStore.create_cache () : nullptr;
+#else
+    OT::VariationStore::cache_t *cache = nullptr;
+#endif
+
     for (unsigned int i = 0; i < count; i++)
     {
-      *first_advance = font->em_scale_y (-(int) vmtx.get_advance (*first_glyph, font));
+      *first_advance = font->em_scale_y (-(int) vmtx.get_advance (*first_glyph, font, cache));
       first_glyph = &StructAtOffsetUnaligned<hb_codepoint_t> (first_glyph, glyph_stride);
       first_advance = &StructAtOffsetUnaligned<hb_position_t> (first_advance, advance_stride);
     }
+
+#ifndef HB_NO_VAR
+    OT::VariationStore::destroy_cache (cache);
+#endif
+  }
   else
   {
     hb_font_extents_t font_extents;

src/hb-ot-hmtx-table.hh

@@ -242,7 +242,7 @@ struct hmtxvmtx
 	return side_bearing;
 
       if (var_table.get_length ())
-	return side_bearing + var_table->get_side_bearing_var (glyph, font->coords, font->num_coords); // TODO Optimize?!
+	return side_bearing + var_table->get_side_bearing_var (glyph, font->coords, font->num_coords);
 
       return _glyf_get_side_bearing_var (font, glyph, T::tableTag == HB_OT_TAG_vmtx);
 #else
@@ -284,7 +284,8 @@ struct hmtxvmtx
     }
 
     unsigned int get_advance (hb_codepoint_t  glyph,
-			      hb_font_t      *font) const
+			      hb_font_t      *font,
+			      VariationStore::cache_t *store_cache = nullptr) const
     {
       unsigned int advance = get_advance (glyph);
 
@@ -293,7 +294,7 @@ struct hmtxvmtx
 	return advance;
 
       if (var_table.get_length ())
-	return advance + roundf (var_table->get_advance_var (glyph, font)); // TODO Optimize?!
+	return advance + roundf (var_table->get_advance_var (glyph, font, store_cache)); // TODO Optimize?!
 
       return _glyf_get_advance_var (font, glyph, T::tableTag == HB_OT_TAG_vmtx);
 #else
@@ -310,7 +311,7 @@ struct hmtxvmtx
 
     unsigned int default_advance;
 
-    private:
+    public:
     hb_blob_ptr_t<hmtxvmtx> table;
     hb_blob_ptr_t<HVARVVAR> var_table;
   };

src/hb-ot-layout-common.hh

@@ -2601,14 +2601,27 @@ struct VarRegionAxis
   DEFINE_SIZE_STATIC (6);
 };
 
+#define REGION_CACHE_ITEM_CACHE_INVALID 2.f
+
 struct VarRegionList
 {
+  using cache_t = float;
+
   float evaluate (unsigned int region_index,
-		  const int *coords, unsigned int coord_len) const
+		  const int *coords, unsigned int coord_len,
+		  cache_t *cache = nullptr) const
   {
     if (unlikely (region_index >= regionCount))
       return 0.;
 
+    float *cached = nullptr;
+    if (cache)
+    {
+      cached = &(cache[region_index]);
+      if (likely (*cached != REGION_CACHE_ITEM_CACHE_INVALID))
+	return *cached;
+    }
+
     const VarRegionAxis *axes = axesZ.arrayZ + (region_index * axisCount);
 
     float v = 1.;
@@ -2618,9 +2631,16 @@ struct VarRegionList
       int coord = i < coord_len ? coords[i] : 0;
       float factor = axes[i].evaluate (coord);
       if (factor == 0.f)
+      {
+        if (cache)
+	  *cached = 0.;
 	return 0.;
+      }
       v *= factor;
     }
+
+    if (cache)
+      *cached = v;
     return v;
   }
 
@@ -2678,7 +2698,8 @@ struct VarData
 
   float get_delta (unsigned int inner,
 		   const int *coords, unsigned int coord_count,
-		   const VarRegionList &regions) const
+		   const VarRegionList &regions,
+		   VarRegionList::cache_t *cache = nullptr) const
   {
     if (unlikely (inner >= itemCount))
       return 0.;
@@ -2695,13 +2716,13 @@ struct VarData
    const HBINT16 *scursor = reinterpret_cast<const HBINT16 *> (row);
    for (; i < scount; i++)
    {
-     float scalar = regions.evaluate (regionIndices.arrayZ[i], coords, coord_count);
+     float scalar = regions.evaluate (regionIndices.arrayZ[i], coords, coord_count, cache);
      delta += scalar * *scursor++;
    }
    const HBINT8 *bcursor = reinterpret_cast<const HBINT8 *> (scursor);
    for (; i < count; i++)
    {
-     float scalar = regions.evaluate (regionIndices.arrayZ[i], coords, coord_count);
+     float scalar = regions.evaluate (regionIndices.arrayZ[i], coords, coord_count, cache);
      delta += scalar * *bcursor++;
    }
 
