--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/harfbuzz/src/hb-ot-shape-fallback.cc	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,615 @@
+/*
+ * Copyright © 2011,2012  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
+ */
+
+#include "hb.hh"
+
+#ifndef HB_NO_OT_SHAPE
+
+#include "hb-ot-shape-fallback.hh"
+#include "hb-kern.hh"
+
+static unsigned int
+recategorize_combining_class (hb_codepoint_t u,
+			      unsigned int klass)
+{
+  if (klass >= 200)
+    return klass;
+
+  /* Thai / Lao need some per-character work. */
+  if ((u & ~0xFF) == 0x0E00u)
+  {
+    if (unlikely (klass == 0))
+    {
+      switch (u)
+      {
+	case 0x0E31u:
+	case 0x0E34u:
+	case 0x0E35u:
+	case 0x0E36u:
+	case 0x0E37u:
+	case 0x0E47u:
+	case 0x0E4Cu:
+	case 0x0E4Du:
+	case 0x0E4Eu:
+	  klass = HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT;
+	  break;
+
+	case 0x0EB1u:
+	case 0x0EB4u:
+	case 0x0EB5u:
+	case 0x0EB6u:
+	case 0x0EB7u:
+	case 0x0EBBu:
+	case 0x0ECCu:
+	case 0x0ECDu:
+	  klass = HB_UNICODE_COMBINING_CLASS_ABOVE;
+	  break;
+
+	case 0x0EBCu:
+	  klass = HB_UNICODE_COMBINING_CLASS_BELOW;
+	  break;
+      }
+    } else {
+      /* Thai virama is below-right */
+      if (u == 0x0E3Au)
+	klass = HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT;
+    }
+  }
+
+  switch (klass)
+  {
+
+    /* Hebrew */
+
+    case HB_MODIFIED_COMBINING_CLASS_CCC10: /* sheva */
+    case HB_MODIFIED_COMBINING_CLASS_CCC11: /* hataf segol */
+    case HB_MODIFIED_COMBINING_CLASS_CCC12: /* hataf patah */
+    case HB_MODIFIED_COMBINING_CLASS_CCC13: /* hataf qamats */
+    case HB_MODIFIED_COMBINING_CLASS_CCC14: /* hiriq */
+    case HB_MODIFIED_COMBINING_CLASS_CCC15: /* tsere */
+    case HB_MODIFIED_COMBINING_CLASS_CCC16: /* segol */
+    case HB_MODIFIED_COMBINING_CLASS_CCC17: /* patah */
+    case HB_MODIFIED_COMBINING_CLASS_CCC18: /* qamats & qamats qatan */
+    case HB_MODIFIED_COMBINING_CLASS_CCC20: /* qubuts */
+    case HB_MODIFIED_COMBINING_CLASS_CCC22: /* meteg */
+      return HB_UNICODE_COMBINING_CLASS_BELOW;
+
+    case HB_MODIFIED_COMBINING_CLASS_CCC23: /* rafe */
+      return HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE;
+
+    case HB_MODIFIED_COMBINING_CLASS_CCC24: /* shin dot */
+      return HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT;
+
+    case HB_MODIFIED_COMBINING_CLASS_CCC25: /* sin dot */
+    case HB_MODIFIED_COMBINING_CLASS_CCC19: /* holam & holam haser for vav */
+      return HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT;
+
+    case HB_MODIFIED_COMBINING_CLASS_CCC26: /* point varika */
+      return HB_UNICODE_COMBINING_CLASS_ABOVE;
+
+    case HB_MODIFIED_COMBINING_CLASS_CCC21: /* dagesh */
+      break;
+
+
+    /* Arabic and Syriac */
+
+    case HB_MODIFIED_COMBINING_CLASS_CCC27: /* fathatan */
+    case HB_MODIFIED_COMBINING_CLASS_CCC28: /* dammatan */
+    case HB_MODIFIED_COMBINING_CLASS_CCC30: /* fatha */
+    case HB_MODIFIED_COMBINING_CLASS_CCC31: /* damma */
+    case HB_MODIFIED_COMBINING_CLASS_CCC33: /* shadda */
+    case HB_MODIFIED_COMBINING_CLASS_CCC34: /* sukun */
+    case HB_MODIFIED_COMBINING_CLASS_CCC35: /* superscript alef */
+    case HB_MODIFIED_COMBINING_CLASS_CCC36: /* superscript alaph */
+      return HB_UNICODE_COMBINING_CLASS_ABOVE;
+
+    case HB_MODIFIED_COMBINING_CLASS_CCC29: /* kasratan */
+    case HB_MODIFIED_COMBINING_CLASS_CCC32: /* kasra */
+      return HB_UNICODE_COMBINING_CLASS_BELOW;
+
+
