2018-04-13 15:02:00

1 files changed, 171 insertions, 0 deletions

diff --git a/tex/context/base/mkiv/font-imp-tracing.lua b/tex/context/base/mkiv/font-imp-tracing.lua
new file mode 100644
index 000000000..e6de494df
--- /dev/null
+++ b/tex/context/base/mkiv/font-imp-tracing.lua
@@ -0,0 +1,171 @@
+if not modules then modules = { } end modules ['font-imp-tracing'] = {
+    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, type = next, type
+local formatters = string.formatters
+
+local fonts              = fonts
+
+local handlers           = fonts.handlers
+local registerotffeature = handlers.otf.features.register
+local registerafmfeature = handlers.afm.features.register
+
+local settings_to_array  = utilities.parsers.settings_to_array
+local setmetatableindex  = table.setmetatableindex
+
+local helpers            = fonts.helpers
+local prependcommands    = helpers.prependcommands
+local charcommand        = helpers.commands.char
+
+local variables          = interfaces.variables
+
+local v_background       = variables.background
+local v_frame            = variables.frame
+local v_empty            = variables.empty
+local v_none             = variables.none
+
+-- for zhichu chen (see mailing list archive): we might add a few more variants
+-- in due time
+--
+-- \definefontfeature[boxed][default][boundingbox=yes] % paleblue
+--
+-- maybe:
+--
+-- \definecolor[DummyColor][s=.75,t=.5,a=1] {\DummyColor test} \nopdfcompression
+--
+-- local gray  = { "pdf", "origin", "/Tr1 gs .75 g" }
+-- local black = { "pdf", "origin", "/Tr0 gs 0 g" }
+
+-- boundingbox={yes|background|frame|empty|<color>}
+
+local bp  = number.dimenfactors.bp
+local r   = 16384 * bp -- 65536 // 4
+local f_1 = formatters["%.6F w 0 %.6F %.6F %.6F re f"]
+local f_2 = formatters["[] 0 d 0 J %.6F w %.6F %.6F %.6F %.6F re S"]
+
+local backcache = setmetatableindex(function(t,h)
+    local h = h * bp
+    local v = setmetatableindex(function(t,d)
+        local d = d * bp
+        local v = setmetatableindex(function(t,w)
+            local v = { "pdf", "origin", f_1(r,-d,w*bp,h+d) }
+            t[w] = v
+            return v
+        end)
+        t[d] = v
+        return v
+    end)
+    t[h] = v
+    return v
+end)
+
+local forecache = setmetatableindex(function(t,h)
+    local h = h * bp
+    local v = setmetatableindex(function(t,d)
+        local d = d * bp
+        local v = setmetatableindex(function(t,w)
+            -- the frame goes through the boundingbox
+            local v = { "pdf", "origin", f_2(r,r/2,-d+r/2,w*bp-r,h+d-r) }
+            t[w] = v
+            return v
+        end)
+        t[d] = v
+        return v
+    end)
+    t[h] = v
+    return v
+end)
+
+local startcolor = nil
+local stopcolor  = nil
+
+local function initialize(tfmdata,key,value)
+    if value then
+        if not backcolors then
+            local vfspecials = backends.pdf.tables.vfspecials
+            startcolor = vfspecials.startcolor
+            stopcolor  = vfspecials.stopcolor
+        end
+        local characters = tfmdata.characters
+        local rulecache  = backcache
+        local showchar   = true
+        local color      = "palegray"
+        if type(value) == "string" then
+            value = settings_to_array(value)
+            for i=1,#value do
+                local v = value[i]
+                if v == v_frame then
+                    rulecache = forecache
+                elseif v == v_background then
+                    rulecache = backcache
+                elseif v == v_empty then
+                    showchar = false
+                elseif v == v_none then
+                    color = nil
+                else
+                    color = v
+                end
+            end
+        end
+        local gray  = color and startcolor(color) or nil
+        local black = gray and stopcolor or nil
+        for unicode, character in next, characters do
+            local width  = character.width  or 0
+            local height = character.height or 0
+            local depth  = character.depth  or 0
+            local rule   = rulecache[height][depth][width]
+            if showchar then
+                local commands = character.commands
+                if commands then
+                    if gray then
+                        character.commands = prependcommands (
+                            commands, gray, rule, black
+                        )
+                    else
+                        character.commands = prependcommands (
+                            commands, rule
+                        )
+                    end
+                else
+                    local char = charcommand[unicode]
+                    if gray then
+                        character.commands = {
+                            gray, rule, black, char
+                        }
+                     else
+                        character.commands = {
+                            rule, char
+                        }
+                    end
+                end
+            else
+                if gray then
+                    character.commands = {
+                        gray, rule, black
+                    }
+                else
+                    character.commands = {
+                        rule
+                    }
+                end
+            end
+        end
+    end
+end
+
+local specification = {
+    name        = "boundingbox",
+    description = "show boundingbox",
+    manipulators = {
+        base = initialize,
+        node = initialize,
+    }
+}
+
+registerotffeature(specification)
+registerafmfeature(specification)