[ot-font/trak] Move trak application to ot-font instead of ot-shape

This is what CoreText does.

Fixes https://github.com/harfbuzz/harfbuzz/issues/5049

src/hb-aat-layout-trak-table.hh

@@ -190,40 +190,15 @@ struct trak
 
   bool has_data () const { return version.to_int (); }
 
-  bool apply (hb_aat_apply_context_t *c) const
+  hb_position_t get_h_tracking (hb_font_t *font, float track = 0.f) const
   {
-    TRACE_APPLY (this);
-
-    float ptem = c->font->ptem;
-    if (unlikely (ptem <= 0.f))
-    {
-      /* https://developer.apple.com/documentation/coretext/1508745-ctfontcreatewithgraphicsfont */
-      ptem = HB_CORETEXT_DEFAULT_FONT_SIZE;
-    }
-
-    hb_buffer_t *buffer = c->buffer;
-    if (HB_DIRECTION_IS_HORIZONTAL (buffer->props.direction))
-    {
-      const TrackData &trackData = this+horizData;
-      float tracking = trackData.get_tracking (this, ptem);
-      hb_position_t advance_to_add = c->font->em_scalef_x (tracking);
-      foreach_grapheme (buffer, start, end)
-      {
-	buffer->pos[start].x_advance += advance_to_add;
-      }
-    }
-    else
-    {
-      const TrackData &trackData = this+vertData;
-      float tracking = trackData.get_tracking (this, ptem);
-      hb_position_t advance_to_add = c->font->em_scalef_y (tracking);
-      foreach_grapheme (buffer, start, end)
-      {
-	buffer->pos[start].y_advance += advance_to_add;
-      }
-    }
-
-    return_trace (true);
+    float ptem = font->ptem > 0.f ? font->ptem : HB_CORETEXT_DEFAULT_FONT_SIZE;
+    return font->em_scalef_x ((this+horizData).get_tracking (this, ptem, track));
+  }
+  hb_position_t get_v_tracking (hb_font_t *font, float track = 0.f) const
+  {
+    float ptem = font->ptem > 0.f ? font->ptem : HB_CORETEXT_DEFAULT_FONT_SIZE;
+    return font->em_scalef_y ((this+vertData).get_tracking (this, ptem, track));
   }
 
   bool sanitize (hb_sanitize_context_t *c) const

src/hb-aat-layout.cc

@@ -34,7 +34,7 @@
 #include "hb-aat-layout-just-table.hh" // Just so we compile it; unused otherwise.
 #include "hb-aat-layout-kerx-table.hh"
 #include "hb-aat-layout-morx-table.hh"
-#include "hb-aat-layout-trak-table.hh"
+#include "hb-aat-layout-trak-table.hh" // Just so we compile it; unused otherwise.
 #include "hb-aat-ltag-table.hh"
 
 #include "hb-ot-layout-gsub-table.hh"
@@ -394,17 +394,6 @@ hb_aat_layout_has_tracking (hb_face_t *face)
   return face->table.trak->has_data ();
 }
 
-void
-hb_aat_layout_track (const hb_ot_shape_plan_t *plan,
-		     hb_font_t *font,
-		     hb_buffer_t *buffer)
-{
-  const AAT::trak& trak = *font->face->table.trak;
-
-  AAT::hb_aat_apply_context_t c (plan, font, buffer);
-  trak.apply (&c);
-}
-
 /**
  * hb_aat_layout_get_feature_types:
  * @face: #hb_face_t to work upon

src/hb-aat-layout.hh

@@ -71,10 +71,5 @@ hb_aat_layout_position (const hb_ot_shape_plan_t *plan,
 			hb_font_t *font,
 			hb_buffer_t *buffer);
 
-HB_INTERNAL void
-hb_aat_layout_track (const hb_ot_shape_plan_t *plan,
-		     hb_font_t *font,
-		     hb_buffer_t *buffer);
-
 
 #endif /* HB_AAT_LAYOUT_HH */

src/hb-coretext-shape.cc

@@ -430,7 +430,7 @@ _hb_coretext_shaper_font_data_create (hb_font_t *font)
   if (unlikely (!face_data)) return nullptr;
   CGFontRef cg_font = (CGFontRef) (const void *) face->data.coretext;
 
-  CGFloat font_size = (CGFloat) (font->ptem <= 0.f ? HB_CORETEXT_DEFAULT_FONT_SIZE : font->ptem);
+  CGFloat font_size = (CGFloat) (font->ptem > 0.f ? font->ptem : HB_CORETEXT_DEFAULT_FONT_SIZE);
   CTFontRef ct_font = create_ct_font (cg_font, font_size);
 
   if (unlikely (!ct_font))

src/hb-ot-font.cc

@@ -36,6 +36,9 @@
 #include "hb-ot-face.hh"
 #include "hb-outline.hh"
 