+    /* Thai */
+
+    case HB_MODIFIED_COMBINING_CLASS_CCC103: /* sara u / sara uu */
+      return HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT;
+
+    case HB_MODIFIED_COMBINING_CLASS_CCC107: /* mai */
+      return HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT;
+
+
+    /* Lao */
+
+    case HB_MODIFIED_COMBINING_CLASS_CCC118: /* sign u / sign uu */
+      return HB_UNICODE_COMBINING_CLASS_BELOW;
+
+    case HB_MODIFIED_COMBINING_CLASS_CCC122: /* mai */
+      return HB_UNICODE_COMBINING_CLASS_ABOVE;
+
+
+    /* Tibetan */
+
+    case HB_MODIFIED_COMBINING_CLASS_CCC129: /* sign aa */
+      return HB_UNICODE_COMBINING_CLASS_BELOW;
+
+    case HB_MODIFIED_COMBINING_CLASS_CCC130: /* sign i*/
+      return HB_UNICODE_COMBINING_CLASS_ABOVE;
+
+    case HB_MODIFIED_COMBINING_CLASS_CCC132: /* sign u */
+      return HB_UNICODE_COMBINING_CLASS_BELOW;
+
+  }
+
+  return klass;
+}
+
+void
+_hb_ot_shape_fallback_mark_position_recategorize_marks (const hb_ot_shape_plan_t *plan HB_UNUSED,
+							hb_font_t *font HB_UNUSED,
+							hb_buffer_t  *buffer)
+{
+#ifdef HB_NO_OT_SHAPE_FALLBACK
+  return;
+#endif
+
+  unsigned int count = buffer->len;
+  hb_glyph_info_t *info = buffer->info;
+  for (unsigned int i = 0; i < count; i++)
+    if (_hb_glyph_info_get_general_category (&info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) {
+      unsigned int combining_class = _hb_glyph_info_get_modified_combining_class (&info[i]);
+      combining_class = recategorize_combining_class (info[i].codepoint, combining_class);
+      _hb_glyph_info_set_modified_combining_class (&info[i], combining_class);
+    }
+}
+
+
+static void
+zero_mark_advances (hb_buffer_t *buffer,
+		    unsigned int start,
+		    unsigned int end,
+		    bool adjust_offsets_when_zeroing)
+{
+  hb_glyph_info_t *info = buffer->info;
+  for (unsigned int i = start; i < end; i++)
+    if (_hb_glyph_info_get_general_category (&info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
+    {
+      if (adjust_offsets_when_zeroing)
+      {
+	buffer->pos[i].x_offset -= buffer->pos[i].x_advance;
+	buffer->pos[i].y_offset -= buffer->pos[i].y_advance;
+      }
+      buffer->pos[i].x_advance = 0;
+      buffer->pos[i].y_advance = 0;
+    }
+}
+
+static inline void
+position_mark (const hb_ot_shape_plan_t *plan HB_UNUSED,
+	       hb_font_t *font,
+	       hb_buffer_t  *buffer,
+	       hb_glyph_extents_t &base_extents,
+	       unsigned int i,
+	       unsigned int combining_class)
+{
+  hb_glyph_extents_t mark_extents;
+  if (!font->get_glyph_extents (buffer->info[i].codepoint, &mark_extents))
+    return;
+
+  hb_position_t y_gap = font->y_scale / 16;
+
+  hb_glyph_position_t &pos = buffer->pos[i];
+  pos.x_offset = pos.y_offset = 0;
+
+
+  /* We don't position LEFT and RIGHT marks. */
+
+  /* X positioning */
+  switch (combining_class)
+  {
+    case HB_UNICODE_COMBINING_CLASS_DOUBLE_BELOW:
+    case HB_UNICODE_COMBINING_CLASS_DOUBLE_ABOVE:
+      if (buffer->props.direction == HB_DIRECTION_LTR) {
+	pos.x_offset += base_extents.x_bearing + base_extents.width - mark_extents.width / 2 - mark_extents.x_bearing;
+	break;
+      } else if (buffer->props.direction == HB_DIRECTION_RTL) {
+	pos.x_offset += base_extents.x_bearing - mark_extents.width / 2 - mark_extents.x_bearing;
+	break;
+      }
+      HB_FALLTHROUGH;
+
+    default:
+    case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW:
+    case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE:
