local format = string.format local byte = string.byte local pack = string.pack local error = error local pairs = pairs local setmetatable = setmetatable local assigned = {} local delayed = {} local compress = xzip.compress local pdfvariable = pdf.variable -- slightly tricky interface: No/nil return means that the objects content -- isn't known yet, while false indicates a delayed object. local function written(pdf, num) num = pdf[num] if not num or num == assigned then return end return num ~= delayed end -- raw: Pass on preencoded stream. Currently ignored. local function stream(pdf, num, dict, content, isfile, raw) if not num then num = pdf:getobj() end if pdf[num] ~= assigned then error[[Invalid object]] end pdf[num] = {offset = pdf.file:seek()} if isfile then local f = io.open(content, 'rb') content = f:read'a' f:close() end local level = not raw and pdfvariable.compresslevel or 0 local filter = '' if level > 0 then local compressed = compress(content, level) if #compressed < #content + 19 then -- Filter has some overhead filter = "/Filter/FlateDecode" content = compressed end end pdf.file:write(format('%i 0 obj\n<<%s%s/Length %i>>stream\n', num, dict, filter, #content)) pdf.file:write(content) pdf.file:write'\nendstream\nendobj\n' return num end local function delayedstream(pdf, num, dict, content, isfile, raw) if not num then num = pdf:getobj() end if pdf[num] ~= assigned then error[[Invalid object]] end pdf[num] = delayed pdf[-num] = {stream, dict, content, isfile, raw} return num end local function indirect(pdf, num, content, isfile, objstream) if not num then num = pdf:getobj() end if pdf[num] ~= assigned then error[[Invalid object]] end if isfile then local f = io.open(content, 'rb') content = f:read'a' f:close() end if objstream ~= false and pdfvariable.objcompresslevel ~= 0 then objstream = objstream or true local objstr = pdf.objstream[objstream] if not objstr then objstr = {objnum = pdf:getobj(), off = 0, {}} pdf.objstream[objstream] = objstr end local i = #objstr pdf[num] = {objstr = objstr.objnum, i = i-1} objstr[1][i] = string.format("%i %i ", num, objstr.off) objstr[i+1] = content objstr.off = objstr.off + #content else pdf[num] = {offset = pdf.file:seek()} pdf.file:write(format('%i 0 obj\n', num)) pdf.file:write(content) pdf.file:write'\nendobj\n' end return num end local function delay(pdf, num, content, isfile) if not num then num = pdf:getobj() end if pdf[num] ~= assigned then error[[Invalid object]] end pdf[num] = delayed pdf[-num] = {indirect, content, isfile} return num end local function reference(pdf, num) local status = pdf[num] if status == delayed then local saved = pdf[-num] pdf[-num] = nil pdf[num] = assigned return saved[1](pdf, num, table.unpack(saved, 2)) elseif status == assigned or not status then error[[Invalid object]] -- else -- Already written end end local function getid(pdf) local id = pdf[0] + 1 pdf[0] = id pdf[id] = assigned return id end local function trailer(pdf) local linked = 0 for k,objstr in next, pdf.objstream do objstr[1] = table.concat(objstr[1]) pdf:stream(objstr.objnum, string.format("/Type/ObjStm/N %i/First %i", #objstr-1, #objstr[1]), table.concat(objstr)) end local nextid = getid(pdf) local myoff = pdf.file:seek() pdf[nextid] = {offset = myoff} local offsets = {} for i=1,nextid do local off = pdf[i].offset if off then offsets[i+1] = pack(">I1I3I2", 1, off, 0) else local objstr = pdf[i].objstr if objstr then offsets[i+1] = pack(">I1I3I2", 2, objstr, pdf[i].i) else offsets[linked+1] = pack(">I1I3I2", 0, i, 255) linked = i end end end offsets[linked+1] = '\0\0\0\0\255\255' pdf[nextid] = assigned -- TODO: Add an /ID according to 14.4 local info = pdf.info and string.format("/Info %i 0 R", pdf.info) or "" stream(pdf, nextid, format([[/Type/XRef/Size %i/W[1 3 2]/Root %i 0 R%s]], nextid+1, pdf.root, info), table.concat(offsets)) pdf.file:write('startxref\n', myoff, '\n%%EOF') end local function close(pdf) trailer(pdf) local size = pdf.file:seek() if #pdf.version ~= 3 then error[[Invalid PDF version]] end pdf.file:seek('set', 5) pdf.file:write(pdf.version) pdf.file:close() return size end local pagetree = require'luametalatex-pdf-pagetree' local pdfmeta = { close = close, getobj = getid, indirect = indirect, stream = stream, newpage = pagetree.newpage, reservepage = pagetree.reservepage, writepages = pagetree.write, delayed = delay, delayedstream = delayedstream, reference = reference, written = written, } pdfmeta.__index = pdfmeta local function open(filename) local file = io.open(filename, 'wb') file:write"%PDF-X.X\n%🖋\n" return setmetatable({file = file, version = '1.7', [0] = 0, pages = {}, objstream = {}}, pdfmeta) end return { open = open, }