1 files changed, 138 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-kern.hh b/gfx/harfbuzz/src/hb-kern.hh
new file mode 100644
index 0000000000..3f952fe7fc
--- /dev/null
+++ b/gfx/harfbuzz/src/hb-kern.hh
@@ -0,0 +1,138 @@
+/*
+ * Copyright © 2017  Google, Inc.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Google Author(s): Behdad Esfahbod
+ */
+
+#ifndef HB_KERN_HH
+#define HB_KERN_HH
+
+#include "hb-open-type.hh"
+#include "hb-aat-layout-common.hh"
+#include "hb-ot-layout-gpos-table.hh"
+
+
+namespace OT {
+
+
+template <typename Driver>
+struct hb_kern_machine_t
+{
+  hb_kern_machine_t (const Driver &driver_,
+		     bool crossStream_ = false) :
+		       driver (driver_),
+		       crossStream (crossStream_) {}
+
+  HB_NO_SANITIZE_SIGNED_INTEGER_OVERFLOW
+  void kern (hb_font_t   *font,
+	     hb_buffer_t *buffer,
+	     hb_mask_t    kern_mask,
+	     bool         scale = true) const
+  {
+    OT::hb_ot_apply_context_t c (1, font, buffer);
+    c.set_lookup_mask (kern_mask);
+    c.set_lookup_props (OT::LookupFlag::IgnoreMarks);
+    auto &skippy_iter = c.iter_input;
+
+    bool horizontal = HB_DIRECTION_IS_HORIZONTAL (buffer->props.direction);
+    unsigned int count = buffer->len;
+    hb_glyph_info_t *info = buffer->info;
+    hb_glyph_position_t *pos = buffer->pos;
+    for (unsigned int idx = 0; idx < count;)
+    {
+      if (!(info[idx].mask & kern_mask))
+      {
+	idx++;
+	continue;
+      }
+
+      skippy_iter.reset (idx, 1);
+      if (!skippy_iter.next ())
+      {
+	idx++;
+	continue;
+      }
+
+      unsigned int i = idx;
+      unsigned int j = skippy_iter.idx;
+
+      hb_position_t kern = driver.get_kerning (info[i].codepoint,
+					       info[j].codepoint);
+
+
+      if (likely (!kern))
+	goto skip;
+
+      if (horizontal)
+      {
+	if (scale)
+	  kern = font->em_scale_x (kern);
+	if (crossStream)
+	{
+	  pos[j].y_offset = kern;
+	  buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT;
+	}
+	else
+	{
+	  hb_position_t kern1 = kern >> 1;
+	  hb_position_t kern2 = kern - kern1;
+	  pos[i].x_advance += kern1;
+	  pos[j].x_advance += kern2;
+	  pos[j].x_offset += kern2;
+	}
+      }
+      else
+      {
+	if (scale)
+	  kern = font->em_scale_y (kern);
+	if (crossStream)
+	{
+	  pos[j].x_offset = kern;
+	  buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT;
+	}
+	else
+	{
+	  hb_position_t kern1 = kern >> 1;
+	  hb_position_t kern2 = kern - kern1;
+	  pos[i].y_advance += kern1;
+	  pos[j].y_advance += kern2;
+	  pos[j].y_offset += kern2;
+	}
+      }
+
+      buffer->unsafe_to_break (i, j + 1);
+
+    skip:
+      idx = skippy_iter.idx;
+    }
+  }
+
+  const Driver &driver;
+  bool crossStream;
+};
+
+
+} /* namespace OT */
+
+
+#endif /* HB_KERN_HH */