Merge pull request #291 from phi-gamma/master

pluggable fontloaders

1 files changed, 74 insertions, 56 deletions

diff --git a/src/luaotfload-colors.lua b/src/luaotfload-colors.lua
index 89884b6..98549c8 100644
--- a/src/luaotfload-colors.lua
+++ b/src/luaotfload-colors.lua
@@ -19,8 +19,7 @@ explanation: http://tug.org/pipermail/luatex/2013-May/004305.html
 
 --doc]]--
 
-local log                   = luaotfload.log
-local logreport             = log.report
+local logreport             = luaotfload and luaotfload.log.report or print
 
 local nodedirect            = node.direct
 local newnode               = nodedirect.new
@@ -44,10 +43,7 @@ local texsettoks            = tex.settoks
 local texgettoks            = tex.gettoks
 
 local stringformat          = string.format
-
-local otffeatures           = fonts.constructors.newfeatures("otf")
 local identifiers           = fonts.hashes.identifiers
-local registerotffeature    = otffeatures.register
 
 local add_color_callback --[[ this used to be a global‽ ]]
 
@@ -101,36 +97,6 @@ local sanitize_color_expression = function (digits)
     return sanitized
 end
 
---[[doc--
-``setcolor`` modifies tfmdata.properties.color in place
---doc]]--
-
---- fontobj -> string -> unit
----
----         (where “string” is a rgb value as three octet
----         hexadecimal, with an optional fourth transparency
----         value)
----
-local setcolor = function (tfmdata, value)
-    local sanitized  = sanitize_color_expression(value)
-    local properties = tfmdata.properties
-
-    if sanitized then
-        properties.color = sanitized
-        add_color_callback()
-    end
-end
-
-registerotffeature {
-    name        = "color",
-    description = "color",
-    initializers = {
-        base = setcolor,
-        node = setcolor,
-    }
-}
-
-
 --- something is carried around in ``res``
 --- for later use by color_handler() --- but what?
 
@@ -192,6 +158,7 @@ local whatsit_t         = nodetype("whatsit")
 local disc_t            = nodetype("disc")
 local pdfliteral_t      = node.subtype("pdf_literal")
 local colorstack_t      = node.subtype("pdf_colorstack")
+local mlist_to_hlist    = node.mlist_to_hlist
 
 local color_callback
 local color_attr        = luatexbase.new_attribute("luaotfload_color_attribute")
@@ -230,8 +197,6 @@ local get_font_color = function (font_id)
     return font_color
 end
 
-local cnt = 0
-
 --[[doc--
 While the second argument and second returned value are apparently
 always nil when the function is called, they temporarily take string
@@ -240,26 +205,24 @@ values during the node list traversal.
 
 --- (node * (string | nil)) -> (node * (string | nil))
 local node_colorize
-node_colorize = function (head, current_color)
+node_colorize = function (head, toplevel, current_color)
     local n = head
     while n do
         local n_id = getid(n)
 
         if n_id == hlist_t or n_id == vlist_t then
-            cnt = cnt + 1
             local n_list = getlist(n)
             if getattribute(n_list, color_attr) then
                 if current_color then
                     head, n, current_color = color_whatsit(head, n, current_color, false)
                 end
             else
-                n_list, current_color = node_colorize(n_list, current_color)
+                n_list, current_color = node_colorize(n_list, false, current_color)
                 if current_color and getsubtype(n) == 1 then -- created by linebreak
                     n_list, _, current_color = color_whatsit(n_list, nodetail(n_list), current_color, false, true)
                 end
                 setfield(n, "head", n_list)
             end
-            cnt = cnt - 1
 
         elseif n_id == glyph_t then
             --- colorization is restricted to those fonts
@@ -303,7 +266,7 @@ node_colorize = function (head, current_color)
         n = getnext(n)
     end
 
-    if cnt == 0 and current_color then
+    if toplevel and current_color then
         head, _, current_color = color_whatsit(head, nodetail(head), current_color, false, true)
     end
 
@@ -314,7 +277,7 @@ end
 --- node -> node
 local color_handler = function (head)
     head = todirect(head)
-    head = node_colorize(head)
+    head = node_colorize(head, true)
     head = tonode(head)
 
     -- now append our page resources
@@ -351,6 +314,8 @@ local color_handler = function (head)
 end
 
 local color_callback_activated = 0
+local add_to_callback          = luatexbase.add_to_callback
+local priority_in_callback     = luatexbase.priority_in_callback
 
 --- unit -> unit
 add_color_callback = function ( )
@@ -360,22 +325,75 @@ add_color_callback = function ( )
     end
 
     if color_callback_activated == 0 then
-        luatexbase.add_to_callback(color_callback,
-                                   color_handler,
-                                   "luaotfload.color_handler")
-        luatexbase.add_to_callback("hpack_filter",
-                                   function (head, groupcode)
-                                       if  groupcode == "hbox"          or
-                                           groupcode == "adjusted_hbox" or
-                                           groupcode == "align_set"     then
-                                           head = color_handler(head)
-                                       end
-                                       return head
-                                   end,
-                                   "luaotfload.color_handler")
+        add_to_callback(color_callback,
+                        color_handler,
+                        "luaotfload.color_handler")
+        add_to_callback("hpack_filter",
+                        function (head, groupcode)
+                            if  groupcode == "hbox"          or
+                                groupcode == "adjusted_hbox" or
+                                groupcode == "align_set"     then
+                                head = color_handler(head)
+                            end
+                            return head
+                        end,
+                        "luaotfload.color_handler")
+        add_to_callback("mlist_to_hlist",
+                        function (head, display_type, need_penalties)
+                            if priority_in_callback("mlist_to_hlist","luaotfload.color_handler") == 1 then
+                                head = mlist_to_hlist(head, display_type, need_penalties)
+                            end
+                            if display_type == "text" then
+                                return head
+                            end
+                            return color_handler(head)
+                        end,
+                        "luaotfload.color_handler")
         color_callback_activated = 1
     end
 end
 
+--[[doc--
+``setcolor`` modifies tfmdata.properties.color in place
+--doc]]--
+
+--- fontobj -> string -> unit
+---
+---         (where “string” is a rgb value as three octet
+---         hexadecimal, with an optional fourth transparency
+---         value)
+---
+local setcolor = function (tfmdata, value)
+    local sanitized  = sanitize_color_expression(value)
+    local properties = tfmdata.properties
+
+    if sanitized then
+        properties.color = sanitized
+        add_color_callback()
+    end
+end
+
+return {
+    init = function ()
+        logreport = luaotfload.log.report
+        if not fonts then
+            logreport ("log", 0, "color",
+                       "OTF mechanisms missing -- did you forget to \z
+                       load a font loader?")
+            return false
+        end
+        fonts.handlers.otf.features.register {
+            name        = "color",
+            description = "color",
+            initializers = {
+                base = setcolor,
+                node = setcolor,
+            }
+        }
+        return true
+    end
+}
+
+
 -- vim:tw=71:sw=4:ts=4:expandtab