MonPropsMarker: set hash properties on monsters

A marker class which will take the monster on top of it, set any number
entries in that monster's props CrawslHashTable member, and then
disappear.

2 files changed, 51 insertions, 0 deletions

diff --git a/crawl-ref/source/dat/clua/lm_mon_prop.lua b/crawl-ref/source/dat/clua/lm_mon_prop.lua
new file mode 100644
index 0000000000..6bc3dd6de9
--- /dev/null
+++ b/crawl-ref/source/dat/clua/lm_mon_prop.lua
@@ -0,0 +1,50 @@
+------------------------------------------------------------------------------
+-- lm_mon_prop.lua:
+--
+-- This marker takes whatever monster is standing on it, sets properties in
+-- the CrawlHashTable member of that monster, then disappears.
+------------------------------------------------------------------------------
+
+MonPropsMarker = { CLASS = "MonPropsMarker" }
+MonPropsMarker.__index = MonPropsMarker
+
+function MonPropsMarker:new(props)
+  if not props then
+    error("MonPropsMarker:new() needs props")
+  end
+  if type(props) ~= "table" then
+    error("MonPropsMarker:new() needs type(props) == table")
+  end
+
+  local mp = { }
+  setmetatable(mp, self)
+  self.__index = self
+
+  mp.props = props
+
+  return mp
+end
+
+function MonPropsMarker:activate(marker)
+  local mon = dgn.mons_at(marker:pos())
+
+  if not mon then
+    crawl.mpr("No monster for MonPropsMarker:activate()")
+    dgn.remove_marker(marker)
+    return
+  end
+
+  for k, v in pairs(self.props) do
+    mon.set_prop(k, v)
+  end
+
+  dgn.remove_marker(marker)
+end
+
+function MonPropsMarker:write(marker, th)
+  error("MonPropsMarker should never be saved")
+end
+
+function MonPropsMarker:read(marker, th)
+  error("MonPropsMarker should never be in save file")
+end
diff --git a/crawl-ref/source/dat/clua/luamark.lua b/crawl-ref/source/dat/clua/luamark.lua
index bc99e10ebd..d8a07f2b71 100644
--- a/crawl-ref/source/dat/clua/luamark.lua
+++ b/crawl-ref/source/dat/clua/luamark.lua
@@ -11,6 +11,7 @@ require('clua/lm_timed.lua')
 require('clua/lm_flags.lua')
 require('clua/lm_fog.lua')
 require('clua/lm_props.lua')
+require('clua/lm_mon_prop.lua')
 require('clua/lm_monst.lua')
 require('clua/lm_mslav.lua')