+    case HB_UNICODE_COMBINING_CLASS_BELOW:
+    case HB_UNICODE_COMBINING_CLASS_ABOVE:
+      /* Center align. */
+      pos.x_offset += base_extents.x_bearing + (base_extents.width - mark_extents.width) / 2 - mark_extents.x_bearing;
+      break;
+
+    case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW_LEFT:
+    case HB_UNICODE_COMBINING_CLASS_BELOW_LEFT:
+    case HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT:
+      /* Left align. */
+      pos.x_offset += base_extents.x_bearing - mark_extents.x_bearing;
+      break;
+
+    case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE_RIGHT:
+    case HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT:
+    case HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT:
+      /* Right align. */
+      pos.x_offset += base_extents.x_bearing + base_extents.width - mark_extents.width - mark_extents.x_bearing;
+      break;
+  }
+
+  /* Y positioning */
+  switch (combining_class)
+  {
+    case HB_UNICODE_COMBINING_CLASS_DOUBLE_BELOW:
+    case HB_UNICODE_COMBINING_CLASS_BELOW_LEFT:
+    case HB_UNICODE_COMBINING_CLASS_BELOW:
+    case HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT:
+      /* Add gap, fall-through. */
+      base_extents.height -= y_gap;
+      HB_FALLTHROUGH;
+
+    case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW_LEFT:
+    case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW:
+      pos.y_offset = base_extents.y_bearing + base_extents.height - mark_extents.y_bearing;
+      /* Never shift up "below" marks. */
+      if ((y_gap > 0) == (pos.y_offset > 0))
+      {
+	base_extents.height -= pos.y_offset;
+	pos.y_offset = 0;
+      }
+      base_extents.height += mark_extents.height;
+      break;
+
+    case HB_UNICODE_COMBINING_CLASS_DOUBLE_ABOVE:
+    case HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT:
+    case HB_UNICODE_COMBINING_CLASS_ABOVE:
+    case HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT:
+      /* Add gap, fall-through. */
+      base_extents.y_bearing += y_gap;
+      base_extents.height -= y_gap;
+      HB_FALLTHROUGH;
+
+    case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE:
+    case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE_RIGHT:
+      pos.y_offset = base_extents.y_bearing - (mark_extents.y_bearing + mark_extents.height);
+      /* Don't shift down "above" marks too much. */
+      if ((y_gap > 0) != (pos.y_offset > 0))
+      {
+	int correction = -pos.y_offset / 2;
+	base_extents.y_bearing += correction;
+	base_extents.height -= correction;
+	pos.y_offset += correction;
+      }
+      base_extents.y_bearing -= mark_extents.height;
+      base_extents.height += mark_extents.height;
+      break;
+  }
+}
+
+static inline void
+position_around_base (const hb_ot_shape_plan_t *plan,
+		      hb_font_t *font,
+		      hb_buffer_t  *buffer,
+		      unsigned int base,
+		      unsigned int end,
+		      bool adjust_offsets_when_zeroing)
+{
+  hb_direction_t horiz_dir = HB_DIRECTION_INVALID;
+
+  buffer->unsafe_to_break (base, end);
+
+  hb_glyph_extents_t base_extents;
+  if (!font->get_glyph_extents (buffer->info[base].codepoint,
+				&base_extents))
+  {
+    /* If extents don't work, zero marks and go home. */
+    zero_mark_advances (buffer, base + 1, end, adjust_offsets_when_zeroing);
+    return;
+  }
+  base_extents.y_bearing += buffer->pos[base].y_offset;
+  /* Use horizontal advance for horizontal positioning.
