2018-04-13 15:02:00

1 files changed, 147 insertions, 0 deletions

diff --git a/tex/context/base/mkiv/font-imp-italics.lua b/tex/context/base/mkiv/font-imp-italics.lua
new file mode 100644
index 000000000..aace899c5
--- /dev/null
+++ b/tex/context/base/mkiv/font-imp-italics.lua
@@ -0,0 +1,147 @@
+if not modules then modules = { } end modules ['font-imp-italics'] = {
+    version   = 1.001,
+    comment   = "companion to font-ini.mkiv and hand-ini.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+local next = next
+
+local fonts              = fonts
+local handlers           = fonts.handlers
+local registerotffeature = handlers.otf.features.register
+local registerafmfeature = handlers.afm.features.register
+
+local function initialize(tfmdata,key,value)
+    for unicode, character in next, tfmdata.characters do
+        local olditalic = character.italic
+        if olditalic and olditalic ~= 0 then
+            character.width  = character.width + olditalic
+            character.italic = 0
+        end
+    end
+end
+
+local specification = {
+    name        = "italicwidths",
+    description = "add italic to width",
+    manipulators = {
+        base = initialize,
+        node = initialize, -- only makes sense for math
+    }
+}
+
+registerotffeature(specification)
+registerafmfeature(specification)
+
+local function initialize(tfmdata,value) -- hm, always value
+    if value then
+        -- the magic 40 and it formula come from Dohyun Kim but we might need another guess
+        local parameters = tfmdata.parameters
+        local italicangle = parameters.italicangle
+        if italicangle and italicangle ~= 0 then
+            local properties = tfmdata.properties
+            local factor = tonumber(value) or 1
+            properties.hasitalics = true
+            properties.autoitalicamount = factor * (parameters.uwidth or 40)/2
+        end
+    end
+end
+
+local specification = {
+    name         = "itlc",
+    description  = "italic correction",
+    initializers = {
+        base = initialize,
+        node = initialize,
+    }
+}
+
+registerotffeature(specification)
+registerafmfeature(specification)
+
+if context then
+
+    local function initialize(tfmdata,value) -- yes no delay
+        tfmdata.properties.textitalics = toboolean(value)
+    end
+
+    local specification = {
+        name         = "textitalics",
+        description  = "use alternative text italic correction",
+        initializers = {
+            base = initialize,
+            node = initialize,
+        }
+    }
+
+    registerotffeature(specification)
+    registerafmfeature(specification)
+
+end
+
+-- no longer used
+
+if context then
+
+ -- local function initializemathitalics(tfmdata,value) -- yes no delay
+ --     tfmdata.properties.mathitalics = toboolean(value)
+ -- end
+ --
+ -- local specification = {
+ --     name         = "mathitalics",
+ --     description  = "use alternative math italic correction",
+ --     initializers = {
+ --         base = initializemathitalics,
+ --         node = initializemathitalics,
+ --     }
+ -- }
+ --
+ -- registerotffeature(specification)
+ -- registerafmfeature(specification)
+
+end
+
+-- -- also not used, only when testing
+
+if context then
+
+    local letter = characters.is_letter
+    local always = true
+
+    local function collapseitalics(tfmdata,key,value)
+        local threshold = value == true and 100 or tonumber(value)
+        if threshold and threshold > 0 then
+            if threshold > 100 then
+                threshold = 100
+            end
+            for unicode, data in next, tfmdata.characters do
+                if always or letter[unicode] or letter[data.unicode] then
+                    local italic = data.italic
+                    if italic and italic ~= 0 then
+                        local width = data.width
+                        if width and width ~= 0 then
+                            local delta = threshold * italic / 100
+                            data.width  = width  + delta
+                            data.italic = italic - delta
+                        end
+                    end
+                end
+            end
+        end
+    end
+
+    local dimensions_specification = {
+        name        = "collapseitalics",
+        description = "collapse italics",
+        manipulators = {
+            base = collapseitalics,
+            node = collapseitalics,
+        }
+    }
+
+    registerotffeature(dimensions_specification)
+    registerafmfeature(dimensions_specification)
+
+end