thai-shaper.c

Pango is a library for layout and rendering of text, with an emphasis on internationalization. Pang

		thai_make_glyph_tis (font_info, ucs2tis (cluster[1]));
	    return n;
	  }
	break;

      case 3:
	if (is_char_type (cluster[0], NoTailCons|BotTailCons|SpltTailCons) &&
	    is_char_type (cluster[1], Tone) &&
	    is_char_type (cluster[2], SaraAm))
	  {
	    glyph_lists[0] =
		thai_make_glyph_tis (font_info, ucs2tis (cluster[0]));
	    glyph_lists[1] = thai_make_glyph_tis (font_info, shaping_table->AmComp[0]);
	    glyph_lists[2] =
		thai_make_glyph_tis (font_info, ucs2tis (cluster[1]));
	    glyph_lists[3] = thai_make_glyph_tis (font_info, shaping_table->AmComp[1]);
	    return 4;
	  }
	else if (is_char_type (cluster[0], UpTailCons) &&
		 is_char_type (cluster[1], Tone) &&
		 is_char_type (cluster[2], SaraAm))
	  {
	    glyph_lists[0] =
		thai_make_glyph_tis (font_info, ucs2tis (cluster[0]));
	    glyph_lists[1] = thai_make_glyph_tis (font_info,
				shiftleft_tone_ad (shaping_table->AmComp[0], shaping_table));
	    glyph_lists[2] = thai_make_glyph_tis (font_info,
				shiftleft_tone_ad (ucs2tis (cluster[1]), shaping_table));
	    glyph_lists[3] = thai_make_glyph_tis (font_info, shaping_table->AmComp[1]);
	    return 4;
	  }
	else if (is_char_type (cluster[0], UpTailCons) &&
		 is_char_type (cluster[1], AboveVowel) &&
		 is_char_type (cluster[2], AboveDiac|Tone))
	  {
	    glyph_lists[0] =
		thai_make_glyph_tis (font_info, ucs2tis (cluster[0]));
	    glyph_lists[1] = thai_make_glyph_tis (font_info,
				shiftleft_av (ucs2tis (cluster[1]), shaping_table));
	    glyph_lists[2] = thai_make_glyph_tis (font_info,
				shiftleft_tone_ad (ucs2tis (cluster[2]), shaping_table));
	    return 3;
	  }
	else if (is_char_type (cluster[0], UpTailCons) &&
		 is_char_type (cluster[1], BelowVowel) &&
		 is_char_type (cluster[2], AboveDiac|Tone))
	  {
	    glyph_lists[0] =
		thai_make_glyph_tis (font_info, ucs2tis (cluster[0]));
	    glyph_lists[1] =
		thai_make_glyph_tis (font_info, ucs2tis (cluster[1]));
	    glyph_lists[2] = thai_make_glyph_tis (font_info,
			shiftdownleft_tone_ad (ucs2tis (cluster[2]), shaping_table));
	    return 3;
	  }
	else if (is_char_type (cluster[0], NoTailCons) &&
		 is_char_type (cluster[1], BelowVowel) &&
		 is_char_type (cluster[2], AboveDiac|Tone))
	  {
	    glyph_lists[0] =
		thai_make_glyph_tis (font_info, ucs2tis (cluster[0]));
	    glyph_lists[1] =
		thai_make_glyph_tis (font_info, ucs2tis (cluster[1]));
	    glyph_lists[2] =
		thai_make_glyph_tis (font_info,
			shiftdown_tone_ad (ucs2tis (cluster[2]), shaping_table));
	    return 3;
	  }
	else if (is_char_type (cluster[0], SpltTailCons) &&
		 is_char_type (cluster[1], BelowVowel) &&
		 is_char_type (cluster[2], AboveDiac|Tone))
	  {
	    glyph_lists[0] = thai_make_glyph_tis (font_info,
				tailcutcons (ucs2tis (cluster[0]), shaping_table));
	    glyph_lists[1] =
		thai_make_glyph_tis (font_info, ucs2tis (cluster[1]));
	    glyph_lists[2] = thai_make_glyph_tis (font_info,
				shiftdown_tone_ad (ucs2tis (cluster[2]), shaping_table));
	    return 3;
	  }
	else if (is_char_type (cluster[0], BotTailCons) &&
		 is_char_type (cluster[1], BelowVowel) &&
		 is_char_type (cluster[2], AboveDiac|Tone))
	  {
	    glyph_lists[0] =
		thai_make_glyph_tis (font_info, ucs2tis (cluster[0]));
	    glyph_lists[1] = thai_make_glyph_tis (font_info,
				shiftdown_bv_bd (ucs2tis (cluster[1]), shaping_table));
	    glyph_lists[2] = thai_make_glyph_tis (font_info,
				shiftdown_tone_ad (ucs2tis (cluster[2]), shaping_table));
	    return 3;
	  }
	else
	  {
	    glyph_lists[0] =
		thai_make_glyph_tis (font_info, ucs2tis (cluster[0]));
	    glyph_lists[1] =
		thai_make_glyph_tis (font_info, ucs2tis (cluster[1]));
	    glyph_lists[2] =
		thai_make_glyph_tis (font_info, ucs2tis (cluster[2]));
	    return 3;
	  }
      break;

