[instancer] compile composite glyphs directly with shifted component

points instead of deltas

src/OT/glyf/CompositeGlyph.hh

@@ -113,8 +113,8 @@ struct CompositeGlyphRecord
     return true;
   }
 
-  unsigned compile_with_deltas (const contour_point_t &p_delta,
-                                char *out) const
+  unsigned compile_with_point (const contour_point_t &point,
+                               char *out) const
   {
     const HBINT8 *p = &StructAfter<const HBINT8> (flags);
 #ifndef HB_NO_BEYOND_64K
@@ -128,18 +128,17 @@ struct CompositeGlyphRecord
     unsigned len_before_val = (const char *)p - (const char *)this;
     if (flags & ARG_1_AND_2_ARE_WORDS)
     {
-      // no overflow, copy and update value with deltas
+      // no overflow, copy value
       hb_memcpy (out, this, len);
 
-      const HBINT16 *px = reinterpret_cast<const HBINT16 *> (p);
       HBINT16 *o = reinterpret_cast<HBINT16 *> (out + len_before_val);
-      o[0] = px[0] + roundf (p_delta.x);
-      o[1] = px[1] + roundf (p_delta.y);
+      o[0] = roundf (point.x);
+      o[1] = roundf (point.y);
     }
     else
     {
-      int new_x = p[0] + roundf (p_delta.x);
-      int new_y = p[1] + roundf (p_delta.y);
+      int new_x = roundf (point.x);
+      int new_y = roundf (point.y);
       if (new_x <= 127 && new_x >= -128 &&
           new_y <= 127 && new_y >= -128)
       {
@@ -150,7 +149,7 @@ struct CompositeGlyphRecord
       }
       else
       {
-        // int8 overflows after deltas applied
+        // new point value has an int8 overflow
         hb_memcpy (out, this, len_before_val);
         
         //update flags
@@ -332,7 +331,7 @@ struct CompositeGlyph
   }
 
   bool compile_bytes_with_deltas (const hb_bytes_t &source_bytes,
-                                  const contour_point_vector_t &deltas,
+                                  const contour_point_vector_t &points_with_deltas,
                                   hb_bytes_t &dest_bytes /* OUT */)
   {
     if (source_bytes.length <= GlyphHeader::static_size ||
@@ -357,8 +356,8 @@ struct CompositeGlyph
     unsigned i = 0, source_comp_len = 0;
     for (const auto &component : it)
     {
-      /* last 4 points in deltas are phantom points and should not be included */
-      if (i >= deltas.length - 4) {
+      /* last 4 points in points_with_deltas are phantom points and should not be included */
+      if (i >= points_with_deltas.length - 4) {
         free (o);
         return false;
       }
@@ -371,7 +370,7 @@ struct CompositeGlyph
       }
       else
       {
-        unsigned new_len = component.compile_with_deltas (deltas[i], p);
+        unsigned new_len = component.compile_with_point (points_with_deltas[i], p);
         p += new_len;
       }
       i++;

src/OT/glyf/Glyph.hh

@@ -205,7 +205,7 @@ struct Glyph
                                   hb_bytes_t &dest_start,  /* IN/OUT */
                                   hb_bytes_t &dest_end /* OUT */)
   {
-    contour_point_vector_t all_points, deltas;
+    contour_point_vector_t all_points, points_with_deltas;
     unsigned composite_contours = 0;
     head_maxp_info_t *head_maxp_info_p = &plan->head_maxp_info;
     unsigned *composite_contours_p = &composite_contours;
@@ -219,7 +219,7 @@ struct Glyph
       composite_contours_p = nullptr;
     }
 
-    if (!get_points (font, glyf, all_points, &deltas, head_maxp_info_p, composite_contours_p, false, false))
+    if (!get_points (font, glyf, all_points, &points_with_deltas, head_maxp_info_p, composite_contours_p, false, false))
       return false;
 
     // .notdef, set type to empty so we only update metrics and don't compile bytes for
@@ -246,7 +246,7 @@ struct Glyph
 
       case COMPOSITE:
         if (!CompositeGlyph (*header, bytes).compile_bytes_with_deltas (dest_start,
-                                                                        deltas,
+                                                                        points_with_deltas,
                                                                         dest_end))
           return false;
         break;
@@ -280,7 +280,7 @@ struct Glyph
   template <typename accelerator_t>
   bool get_points (hb_font_t *font, const accelerator_t &glyf_accelerator,
 		   contour_point_vector_t &all_points /* OUT */,
-		   contour_point_vector_t *deltas = nullptr, /* OUT */
+		   contour_point_vector_t *points_with_deltas = nullptr, /* OUT */
 		   head_maxp_info_t * head_maxp_info = nullptr, /* OUT */
 		   unsigned *composite_contours = nullptr, /* OUT */
 		   bool shift_points_hori = true,
@@ -364,12 +364,6 @@ struct Glyph
       phantoms[PHANTOM_BOTTOM].y = v_orig - (int) v_adv;
     }
 
-    if (deltas != nullptr && depth == 0 && type == COMPOSITE)
-    {
-      if (unlikely (!deltas->resize (points.length))) return false;
-      deltas->copy_vector (points);
-    }
-
 #ifndef HB_NO_VAR
     glyf_accelerator.gvar->apply_deltas_to_points (gid,
 						   coords,
@@ -378,13 +372,10 @@ struct Glyph
 
     // mainly used by CompositeGlyph calculating new X/Y offset value so no need to extend it
     // with child glyphs' points
-    if (deltas != nullptr && depth == 0 && type == COMPOSITE)
+    if (points_with_deltas != nullptr && depth == 0 && type == COMPOSITE)
     {
-      for (unsigned i = 0 ; i < points.length; i++)
-      {
-        deltas->arrayZ[i].x = points.arrayZ[i].x - deltas->arrayZ[i].x;
-        deltas->arrayZ[i].y = points.arrayZ[i].y - deltas->arrayZ[i].y;
-      }
+      if (unlikely (!points_with_deltas->resize (points.length))) return false;
+      points_with_deltas->copy_vector (points);
     }
 
     switch (type) {
@@ -405,7 +396,7 @@ struct Glyph
 				       .get_points (font,
 						    glyf_accelerator,
 						    comp_points,
-						    deltas,
+						    points_with_deltas,
 						    head_maxp_info,
 						    composite_contours,
 						    shift_points_hori,
@@ -481,7 +472,7 @@ struct Glyph
 				       .get_points (font,
 						    glyf_accelerator,
 						    comp_points,
-						    deltas,
+						    points_with_deltas,
 						    head_maxp_info,
 						    nullptr,
 						    shift_points_hori,