[instancer ]update OS_2/post/glyf tables to accept Triple for axes positions

src/OT/glyf/glyf.hh

@@ -487,7 +487,7 @@ glyf::_create_font_for_instancing (const hb_subset_plan_t *plan) const
   {
     hb_variation_t var;
     var.tag = _.first;
-    var.value = _.second;
+    var.value = _.second.middle;
     vars.push (var);
   }
 

src/hb-ot-os2-table.hh

@@ -249,7 +249,7 @@ struct OS2
     if (c->plan->user_axes_location.has (HB_TAG ('w','g','h','t')) &&
         !c->plan->pinned_at_default)
     {
-      float weight_class = c->plan->user_axes_location.get (HB_TAG ('w','g','h','t'));
+      float weight_class = c->plan->user_axes_location.get (HB_TAG ('w','g','h','t')).middle;
       if (!c->serializer->check_assign (os2_prime->usWeightClass,
                                         roundf (hb_clamp (weight_class, 1.0f, 1000.0f)),
                                         HB_SERIALIZE_ERROR_INT_OVERFLOW))
@@ -259,7 +259,7 @@ struct OS2
     if (c->plan->user_axes_location.has (HB_TAG ('w','d','t','h')) &&
         !c->plan->pinned_at_default)
     {
-      float width = c->plan->user_axes_location.get (HB_TAG ('w','d','t','h'));
+      float width = c->plan->user_axes_location.get (HB_TAG ('w','d','t','h')).middle;
       if (!c->serializer->check_assign (os2_prime->usWidthClass,
                                         roundf (map_wdth_to_widthclass (width)),
                                         HB_SERIALIZE_ERROR_INT_OVERFLOW))

src/hb-ot-post-table.hh

@@ -117,7 +117,7 @@ struct post
     if (c->plan->user_axes_location.has (HB_TAG ('s','l','n','t')) &&
         !c->plan->pinned_at_default)
     {
-      float italic_angle = c->plan->user_axes_location.get (HB_TAG ('s','l','n','t'));
+      float italic_angle = c->plan->user_axes_location.get (HB_TAG ('s','l','n','t')).middle;
       italic_angle = hb_max (-90.f, hb_min (italic_angle, 90.f));
       post_prime->italicAngle.set_float (italic_angle);
     }