Make fthbfont and derivatives use common HarfBuzz code in hbfont.c

* src/font.h (fthbfont_shape, fthbfont_combining_capability)
[HAVE_HARFBUZZ]: Remove prototypes.

* src/ftfont.c: Don't include math.h.
(uni_combining, uni_general, uni_mirroring, get_hb_unicode_funcs)
(fthbfont_shape_by_hb, fthbfont_combining_capability, fthbfont_shape)
[HAVE_HARFBUZZ]: Remove functions.

* src/ftfont.c (syms_of_ftfont_for_pdumper) [HAVE_HARFBUZZ]:
* src/xftfont.c (syms_of_xftfont_for_pdumper) [HAVE_HARFBUZZ]:
* src/ftcrfont.c (syms_of_ftcrfont_for_pdumper) [HAVE_HARFBUZZ]: Use
hbfont_shape and hbfont_combining_capability instead of fthbfont_shape
and fthbfont_combining_capability, respectively.

4 files changed, 6 insertions, 299 deletions

diff --git a/src/font.h b/src/font.h
index 99b95836d7a..1f35744642b 100644
--- a/src/font.h
+++ b/src/font.h
@@ -928,9 +928,7 @@ extern void ftfont_filter_properties (Lisp_Object, Lisp_Object);
 extern void ftfont_text_extents (struct font *, const unsigned *, int,
                                  struct font_metrics *);
 #ifdef HAVE_HARFBUZZ
-extern Lisp_Object fthbfont_combining_capability (struct font *);
 extern hb_font_t *fthbfont_begin_hb_font (struct font *, double *);
-extern Lisp_Object fthbfont_shape (Lisp_Object, Lisp_Object);
 #endif  /* HAVE_HARFBUZZ */
 extern void syms_of_ftfont (void);
 #endif  /* HAVE_FREETYPE */
diff --git a/src/ftcrfont.c b/src/ftcrfont.c
index 79bf68141dc..0c3b74ff289 100644
--- a/src/ftcrfont.c
+++ b/src/ftcrfont.c
@@ -612,8 +612,8 @@ syms_of_ftcrfont_for_pdumper (void)
   ftcrhbfont_driver.type = Qftcrhb;
   ftcrhbfont_driver.list = ftcrhbfont_list;
   ftcrhbfont_driver.match = ftcrhbfont_match;
-  ftcrhbfont_driver.shape = fthbfont_shape;
-  ftcrhbfont_driver.combining_capability = fthbfont_combining_capability;
+  ftcrhbfont_driver.shape = hbfont_shape;
+  ftcrhbfont_driver.combining_capability = hbfont_combining_capability;
   ftcrhbfont_driver.begin_hb_font = ftcrhbfont_begin_hb_font;
   ftcrhbfont_driver.end_hb_font = ftcrhbfont_end_hb_font;
   register_font_driver (&ftcrhbfont_driver, NULL);
diff --git a/src/ftfont.c b/src/ftfont.c
index 5694c49aaf9..97ab4d0e377 100644
--- a/src/ftfont.c
+++ b/src/ftfont.c
@@ -21,7 +21,6 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #include <config.h>
 #include <stdio.h>
-#include <math.h>
 #include <fontconfig/fontconfig.h>
 #include <fontconfig/fcfreetype.h>
 
@@ -2851,296 +2850,6 @@ fthbfont_begin_hb_font (struct font *font, double *position_unit)
   return ftfont_info->hb_font;
 }
 
-static hb_unicode_combining_class_t
-uni_combining (hb_unicode_funcs_t *funcs, hb_codepoint_t ch, void *user_data)
