DFHack · lethosor · May 18, 2018 · May 16, 2018 · May 17, 2018 · May 17, 2018
diff --git a/bodyswap.lua b/bodyswap.lua
@@ -0,0 +1,142 @@
+-- Shifts player control over to another unit in adventure mode.
+-- author: Atomic Chicken
+-- based on "assumecontrol.lua" by maxthyme, as well as the defunct advtools plugin "adv-bodyswap"
+-- calls "modtools/create-unit" for nemesis and histfig creation
+
+--@ module = true
+
+local utils = require 'utils'
+validArgs = validArgs or utils.invert({
+'unit',
+'help'
+})
+local args = utils.processArgs({...}, validArgs)
+
+local usage = [====[
+
+bodyswap
+========
+This script allows the player to gain control over a new unit in adventurer mode
+whilst simultaneously loosing control over their current character.
+
+To specify the target unit, simply select it in the user interface,
+such as by opening the unit's status screen or viewing its description
+and enter "bodyswap" in the DFHack console.
+
+Alternatively, the target unit can be specified by its unit id as shown below.
+
+Arguments::
+
+    -unit id
+        replace "id" with the unit id of your target
+        example:
+            bodyswap -unit 42
+
+]====]
+
+if args.help then
+ print(usage)
+ return
+end
+
+if not dfhack.world.isAdventureMode() then
+  qerror("This script can only be used in adventure mode!")
+end
+
+function setNewAdvNemFlags(nem)
+  nem.flags.ACTIVE_ADVENTURER = true
+  nem.flags.RETIRED_ADVENTURER = false
+  nem.flags.ADVENTURER = true
+end
+function setOldAdvNemFlags(nem)
+  nem.flags.ACTIVE_ADVENTURER = false
+  nem.flags.RETIRED_ADVENTURER = true
+  nem.unit.idle_area.x = nem.unit.pos.x
+  nem.unit.idle_area.y = nem.unit.pos.y
+  nem.unit.idle_area.z = nem.unit.pos.z
+end
+
+function clearNemesisFromLinkedSites(nem)
+-- this is a workaround for a bug which tends to cause duplication of the unit entry in df.global.world.units.active when the site to which a historical figure is linked is reloaded with the unit present
+-- appears to fix the problem without causing any noticeable issues
+  if not nem.figure then
+    return
+  end
+  for _,link in ipairs(nem.figure.site_links) do
+    local site = df.world_site.find(link.site)
+    for i = #site.unk_1.nemesis-1,0,-1 do
+      if site.unk_1.nemesis[i] == nem.id then
+        site.unk_1.nemesis:erase(i)
+      end
+    end
+  end
+end
+
+function createNemesis(unit)
+  local nemesis = reqscript('modtools/create-unit').createNemesis(unit,unit.civ_id)
+  nemesis.figure.flags.never_cull = true
+  return nemesis
+end
+
+function swapAdvUnit(newUnit)
+
+  if not newUnit then
+    qerror('Target unit not specified!')
+  end
+
+  local oldUnit = df.nemesis_record.find(df.global.ui_advmode.player_id).unit
+  if newUnit == oldUnit then
+    return
+  end
+
+  local activeUnits = df.global.world.units.active
+  local oldUnitIndex
+  if activeUnits[0] == oldUnit then
+    oldUnitIndex = 0
+  else -- unlikely; this is just in case
+    for i,u in pairs(activeUnits) do
+      if u == oldUnit then
+        oldUnitIndex = i
+        break
+      end
+    end
+  end
+  local newUnitIndex
+  for i,u in pairs(activeUnits) do
+    if u == newUnit then
+      newUnitIndex = i
+      break
+    end
+  end
+
+  if not newUnitIndex then
+    qerror("Target unit index not found!")
+  end
+
+  activeUnits[newUnitIndex] = oldUnit
+  activeUnits[oldUnitIndex] = newUnit
+
+  local newNem = dfhack.units.getNemesis(newUnit) or createNemesis(newUnit)
+  if newNem then
+    local oldNem = dfhack.units.getNemesis(oldUnit)
+    if oldNem then
+      setOldAdvNemFlags(oldNem)
+    end
+    setNewAdvNemFlags(newNem)
+    clearNemesisFromLinkedSites(newNem)
+    df.global.ui_advmode.player_id = newNem.id
+  end
+end
+
+if not dfhack_flags.module then
+  local unit = args.unit and df.unit.find(tonumber(args.unit)) or dfhack.gui.getSelectedUnit()
+  if not unit then
+    print("Enter the following if you require assistance: bodyswap -help")
+    if args.unit then
+      qerror("Invalid unit id: "..args.unit)
+    else
+      qerror("Target unit not specified!")
+    end
+  end
+  swapAdvUnit(unit)
+end