src/luatexja-xkanji.lua

   1 ------------------------------------------------------------------------
   2 -- MAIN PROCESS STEP 3: insert \xkanjiskip (prefix: none)
   3 ------------------------------------------------------------------------
   4
   5 local node_type = node.type
   6 local node_new = node.new
   7 local node_prev = node.prev
   8 local node_next = node.next
   9 local has_attr = node.has_attribute
  10 local node_insert_before = node.insert_before
  11 local node_insert_after = node.insert_after
  12 local node_hpack = node.hpack
  13
  14 local id_penalty = node.id('penalty')
  15 local id_glyph = node.id('glyph')
  16 local id_glue = node.id('glue')
  17 local id_glue_spec = node.id('glue_spec')
  18 local id_kern = node.id('kern')
  19 local id_hlist = node.id('hlist')
  20 local id_ins = node.id('ins')
  21 local id_mark = node.id('mark')
  22 local id_adjust = node.id('adjust')
  23 local id_math = node.id('math')
  24 local id_whatsit = node.id('whatsit')
  25
  26 local attr_icflag = luatexbase.attributes['ltj@icflag']
  27 local attr_curjfnt = luatexbase.attributes['ltj@curjfnt']
  28
  29 local kanji_skip
  30 local xkanji_skip
  31 local no_skip = 0
  32 local after_schar = 1
  33 local after_wchar = 2
  34 local insert_skip = no_skip
  35
  36 -- (glyph_node nr) ... (node nq) <GLUE> ,,, (node np)
  37 local np, nq, nrc
  38 local no_skip = 0
  39 local after_schar = 1
  40 local after_wchar = 2 -- nr is a Japanese glyph_node
  41 local insert_skip = no_skip
  42
  43 local cstb_get_inhibit_xsp_table = ltj.int_get_inhibit_xsp_table
  44
  45 local function is_japanese_glyph_node(p)
  46    return p and (p.id==id_glyph)
  47    and (p.font==has_attr(p,attr_curjfnt))
  48 end
  49
  50 -- the following 2 functions are the lowest part.
  51 -- cx: the Kanji code of np
  52 local function insert_ascii_kanji_xkskip(head,q,cx)
  53    if cstb_get_inhibit_xsp_table(cx)<=1 then return end
  54    local g = node_new(id_glue)
  55    g.subtype = 0; g.spec = node.copy(xkanji_skip)
  56    node_insert_after(head, q, g)
  57 end
  58
  59 local function insert_kanji_ascii_xkskip(head,q,p)
  60    local g=true
  61    local c = p.char
  62    while p.components and p.subtype
  63       and math.floor(p.subtype/2)%2==1 do
  64       p = p.components; c = p.char
  65    end
  66    if cstb_get_inhibit_xsp_table(c)%2 == 1 then
  67       if cstb_get_inhibit_xsp_table(nrc)%2 == 0 then g = false end
  68    else g = false
  69    end
  70    if g then
  71       g = node_new(id_glue)
  72       g.subtype = 0; g.spec = node.copy(xkanji_skip)
  73       node_insert_after(head, q, g)
  74    end
  75 end
  76
  77
  78 local function set_insert_skip_after_achar(p)
  79    local c = p.char
  80    while p.components and p.subtype
  81       and math.floor(p.subtype/2)%2 == 1 do
  82       p=node.tail(p.components); c = p.char
  83    end
  84   if cstb_get_inhibit_xsp_table(c)>=2 then
  85      insert_skip = after_schar
  86   else
  87      insert_skip = no_skip
  88   end
  89 end
  90
  91 -- When p is a glyph_node ...
  92 local function insks_around_char(head)
  93    if is_japanese_glyph_node(np) then
  94       if insert_skip==after_wchar then
  95          local g = node_new(id_glue)
  96          g.subtype=0; g.spec=node.copy(kanji_skip)
  97          node_insert_before(head, np, g)
  98       elseif insert_skip==after_schar then
  99          insert_ascii_kanji_xkskip(head, nq, np.char)
 100       end
 101       insert_skip=after_wchar; nrc = np.char
 102    else
 103       if insert_skip==after_wchar then
 104          insert_kanji_ascii_xkskip(head, nq, np)
 105       end
 106       set_insert_skip_after_achar(np)
 107    end
 108    nq = np
 109 end
 110
 111 -- Return first and last glyph nodes in a hbox
 112 local first_char = nil
 113 local last_char = nil
 114 local find_first_char = nil
 115 local function check_box(box_ptr)
 116    local p = box_ptr; local found_visible_node = false
 117    while p do
 118       if p.id==id_glyph then
 119          repeat
 120             if find_first_char then
 121                first_char = p; find_first_char = false
 122             end
 123             last_char = p; found_visible_node = true; p=node_next(p)
 124             if not p then return found_visible_node end
 125          until p.id~=id_glyph
 126       end
 127       if p.id==id_hlist then
 128          found_visible_node = true
 129          if p.shift==0 then
 130             if check_box(p.head) then found_visible_node = true end
 131          else if find_first_char then
 132                find_first_char = false
 133             else
 134                last_char = nil
 135             end
 136          end
 137       elseif p.id==id_ins    or p.id==id_mark
 138           or p.id==id_adjust or p.id==id_whatsit
 139           or p.id==id_penalty then
 140          p=p
 141       else
 142          found_visible_node = true
 143          if find_first_char then
 144             find_first_char = false
 145          else
 146             last_char = nil
 147          end
 148       end
 149       p = node_next(p)
 150    end
 151    return found_visible_node
 152 end
 153
 154 -- When np is a hlist_node ...