@@ -2846,9 +2867,28 @@ struct VarData
 
 struct VariationStore
 {
+  using cache_t = VarRegionList::cache_t;
+
+  cache_t *create_cache () const
+  {
+    auto &r = this+regions;
+    unsigned count = r.regionCount;
+
+    float *cache = (float *) hb_malloc (sizeof (float) * count);
+    if (unlikely (!cache)) return nullptr;
+
+    for (unsigned i = 0; i < count; i++)
+      cache[i] = REGION_CACHE_ITEM_CACHE_INVALID;
+
+    return cache;
+  }
+
+  static void destroy_cache (cache_t *cache) { hb_free (cache); }
+
   private:
   float get_delta (unsigned int outer, unsigned int inner,
-		   const int *coords, unsigned int coord_count) const
+		   const int *coords, unsigned int coord_count,
+		   VarRegionList::cache_t *cache = nullptr) const
   {
 #ifdef HB_NO_VAR
     return 0.f;
@@ -2859,16 +2899,18 @@ struct VariationStore
 
     return (this+dataSets[outer]).get_delta (inner,
 					     coords, coord_count,
-					     this+regions);
+					     this+regions,
+					     cache);
   }
 
   public:
   float get_delta (unsigned int index,
-		   const int *coords, unsigned int coord_count) const
+		   const int *coords, unsigned int coord_count,
+		   VarRegionList::cache_t *cache = nullptr) const
   {
     unsigned int outer = index >> 16;
     unsigned int inner = index & 0xFFFF;
-    return get_delta (outer, inner, coords, coord_count);
+    return get_delta (outer, inner, coords, coord_count, cache);
   }
 
   bool sanitize (hb_sanitize_context_t *c) const
@@ -2995,6 +3037,8 @@ struct VariationStore
   DEFINE_SIZE_ARRAY_SIZED (8, dataSets);
 };
 
+#undef REGION_CACHE_ITEM_CACHE_INVALID
+
 /*
  * Feature Variations
  */
@@ -3462,11 +3506,15 @@ struct VariationDevice
 
   private:
 
-  hb_position_t get_x_delta (hb_font_t *font, const VariationStore &store) const
+  hb_position_t get_x_delta (hb_font_t *font,
-  { return font->em_scalef_x (get_delta (font, store)); }
+			     const VariationStore &store,
+			     VariationStore::cache_t *store_cache = nullptr) const
+  { return font->em_scalef_x (get_delta (font, store, store_cache)); }
 
-  hb_position_t get_y_delta (hb_font_t *font, const VariationStore &store) const
+  hb_position_t get_y_delta (hb_font_t *font,
-  { return font->em_scalef_y (get_delta (font, store)); }
+			     const VariationStore &store,
+			     VariationStore::cache_t *store_cache = nullptr) const
+  { return font->em_scalef_y (get_delta (font, store, store_cache)); }
 
   VariationDevice* copy (hb_serialize_context_t *c, const hb_map_t *layout_variation_idx_map) const
   {
@@ -3500,9 +3548,11 @@ struct VariationDevice
 
   private:
 
-  float get_delta (hb_font_t *font, const VariationStore &store) const
+  float get_delta (hb_font_t *font,
+		   const VariationStore &store,
+		   VariationStore::cache_t *store_cache = nullptr) const
   {
-    return store.get_delta (varIdx, font->coords, font->num_coords);
+    return store.get_delta (varIdx, font->coords, font->num_coords, (VariationStore::cache_t *) store_cache);
   }
 
   protected:
@@ -3525,7 +3575,9 @@ struct DeviceHeader
 
 struct Device
 {
-  hb_position_t get_x_delta (hb_font_t *font, const VariationStore &store=Null (VariationStore)) const
+  hb_position_t get_x_delta (hb_font_t *font,
+			     const VariationStore &store=Null (VariationStore),
+			     VariationStore::cache_t *store_cache = nullptr) const
   {
     switch (u.b.format)
     {
@@ -3535,13 +3587,15 @@ struct Device
 #endif
 #ifndef HB_NO_VAR
     case 0x8000:
-      return u.variation.get_x_delta (font, store);
+      return u.variation.get_x_delta (font, store, store_cache);
 #endif
     default:
       return 0;
     }
   }
-  hb_position_t get_y_delta (hb_font_t *font, const VariationStore &store=Null (VariationStore)) const
+  hb_position_t get_y_delta (hb_font_t *font,
+			     const VariationStore &store=Null (VariationStore),
+			     VariationStore::cache_t *store_cache = nullptr) const
   {
     switch (u.b.format)
     {
@@ -3551,7 +3605,7 @@ struct Device
 #endif
 #ifndef HB_NO_VAR
     case 0x8000:
-      return u.variation.get_y_delta (font, store);
+      return u.variation.get_y_delta (font, store, store_cache);
 #endif
     default:
       return 0;

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

@@ -146,23 +146,24 @@ struct ValueFormat : HBUINT16
     if (!use_x_device && !use_y_device) return ret;
 
     const VariationStore &store = c->var_store;
+    auto *cache = c->var_store_cache;
 
