Update bundled HarfBuzz-NG copy to 1.7.4

This is the latest released version, fixing a large amount
of bugs and adding Unicode 10 support.

[ChangeLog] Bundled HarfBuzz-NG copy updated to 1.7.4

Change-Id: Idc8092dfc4e593d64fff2fd51ff9e1b3d84049a7
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 114 insertions, 9 deletions

diff --git a/src/3rdparty/harfbuzz-ng/src/hb-ot-hmtx-table.hh b/src/3rdparty/harfbuzz-ng/src/hb-ot-hmtx-table.hh
index a9606b3d27..e710aee42e 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-ot-hmtx-table.hh
+++ b/src/3rdparty/harfbuzz-ng/src/hb-ot-hmtx-table.hh
@@ -28,6 +28,9 @@
 #define HB_OT_HMTX_TABLE_HH
 
 #include "hb-open-type-private.hh"
+#include "hb-ot-hhea-table.hh"
+#include "hb-ot-os2-table.hh"
+#include "hb-ot-var-hvar-table.hh"
 
 
 namespace OT {
@@ -50,13 +53,9 @@ struct LongMetric
   DEFINE_SIZE_STATIC (4);
 };
 
-struct _mtx
+template <typename T>
+struct hmtxvmtx
 {
-  static const hb_tag_t tableTag = HB_TAG('_','m','t','x');
-
-  static const hb_tag_t hmtxTag	= HB_OT_TAG_hmtx;
-  static const hb_tag_t vmtxTag	= HB_OT_TAG_vmtx;
-
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
@@ -65,7 +64,107 @@ struct _mtx
     return_trace (true);
   }
 
-  public:
+  struct accelerator_t
+  {
+    inline void init (hb_face_t *face,
+		      unsigned int default_advance_ = 0)
+    {
+      default_advance = default_advance_ ? default_advance_ : face->get_upem ();
+
+      bool got_font_extents = false;
+      if (T::os2Tag)
+      {
+	hb_blob_t *os2_blob = Sanitizer<os2>::sanitize (face->reference_table (T::os2Tag));
+	const os2 *os2_table = Sanitizer<os2>::lock_instance (os2_blob);
+#define USE_TYPO_METRICS (1u<<7)
+	if (0 != (os2_table->fsSelection & USE_TYPO_METRICS))
+	{
+	  ascender = os2_table->sTypoAscender;
+	  descender = os2_table->sTypoDescender;
+	  line_gap = os2_table->sTypoLineGap;
+	  got_font_extents = (ascender | descender) != 0;
+	}
+	hb_blob_destroy (os2_blob);
+      }
+
+      hb_blob_t *_hea_blob = Sanitizer<_hea>::sanitize (face->reference_table (T::headerTag));
+      const _hea *_hea_table = Sanitizer<_hea>::lock_instance (_hea_blob);
+      num_advances = _hea_table->numberOfLongMetrics;
+      if (!got_font_extents)
+      {
+	ascender = _hea_table->ascender;
+	descender = _hea_table->descender;
+	line_gap = _hea_table->lineGap;
+	got_font_extents = (ascender | descender) != 0;
+      }
+      hb_blob_destroy (_hea_blob);
+
+      has_font_extents = got_font_extents;
+
+      blob = Sanitizer<hmtxvmtx>::sanitize (face->reference_table (T::tableTag));
+
+      /* Cap num_metrics() and num_advances() based on table length. */
+      unsigned int len = hb_blob_get_length (blob);
+      if (unlikely (num_advances * 4 > len))
+	num_advances = len / 4;
+      num_metrics = num_advances + (len - 4 * num_advances) / 2;
+
+      /* We MUST set num_metrics to zero if num_advances is zero.
+       * Our get_advance() depends on that. */
+      if (unlikely (!num_advances))
+      {
+	num_metrics = num_advances = 0;
+	hb_blob_destroy (blob);
+	blob = hb_blob_get_empty ();
+      }
+      table = Sanitizer<hmtxvmtx>::lock_instance (blob);
+
+      var_blob = Sanitizer<HVARVVAR>::sanitize (face->reference_table (T::variationsTag));
+      var_table = Sanitizer<HVARVVAR>::lock_instance (var_blob);
+    }
+
+    inline void fini (void)
+    {
+      hb_blob_destroy (blob);
+      hb_blob_destroy (var_blob);
+    }
+
+    inline unsigned int get_advance (hb_codepoint_t  glyph,
+				     hb_font_t      *font) const
+    {
+      if (unlikely (glyph >= num_metrics))
+      {
+	/* If num_metrics is zero, it means we don't have the metrics table
+	 * for this direction: return default advance.  Otherwise, it means that the
+	 * glyph index is out of bound: return zero. */
+	if (num_metrics)
+	  return 0;
+	else
+	  return default_advance;
+      }
+
+      return table->longMetric[MIN (glyph, (uint32_t) num_advances - 1)].advance
+	   + var_table->get_advance_var (glyph, font->coords, font->num_coords); // TODO Optimize?!
+    }
+
+    public:
+    bool has_font_extents;
+    unsigned short ascender;
+    unsigned short descender;
+    unsigned short line_gap;
+
+    private:
+    unsigned int num_metrics;
+    unsigned int num_advances;
+    unsigned int default_advance;
+
+    const hmtxvmtx *table;
+    hb_blob_t *blob;
+    const HVARVVAR *var_table;
+    hb_blob_t *var_blob;
+  };
+
+  protected:
   LongMetric	longMetric[VAR];	/* Paired advance width and leading
 					 * bearing values for each glyph. The
 					 * value numOfHMetrics comes from
@@ -91,11 +190,17 @@ struct _mtx
   DEFINE_SIZE_ARRAY2 (0, longMetric, leadingBearingX);
 };
 
-struct hmtx : _mtx {
+struct hmtx : hmtxvmtx<hmtx> {
   static const hb_tag_t tableTag	= HB_OT_TAG_hmtx;
+  static const hb_tag_t headerTag	= HB_OT_TAG_hhea;
+  static const hb_tag_t variationsTag	= HB_OT_TAG_HVAR;
+  static const hb_tag_t os2Tag		= HB_OT_TAG_os2;
 };
-struct vmtx : _mtx {
+struct vmtx : hmtxvmtx<vmtx> {
   static const hb_tag_t tableTag	= HB_OT_TAG_vmtx;
+  static const hb_tag_t headerTag	= HB_OT_TAG_vhea;
+  static const hb_tag_t variationsTag	= HB_OT_TAG_VVAR;
+  static const hb_tag_t os2Tag		= HB_TAG_NONE;
 };
 
 } /* namespace OT */