diff options
Diffstat (limited to 'tex/context/base/mkiv/spac-chr.lua')
| -rw-r--r-- | tex/context/base/mkiv/spac-chr.lua | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/tex/context/base/mkiv/spac-chr.lua b/tex/context/base/mkiv/spac-chr.lua new file mode 100644 index 000000000..3eb348586 --- /dev/null +++ b/tex/context/base/mkiv/spac-chr.lua @@ -0,0 +1,304 @@ +if not modules then modules = { } end modules ['spac-chr'] = { + version = 1.001, + comment = "companion to spac-chr.mkiv", + author = "Hans Hagen, PRAGMA-ADE, Hasselt NL", + copyright = "PRAGMA ADE / ConTeXt Development Team", + license = "see context related readme files" +} + +local byte, lower = string.byte, string.lower + +-- beware: attribute copying is bugged ... there will be a proper luatex helper +-- for this + +-- to be redone: characters will become tagged spaces instead as then we keep track of +-- spaceskip etc + +-- todo: only setattr when export / use properties + +local next = next + +local trace_characters = false trackers.register("typesetters.characters", function(v) trace_characters = v end) +local trace_nbsp = false trackers.register("typesetters.nbsp", function(v) trace_nbsp = v end) + +local report_characters = logs.reporter("typesetting","characters") + +local nodes, node = nodes, node + +local nuts = nodes.nuts + +local tonode = nuts.tonode +local tonut = nuts.tonut + +local getfield = nuts.getfield +local setfield = nuts.setfield +local getnext = nuts.getnext +local getprev = nuts.getprev +local getid = nuts.getid +local getattr = nuts.getattr +local setattr = nuts.setattr +local getfont = nuts.getfont +local getchar = nuts.getchar +local setsubtype = nuts.setsubtype + +local setcolor = nodes.tracers.colors.set + +local insert_node_before = nuts.insert_before +local insert_node_after = nuts.insert_after +local remove_node = nuts.remove +local copy_node_list = nuts.copy_list +local traverse_id = nuts.traverse_id + +local tasks = nodes.tasks + +local nodepool = nuts.pool +local new_penalty = nodepool.penalty +local new_glue = nodepool.glue +local new_kern = nodepool.kern +local new_rule = nodepool.rule + +local nodecodes = nodes.nodecodes +local skipcodes = nodes.skipcodes +local glyph_code = nodecodes.glyph +local glue_code = nodecodes.glue + +local space_skip_code = skipcodes["spaceskip"] + +local chardata = characters.data +local is_punctuation = characters.is_punctuation + +local typesetters = typesetters + +local unicodeblocks = characters.blocks + +local characters = typesetters.characters or { } -- can be predefined +typesetters.characters = characters + +local fonthashes = fonts.hashes +local fontparameters = fonthashes.parameters +local fontcharacters = fonthashes.characters +local fontquads = fonthashes.quads + +local setmetatableindex = table.setmetatableindex + +local a_character = attributes.private("characters") +local a_alignstate = attributes.private("alignstate") + +local c_zero = byte('0') +local c_period = byte('.') + +local function inject_quad_space(unicode,head,current,fraction) + local attr = getfield(current,"attr") + if fraction ~= 0 then + fraction = fraction * fontquads[getfont(current)] + end + local glue = new_glue(fraction) + setfield(glue,"attr",attr) + setfield(current,"attr",nil) + setattr(glue,a_character,unicode) + head, current = insert_node_after(head,current,glue) + return head, current +end + +local function inject_char_space(unicode,head,current,parent) + local attr = getfield(current,"attr") + local font = getfont(current) + local char = fontcharacters[font][parent] + local glue = new_glue(char and char.width or fontparameters[font].space) + setfield(glue,"attr",attr) + setfield(current,"attr",nil) + setattr(glue,a_character,unicode) + head, current = insert_node_after(head,current,glue) + return head, current +end + +local function inject_nobreak_space(unicode,head,current,space,spacestretch,spaceshrink) + local attr = getfield(current,"attr") + local glue = new_glue(space,spacestretch,spaceshrink) + local penalty = new_penalty(10000) + setfield(glue,"attr",attr) + setfield(current,"attr",nil) + setattr(glue,a_character,unicode) -- bombs + head, current = insert_node_after(head,current,penalty) + if trace_nbsp then + local rule = new_rule(space) + local kern = new_kern(-space) + local penalty = new_penalty(10000) + setcolor(rule,"orange") + head, current = insert_node_after(head,current,rule) + head, current = insert_node_after(head,current,kern) + head, current = insert_node_after(head,current,penalty) + end + head, current = insert_node_after(head,current,glue) + return head, current +end + +local function nbsp(head,current) + local para = fontparameters[getfont(current)] + if getattr(current,a_alignstate) == 1 then -- flushright + head, current = inject_nobreak_space(0x00A0,head,current,para.space,0,0) + setsubtype(current,space_skip_code) + else + head, current = inject_nobreak_space(0x00A0,head,current,para.space,para.spacestretch,para.spaceshrink) + end + return head, current +end + +-- assumes nuts or nodes, depending on callers .. so no tonuts here + +function characters.replacenbsp(head,original) + local head, current = nbsp(head,original) + head = remove_node(head,original,true) + return head, current +end + +function characters.replacenbspaces(head) + for current in traverse_id(glyph_code,head) do + if getchar(current) == 0x00A0 then + local h = nbsp(head,current) + if h then + head = remove_node(h,current,true) + end + end + end + return head +end + +-- This initialization might move someplace else if we need more of it. The problem is that +-- this module depends on fonts so we have an order problem. + +local nbsphash = { } setmetatableindex(nbsphash,function(t,k) + for i=unicodeblocks.devanagari.first,unicodeblocks.devanagari.last do nbsphash[i] = true end + for i=unicodeblocks.kannada .first,unicodeblocks.kannada .last do nbsphash[i] = true end + setmetatableindex(nbsphash,nil) + return nbsphash[k] +end) + +local methods = { + + -- The next one uses an attribute assigned to the character but still we + -- don't have the 'local' value. + + [0x001F] = function(head,current) + local next = getnext(current) + if next and getid(next) == glyph_code then + local char = getchar(next) + head, current = remove_node(head,current,true) + if not is_punctuation[char] then + local p = fontparameters[getfont(next)] + head, current = insert_node_before(head,current,new_glue(p.space,p.space_stretch,p.space_shrink)) + end + end + end, + + [0x00A0] = function(head,current) -- nbsp + local next = getnext(current) + if next and getid(next) == glyph_code then + local char = getchar(next) + if char == 0x200C or char == 0x200D then -- nzwj zwj + next = getnext(next) + if next and nbsphash[getchar(next)] then + return false + end + elseif nbsphash[char] then + return false + end + end + local prev = getprev(current) + if prev and getid(prev) == glyph_code and nbsphash[getchar(prev)] then + return false + end + return nbsp(head,current) + end, + + [0x2000] = function(head,current) -- enquad + return inject_quad_space(0x2000,head,current,1/2) + end, + + [0x2001] = function(head,current) -- emquad + return inject_quad_space(0x2001,head,current,1) + end, + + [0x2002] = function(head,current) -- enspace + return inject_quad_space(0x2002,head,current,1/2) + end, + + [0x2003] = function(head,current) -- emspace + return inject_quad_space(0x2003,head,current,1) + end, + + [0x2004] = function(head,current) -- threeperemspace + return inject_quad_space(0x2004,head,current,1/3) + end, + + [0x2005] = function(head,current) -- fourperemspace + return inject_quad_space(0x2005,head,current,1/4) + end, + + [0x2006] = function(head,current) -- sixperemspace + return inject_quad_space(0x2006,head,current,1/6) + end, + + [0x2007] = function(head,current) -- figurespace + return inject_char_space(0x2007,head,current,c_zero) + end, + + [0x2008] = function(head,current) -- punctuationspace + return inject_char_space(0x2008,head,current,c_period) + end, + + [0x2009] = function(head,current) -- breakablethinspace + return inject_quad_space(0x2009,head,current,1/8) -- same as next + end, + + [0x200A] = function(head,current) -- hairspace + return inject_quad_space(0x200A,head,current,1/8) -- same as previous (todo) + end, + + [0x200B] = function(head,current) -- zerowidthspace + return inject_quad_space(0x200B,head,current,0) + end, + + [0x202F] = function(head,current) -- narrownobreakspace + return inject_nobreak_space(0x202F,head,current,fontquads[getfont(current)]/8) + end, + + [0x205F] = function(head,current) -- math thinspace + return inject_nobreak_space(0x205F,head,current,fontparameters[getfont(current)].space/8) + end, + + -- [0xFEFF] = function(head,current) -- zerowidthnobreakspace + -- return head, current + -- end, + +} + +characters.methods = methods + +function characters.handler(head) -- todo: use traverse_id + head = tonut(head) + local current = head + local done = false + while current do + local id = getid(current) + if id == glyph_code then + local next = getnext(current) + local char = getchar(current) + local method = methods[char] + if method then + if trace_characters then + report_characters("replacing character %C, description %a",char,lower(chardata[char].description)) + end + local h = method(head,current) + if h then + head = remove_node(h,current,true) + end + done = true + end + current = next + else + current = getnext(current) + end + end + return tonode(head), done +end |