From 14ff3cbe0f30dea24e1bb175b1e8e41039f6afdc Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Thu, 4 Oct 2018 11:34:21 +0200
Subject: [PATCH] Apply morx if there's no GSUB!

---
 src/hb-ot-shape.cc                            | 23 +++++++++----
 src/hb-ot-shape.hh                            |  5 +++
 .../data/text-rendering-tests/DISABLED        | 32 -------------------
 .../text-rendering-tests/Makefile.sources     | 14 ++++----
 4 files changed, 29 insertions(+), 45 deletions(-)

diff --git a/src/hb-ot-shape.cc b/src/hb-ot-shape.cc
index 748af9693..9e87b300b 100644
--- a/src/hb-ot-shape.cc
+++ b/src/hb-ot-shape.cc
@@ -63,9 +63,14 @@ hb_ot_shape_planner_t::compile (hb_ot_shape_plan_t &plan,
   plan.kerning_requested = !!plan.kern_mask;
   plan.has_gpos_mark = !!plan.map.get_1_mask (HB_TAG ('m','a','r','k'));
 
+  plan.apply_morx = !hb_ot_layout_has_substitution (face) &&
+		     hb_aat_layout_has_substitution (face);
+
   bool disable_gpos = plan.shaper->gpos_tag &&
 		      plan.shaper->gpos_tag != plan.map.chosen_script[1];
-  plan.fallback_positioning = disable_gpos || !hb_ot_layout_has_positioning (face);
+  plan.apply_gpos = !disable_gpos && hb_ot_layout_has_positioning (face);
+
+  plan.fallback_positioning = !plan.apply_gpos;
   plan.fallback_glyph_classes = !hb_ot_layout_has_glyph_classes (face);
 }
 
@@ -217,7 +222,13 @@ _hb_ot_shaper_shape_plan_data_create (hb_shape_plan_t    *shape_plan,
 
   hb_ot_shape_planner_t planner (shape_plan);
 
-  planner.shaper = hb_ot_shape_complex_categorize (&planner);
+  /* Ugly that we have to do this here...
+   * If we are going to apply morx, choose default shaper. */
+  if (!hb_ot_layout_has_substitution (planner.face) &&
+       hb_aat_layout_has_substitution (planner.face))
+    planner.shaper = &_hb_ot_complex_shaper_default;
+  else
+    planner.shaper = hb_ot_shape_complex_categorize (&planner);
 
   hb_ot_shape_collect_features (&planner, &shape_plan->props,
 				user_features, num_user_features);
@@ -661,10 +672,10 @@ hb_ot_substitute_complex (hb_ot_shape_context_t *c)
   if (c->plan->fallback_glyph_classes)
     hb_synthesize_glyph_classes (c);
 
-  c->plan->substitute (c->font, buffer);
-
-  if (0) /* XXX Call morx instead. */
+  if (unlikely (c->plan->apply_morx))
     hb_aat_layout_substitute (c->font, c->buffer);
+  else
+    c->plan->substitute (c->font, buffer);
 }
 
 static inline void
@@ -784,7 +795,7 @@ hb_ot_position_complex (hb_ot_shape_context_t *c)
       break;
   }
 
-  if (likely (!c->plan->fallback_positioning))
+  if (c->plan->apply_gpos)
     c->plan->position (c->font, c->buffer);
 
   switch (c->plan->shaper->zero_width_marks)
diff --git a/src/hb-ot-shape.hh b/src/hb-ot-shape.hh
index 88c72dc15..23c385aa1 100644
--- a/src/hb-ot-shape.hh
+++ b/src/hb-ot-shape.hh
@@ -49,6 +49,11 @@ struct hb_ot_shape_plan_t
   bool fallback_positioning : 1;
   bool fallback_glyph_classes : 1;
 
+  bool apply_morx : 1;
+
+  bool apply_gpos : 1;
+
+
   inline void collect_lookups (hb_tag_t table_tag, hb_set_t *lookups) const
   {
     unsigned int table_index;
diff --git a/test/shaping/data/text-rendering-tests/DISABLED b/test/shaping/data/text-rendering-tests/DISABLED
index 1ce62e072..8539c0ee1 100644
--- a/test/shaping/data/text-rendering-tests/DISABLED
+++ b/test/shaping/data/text-rendering-tests/DISABLED
@@ -1,38 +1,6 @@
 # Non-Unicode cmap
 tests/CMAP-3.tests
 
-# Not hooked up
-tests/MORX-1.tests
-tests/MORX-2.tests
-tests/MORX-3.tests
-tests/MORX-4.tests
-tests/MORX-5.tests
-tests/MORX-6.tests
-tests/MORX-7.tests
-tests/MORX-8.tests
-tests/MORX-9.tests
-tests/MORX-10.tests
-tests/MORX-11.tests
-tests/MORX-12.tests
-tests/MORX-13.tests
-tests/MORX-14.tests
-tests/MORX-16.tests
-tests/MORX-17.tests
-tests/MORX-18.tests
-tests/MORX-19.tests
-tests/MORX-20.tests
-tests/MORX-21.tests
-tests/MORX-22.tests
-tests/MORX-23.tests
-tests/MORX-25.tests
-tests/MORX-26.tests
-tests/MORX-27.tests
-tests/MORX-28.tests
-tests/MORX-29.tests
-tests/MORX-30.tests
-tests/MORX-31.tests
-tests/MORX-32.tests
-
 # Rounding differences
 tests/SHARAN-1.tests
 tests/SHBALI-1.tests
diff --git a/test/shaping/data/text-rendering-tests/Makefile.sources b/test/shaping/data/text-rendering-tests/Makefile.sources
index 5c8cd03f9..6fe174e49 100644
--- a/test/shaping/data/text-rendering-tests/Makefile.sources
+++ b/test/shaping/data/text-rendering-tests/Makefile.sources
@@ -28,12 +28,6 @@ TESTS = \
 	tests/HVAR-2.tests \
 	tests/KERN-1.tests \
 	tests/KERN-2.tests \
-	tests/SHBALI-3.tests \
-	tests/SHKNDA-1.tests \
-	$(NULL)
-
-DISBALED_TESTS = \
-	tests/CMAP-3.tests \
 	tests/MORX-10.tests \
 	tests/MORX-11.tests \
 	tests/MORX-12.tests \
@@ -56,7 +50,6 @@ DISBALED_TESTS = \
 	tests/MORX-2.tests \
 	tests/MORX-30.tests \
 	tests/MORX-31.tests \
-	tests/MORX-32.tests \
 	tests/MORX-3.tests \
 	tests/MORX-4.tests \
 	tests/MORX-5.tests \
@@ -64,9 +57,16 @@ DISBALED_TESTS = \
 	tests/MORX-7.tests \
 	tests/MORX-8.tests \
 	tests/MORX-9.tests \
+	tests/SHBALI-3.tests \
+	tests/SHKNDA-1.tests \
+	$(NULL)
+
+DISBALED_TESTS = \
+	tests/CMAP-3.tests \
 	tests/SHARAN-1.tests \
 	tests/SHBALI-1.tests \
 	tests/SHBALI-2.tests \
 	tests/SHKNDA-2.tests \
 	tests/SHKNDA-3.tests \
+	tests/MORX-32.tests \
 	$(NULL)