+   * Generally a better idea.  Also works for zero-ink glyphs.  See:
+   * https://github.com/harfbuzz/harfbuzz/issues/1532 */
+  base_extents.x_bearing = 0;
+  base_extents.width = font->get_glyph_h_advance (buffer->info[base].codepoint);
+
+  unsigned int lig_id = _hb_glyph_info_get_lig_id (&buffer->info[base]);
+  /* Use integer for num_lig_components such that it doesn't convert to unsigned
+   * when we divide or multiply by it. */
+  int num_lig_components = _hb_glyph_info_get_lig_num_comps (&buffer->info[base]);
+
+  hb_position_t x_offset = 0, y_offset = 0;
+  if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
+    x_offset -= buffer->pos[base].x_advance;
+    y_offset -= buffer->pos[base].y_advance;
+  }
+
+  hb_glyph_extents_t component_extents = base_extents;
+  int last_lig_component = -1;
+  unsigned int last_combining_class = 255;
+  hb_glyph_extents_t cluster_extents = base_extents; /* Initialization is just to shut gcc up. */
+  hb_glyph_info_t *info = buffer->info;
+  for (unsigned int i = base + 1; i < end; i++)
+    if (_hb_glyph_info_get_modified_combining_class (&info[i]))
+    {
+      if (num_lig_components > 1) {
+	unsigned int this_lig_id = _hb_glyph_info_get_lig_id (&info[i]);
+	int this_lig_component = _hb_glyph_info_get_lig_comp (&info[i]) - 1;
+	/* Conditions for attaching to the last component. */
+	if (!lig_id || lig_id != this_lig_id || this_lig_component >= num_lig_components)
+	  this_lig_component = num_lig_components - 1;
+	if (last_lig_component != this_lig_component)
+	{
+	  last_lig_component = this_lig_component;
+	  last_combining_class = 255;
+	  component_extents = base_extents;
+	  if (unlikely (horiz_dir == HB_DIRECTION_INVALID)) {
+	    if (HB_DIRECTION_IS_HORIZONTAL (plan->props.direction))
+	      horiz_dir = plan->props.direction;
+	    else
+	      horiz_dir = hb_script_get_horizontal_direction (plan->props.script);
+	  }
+	  if (horiz_dir == HB_DIRECTION_LTR)
+	    component_extents.x_bearing += (this_lig_component * component_extents.width) / num_lig_components;
+	  else
+	    component_extents.x_bearing += ((num_lig_components - 1 - this_lig_component) * component_extents.width) / num_lig_components;
+	  component_extents.width /= num_lig_components;
+	}
+      }
+
+      unsigned int this_combining_class = _hb_glyph_info_get_modified_combining_class (&info[i]);
+      if (last_combining_class != this_combining_class)
+      {
+	last_combining_class = this_combining_class;
+	cluster_extents = component_extents;
+      }
+
+      position_mark (plan, font, buffer, cluster_extents, i, this_combining_class);
+
+      buffer->pos[i].x_advance = 0;
+      buffer->pos[i].y_advance = 0;
