-- -- ltj-lineskip.lua -- luatexja.load_module 'base'; local ltjb = luatexja.base luatexja.load_module 'direction'; local ltjd = luatexja.direction luatexja.lineskip = luatexja.lineskip or {} local to_direct = node.direct.todirect local to_node = node.direct.tonode local ltjl = luatexja.lineskip local id_glue = node.id 'glue' local id_penalty = node.id 'penalty' local id_hlist = node.id 'hlist' local getlist = node.direct.getlist local node_new = node.direct.new local node_prev = node.direct.getprev local node_next = node.direct.getnext local getid = node.direct.getid local getsubtype = node.direct.getsubtype local getdepth = node.direct.getdepth local getheight = node.direct.getheight local texget = tex.get local node_getglue = node.getglue local setglue = node.direct.setglue local setsubtype = node.direct.setsubtype local function copy_glue (new_glue, old_glue_name, subtype, new_w) setsubtype(new_glue, subtype) local w,st,sp,sto,spo = texget(old_glue_name, true) setglue(new_glue, new_w or w, st, sp, sto, spo) end ltjl.copy_glue = copy_glue function ltjl.p_dummy(before, after) return nil, 0 end function ltjl.l_dummy(dist, g, adj, normal, bw, loc) if dist < tex.lineskiplimit then copy_glue(g, 'lineskip', 1, texget('lineskip', false) + adj) else copy_glue(g, 'baselineskip', 2, normal) end end local ltj_profiler, ltj_skip = ltjl.p_dummy, ltjl.l_dummy function ltjl.setting(profiler, skip_method) ltj_profiler = ltjl['p_'..tostring(profiler)] or ltjl.p_dummy ltj_skip = ltjl['l_'..tostring(skip_method)] or ltjl.l_dummy end do local backup function ltjl.setting_backup() backup = { ltj_profiler, ltj_skip } ltj_profiler, ltj_skip = ltjl.p_dummy, ltjl.l_dummy end function ltjl.setting_restore() if backup then ltj_profiler, ltj_skip, backup = backup[1], backup[2], nil end end end do local traverse_id = node.direct.traverse_id local function adjust_glue(nh) local h = to_direct(nh) local bw = texget('baselineskip',false) for x in traverse_id(id_glue, h) do local xs = getsubtype(x) if (xs==1) or (xs==2) then local p, n = node_prev(x), node_next(x) if p then local pid = getid(p) while (id_glue<=pid) and (pid<=id_penalty) and node_prev(p) do p = node_prev(p); pid = getid(p) end if pid==id_hlist and getid(n)==id_hlist then local normal = bw - getdepth(p) - getheight(n) local lmin, adj = ltj_profiler(p, n, false, bw) ltj_skip(lmin or normal, x, adj, normal, bw) end end end end return true end ltjb.add_to_callback('post_linebreak_filter', adjust_glue, 'ltj.lineskip', 10000) end do local p_dummy = ltjl.p_dummy local make_dir_whatsit = luatexja.direction.make_dir_whatsit local get_dir_count = luatexja.direction.get_dir_count local getwhd = node.direct.getwhd local setnext = node.direct.setnext local getnest = tex.getnest local function dir_adjust_append_vlist(b, loc, prev, mirrored) local old_b = to_direct(b) local new_b = loc=='box' and make_dir_whatsit(old_b, old_b, get_dir_count(), 'append_vlist') or old_b local _, ht, dp = getwhd(new_b) if prev > -65536000 then local bw = texget('baselineskip', false) local normal = bw - prev - (mirrored and dp or ht) local lmin, adj = nil, 0 local tail = to_direct(getnest().tail) if p_dummy~=ltj_profiler then while tail and (id_glue<=getid(tail)) and (getid(tail)<=id_penalty) do tail = node_prev(tail) end end if tail then if getid(tail)==id_hlist and getid(new_b)==id_hlist then if getdepth(tail)==prev then lmin, adj = ltj_profiler(tail, new_b, mirrored, bw) end end end local g = node_new(id_glue) ltj_skip(lmin or normal, g, adj, normal, bw, loc) setnext(g, new_b); return to_node(g), (mirrored and ht or dp) else return to_node(new_b), (mirrored and ht or dp) end end ltjb.add_to_callback('append_to_vlist_filter', dir_adjust_append_vlist, 'ltj.lineskip', 10000) end