-{
-  Lisp_Object table, combining;
-
-  /* FIXME: Is it efficient to load the table each time? */
-  table = Funicode_property_table_internal (intern ("canonical-combining-class"));
-  combining = Fget_unicode_property_internal (table, make_fixnum (ch));
-
-  if (INTEGERP (combining))
-    return (hb_unicode_combining_class_t) XFIXNUM (combining);
-
-  return HB_UNICODE_COMBINING_CLASS_NOT_REORDERED;
-}
-
-static hb_unicode_general_category_t
-uni_general (hb_unicode_funcs_t *funcs, hb_codepoint_t ch, void *user_data)
-{
-  Lisp_Object category = CHAR_TABLE_REF (Vunicode_category_table, ch);
-
-  if (INTEGERP (category))
-    {
-    switch (XFIXNUM (category))
-      {
-      case UNICODE_CATEGORY_Cc:
-        return HB_UNICODE_GENERAL_CATEGORY_CONTROL;
-      case UNICODE_CATEGORY_Cf:
-        return HB_UNICODE_GENERAL_CATEGORY_FORMAT;
-      case UNICODE_CATEGORY_Cn:
-        return HB_UNICODE_GENERAL_CATEGORY_UNASSIGNED;
-      case UNICODE_CATEGORY_Co:
-        return HB_UNICODE_GENERAL_CATEGORY_PRIVATE_USE;
-      case UNICODE_CATEGORY_Cs:
-        return HB_UNICODE_GENERAL_CATEGORY_SURROGATE;
-      case UNICODE_CATEGORY_Ll:
-        return HB_UNICODE_GENERAL_CATEGORY_LOWERCASE_LETTER;
-      case UNICODE_CATEGORY_Lm:
-        return HB_UNICODE_GENERAL_CATEGORY_MODIFIER_LETTER;
-      case UNICODE_CATEGORY_Lo:
-        return HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER;
-      case UNICODE_CATEGORY_Lt:
-        return HB_UNICODE_GENERAL_CATEGORY_TITLECASE_LETTER;
-      case UNICODE_CATEGORY_Lu:
-        return HB_UNICODE_GENERAL_CATEGORY_UPPERCASE_LETTER;
-      case UNICODE_CATEGORY_Mc:
-        return HB_UNICODE_GENERAL_CATEGORY_SPACING_MARK;
-      case UNICODE_CATEGORY_Me:
-        return HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK;
-      case UNICODE_CATEGORY_Mn:
-        return HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK;
-      case UNICODE_CATEGORY_Nd:
-        return HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER;
-      case UNICODE_CATEGORY_Nl:
-        return HB_UNICODE_GENERAL_CATEGORY_LETTER_NUMBER;
-      case UNICODE_CATEGORY_No:
-        return HB_UNICODE_GENERAL_CATEGORY_OTHER_NUMBER;
-      case UNICODE_CATEGORY_Pc:
-        return HB_UNICODE_GENERAL_CATEGORY_CONNECT_PUNCTUATION;
-      case UNICODE_CATEGORY_Pd:
-        return HB_UNICODE_GENERAL_CATEGORY_DASH_PUNCTUATION;
-      case UNICODE_CATEGORY_Pe:
-        return HB_UNICODE_GENERAL_CATEGORY_CLOSE_PUNCTUATION;
-      case UNICODE_CATEGORY_Pf:
-        return HB_UNICODE_GENERAL_CATEGORY_FINAL_PUNCTUATION;
-      case UNICODE_CATEGORY_Pi:
-        return HB_UNICODE_GENERAL_CATEGORY_INITIAL_PUNCTUATION;
-      case UNICODE_CATEGORY_Po:
-        return HB_UNICODE_GENERAL_CATEGORY_OTHER_PUNCTUATION;
-      case UNICODE_CATEGORY_Ps:
-        return HB_UNICODE_GENERAL_CATEGORY_OPEN_PUNCTUATION;
-      case UNICODE_CATEGORY_Sc:
-        return HB_UNICODE_GENERAL_CATEGORY_CURRENCY_SYMBOL;
-      case UNICODE_CATEGORY_Sk:
-        return HB_UNICODE_GENERAL_CATEGORY_MODIFIER_SYMBOL;
-      case UNICODE_CATEGORY_Sm:
-        return HB_UNICODE_GENERAL_CATEGORY_MATH_SYMBOL;
-      case UNICODE_CATEGORY_So:
-        return HB_UNICODE_GENERAL_CATEGORY_OTHER_SYMBOL;
-      case UNICODE_CATEGORY_Zl:
-        return HB_UNICODE_GENERAL_CATEGORY_LINE_SEPARATOR;
-      case UNICODE_CATEGORY_Zp:
-        return HB_UNICODE_GENERAL_CATEGORY_PARAGRAPH_SEPARATOR;
-      case UNICODE_CATEGORY_Zs:
-        return HB_UNICODE_GENERAL_CATEGORY_SPACE_SEPARATOR;
-      case UNICODE_CATEGORY_UNKNOWN:
-        return HB_UNICODE_GENERAL_CATEGORY_UNASSIGNED;
-      }
-    }
-
-  return HB_UNICODE_GENERAL_CATEGORY_UNASSIGNED;
-}
-
-static hb_codepoint_t
-uni_mirroring (hb_unicode_funcs_t *funcs, hb_codepoint_t ch, void *user_data)
-{
-  return bidi_mirror_char (ch);
-}
-
-static hb_unicode_funcs_t *
-get_hb_unicode_funcs (void)
-{
-  /* Subclass HarfBuzz's default Unicode functions and override functions that
-   * use data Emacs can provide. This way changing Emacs data is reflected in
-   * the shaped output. */
-  hb_unicode_funcs_t *funcs = hb_unicode_funcs_create (hb_unicode_funcs_get_default ());
-
-  hb_unicode_funcs_set_combining_class_func (funcs, uni_combining, NULL, NULL);
-  hb_unicode_funcs_set_general_category_func (funcs, uni_general, NULL, NULL);
-  hb_unicode_funcs_set_mirroring_func (funcs, uni_mirroring, NULL, NULL);
-
-  /* Use default implmentation for Unicode composition/decomposition, we might
-   * want to revisit this later.
-  hb_unicode_funcs_set_compose_func (funcs, uni_compose, NULL, NULL);
-  hb_unicode_funcs_set_decompose_func (funcs, uni_decompose, NULL, NULL);
-  */
-
-  /* Emacs own script mapping for characters differs from Unicode, so we want
-   * to keep the default HarfBuzz's implementation here.
-  hb_unicode_funcs_set_script_func (funcs, uni_script, NULL, NULL);
-  */
-
-  return funcs;
-}
-
-static Lisp_Object
-fthbfont_shape_by_hb (Lisp_Object lgstring, struct font *font,
-                      Lisp_Object direction)
-{
-  ptrdiff_t glyph_len = 0, text_len = LGSTRING_GLYPH_LEN (lgstring);
-  ptrdiff_t i;
-
-  hb_glyph_info_t *info;
-  hb_glyph_position_t *pos;
-
-  /* Cache the HarfBuzz buffer for better performance and less allocations.