+#ifndef HB_NO_AAT
+#include "hb-aat-layout-trak-table.hh"
+#endif
 #include "hb-ot-cmap-table.hh"
 #include "hb-ot-glyf-table.hh"
 #include "hb-ot-cff2-table.hh"
@@ -73,6 +76,10 @@ struct hb_ot_font_t
 {
   const hb_ot_face_t *ot_face;
 
+#ifndef HB_NO_AAT
+  bool apply_trak;
+#endif
+
 #ifndef HB_NO_OT_FONT_CMAP_CACHE
   hb_ot_font_cmap_cache_t *cmap_cache;
 #endif
@@ -91,6 +98,11 @@ _hb_ot_font_create (hb_font_t *font)
 
   ot_font->ot_face = &font->face->table;
 
+#ifndef HB_NO_AAT
+  /* According to Ned, trak is applied by default for "modern fonts", as detected by presence of STAT table. */
+  ot_font->apply_trak = font->face->table.STAT->has_data () && font->face->table.trak->has_data ();
+#endif
+
 #ifndef HB_NO_OT_FONT_CMAP_CACHE
   // retry:
   auto *cmap_cache  = (hb_ot_font_cmap_cache_t *) hb_face_get_user_data (font->face,
@@ -200,7 +212,6 @@ hb_ot_get_glyph_h_advances (hb_font_t* font, void* font_data,
 			    unsigned advance_stride,
 			    void *user_data HB_UNUSED)
 {
-
   const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
   const hb_ot_face_t *ot_face = ot_font->ot_face;
   const OT::hmtx_accelerator_t &hmtx = *ot_face->hmtx;
@@ -292,6 +303,20 @@ hb_ot_get_glyph_h_advances (hb_font_t* font, void* font_data,
       first_advance = &StructAtOffsetUnaligned<hb_position_t> (first_advance, advance_stride);
     }
   }
+
+#ifndef HB_NO_AAT
+  if (ot_font->apply_trak)
+  {
+    hb_position_t tracking = font->face->table.trak->get_h_tracking (font);
+    first_advance = orig_first_advance;
+    for (unsigned int i = 0; i < count; i++)
+    {
+      *first_advance += tracking;
+      first_glyph = &StructAtOffsetUnaligned<hb_codepoint_t> (first_glyph, glyph_stride);
+      first_advance = &StructAtOffsetUnaligned<hb_position_t> (first_advance, advance_stride);
+    }
+  }
+#endif
 }
 
 #ifndef HB_NO_VERTICAL
@@ -356,6 +381,20 @@ hb_ot_get_glyph_v_advances (hb_font_t* font, void* font_data,
       first_advance = &StructAtOffsetUnaligned<hb_position_t> (first_advance, advance_stride);
     }
   }
+
+#ifndef HB_NO_AAT
+  if (ot_font->apply_trak)
+  {
+    hb_position_t tracking = font->face->table.trak->get_v_tracking (font);
+    first_advance = orig_first_advance;
+    for (unsigned int i = 0; i < count; i++)
+    {
+      *first_advance += tracking;
+      first_glyph = &StructAtOffsetUnaligned<hb_codepoint_t> (first_glyph, glyph_stride);
+      first_advance = &StructAtOffsetUnaligned<hb_position_t> (first_advance, advance_stride);
+    }
+  }
+#endif
 }
 #endif
 

src/hb-ot-shape.cc

@@ -205,14 +205,6 @@ hb_ot_shape_planner_t::compile (hb_ot_shape_plan_t           &plan,
      https://github.com/harfbuzz/harfbuzz/issues/2967. */
   if (plan.apply_morx)
     plan.adjust_mark_positioning_when_zeroing = false;
-
-  /* According to Ned, trak is applied by default for "modern fonts", as detected by presence of STAT table. */
-#ifndef HB_NO_STYLE
-  plan.apply_trak = hb_aat_layout_has_tracking (face) && face->table.STAT->has_data ();
-#else
-  plan.apply_trak = false;
-#endif
-
 #endif
 }
 
@@ -277,11 +269,6 @@ hb_ot_shape_plan_t::position (hb_font_t   *font,
 #endif
   else if (this->apply_fallback_kern)
     _hb_ot_shape_fallback_kern (this, font, buffer);
-
-#ifndef HB_NO_AAT_SHAPE
-  if (this->apply_trak)
-    hb_aat_layout_track (this, font, buffer);
-#endif
 }
 
 

src/hb-ot-shape.hh

@@ -108,11 +108,9 @@ struct hb_ot_shape_plan_t
 #ifndef HB_NO_AAT_SHAPE
   bool apply_kerx : 1;
   bool apply_morx : 1;
-  bool apply_trak : 1;
 #else
   static constexpr bool apply_kerx = false;
   static constexpr bool apply_morx = false;
-  static constexpr bool apply_trak = false;
 #endif
 
   void collect_lookups (hb_tag_t table_tag, hb_set_t *lookups) const