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-rw-r--r--otfl-font-clr.lua168
1 files changed, 168 insertions, 0 deletions
diff --git a/otfl-font-clr.lua b/otfl-font-clr.lua
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--- /dev/null
+++ b/otfl-font-clr.lua
@@ -0,0 +1,168 @@
+if not modules then modules = { } end modules ['font-clr'] = {
+ version = 1.001,
+ comment = "companion to font-otf.lua (font color)",
+ author = "Khaled Hosny",
+ copyright = "Khaled Hosny",
+ license = "GPL"
+}
+
+fonts.triggers = fonts.triggers or { }
+fonts.initializers = fonts.initializers or { }
+fonts.initializers.common = fonts.initializers.common or { }
+
+local initializers, format = fonts.initializers, string.format
+
+table.insert(fonts.triggers,"color")
+
+function initializers.common.color(tfmdata,value)
+ if value then
+ tfmdata.color = value
+ luaotfload.add_color_callback()
+ end
+end
+
+initializers.base.otf.color = initializers.common.color
+initializers.node.otf.color = initializers.common.color
+
+local function hex2dec(hex,one)
+ if one then
+ return format("%.1g", tonumber(hex, 16)/255)
+ else
+ return format("%.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 = format("/TransGs%s<</ca %s/CA %s>>", a, a, a)
+ res = format("%s%s", res, res:find(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 = hex:find('(..)(..)(..)')
+ elseif #hex == 8 then
+ _, _, r, g, b, a = hex:find('(..)(..)(..)(..)')
+ a = hex2dec(a,true)
+ pageresources(a)
+ end
+ else
+ return nil
+ end
+ r = hex2dec(r)
+ g = hex2dec(g)
+ b = hex2dec(b)
+ if a then
+ push = format('/TransGs%g gs %s %s %s rg', a, r, g, b)
+ pop = '0 g /TransGs1 gs'
+ else
+ push = format('%s %s %s rg', r, g, b)
+ pop = '0 g'
+ end
+ return push, pop
+end
+
+local glyph = node.id('glyph')
+local hlist = node.id('hlist')
+local vlist = node.id('vlist')
+local whatsit = node.id('whatsit')
+local pgi = node.id('page_insert')
+local sbox = node.id('sub_box')
+
+local function lookup_next_color(head)
+ for n in node.traverse(head) do
+ if n.id == glyph then
+ if fonts.ids[n.font] and fonts.ids[n.font].color then
+ return fonts.ids[n.font].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
+
+function luaotfload.node_colorize(head, current_color, next_color)
+ for n in node.traverse(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 = luaotfload.node_colorize(n.list, current_color, next_color_in)
+ elseif n.id == glyph then
+ local tfmdata = fonts.ids[n.font]
+ if tfmdata and tfmdata.color then
+ if tfmdata.color ~= current_color then
+ local pushcolor = hex_to_rgba(tfmdata.color)
+ local push = node.new(whatsit, 8)
+ push.mode = 1
+ push.data = pushcolor
+ head = node.insert_before(head, n, push)
+ current_color = tfmdata.color
+ end
+ local next_color_in = lookup_next_color (n.next) or next_color
+ if next_color_in ~= tfmdata.color then
+ local _, popcolor = hex_to_rgba(tfmdata.color)
+ local pop = node.new(whatsit, 8)
+ pop.mode = 1
+ pop.data = popcolor
+ head = node.insert_after(head, n, pop)
+ current_color = nil
+ end
+ end
+ end
+ end
+ return head, current_color
+end
+
+function luaotfload.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 = tex.pdfpageresources:gsub(r, "")
+ end
+ local h = luaotfload.node_colorize(head, nil, nil)
+ -- now append our page resources
+ if res and res:find("%S") then -- test for non-empty string
+ local r = "/ExtGState<<"..res..">>"
+ tex.pdfpageresources = tex.pdfpageresources..r
+ end
+ return h
+end
+
+luaotfload.color_callback_activated = 0
+local message_displayed = 0
+
+function luaotfload.add_color_callback()
+ if tex.luatexversion < 44 then
+ if message_displayed == 0 then
+ luatextra.module_warning("luaotfload","You must have a LuaTeX with version >= 0.44 in order to get colors working, colors won't work.")
+ message_displayed = 1
+ end
+ elseif luaotfload.color_callback_activated == 0 then
+ callback.add("pre_output_filter", luaotfload.colorize, "loaotfload.colorize")
+ luaotfload.color_callback_activated = 1
+ end
+end
+
+function luaotfload.remove_color_callback()
+ if luaotfload.color_callback_activated == 1 then
+ callback.remove("pre_output_filter", "loaotfload.colorize")
+ luaotfload.color_callback_activated = 0
+ end
+end