-   * We intentionally never destroy the buffer. */
-  static hb_buffer_t *hb_buffer = NULL;
-  if (! hb_buffer)
-    {
-      hb_buffer = hb_buffer_create ();
-      hb_unicode_funcs_t* ufuncs = get_hb_unicode_funcs();
-      hb_buffer_set_unicode_funcs(hb_buffer, ufuncs);
-    }
-
-  hb_buffer_clear_contents (hb_buffer);
-  hb_buffer_pre_allocate (hb_buffer, text_len);
-
-  for (i = 0; i < text_len; i++)
-    {
-      Lisp_Object g = LGSTRING_GLYPH (lgstring, i);
-      int c;
-
-      if (NILP (g))
-        break;
-      c = LGLYPH_CHAR (g);
-      hb_buffer_add (hb_buffer, c, i);
-    }
-
-  text_len = i;
-  if (!text_len)
-    return Qnil;
-
-  hb_buffer_set_content_type (hb_buffer, HB_BUFFER_CONTENT_TYPE_UNICODE);
-  hb_buffer_set_cluster_level (hb_buffer, HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS);
-
-  /* If the caller didn't provide a meaningful DIRECTION, default to L2R. */
-  hb_direction_t dir = HB_DIRECTION_LTR;
-  if (EQ (direction, QL2R))
-    dir = HB_DIRECTION_LTR;
-  else if (EQ (direction, QR2L))
-    dir = HB_DIRECTION_RTL;
-  hb_buffer_set_direction (hb_buffer, dir);
-
-  /* Leave the script determination to HarfBuzz, until Emacs has a
-     better idea of the script of LGSTRING.  FIXME. */
-#if 0
-  hb_buffer_set_script (hb_buffer, XXX);
-#endif
-
-  /* FIXME: This can only handle the single global language, which
-     normally comes from the locale.  In addition, if
-     current-iso639-language is a list, we arbitrarily use the first
-     one.  We should instead have a notion of the language of the text
-     being shaped.  */
-  Lisp_Object lang = Vcurrent_iso639_language;
-  if (CONSP (Vcurrent_iso639_language))
-    lang = XCAR (Vcurrent_iso639_language);
-  if (SYMBOLP (lang))
-    {
-      Lisp_Object lang_str = SYMBOL_NAME (lang);
-      hb_buffer_set_language (hb_buffer,
-                              hb_language_from_string (SSDATA (lang_str),
-                                                       SBYTES (lang_str)));
-    }
-
-  /* Guess the default properties for when they cannot be determined
-     above. FIXME: drop once script handling is fixed above. */
-  hb_buffer_guess_segment_properties (hb_buffer);
-
-  double position_unit;
-  hb_font_t *hb_font = font->driver->begin_hb_font (font, &position_unit);
-  if (!hb_font)
-    return make_fixnum (0);
-
-  hb_bool_t success = hb_shape_full (hb_font, hb_buffer, NULL, 0, NULL);
-  if (font->driver->end_hb_font)
-    font->driver->end_hb_font (font, hb_font);
-  if (!success)
-    return Qnil;
-
-  glyph_len = hb_buffer_get_length (hb_buffer);
-  /* FIXME: can't we just grew the lgstring in this case? Givving up is an
-   * overly heavy handed solution. */
-  if (glyph_len > LGSTRING_GLYPH_LEN (lgstring))
-    return Qnil;
-
-  /* Somewhere up the pipeline wants the glyphs in logical order, while keeping
-   * clusters in visual order. I don't know where exactly, but lets satisfy
-   * that. */
-  if (HB_DIRECTION_IS_BACKWARD (hb_buffer_get_direction (hb_buffer)))
-    hb_buffer_reverse_clusters (hb_buffer);
-
-  info = hb_buffer_get_glyph_infos (hb_buffer, NULL);
-  pos = hb_buffer_get_glyph_positions (hb_buffer, NULL);
-  for (i = 0; i < glyph_len; i++)
-    {
-      Lisp_Object lglyph = LGSTRING_GLYPH (lgstring, i);
-      EMACS_INT from, to;
