crop.lua

local base = require("packages.base")

local package = pl.class(base)
package._name = "crop"

local mm = 2.83465
local bleed = 3 * mm
local trim = 10 * mm
local len

local outcounter, cropbinding

-- See https://github.com/sile-typesetter/sile/pull/1470#discussion_r964040477
function package.mirrorMaster (_, existing, new)
   if not SILE.scratch.masters[new] then
      SILE.scratch.masters[new] = { frames = {} }
   end
   if not SILE.scratch.masters[existing] then
      SU.error("Can't find master " .. existing)
   end
   for name, frame in pairs(SILE.scratch.masters[existing].frames) do
      local newframe = pl.tablex.deepcopy(frame)
      if frame:isAbsoluteConstraint("right") then
         newframe.constraints.left = "2 * left(page) + 100%pw-(" .. frame.constraints.right .. ")"
      end
      if frame:isAbsoluteConstraint("left") then
         newframe.constraints.right = "2 * left(page) + 100%pw-(" .. frame.constraints.left .. ")"
      end
      SILE.scratch.masters[new].frames[name] = newframe
      if frame == SILE.scratch.masters[existing].firstContentFrame then
         SILE.scratch.masters[new].firstContentFrame = newframe
      end
   end
end

function package._setupCrop (_, args)
   if args then
      bleed = args.bleed or bleed
      trim = args.trim or trim
   end
   len = trim - bleed
   local papersize = SILE.documentState.paperSize
   local w = papersize[1] + (trim * (cropbinding and 2 or 2))
   local h = papersize[2] + (trim * 2)
   SILE.documentState.paperSize = SILE.papersize(w .. "pt x " .. h .. "pt")
   local page = SILE.getFrame("page")
   page:constrain("left", trim)
   page:constrain("right", page.constraints.right + trim)
   page:constrain("top", trim)
   page:constrain("bottom", page.constraints.bottom + trim)
   page:invalidate()
   if SILE.typesetter and SILE.typesetter.frame then
      SILE.typesetter.frame:init()
   end
end

local function _outputCropMarks ()
   local page = SILE.getFrame("page")

   -- Top left
   SILE.outputter:drawRule(page:left() - bleed, page:top(), -len, 0.5)
   SILE.outputter:drawRule(page:left(), page:top() - bleed, 0.5, -len)

   -- Top  right
   SILE.outputter:drawRule(page:right() + bleed, page:top(), len, 0.5)
   SILE.outputter:drawRule(page:right(), page:top() - bleed, 0.5, -len)

   -- Bottom left
   SILE.outputter:drawRule(page:left() - bleed, page:bottom(), -len, 0.5)
   SILE.outputter:drawRule(page:left(), page:bottom() + bleed, 0.5, len)

   -- Bottom right
   SILE.outputter:drawRule(page:right() + bleed, page:bottom(), len, 0.5)
   SILE.outputter:drawRule(page:right(), page:bottom() + bleed, 0.5, len)

   local statelen = #SILE.typesetter.state.nodes
   local hbox = SILE.call("hbox", {}, function ()
      SILE.settings:temporarily(function ()
         SILE.call("noindent")
         SILE.call(
            "font",
            { family = "Libertinus Serif", size = bleed * 0.8, weight = 400, style = nil, features = nil }
         )
         SILE.call("crop:header")
      end)
   end)
   pl.tablex.clear(SILE.typesetter.state.nodes, statelen)

   SILE.typesetter.frame.state.cursorX = page:left() + bleed
   SILE.typesetter.frame.state.cursorY = page:top() - bleed - len / 2 + 2
   outcounter = outcounter + 1

   if hbox then
      for i = 1, #hbox.value do
         hbox.value[i]:outputYourself(SILE.typesetter, { ratio = 1 })
      end
   end
end

function package:_init (args)
   base._init(self, args)

   -- See https://github.com/sile-typesetter/sile/pull/1470#discussion_r964040477
   self:export("mirrorMaster", self.mirrorMaster)

   outcounter = 1
   cropbinding = self.class.options.binding == "stapled"
   self:_setupCrop(args)

   self.class:registerHook("endpage", _outputCropMarks)
end

function package:registerCommands ()
   self:registerCommand("crop:header", function (_, _)
      SILE.call("meta:surum")
      SILE.typesetter:typeset(" (" .. outcounter .. ") " .. os.getenv("HOSTNAME") .. " / " .. os.date("%Y-%m-%d, %X"))
   end)
end

return package