Footstep sounds

This adds a system for footstep sounds
 - Only xenomorphs and humans currently use it, could expand to robutts
   and simple_animals easily, but haven't.
 - Only enabled for three turf types currently:
  - Plating (ala Maintnance)
  - Carpets
  - Wooden floors

code/game/turfs/simulated/floor.dm

@@ -115,6 +115,12 @@ var/list/wood_icons = list("wood","wood-broken")
 	else if(is_plating())
 		if(!broken && !burnt)
 			icon_state = icon_plating //Because asteroids are 'platings' too.
+
+			footstep_sounds = list(
+				"human" = list('sound/effects/footstep/plating_human.ogg'),
+				"xeno"  = list('sound/effects/footstep/plating_xeno.ogg')
+			)
+
 	else if(is_light_floor())
 		var/obj/item/stack/tile/light/T = floor_tile
 		if(T.on)
@@ -193,11 +199,20 @@ var/list/wood_icons = list("wood","wood-broken")
 
 				icon_state = "carpet[connectdir]-[diagonalconnect]"
 
+				footstep_sounds = list(
+					"human" = list('sound/effects/footstep/carpet_human.ogg'),
+					"xeno"  = list('sound/effects/footstep/carpet_xeno.ogg')
+				)
+
 	else if(is_wood_floor())
 		if(!broken && !burnt)
 			if( !(icon_state in wood_icons) )
 				icon_state = "wood"
-				//world << "[icon_state]y's got [icon_state]"
+
+				footstep_sounds = list(
+					"human" = list('sound/effects/footstep/wood_all.ogg'), //@RonaldVanWonderen of Freesound.org
+					"xeno"  = list('sound/effects/footstep/wood_all.ogg')  //@RonaldVanWonderen of Freesound.org
+				)
 
 
 /turf/simulated/floor/return_siding_icon_state()

code/game/turfs/simulated/floor_types.dm

@@ -31,6 +31,11 @@
 	icon_state = "wood"
 	floor_tile = new/obj/item/stack/tile/wood
 
+	footstep_sounds = list(
+		"human" = list('sound/effects/footstep/wood_all.ogg'), //@RonaldVanWonderen of Freesound.org
+		"xeno"  = list('sound/effects/footstep/wood_all.ogg')  //@RonaldVanWonderen of Freesound.org
+	)
+
 /turf/simulated/floor/vault
 	icon_state = "rockvault"
 
@@ -131,6 +136,11 @@
 	floor_tile = null
 	intact = 0
 
+	footstep_sounds = list(
+	"human" = list('sound/effects/footstep/plating_human.ogg'),
+	"xeno"  = list('sound/effects/footstep/plating_xeno.ogg')
+	)
+
 /turf/simulated/floor/plating/airless
 	icon_state = "plating"
 	name = "airless plating"
@@ -246,6 +256,11 @@
 	icon_state = "carpet"
 	floor_tile = new/obj/item/stack/tile/carpet
 
+	footstep_sounds = list(
+		"human" = list('sound/effects/footstep/carpet_human.ogg'),
+		"xeno"  = list('sound/effects/footstep/carpet_xeno.ogg')
+	)
+
 	New()
 		floor_tile.New() //I guess New() isn't ran on objects spawned without the definition of a turf to house them, ah well.
 		if(!icon_state)

code/game/turfs/turf.dm

@@ -29,6 +29,8 @@
 
 	var/image/obscured	//camerachunks
 
+	var/list/footstep_sounds = list()
+
 /turf/New()
 	..()
 	for(var/atom/movable/AM in src)

code/modules/mob/living/carbon/alien/alien.dm

@@ -295,3 +295,16 @@ Des: Removes all infected images from the alien.
 #undef HEAT_DAMAGE_LEVEL_1
 #undef HEAT_DAMAGE_LEVEL_2
 #undef HEAT_DAMAGE_LEVEL_3
+
+/mob/living/carbon/alien/handle_footstep(turf/T)
+	if(..())
+		if(T.footstep_sounds["xeno"])
+			var/S = pick(T.footstep_sounds["xeno"])
+			if(S)
+				if(m_intent == "run")
+					if(!(step_count % 2)) //every other turf makes a sound
+						return 0
+				if(leaping)
+					return 0
+				playsound(T, S, 6, 1, -(world.view/2)) //xenos are quiet fuckers
+	return 0

code/modules/mob/living/carbon/human/human_movement.dm

@@ -81,4 +81,22 @@
 			if(!has_gravity(loc))
 				return
 			var/obj/item/clothing/shoes/S = shoes
-			S.step_action(src)
+			S.step_action(src)
+
+/mob/living/carbon/human/handle_footstep(turf/T)
+	if(..())
+		if(T.footstep_sounds["human"])
+			var/S = pick(T.footstep_sounds["human"])
+			if(S)
+				if(m_intent == "run")
+					if(!(step_count % 2)) //every other turf makes a sound
+						return 0
+				playsound(T, S, shoes ? 15 : 7, 1, shoes ? 0 : -(world.view/2))
+					//this looks insane but it actually is quite simple
+					//play sound at turf T, using sound S
+					//volume = 15 w/ shoes, volume = 7 w/o shoes
+					//do use vary
+					//add negative world.view/2 if not wearing shoes
+				return 1
+
+	return 0

code/modules/mob/living/living.dm

@@ -492,10 +492,18 @@
 	if (s_active && !( s_active in contents ) && get_turf(s_active) != get_turf(src))	//check !( s_active in contents ) first so we hopefully don't have to call get_turf() so much.
 		s_active.close(src)
 
+	handle_footstep(loc)
+	step_count++
+
 	if(update_slimes)
 		for(var/mob/living/carbon/slime/M in view(1,src))
 			M.UpdateFeed(src)
 
+/mob/living/proc/handle_footstep(turf/T)
+	if(istype(T))
+		return 1
+	return 0
+
 /*//////////////////////
 	START RESIST PROCS
 *///////////////////////

code/modules/mob/living/living_defines.dm

@@ -51,4 +51,5 @@
 	var/list/icon/pipes_shown = list()
 	var/last_played_vent
 
-	var/list/datum/action/actions = list()
+	var/list/datum/action/actions = list()
+	var/step_count = 0