Merge pull request #123 from phi-gamma/master

refine AFM support

4 files changed, 153 insertions, 38 deletions

diff --git a/filegraph.dot b/filegraph.dot
index e412279..f69c751 100644
--- a/filegraph.dot
+++ b/filegraph.dot
@@ -63,6 +63,17 @@ strict digraph luaotfload_files { //looks weird with circo ...
     luaotfload_libs -> font_names [label="luaotfload-database.lua"]
     luaotfload_libs -> typo_krn   [label="luaotfload-extralibs.lua"]
 
+    luaotfload_libs -> font_afm   [label="luaotfload-loaders.lua"]
+    luaotfload_libs -> font_afk   [label="luaotfload-loaders.lua"]
+
+    subgraph cluster_afm { rank = same;
+                           label = "AFM support";
+                           node [style=filled, color=white];
+                           style     = "filled,rounded";
+                           color     = "grey90:white";
+                           font_afm;
+                           font_afk; }
+
     mkstatus    -> status     [label="generates from distribution files",
                                style=dashed]
 
@@ -147,6 +158,22 @@ strict digraph luaotfload_files { //looks weird with circo ...
                        style  = "filled,rounded",
                        penwidth=2]
 
+    font_afk [label  = "luaotfload-font-afk.lua",
+              shape  = rect,
+              width  = "3.2cm",
+              height = "1.2cm",
+              color  = "#01012222",
+              style  = "filled,rounded",
+              penwidth=2]
+
+    font_afm [label  = "luaotfload-font-afm.lua",
+              shape  = rect,
+              width  = "3.2cm",
+              height = "1.2cm",
+              color  = "#01012222",
+              style  = "filled,rounded",
+              penwidth=2]
+
     typo_krn [label  = "luaotfload-typo-krn.lua",
               shape  = rect,
               width  = "3.2cm",
diff --git a/luaotfload-loaders.lua b/luaotfload-loaders.lua
index fd7c8c6..6d6f409 100644
--- a/luaotfload-loaders.lua
+++ b/luaotfload-loaders.lua
@@ -1,35 +1,27 @@
 if not modules then modules = { } end modules ["loaders"] = {
-    version   = "2.3a",
+    version   = "2.4",
     comment   = "companion to luaotfload.lua",
     author    = "Hans Hagen, Khaled Hosny, Elie Roux, Philipp Gesang",
     copyright = "PRAGMA ADE / ConTeXt Development Team",
     license   = "see context related readme files"
 }
 
-local fonts   = fonts
-local readers = fonts.readers
+local fonts           = fonts
+local readers         = fonts.readers
+local handlers        = fonts.handlers
+local formats         = fonts.formats
 
----
---- opentype reader (from font-otf.lua):
---- (spec : table) -> (suffix : string) -> (format : string) -> (font : table)
----
-
-local pfb_reader = function (specification)
-  return readers.opentype(specification,"pfb","type1")
-end
-
-local pfa_reader = function (specification)
-  return readers.opentype(specification,"pfa","type1")
-end
-
-fonts.formats.pfb  = "type1"
-fonts.readers.pfb  = pfb_reader
-fonts.handlers.pfb = { }  --- empty, as with tfm
-
-fonts.formats.pfa  = "type1"
-fonts.readers.pfa  = pfa_reader
-fonts.handlers.pfa = { }
+local lfsisfile       = lfs.isfile
+local fileaddsuffix   = file.addsuffix
+local filebasename    = file.basename
+local stringsub       = string.sub
+local stringlower     = string.lower
+local stringupper     = string.upper
+local findbinfile     = resolvers.findbinfile
 
+local lpeg            = require "lpeg"
+local lpegmatch       = lpeg.match
+local P, S, Cp        = lpeg.P, lpeg.S, lpeg.Cp
 
 resolvers.openbinfile = function (filename)
     if filename and filename ~= "" then
@@ -61,6 +53,31 @@ resolvers.loadbinfile = function (filename, filetype)
 
 end
 
+--- this function is required because AFM precedes TFM in the reader
+--- chain (see definers.loadfont() in font-def.lua
+
+local check_tfm = function (specification, fullname)
+
+    local foundname = findbinfile (fullname, "tfm") or ""
+
+    if foundname == "" then
+        foundname = findbinfile (fullname, "ofm") or ""
+    end
+
+    if foundname == "" then
+        foundname = fonts.names.getfilename (fullname,"tfm") or ""
+    end
+
+    if foundname ~= "" then
+        specification.filename = foundname
+        specification.format   = "ofm"
+        return font.read_tfm (specification.filename,
+                              specification.size)
+    end
+end
+
+readers.check_tfm = check_tfm
+
 --[[ <EXPERIMENTAL> ]]
 
 --[[doc--
@@ -87,4 +104,65 @@ require "luaotfload-font-afk.lua"
 
 --[[ </EXPERIMENTAL> ]]
 