+      buffer->pos[i].x_offset += x_offset;
+      buffer->pos[i].y_offset += y_offset;
+
+    } else {
+      if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
+	x_offset -= buffer->pos[i].x_advance;
+	y_offset -= buffer->pos[i].y_advance;
+      } else {
+	x_offset += buffer->pos[i].x_advance;
+	y_offset += buffer->pos[i].y_advance;
+      }
+    }
+}
+
+static inline void
+position_cluster (const hb_ot_shape_plan_t *plan,
+		  hb_font_t *font,
+		  hb_buffer_t  *buffer,
+		  unsigned int start,
+		  unsigned int end,
+		  bool adjust_offsets_when_zeroing)
+{
+  if (end - start < 2)
+    return;
+
+  /* Find the base glyph */
+  hb_glyph_info_t *info = buffer->info;
+  for (unsigned int i = start; i < end; i++)
+    if (!_hb_glyph_info_is_unicode_mark (&info[i]))
+    {
+      /* Find mark glyphs */
+      unsigned int j;
+      for (j = i + 1; j < end; j++)
+	if (!_hb_glyph_info_is_unicode_mark (&info[j]))
+	  break;
+
+      position_around_base (plan, font, buffer, i, j, adjust_offsets_when_zeroing);
+
+      i = j - 1;
+    }
+}
+
+void
+_hb_ot_shape_fallback_mark_position (const hb_ot_shape_plan_t *plan,
+				     hb_font_t *font,
+				     hb_buffer_t  *buffer,
+				     bool adjust_offsets_when_zeroing)
+{
+#ifdef HB_NO_OT_SHAPE_FALLBACK
+  return;
+#endif
+
+  if (!buffer->message (font, "start fallback mark"))
+    return;
+
+  _hb_buffer_assert_gsubgpos_vars (buffer);
+
+  unsigned int start = 0;
+  unsigned int count = buffer->len;
+  hb_glyph_info_t *info = buffer->info;
+  for (unsigned int i = 1; i < count; i++)
+    if (likely (!_hb_glyph_info_is_unicode_mark (&info[i]))) {
+      position_cluster (plan, font, buffer, start, i, adjust_offsets_when_zeroing);
+      start = i;
+    }
+  position_cluster (plan, font, buffer, start, count, adjust_offsets_when_zeroing);
+
+  (void) buffer->message (font, "end fallback mark");
+}
+
+
+#ifndef HB_DISABLE_DEPRECATED
+struct hb_ot_shape_fallback_kern_driver_t
+{
+  hb_ot_shape_fallback_kern_driver_t (hb_font_t   *font_,
+				      hb_buffer_t *buffer) :
+    font (font_), direction (buffer->props.direction) {}
+
+  hb_position_t get_kerning (hb_codepoint_t first, hb_codepoint_t second) const
+  {
+    hb_position_t kern = 0;
+    font->get_glyph_kerning_for_direction (first, second,
+					   direction,
+					   &kern, &kern);
+    return kern;
+  }
+
+  hb_font_t *font;
+  hb_direction_t direction;
+};
+#endif
+
+/* Performs font-assisted kerning. */
+void
+_hb_ot_shape_fallback_kern (const hb_ot_shape_plan_t *plan,
+			    hb_font_t *font,
+			    hb_buffer_t *buffer)
+{
+#ifdef HB_NO_OT_SHAPE_FALLBACK
+  return;
+#endif
+
+#ifndef HB_DISABLE_DEPRECATED
+  if (HB_DIRECTION_IS_HORIZONTAL (buffer->props.direction) ?
