+core.registered_on_player_hpchanges = { modifiers = { }, loggers = { } }
+
+function core.registered_on_player_hpchange(player, hp_change)
+ local last = false
+ for i = #core.registered_on_player_hpchanges.modifiers, 1, -1 do
+ local func = core.registered_on_player_hpchanges.modifiers[i]
+ hp_change, last = func(player, hp_change)
+ if type(hp_change) ~= "number" then
+ local debuginfo = debug.getinfo(func)
+ error("The register_on_hp_changes function has to return a number at " ..
+ debuginfo.short_src .. " line " .. debuginfo.linedefined)
+ end
+ if last then
+ break
+ end
+ end
+ for i, func in ipairs(core.registered_on_player_hpchanges.loggers) do
+ func(player, hp_change)
+ end
+ return hp_change
+end
+
+function core.register_on_player_hpchange(func, modifier)
+ if modifier then
+ table.insert(core.registered_on_player_hpchanges.modifiers, func)
+ else
+ table.insert(core.registered_on_player_hpchanges.loggers, func)
+ end
+ core.callback_origins[func] = {
+ mod = core.get_current_modname() or "??",
+ name = debug.getinfo(1, "n").name or "??"
+ }
+end
+