1 files changed, 147 insertions, 0 deletions
diff --git a/tex/context/base/mkiv/back-pdf.lua b/tex/context/base/mkiv/back-pdf.lua
new file mode 100644
index 000000000..5d007ed43
--- /dev/null
+++ b/tex/context/base/mkiv/back-pdf.lua
@@ -0,0 +1,147 @@
+if not modules then modules = { } end modules ['back-pdf'] = {
+    version   = 1.001,
+    comment   = "companion to back-pdf.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+-- we could do \pdfmatrix sx <> sy <> etc
+
+local tonumber = tonumber
+local sind, cosd = math.sind, math.cosd
+local insert, remove = table.insert, table.remove
+
+local codeinjections = backends.pdf.codeinjections
+
+local context        = context
+
+local scanners       = tokens.scanners
+local scanstring     = scanners.string
+local scannumber     = scanners.number
+local scaninteger    = scanners.integer
+local scankeyword    = scanners.keyword
+
+local scanners       = interfaces.scanners
+
+local outputfilename
+
+function codeinjections.getoutputfilename()
+    if not outputfilename then
+        outputfilename = file.addsuffix(tex.jobname,"pdf")
+    end
+    return outputfilename
+end
+
+backends.install("pdf")
+
+local f_matrix = string.formatters["%F %F %F %F"] -- 0.8 is default
+
+scanners.pdfrotation = function() -- a
+    -- todo: check for 1 and 0 and flush sparse
+    local a = scannumber()
+    local s, c = sind(a), cosd(a)
+    context(f_matrix(c,s,-s,c))
+end
+
+-- experimental code (somewhat weird here) .. todo: nodeinjections .. this will only work
+-- out well if we also calculate the accumulated cm and wrap inclusions / annotations in
+-- the accumulated ... it's a mess
+--
+-- we could also do the save restore wrapping here + colorhack
+
+local pdfsave      = nodes.pool.pdfsave
+local pdfrestore   = nodes.pool.pdfrestore
+local pdfsetmatrix = nodes.pool.pdfsetmatrix
+
+local stack        = { }
+local restore      = true -- false
+
+scanners.pdfstartrotation = function()
+    local a = scannumber()
+    if a == 0 then
+        insert(stack,false)
+    else
+        local s, c = sind(a), cosd(a)
+        context(pdfsave())
+        context(pdfsetmatrix(c,s,-s,c))
+        insert(stack,restore and { c, -s, s, c } or true)
+    end
+end
+
+scanners.pdfstartscaling = function() -- at the tex end we use sx and sy instead of rx and ry
+    local rx, ry = 1, 1
+    while true do
+        if scankeyword("rx") then
+            rx = scannumber()
+        elseif scankeyword("ry") then
+            ry = scannumber()
+     -- elseif scankeyword("revert") then
+     --     local top = stack[#stack]
+     --     if top then
+     --         rx = top[1]
+     --         ry = top[4]
+     --     else
+     --         rx = 1
+     --         ry = 1
+     --     end
+        else
+            break
+        end
+    end
+    if rx == 1 and ry == 1 then
+        insert(stack,false)
+    else
+        if rx == 0 then
+            rx = 0.0001
+        end
+        if ry == 0 then
+            ry = 0.0001
+        end
+        context(pdfsave())
+        context(pdfsetmatrix(rx,0,0,ry))
+        insert(stack,restore and { 1/rx, 0, 0, 1/ry } or true)
+    end
+end
+
+scanners.pdfstartmatrix = function() -- rx sx sy ry  -- tx, ty
+    local rx, sx, sy, ry = 1, 0, 0, 1
+    while true do
+            if scankeyword("rx") then rx = scannumber()
+        elseif scankeyword("ry") then ry = scannumber()
+        elseif scankeyword("sx") then sx = scannumber()
+        elseif scankeyword("sy") then sy = scannumber()
+        else   break end
+    end
+    if rx == 1 and sx == 0 and sy == 0 and ry == 1 then
+        insert(stack,false)
+    else
+        context(pdfsave())
+        context(pdfsetmatrix(rx,sx,sy,ry))
+        insert(stack,store and { -rx, -sx, -sy, -ry } or true)
+    end
+end
+
+local function pdfstopsomething()
+    local top = remove(stack)
+    if top == false then
+        -- not wrapped
+    elseif top == true then
+        context(pdfrestore())
+    elseif top then
+        context(pdfsetmatrix(unpack(top))) -- not really needed anymore
+        context(pdfrestore())
+    else
+        -- nesting error
+    end
+end
+
+scanners.pdfstoprotation = pdfstopsomething
+scanners.pdfstopscaling  = pdfstopsomething
+scanners.pdfstopmatrix   = pdfstopsomething
+
+scanners.pdfstartmirroring = function()
+    context(pdfsetmatrix(-1,0,0,1))
+end
+
+scanners.pdfstopmirroring = scanners.pdfstartmirroring