So. Some themes have objects that seem to be large natural extensions of the landscape. Masks allow maintaining that. Lemme know if it doesn't look good. If it doesn't, can still use for ice/bounce/indestructible. Indestructible bunker object for example.
/*
** $Id: ldebug.h,v 2.3.1.1 2007/12/27 13:02:25 roberto Exp $
** Auxiliary functions from Debug Interface module
** See Copyright Notice in lua.h
*/
#ifndef ldebug_h
#define ldebug_h
#include "lstate.h"
#define pcRel(pc, p) (cast(int, (pc) - (p)->code) - 1)
#define getline(f,pc) (((f)->lineinfo) ? (f)->lineinfo[pc] : 0)
#define resethookcount(L) (L->hookcount = L->basehookcount)
LUAI_FUNC void luaG_typeerror (lua_State *L, const TValue *o,
const char *opname);
LUAI_FUNC void luaG_concaterror (lua_State *L, StkId p1, StkId p2);
LUAI_FUNC void luaG_aritherror (lua_State *L, const TValue *p1,
const TValue *p2);
LUAI_FUNC int luaG_ordererror (lua_State *L, const TValue *p1,
const TValue *p2);
LUAI_FUNC void luaG_runerror (lua_State *L, const char *fmt, ...);
LUAI_FUNC void luaG_errormsg (lua_State *L);
LUAI_FUNC int luaG_checkcode (const Proto *pt);
LUAI_FUNC int luaG_checkopenop (Instruction i);
#endif