      default: /* e.g. Lao cluster with below cons + upper/lower vowel + tone */
	{
	  gint i;
	  for (i = 0; i < num_chrs; i++)
	    glyph_lists[i] = thai_make_glyph_tis (font_info, ucs2tis (cluster[i]));
	  return num_chrs;
	}
    }

    return 0;
}

static gint
get_glyphs_list (ThaiFontInfo	*font_info,
		 PangoScript     script,
		 gunichar	*cluster,
		 gint		num_chrs,
		 PangoGlyph	*glyph_lists)
{
  gint i;

  switch (script)
    {
      case PANGO_SCRIPT_THAI:
	switch (font_info->font_set)
	  {
	    default:
	    case THAI_FONT_NONE:
	      for (i=0; i < num_chrs; i++)
		glyph_lists[i] = thai_make_unknown_glyph (font_info, cluster[i]);
	      return num_chrs;

	    case THAI_FONT_TIS:
	      /* TIS620-0 + Wtt2.0 Extension
	       */
	      return get_adjusted_glyphs_list (font_info, cluster,
		      num_chrs, glyph_lists, &tis620_0_shape_table);

	    case THAI_FONT_TIS_MAC:
	      /* MacIntosh Extension
	       */
	      return get_adjusted_glyphs_list (font_info, cluster,
		      num_chrs, glyph_lists, &Mac_shape_table);

	    case THAI_FONT_TIS_WIN:
	      /* Microsoft Extension
	       */
	      return get_adjusted_glyphs_list (font_info, cluster,
		      num_chrs, glyph_lists, &Win_shape_table);
	  }
	break;

      case PANGO_SCRIPT_LAO:
	return get_adjusted_glyphs_list (font_info, cluster,
		num_chrs, glyph_lists, &Lao_shape_table);

      default:
	for (i=0; i < num_chrs; i++)
	  glyph_lists[i] = thai_make_unknown_glyph (font_info, cluster[i]);
	return num_chrs;
    }

  return 0;			/* Quiet GCC */
}

static void
add_cluster (ThaiFontInfo	*font_info,
	     PangoScript         script,
	     PangoGlyphString	*glyphs,
	     gint		cluster_start,
	     gunichar		*cluster,
	     gint		num_chrs)
{
  PangoGlyph glyphs_list[MAX_GLYPHS];
  gint num_glyphs;
  gint i;

  if (isthai (cluster[0]))
    {
      num_glyphs = get_glyphs_list(font_info, script, cluster, num_chrs, glyphs_list);
      for (i=0; i<num_glyphs; i++)
	add_glyph (font_info, glyphs, cluster_start, glyphs_list[i],
		   i == 0 ? FALSE : TRUE);
    }
  else if (islao (cluster[0]))
    {
      num_glyphs = get_glyphs_list(font_info, script, cluster, num_chrs, glyphs_list);
      for (i=0; i<num_glyphs; i++)
	add_glyph (font_info, glyphs, cluster_start, glyphs_list[i],
		   i == 0 ? FALSE : TRUE);
    }
  else
    {
      g_assert (num_chrs == 1);
      add_glyph (font_info, glyphs, cluster_start,
		 thai_make_glyph_uni (font_info, cluster[0]),
		 FALSE);
    }
}

static gboolean
is_wtt_composible (gunichar cur_wc, gunichar nxt_wc)
{
  switch (TAC_compose_input(cur_wc, nxt_wc))
    {
      case 'A':
      case 'S':
      case 'R':
      case 'X':
	return FALSE;

      case 'C':
	return TRUE;
    }

  g_assert_not_reached ();
  return FALSE;
}

static const char *
get_next_cluster(const char	*text,
		 gint		length,
		 gunichar       *cluster,
		 gint		*num_chrs)
{
  PangoScript cluster_script = PANGO_SCRIPT_INVALID_CODE, cur_script;
  const char *p;
  gint n_chars = 0;
  gunichar current;

  for (p = text; p < text + length; p = g_utf8_next_char (p))
    {
      current = g_utf8_get_char (p);
      cur_script = pango_script_for_unichar (current);
      if (cluster_script == PANGO_SCRIPT_INVALID_CODE)
	cluster_script = cur_script;
      if (cur_script != cluster_script ||
	  (n_chars > 0 &&
	   !is_wtt_composible (cluster[n_chars - 1], current)))
	break;
      cluster[n_chars++] = current;
    }

  *num_chrs = n_chars;
  return p;
}

void
thai_set_glyphs (ThaiFontInfo     *font_info,
		 const char       *text,
		 gint              length,
		 PangoScript       script,
		 PangoGlyphString *glyphs)
{
  gint n_chars;
  const char *p;
  const char *log_cluster;
  gunichar cluster[MAX_CLUSTER_CHRS];

  pango_glyph_string_set_size (glyphs, 0);

  p = text;
  while (p < text + length)
    {
	log_cluster = p;
	p = get_next_cluster (p, text + length - p, cluster, &n_chars);
	add_cluster (font_info, script, glyphs, log_cluster - text, cluster, n_chars);
    }
}