diff options
Diffstat (limited to 'luaotfload-colors.lua')
| -rw-r--r-- | luaotfload-colors.lua | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/luaotfload-colors.lua b/luaotfload-colors.lua new file mode 100644 index 0000000..3d8bfab --- /dev/null +++ b/luaotfload-colors.lua @@ -0,0 +1,187 @@ +if not modules then modules = { } end modules ['luaotfload-colors'] = { + version = 1.001, + comment = "companion to luaotfload.lua (font color)", + author = "Khaled Hosny and Elie Roux", + copyright = "Luaotfload Development Team", + license = "GPL" +} + +local newnode = node.new +local nodetype = node.id +local traverse_nodes = node.traverse +local insert_node_before = node.insert_before +local insert_node_after = node.insert_after + +local stringformat = string.format +local stringgsub = string.gsub +local stringfind = string.find + +local otffeatures = fonts.constructors.newfeatures("otf") +local ids = fonts.hashes.identifiers +local registerotffeature = otffeatures.register + +local function setcolor(tfmdata,value) + local sanitized + local properties = tfmdata.properties + + if value then + value = tostring(value) + if #value == 6 or #value == 8 then + sanitized = value + elseif #value == 7 then + _, _, sanitized = stringfind(value, "(......)") + elseif #value > 8 then + _, _, sanitized = stringfind(value, "(........)") + else + -- broken color code ignored, issue a warning? + end + end + + if sanitized then + tfmdata.properties.color = sanitized + add_color_callback() + end +end + +registerotffeature { + name = "color", + description = "color", + initializers = { + base = setcolor, + node = setcolor, + } +} + +local function hex2dec(hex,one) + if one then + return stringformat("%.1g", tonumber(hex, 16)/255) + else + return stringformat("%.3g", tonumber(hex, 16)/255) + end +end + +local res + +local function pageresources(a) + local res2 + if not res then + res = "/TransGs1<</ca 1/CA 1>>" + end + res2 = stringformat("/TransGs%s<</ca %s/CA %s>>", a, a, a) + res = stringformat("%s%s", res, stringfind(res, res2) and "" or res2) +end + +local function hex_to_rgba(hex) + local r, g, b, a, push, pop, res3 + if hex then + if #hex == 6 then + _, _, r, g, b = stringfind(hex, '(..)(..)(..)') + elseif #hex == 8 then + _, _, r, g, b, a = stringfind(hex, '(..)(..)(..)(..)') + a = hex2dec(a,true) + pageresources(a) + end + else + return nil + end + r = hex2dec(r) + g = hex2dec(g) + b = hex2dec(b) + if a then + push = stringformat('/TransGs%g gs %s %s %s rg', a, r, g, b) + pop = '0 g /TransGs1 gs' + else + push = stringformat('%s %s %s rg', r, g, b) + pop = '0 g' + end + return push, pop +end + +local glyph = nodetype('glyph') +local hlist = nodetype('hlist') +local vlist = nodetype('vlist') +local whatsit = nodetype('whatsit') +local pgi = nodetype('page_insert') +local sbox = nodetype('sub_box') + +local function lookup_next_color(head) + for n in traverse_nodes(head) do + if n.id == glyph then + if ids[n.font] and ids[n.font].properties and ids[n.font].properties.color then + return ids[n.font].properties.color + else + return -1 + end + elseif n.id == vlist or n.id == hlist or n.id == sbox then + local r = lookup_next_color(n.list) + if r == -1 then + return -1 + elseif r then + return r + end + elseif n.id == whatsit or n.id == pgi then + return -1 + end + end + return nil +end + +local function node_colorize(head, current_color, next_color) + for n in traverse_nodes(head) do + if n.id == hlist or n.id == vlist or n.id == sbox then + local next_color_in = lookup_next_color(n.next) or next_color + n.list, current_color = node_colorize(n.list, current_color, next_color_in) + elseif n.id == glyph then + local tfmdata = ids[n.font] + if tfmdata and tfmdata.properties and tfmdata.properties.color then + if tfmdata.properties.color ~= current_color then + local pushcolor = hex_to_rgba(tfmdata.properties.color) + local push = newnode(whatsit, 8) + push.mode = 1 + push.data = pushcolor + head = insert_node_before(head, n, push) + current_color = tfmdata.properties.color + end + local next_color_in = lookup_next_color (n.next) or next_color + if next_color_in ~= tfmdata.properties.color then + local _, popcolor = hex_to_rgba(tfmdata.properties.color) + local pop = newnode(whatsit, 8) + pop.mode = 1 + pop.data = popcolor + head = insert_node_after(head, n, pop) + current_color = nil + end + end + end + end + return head, current_color +end + +local function font_colorize(head) + -- check if our page resources existed in the previous run + -- and remove it to avoid duplicating it later + if res then + local r = "/ExtGState<<"..res..">>" + tex.pdfpageresources = stringgsub(tex.pdfpageresources, r, "") + end + local h = node_colorize(head, nil, nil) + -- now append our page resources + if res and stringfind(res, "%S") then -- test for non-empty string + local r = "/ExtGState<<"..res..">>" + tex.pdfpageresources = tex.pdfpageresources..r + end + return h +end + +local color_callback_activated = 0 + +function add_color_callback() + if color_callback_activated == 0 then + luatexbase.add_to_callback( + "pre_output_filter", font_colorize, "luaotfload.colorize") + color_callback_activated = 1 + end +end + +-- vim:tw=71:sw=4:ts=4:expandtab + |