+--[[doc--
+
+    The PFB/PFA reader checks whether there is a corresponding AFM file
+    and hands the spec over to the AFM loader if appropriate.  Context
+    uses string.gsub() to accomplish this but that can cause collateral
+    damage.
+
+--doc]]--
+
+local mk_type1_reader = function (format)
+
+  format          = stringlower (format)
+  local first     = stringsub (format, 1, 1)
+  local second    = stringsub (format, 2, 2)
+  local third     = stringsub (format, 3, 3)
+
+  local p_format      = P"."
+                      * (P(first)   + P(stringupper (first)))
+                      * (P(second)  + P(stringupper (second)))
+                      * (P(third)   + P(stringupper (third)))
+  ---                  we have to be careful here so we don’t affect
+  ---                  harmless substrings
+                      * (P"("    --- subfont
+                       + P":"    --- feature list
+                       + P(-1))  --- end of string
+  local no_format     = 1 - p_format
+  local p_format_file = no_format^1 * Cp() * p_format * Cp()
+
+  local reader = function (specification, method)
+
+    local afmfile = fileaddsuffix (specification.name, "afm")
+
+    if lfsisfile (afmfile) then
+      --- switch to afm reader
+      logs.names_report ("log", 0, "type1",
+                         "Found corresponding AFM file %s, using that.",
+                         filebasename (afmfile))
+      local oldspec = specification.specification
+      local before, after = lpegmatch (p_format_file, oldspec)
+      specification.specification = stringsub (oldspec, 1, before)
+                                 .. "afm"
+                                 .. stringsub (oldspec, after - 1)
+      specification.forced = "afm"
+      return readers.afm (specification, method)
+    end
+
+    --- else read pfb via opentype mechanism
+    return readers.opentype (specification, format, "type1")
+  end
+
+  return reader
+end
+
+formats.pfa  = "type1"
+readers.pfa  = mk_type1_reader "pfa"
+handlers.pfa = { }
+
+formats.pfb  = "type1"
+readers.pfb  = mk_type1_reader "pfb"
+handlers.pfb = { }  --- empty, as with tfm
+
 -- vim:tw=71:sw=2:ts=2:expandtab
diff --git a/luaotfload.dtx b/luaotfload.dtx
index 4802844..56e9d4d 100644
--- a/luaotfload.dtx
+++ b/luaotfload.dtx
@@ -1178,7 +1178,7 @@ and the derived files
 %
 % Also, the merged file at some point
 % loads the Adobe Glyph List from a \LUA table that is contained in
-% \fileent{luaotfload-glyphlist.lua}, which is automatically generated by the %
+% \fileent{luaotfload-glyphlist.lua}, which is automatically generated by the
 % script \fileent{mkglyphlist}.\footnote{%
 %   See \fileent{luaotfload-font-enc.lua}.
 %   The hard-coded file name is why we have to replace the procedure
@@ -1199,20 +1199,28 @@ and the derived files
 %       \normalitem{\fileent{#1}}%
 %       \space--\hskip1em
 %     }
-%     \ouritem {luaotfload-features.lua}   font feature handling;
-%                                          incorporates some of the code from
-%                                          \fileent{font-otc} from \CONTEXT;
-%     \ouritem {luaotfload-override.lua}   overrides the \CONTEXT logging
-%                                          functionality.
-%     \ouritem {luaotfload-loaders.lua}    registers the \OpenType
-%                                          font reader as handler for
-%                                          Postscript fonts
-%                                          (\abbrev{pfa}, \abbrev{pfb}).
-%     \ouritem {luaotfload-database.lua}   font names database.
-%     \ouritem {luaotfload-colors.lua}     color handling.
-%     \ouritem {luaotfload-auxiliary.lua}  access to internal functionality
-%                                          for package authors
-%                                          (proposals for additions welcome).
+%     \ouritem {luaotfload-features.lua}     font feature handling;
+%                                            incorporates some of the code from
+%                                            \fileent{font-otc} from \CONTEXT;
+%     \ouritem {luaotfload-override.lua}     overrides the \CONTEXT logging
+%                                            functionality.
+%     \ouritem {luaotfload-loaders.lua}      registers the \OpenType
+%                                            font reader as handler for
+%                                            Postscript fonts
+%                                            (\abbrev{pfa}, \abbrev{pfb}).
+%     \ouritem {luaotfload-database.lua}     font names database.
+%     \ouritem {luaotfload-colors.lua}       color handling.
+%     \ouritem {luaotfload-auxiliary.lua}    access to internal functionality
+%                                            for package authors
+%                                            (proposals for additions welcome).
+%     \ouritem {luaotfload-extralibs.lua}    layer for loading of further
+%                                            Context libraries.
+%     \ouritem {luaotfload-letterspace.lua}  font-based letterspacing.
+%     \ouritem {luaotfload-typo-krn.lua}     attribute-based letterspacing.
+%     \ouritem {luaotfload-font-afm.lua}     \abbrev{afm} loading.
+%     \ouritem {luaotfload-font-afk.lua}     supplementary glyph
+%                                            information for \abbrev{afm}
+%                                            fonts.
 % \end{itemize}
 %
 % \begin{figure}[b]
diff --git a/mkstatus b/mkstatus
index 16d0b5d..5cd73d8 100755
--- a/mkstatus
+++ b/mkstatus
@@ -42,6 +42,8 @@ local names = {
   "luaotfload-diagnostics.lua",
   "luaotfload-extralibs.lua",
   "luaotfload-features.lua",
+  "luaotfload-font-afk.lua",
+  "luaotfload-font-afm.lua",
   "luaotfload-fonts-cbk.lua",
   "luaotfload-fonts-def.lua",
   "luaotfload-fonts-enc.lua",