     /* pixel -> fractional pixel */
     if (format & xPlaDevice) {
-      if (use_x_device) glyph_pos.x_offset  += (base + get_device (values, &ret)).get_x_delta (font, store);
+      if (use_x_device) glyph_pos.x_offset  += (base + get_device (values, &ret)).get_x_delta (font, store, cache);
       values++;
     }
     if (format & yPlaDevice) {
-      if (use_y_device) glyph_pos.y_offset  += (base + get_device (values, &ret)).get_y_delta (font, store);
+      if (use_y_device) glyph_pos.y_offset  += (base + get_device (values, &ret)).get_y_delta (font, store, cache);
       values++;
     }
     if (format & xAdvDevice) {
-      if (horizontal && use_x_device) glyph_pos.x_advance += (base + get_device (values, &ret)).get_x_delta (font, store);
+      if (horizontal && use_x_device) glyph_pos.x_advance += (base + get_device (values, &ret)).get_x_delta (font, store, cache);
       values++;
     }
     if (format & yAdvDevice) {
       /* y_advance values grow downward but font-space grows upward, hence negation */
-      if (!horizontal && use_y_device) glyph_pos.y_advance -= (base + get_device (values, &ret)).get_y_delta (font, store);
+      if (!horizontal && use_y_device) glyph_pos.y_advance -= (base + get_device (values, &ret)).get_y_delta (font, store, cache);
       values++;
     }
     return ret;
@@ -465,9 +466,9 @@ struct AnchorFormat3
     *y = font->em_fscale_y (yCoordinate);
 
     if (font->x_ppem || font->num_coords)
-      *x += (this+xDeviceTable).get_x_delta (font, c->var_store);
+      *x += (this+xDeviceTable).get_x_delta (font, c->var_store, c->var_store_cache);
     if (font->y_ppem || font->num_coords)
-      *y += (this+yDeviceTable).get_y_delta (font, c->var_store);
+      *y += (this+yDeviceTable).get_y_delta (font, c->var_store, c->var_store_cache);
   }
 
   bool sanitize (hb_sanitize_context_t *c) const

src/hb-ot-layout-gsubgpos.hh

@@ -621,16 +621,17 @@ struct hb_ot_apply_context_t :
 
   skipping_iterator_t iter_input, iter_context;
 
+  unsigned int table_index; /* GSUB/GPOS */
   hb_font_t *font;
   hb_face_t *face;
   hb_buffer_t *buffer;
   recurse_func_t recurse_func;
   const GDEF &gdef;
   const VariationStore &var_store;
+  VariationStore::cache_t *var_store_cache;
 
   hb_direction_t direction;
   hb_mask_t lookup_mask;
-  unsigned int table_index; /* GSUB/GPOS */
   unsigned int lookup_index;
   unsigned int lookup_props;
   unsigned int nesting_level_left;
@@ -648,6 +649,7 @@ struct hb_ot_apply_context_t :
 			 hb_font_t *font_,
 			 hb_buffer_t *buffer_) :
 			iter_input (), iter_context (),
+			table_index (table_index_),
 			font (font_), face (font->face), buffer (buffer_),
 			recurse_func (nullptr),
 			gdef (
@@ -658,9 +660,15 @@ struct hb_ot_apply_context_t :
 #endif
 			     ),
 			var_store (gdef.get_var_store ()),
+			var_store_cache (
+#ifndef HB_NO_VAR
+					 table_index == 1 && font->num_coords ? var_store.create_cache () : nullptr
+#else
+					 nullptr
+#endif
+					),
 			direction (buffer_->props.direction),
 			lookup_mask (1),
-			table_index (table_index_),
 			lookup_index ((unsigned int) -1),
 			lookup_props (0),
 			nesting_level_left (HB_MAX_NESTING_LEVEL),
@@ -669,7 +677,15 @@ struct hb_ot_apply_context_t :
 			auto_zwj (true),
 			per_syllable (false),
 			random (false),
-			random_state (1) { init_iters (); }
+			random_state (1)
+  { init_iters (); }
+
+  ~hb_ot_apply_context_t ()
+  {
+#ifndef HB_NO_VAR
+    VariationStore::destroy_cache (var_store_cache);
+#endif
+  }
 
   void init_iters ()
   {

src/hb-ot-var-hvar-table.hh

@@ -319,10 +319,15 @@ struct HVARVVAR
 						hvar_plan.index_map_plans.as_array ()));
   }
 
-  float get_advance_var (hb_codepoint_t glyph, hb_font_t *font) const
+  float get_advance_var (hb_codepoint_t  glyph,
+			 hb_font_t      *font,
+			 VariationStore::cache_t *store_cache = nullptr) const
   {
     uint32_t varidx = (this+advMap).map (glyph);
-    return (this+varStore).get_delta (varidx, font->coords, font->num_coords);
+    return (this+varStore).get_delta (varidx,
+				      font->coords,
+				      font->num_coords,
+				      store_cache);
   }
 
   float get_side_bearing_var (hb_codepoint_t glyph,
@@ -335,7 +340,7 @@ struct HVARVVAR
 
   bool has_side_bearing_deltas () const { return lsbMap && rsbMap; }
 
-  protected:
+  public:
   FixedVersion<>version;	/* Version of the metrics variation table
 				 * initially set to 0x00010000u */
   Offset32To<VariationStore>