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authorPhilipp Gesang <phg42.2a@gmail.com>2013-05-01 19:34:11 +0200
committerPhilipp Gesang <phg42.2a@gmail.com>2013-05-01 19:34:11 +0200
commit3d757d9ac865a0751750b1b358f9fa1781d97883 (patch)
treebf1f9c4b2633dd65fc648cb3668e5adc959febd6
parent7cf60286cb69e8b5ffc47c06bdc9a18bb941e306 (diff)
downloadluaotfload-3d757d9ac865a0751750b1b358f9fa1781d97883.tar.gz
add capheight callback
-rw-r--r--luaotfload-auxiliary.lua58
1 files changed, 55 insertions, 3 deletions
diff --git a/luaotfload-auxiliary.lua b/luaotfload-auxiliary.lua
index 2d55db5..01e1bc0 100644
--- a/luaotfload-auxiliary.lua
+++ b/luaotfload-auxiliary.lua
@@ -3,7 +3,7 @@
-- FILE: luaotfload-auxiliary.lua
-- DESCRIPTION: part of luaotfload
-- REQUIREMENTS: luaotfload 2.2
--- AUTHOR: Philipp Gesang (Phg), <phg42.2a@gmail.com>
+-- AUTHOR: Khaled Hosny, Élie Roux, Philipp Gesang
-- VERSION: 1.0
-- CREATED: 2013-05-01 14:40:50+0200
-----------------------------------------------------------------------
@@ -27,6 +27,7 @@ local utf8 = unicode.utf8
local stringlower = string.lower
local stringformat = string.format
local stringgsub = string.gsub
+local stringbyte = string.byte
-----------------------------------------------------------------------
--- font patches
@@ -86,6 +87,57 @@ luatexbase.add_to_callback(
patch_cambria_domh,
"luaotfload.aux.patch_cambria_domh")
+--[[doc--
+
+Comment from fontspec:
+
+ “Here we patch fonts tfm table to emulate \XeTeX's \cs{fontdimen8},
+ which stores the caps-height of the font. (Cf.\ \cs{fontdimen5} which
+ stores the x-height.)
+
+ Falls back to measuring the glyph if the font doesn't contain the
+ necessary information.
+ This needs to be extended for fonts that don't contain an `X'.”
+
+--doc]]--
+
+local set_capheight = function (fontdata)
+ local shared = fontdata.shared
+ local parameters = fontdata.parameters
+ local capheight
+ if shared then
+ local units_per_em = parameters.units
+ local size = parameters.size
+ local os2_capheight = shared.rawdata.metadata.pfminfo.os2_capheight
+
+ if os2_capheight > 0 then
+ capheight = os2_capheight / units_per_em * size
+ else
+ local X8 = stringbyte"X"
+ if fontdata.characters[X8] then
+ capheight = fontdata.characters[X8].height
+ else
+ capheight = parameters.ascender / units_per_em * size
+ end
+ end
+ else
+ local X8 = stringbyte"X"
+ if fontdata.characters[X8] then
+ capheight = fontdata.characters[X8].height
+ end
+ end
+ if capheight then
+ --- is this legit? afaics there’s nothing else on the
+ --- array part of that table
+ fontdata.parameters[8] = capheight
+ end
+end
+
+luatexbase.add_to_callback(
+ "luaotfload.patch_font",
+ set_capheight,
+ "luaotfload.aux.set_capheight")
+
-----------------------------------------------------------------------
--- glyphs
-----------------------------------------------------------------------
@@ -236,8 +288,8 @@ accounted for in the script with tag “asked_script” in feature
--doc]]--
--- int -> string -> string -> string -> bool
-local provides_feature = function(font_id, asked_script,
- asked_language, asked_feature)
+local provides_feature = function (font_id, asked_script,
+ asked_language, asked_feature)
asked_script = stringlower(asked_script)
asked_language = stringlower(asked_language)
asked_feature = lpegmatch(strip_garbage, asked_feature)