+      !font->has_glyph_h_kerning_func () :
+      !font->has_glyph_v_kerning_func ())
+    return;
+
+  if (!buffer->message (font, "start fallback kern"))
+    return;
+
+  bool reverse = HB_DIRECTION_IS_BACKWARD (buffer->props.direction);
+
+  if (reverse)
+    buffer->reverse ();
+
+  hb_ot_shape_fallback_kern_driver_t driver (font, buffer);
+  OT::hb_kern_machine_t<hb_ot_shape_fallback_kern_driver_t> machine (driver);
+  machine.kern (font, buffer, plan->kern_mask, false);
+
+  if (reverse)
+    buffer->reverse ();
+
+  (void) buffer->message (font, "end fallback kern");
+#endif
+}
+
+
+/* Adjusts width of various spaces. */
+void
+_hb_ot_shape_fallback_spaces (const hb_ot_shape_plan_t *plan HB_UNUSED,
+			      hb_font_t *font,
+			      hb_buffer_t  *buffer)
+{
+  hb_glyph_info_t *info = buffer->info;
+  hb_glyph_position_t *pos = buffer->pos;
+  bool horizontal = HB_DIRECTION_IS_HORIZONTAL (buffer->props.direction);
+  unsigned int count = buffer->len;
+  for (unsigned int i = 0; i < count; i++)
+    if (_hb_glyph_info_is_unicode_space (&info[i]) && !_hb_glyph_info_ligated (&info[i]))
+    {
+      /* If font had no ASCII space and we used the invisible glyph, give it a 1/4 EM default advance. */
+      if (buffer->invisible && info[i].codepoint == buffer->invisible)
+      {
+        if (horizontal)
+	  pos[i].x_advance = +font->x_scale / 4;
+        else
+	  pos[i].y_advance = -font->y_scale / 4;
+      }
+
+      hb_unicode_funcs_t::space_t space_type = _hb_glyph_info_get_unicode_space_fallback_type (&info[i]);
+      hb_codepoint_t glyph;
+      typedef hb_unicode_funcs_t t;
+      switch (space_type)
+      {
+	case t::NOT_SPACE: /* Shouldn't happen. */
+	case t::SPACE:
+	  break;
+
+	case t::SPACE_EM:
+	case t::SPACE_EM_2:
+	case t::SPACE_EM_3:
+	case t::SPACE_EM_4:
+	case t::SPACE_EM_5:
+	case t::SPACE_EM_6:
+	case t::SPACE_EM_16:
+	  if (horizontal)
+	    pos[i].x_advance = +(font->x_scale + ((int) space_type)/2) / (int) space_type;
+	  else
+	    pos[i].y_advance = -(font->y_scale + ((int) space_type)/2) / (int) space_type;
+	  break;
+
+	case t::SPACE_4_EM_18:
+	  if (horizontal)
+	    pos[i].x_advance = (int64_t) +font->x_scale * 4 / 18;
+	  else
+	    pos[i].y_advance = (int64_t) -font->y_scale * 4 / 18;
+	  break;
+
+	case t::SPACE_FIGURE:
+	  for (char u = '0'; u <= '9'; u++)
+	    if (font->get_nominal_glyph (u, &glyph))
+	    {
+	      if (horizontal)
+		pos[i].x_advance = font->get_glyph_h_advance (glyph);
+	      else
+		pos[i].y_advance = font->get_glyph_v_advance (glyph);
+	      break;
+	    }
+	  break;
+
+	case t::SPACE_PUNCTUATION:
+	  if (font->get_nominal_glyph ('.', &glyph) ||
+	      font->get_nominal_glyph (',', &glyph))
+	  {
+	    if (horizontal)
+	      pos[i].x_advance = font->get_glyph_h_advance (glyph);
+	    else
+	      pos[i].y_advance = font->get_glyph_v_advance (glyph);
+	  }
+	  break;
+
+	case t::SPACE_NARROW:
+	  /* Half-space?
+	   * Unicode doc https://unicode.org/charts/PDF/U2000.pdf says ~1/4 or 1/5 of EM.
+	   * However, in my testing, many fonts have their regular space being about that
+	   * size.  To me, a percentage of the space width makes more sense.  Half is as
+	   * good as any. */
+	  if (horizontal)
+	    pos[i].x_advance /= 2;
+	  else
+	    pos[i].y_advance /= 2;
+	  break;
+      }
+    }
+}
+
+
+#endif