Polaris/code/game/turfs/turf.dm

/turf
	icon = 'icons/turf/floors.dmi'
	level = 1
	var/holy = 0

	// Initial air contents (in moles)
	var/oxygen = 0
	var/carbon_dioxide = 0
	var/nitrogen = 0
	var/phoron = 0

	//Properties for airtight tiles (/wall)
	var/thermal_conductivity = 0.05
	var/heat_capacity = 1

	//Properties for both
	var/temperature = T20C      // Initial turf temperature.
	var/blocks_air = 0          // Does this turf contain air/let air through?

	// General properties.
	var/icon_old = null
	var/pathweight = 1          // How much does it cost to pathfind over this turf?
	var/blessed = 0             // Has the turf been blessed?
	var/dynamic_lighting = 1    // Does the turf use dynamic lighting?

	var/list/decals

/turf/New()
	..()
	for(var/atom/movable/AM as mob|obj in src)
		spawn( 0 )
			src.Entered(AM)
			return
	turfs |= src

	if(dynamic_lighting)
		luminosity = 0
	else
		luminosity = 1

/turf/proc/update_icon()
	return

/turf/Destroy()
	turfs -= src
	..()

/turf/ex_act(severity)
	return 0

/turf/proc/is_space()
	return 0

/turf/proc/is_intact()
	return 0

/turf/attack_hand(mob/user)
	if(!(user.canmove) || user.restrained() || !(user.pulling))
		return 0
	if(user.pulling.anchored || !isturf(user.pulling.loc))
		return 0
	if(user.pulling.loc != user.loc && get_dist(user, user.pulling) > 1)
		return 0
	if(ismob(user.pulling))
		var/mob/M = user.pulling
		var/atom/movable/t = M.pulling
		M.stop_pulling()
		step(user.pulling, get_dir(user.pulling.loc, src))
		M.start_pulling(t)
	else
		step(user.pulling, get_dir(user.pulling.loc, src))
	return 1

/turf/Enter(atom/movable/mover as mob|obj, atom/forget as mob|obj|turf|area)
	if(movement_disabled && usr.ckey != movement_disabled_exception)
		usr << "<span class='warning'>Movement is admin-disabled.</span>" //This is to identify lag problems
		return

	..()

	if (!mover || !isturf(mover.loc))
		return 1

	//First, check objects to block exit that are not on the border
	for(var/obj/obstacle in mover.loc)
		if(!(obstacle.flags & ON_BORDER) && (mover != obstacle) && (forget != obstacle))
			if(!obstacle.CheckExit(mover, src))
				mover.Bump(obstacle, 1)
				return 0

	//Now, check objects to block exit that are on the border
	for(var/obj/border_obstacle in mover.loc)
		if((border_obstacle.flags & ON_BORDER) && (mover != border_obstacle) && (forget != border_obstacle))
			if(!border_obstacle.CheckExit(mover, src))
				mover.Bump(border_obstacle, 1)
				return 0

	//Next, check objects to block entry that are on the border
	for(var/obj/border_obstacle in src)
		if(border_obstacle.flags & ON_BORDER)
			if(!border_obstacle.CanPass(mover, mover.loc, 1, 0) && (forget != border_obstacle))
				mover.Bump(border_obstacle, 1)
				return 0

	//Then, check the turf itself
	if (!src.CanPass(mover, src))
		mover.Bump(src, 1)
		return 0

	//Finally, check objects/mobs to block entry that are not on the border
	for(var/atom/movable/obstacle in src)
		if(!(obstacle.flags & ON_BORDER))
			if(!obstacle.CanPass(mover, mover.loc, 1, 0) && (forget != obstacle))
				mover.Bump(obstacle, 1)
				return 0
	return 1 //Nothing found to block so return success!

var/const/enterloopsanity = 100
/turf/Entered(atom/atom as mob|obj)

	if(movement_disabled)
		usr << "<span class='warning'>Movement is admin-disabled.</span>" //This is to identify lag problems
		return
	..()

	if(!istype(atom, /atom/movable))
		return

	var/atom/movable/A = atom

	if(ismob(A))
		var/mob/M = A
		if(!M.lastarea)
			M.lastarea = get_area(M.loc)
		if(M.lastarea.has_gravity == 0)
			inertial_drift(M)
		else if(is_space())
			M.inertia_dir = 0
			M.make_floating(0)
	..()
	var/objects = 0
	if(A && (A.flags & PROXMOVE))
		for(var/atom/thing as mob|obj|turf|area in range(1))
			if(objects > enterloopsanity) break
			objects++
			spawn(0)
				A.HasProximity(thing, 1)
				if ((thing && A) && (thing.flags & PROXMOVE))
					thing.HasProximity(A, 1)
	return

/turf/proc/adjacent_fire_act(turf/simulated/floor/source, temperature, volume)
	return

/turf/proc/is_plating()
	return 0

/turf/proc/inertial_drift(atom/movable/A as mob|obj)
	if(!(A.last_move))	return
	if((istype(A, /mob/) && src.x > 2 && src.x < (world.maxx - 1) && src.y > 2 && src.y < (world.maxy-1)))
		var/mob/M = A
		if(M.Process_Spacemove(1))
			M.inertia_dir  = 0
			return
		spawn(5)
			if((M && !(M.anchored) && !(M.pulledby) && (M.loc == src)))
				if(M.inertia_dir)
					step(M, M.inertia_dir)
					return
				M.inertia_dir = M.last_move
				step(M, M.inertia_dir)
	return

/turf/proc/levelupdate()
	for(var/obj/O in src)
		O.hide(O.hides_under_flooring() && !is_plating())

/turf/proc/AdjacentTurfs()
	var/L[] = new()
	for(var/turf/simulated/t in oview(src,1))
		if(!t.density)
			if(!LinkBlocked(src, t) && !TurfBlockedNonWindow(t))
				L.Add(t)
	return L

/turf/proc/CardinalTurfs()
	var/L[] = new()
	for(var/turf/simulated/T in AdjacentTurfs())
		if(T.x == src.x || T.y == src.y)
			L.Add(T)
	return L

/turf/proc/Distance(turf/t)
	if(get_dist(src,t) == 1)
		var/cost = (src.x - t.x) * (src.x - t.x) + (src.y - t.y) * (src.y - t.y)
		cost *= (pathweight+t.pathweight)/2
		return cost
	else
		return get_dist(src,t)

/turf/proc/AdjacentTurfsSpace()
	var/L[] = new()
	for(var/turf/t in oview(src,1))
		if(!t.density)
			if(!LinkBlocked(src, t) && !TurfBlockedNonWindow(t))
				L.Add(t)
	return L

/turf/proc/process()
	return PROCESS_KILL

/turf/proc/contains_dense_objects()
	if(density)
		return 1
	for(var/atom/A in src)
		if(A.density && !(A.flags & ON_BORDER))
			return 1
	return 0