 155 local function insks_around_hbox(head)
 156    if np.shift==0 then
 157       find_first_char = true; first_char = nil; last_char = nil
 158       if check_box(np.head) then
 159          -- first char
 160          if is_japanese_glyph_node(first_char) then
 161             nrc = first_char.char
 162             if insert_skip==after_schar then
 163                insert_ascii_kanji_xkskip(head, nq, first_char.char)
 164             elseif insert_skip==after_wchar then
 165                local g = node_new(id_glue)
 166                g.subtype = 0; g.spec = node.copy(kanji_skip)
 167                node_insert_before(head, np, g)
 168             end
 169             insert_skip = after_wchar
 170          elseif first_char then
 171             if insert_skip==after_wchar then
 172                insert_kanji_ascii_xkskip(head, nq, first_char)
 173             end
 174             set_insert_skip_after_achar(first_char)
 175          end
 176          -- last char
 177          if is_japanese_glyph_node(last_char) then
 178             if is_japanese_glyph_node(node_next(np)) then
 179                local g = node_new(id_glue)
 180                g.subtype = 0; g.spec = node.copy(kanji_skip)
 181                node_insert_after(head, np, g)
 182             end
 183             insert_skip = after_wchar; nrc = last_char.char
 184          elseif last_char then
 185             set_insert_skip_after_achar(last_char)
 186          else insert_skip = no_skip
 187          end
 188       else insert_skip = no_skip
 189       end
 190    else insert_skip = no_skip
 191    end
 192    nq = np
 193 end
 194
 195 -- When np is a penalty ...
 196 local function insks_around_penalty(head)
 197    nq = np
 198 end
 199
 200 -- When np is a kern ...
 201 --
 202 local function insks_around_kern(head)
 203    if np.subtype==1 then -- \kern or \/
 204       local i = has_attr(np, attr_icflag)
 205       if not i then -- \kern
 206          insert_skip = no_skip
 207       elseif i==1 then
 208          nq = np
 209       end
 210    elseif np.subtype==2 then
 211       -- (np = kern from \accent) .. (accent char) .. (kern from \accent) .. (glyph)
 212       np = node_next(node_next(np))
 213    end
 214 end
 215
 216 -- When np is a math_node ...
 217 local function insks_around_math(head)
 218    local g = { char = -1 }
 219    if (np.subtype==0) and (insert_skip==after_wchar) then
 220       insert_kanji_ascii_xkskip(head, nq, g)
 221       insert_skip = no_skip
 222    else
 223       nq = np; set_insert_skip_after_achar(g)
 224    end
 225 end
 226
 227 function ltj.int_insert_kanji_skip(head)
 228    if ltj.auto_spacing then
 229       kanji_skip=tex.skip['kanjiskip']
 230    else
 231       kanji_skip=node_new(id_glue_spec)
 232       kanji_skip.width=0;  kanji_skip.stretch=0; kanji_skip.shrink=0
 233    end
 234    if ltj.auto_xspacing then
 235       xkanji_skip=tex.skip['xkanjiskip']
 236    else
 237       xkanji_skip=node_new(id_glue_spec)
 238       xkanji_skip.width=0;  xkanji_skip.stretch=0; xkanji_skip.shrink=0
 239    end
 240    np = head; nq = nil; insert_skip = no_skip
 241    while np do
 242       if np.id==id_glyph then
 243          repeat
 244             insks_around_char(head); np=node_next(np)
 245          until (not np) or np.id~=id_glyph
 246       else
 247          if np.id==id_hlist then
 248             insks_around_hbox(head)
 249          elseif np.id==id_penalty then
 250             insks_around_penalty(head)
 251          elseif np.id==id_kern then
 252             insks_around_kern(head)
 253          elseif np.id==id_math then
 254             insks_around_math(head)
 255          elseif np.id==id_ins    or np.id==id_mark
 256              or np.id==id_adjust or np.id==id_whatsit then
 257             -- do nothing
 258             np = np
 259          else
 260             -- rule, disc, glue, margin_kern
 261             insert_skip = no_skip
 262          end
 263          np = node_next(np)
 264       end
 265    end
 266    return head
 267 end