-      struct font_metrics metrics = {.width = 0};
-      int xoff, yoff, wadjust;
-      ptrdiff_t j = i;
-
-      if (NILP (lglyph))
-        {
-          lglyph = LGLYPH_NEW ();
-          LGSTRING_SET_GLYPH (lgstring, i, lglyph);
-        }
-
-      from = to = info[i].cluster;
-      /* FIXME: what does “from” mean here? */
-      LGLYPH_SET_FROM (lglyph, from);
-
-      /* FIXME: what does “to” mean here? */
-      for (j = i; j < glyph_len && info[j].cluster == info[i].cluster; j++)
-        ;
-      to = (j == glyph_len) ? text_len - 1 : info[j].cluster - 1;
-      LGLYPH_SET_TO (lglyph, to);
-
-      /* FIXME: is this really needed? Not all glyphs map directly to a single character */
-      LGLYPH_SET_CHAR (lglyph, LGLYPH_CHAR (LGSTRING_GLYPH (lgstring, from)));
-      LGLYPH_SET_CODE (lglyph, info[i].codepoint);
-
-      unsigned code = info[i].codepoint;
-      font->driver->text_extents (font, &code, 1, &metrics);
-      LGLYPH_SET_WIDTH (lglyph, metrics.width);
-      LGLYPH_SET_LBEARING (lglyph, metrics.lbearing);
-      LGLYPH_SET_RBEARING (lglyph, metrics.rbearing);
-      LGLYPH_SET_ASCENT (lglyph, metrics.ascent);
-      LGLYPH_SET_DESCENT (lglyph, metrics.descent);
-
-      xoff = lround (pos[i].x_offset * position_unit);
-      yoff = - lround (pos[i].y_offset * position_unit);
-      wadjust = lround (pos[i].x_advance * position_unit);
-      if (xoff || yoff || wadjust != metrics.width)
-        {
-          Lisp_Object vec = make_uninit_vector (3);
-          ASET (vec, 0, make_fixnum (xoff));
-          ASET (vec, 1, make_fixnum (yoff));
-          ASET (vec, 2, make_fixnum (wadjust));
-          LGLYPH_SET_ADJUSTMENT (lglyph, vec);
-        }
-    }
-
-  return make_fixnum (glyph_len);
-}
-
-Lisp_Object
-fthbfont_combining_capability (struct font *font)
-{
-  return Qt;
-}
-
-Lisp_Object
-fthbfont_shape (Lisp_Object lgstring, Lisp_Object direction)
-{
-  struct font *font = CHECK_FONT_GET_OBJECT (LGSTRING_FONT (lgstring));
-
-  return fthbfont_shape_by_hb (lgstring, font, direction);
-}
-
 #endif /* HAVE_HARFBUZZ */
 
 static const char *const ftfont_booleans [] = {
@@ -3282,8 +2991,8 @@ syms_of_ftfont_for_pdumper (void)
 #ifdef HAVE_HARFBUZZ
   fthbfont_driver = ftfont_driver;
   fthbfont_driver.type = Qfreetypehb;
-  fthbfont_driver.shape = fthbfont_shape;
-  fthbfont_driver.combining_capability = fthbfont_combining_capability;
+  fthbfont_driver.shape = hbfont_shape;
+  fthbfont_driver.combining_capability = hbfont_combining_capability;
   fthbfont_driver.begin_hb_font = fthbfont_begin_hb_font;
   register_font_driver (&fthbfont_driver, NULL);
 #endif  /* HAVE_HARFBUZZ */
diff --git a/src/xftfont.c b/src/xftfont.c
index 08e4edb535a..c1b93b76f57 100644
--- a/src/xftfont.c
+++ b/src/xftfont.c
@@ -699,8 +699,8 @@ syms_of_xftfont_for_pdumper (void)
   xfthbfont_driver.type = Qxfthb;
   xfthbfont_driver.list = xfthbfont_list;
   xfthbfont_driver.match = xfthbfont_match;
-  xfthbfont_driver.shape = fthbfont_shape;
-  xfthbfont_driver.combining_capability = fthbfont_combining_capability;
+  xfthbfont_driver.shape = hbfont_shape;
+  xfthbfont_driver.combining_capability = hbfont_combining_capability;
   xfthbfont_driver.begin_hb_font = xfthbfont_begin_hb_font;
   xfthbfont_driver.end_hb_font = xfthbfont_end_hb_font;
   register_font_driver (&xfthbfont_driver, NULL);