Gas overlay varied sprites

__DEFINES/gases.dm

@@ -7,3 +7,13 @@
 #define GAS_VOLATILE "volatile_fuel"
 #define GAS_OXAGENT  "oxygen_agent_b"
 #define GAS_RADON  "radon"
+
+#define SHOW_PLASMA   1
+#define SHOW_SLEEPING 2
+#define SHOW_CRYOTHEUM 4
+
+var/static/list/gas2show = list(
+		GAS_PLASMA = SHOW_PLASMA,
+		GAS_SLEEPING = SHOW_SLEEPING,
+		GAS_CRYOTHEUM = SHOW_CRYOTHEUM,
+	)

code/modules/ZAS/Turf.dm

@@ -1,16 +1,25 @@
-/turf/simulated/var/zone/zone
-/turf/simulated/var/open_directions
-
-/turf/var/needs_air_update = 0
-/turf/var/datum/gas_mixture/air
-
-/turf/var/tmp/list/connection/connections
-
-/turf/simulated/proc/update_graphic(list/graphic_add = null, list/graphic_remove = null)
-	if(graphic_add && graphic_add.len)
-		vis_contents += graphic_add
-	if(graphic_remove && graphic_remove.len)
-		vis_contents -= graphic_remove
+/turf/simulated
+	var/zone/zone
+	var/open_directions
+	var/gases_shown = 0
+
+/turf
+	var/needs_air_update = 0
+	var/datum/gas_mixture/air
+	var/tmp/list/connection/connections
+
+/turf/simulated/proc/update_graphic(graphic_add = 0, graphic_remove = 0)
+	if(graphic_add || graphic_remove)
+		if(graphic_add)
+			gases_shown |= graphic_add
+		if(graphic_remove)
+			gases_shown &= ~graphic_remove
+		for(var/gaslist in XGM.tile_overlay)
+			for(var/gas_overlay in XGM.tile_overlay[gaslist])
+				vis_contents -= gas_overlay
+		for(var/overlay in gas2show)
+			if(gases_shown & gas2show[overlay])
+				vis_contents += pick(XGM.tile_overlay[overlay])
 
 /turf/proc/update_air_properties()
 	var/block = c_airblock(src)

code/modules/ZAS/XGM.dm

@@ -46,7 +46,7 @@
 	specific_heat[gas.id] = gas.specific_heat
 	molar_mass[gas.id] = gas.molar_mass
 	flags[gas.id] = gas.flags
-	if(gas.tile_overlay)
+	if(gas.tile_overlay?.len)
 		tile_overlay[gas.id] = gas.tile_overlay
 	if(isnum(gas.overlay_limit))
 		overlay_limit[gas.id] = gas.overlay_limit

code/modules/ZAS/XGM_gases.dm

@@ -5,7 +5,7 @@
 	var/specific_heat = 20	// J/(mol*K)
 	var/molar_mass = 0.032	// kg/mol
 
-	var/tile_overlay = null //The overlay to draw over tiles containing this gas if it is visible. Can be anything that the overlays list will accept.
+	var/list/tile_overlay = null //The overlay to draw over tiles containing this gas if it is visible. Can be anything that the overlays list will accept.
 	var/overlay_limit = null //If the molar_density of this gas in a zone is strictly greater than this number, it is visible.
 
 	var/flags = 0
@@ -70,7 +70,11 @@
 	//and following a N/Z ratio of 1.5, the molar mass of a monatomic gas is:
 	molar_mass = 0.405	// kg/mol
 
-	tile_overlay = new /obj/effect/overlay/gas_overlay/plasma()
+	tile_overlay = newlist(
+			/obj/effect/overlay/gas_overlay/plasma,
+			/obj/effect/overlay/gas_overlay/plasma/two,
+			/obj/effect/overlay/gas_overlay/plasma/three
+		)
 	overlay_limit = MOLES_PLASMA_VISIBLE / CELL_VOLUME
 	flags = XGM_GAS_NOTEWORTHY | XGM_GAS_LOGGED
 
@@ -81,14 +85,24 @@
 	name = "plasma"
 	icon_state = "plasma"
 
+/obj/effect/overlay/gas_overlay/plasma/two
+	icon_state = "plasma2"
+
+/obj/effect/overlay/gas_overlay/plasma/three
+	icon_state = "plasma3"
+
 /datum/gas/sleeping_agent
 	id = GAS_SLEEPING
 	name = "Sleeping Agent"
 	short_name = "N<sub>2</sub>O"
 	specific_heat = 40	// J/(mol*K)
 	molar_mass = 0.044	// kg/mol. N₂O
 
-	tile_overlay = new /obj/effect/overlay/gas_overlay/sleeping_agent()
+	tile_overlay = newlist(
+			/obj/effect/overlay/gas_overlay/sleeping_agent,
+			/obj/effect/overlay/gas_overlay/sleeping_agent/two,
+			/obj/effect/overlay/gas_overlay/sleeping_agent/three
+		)
 	overlay_limit = 1 / CELL_VOLUME
 	flags = XGM_GAS_NOTEWORTHY | XGM_GAS_LOGGED
 
@@ -99,6 +113,12 @@
 	name = "sleeping agent"
 	icon_state = "sleeping_agent"
 
+/obj/effect/overlay/gas_overlay/sleeping_agent/two
+	icon_state = "sleeping_agent2"
+
+/obj/effect/overlay/gas_overlay/sleeping_agent/three
+	icon_state = "sleeping_agent3"
+
 /datum/gas/volatile_fuel
 	id = GAS_VOLATILE
 	name = "Volatile Fuel"
@@ -133,7 +153,14 @@
 
 	molar_mass = 0.032
 
-	tile_overlay = new /obj/effect/overlay/gas_overlay/cryotheum()
+	tile_overlay = newlist(
+			/obj/effect/overlay/gas_overlay/cryotheum,
+			/obj/effect/overlay/gas_overlay/cryotheum/two,
+			/obj/effect/overlay/gas_overlay/cryotheum/three,
+			/obj/effect/overlay/gas_overlay/cryotheum/four,
+			/obj/effect/overlay/gas_overlay/cryotheum/five,
+			/obj/effect/overlay/gas_overlay/cryotheum/six
+		)
 	overlay_limit = MOLES_CRYOTHEUM_VISIBLE / CELL_VOLUME
 	flags = XGM_GAS_NOTEWORTHY | XGM_GAS_LOGGED
 
@@ -144,6 +171,21 @@
 	name = "cryotheum"
 	icon_state = "cryotheum"
 
+/obj/effect/overlay/gas_overlay/cryotheum/two
+	icon_state = "cryotheum2"
+
+/obj/effect/overlay/gas_overlay/cryotheum/three
+	icon_state = "cryotheum3"
+
+/obj/effect/overlay/gas_overlay/cryotheum/four
+	icon_state = "cryotheum4"
+
+/obj/effect/overlay/gas_overlay/cryotheum/five
+	icon_state = "cryotheum5"
+
+/obj/effect/overlay/gas_overlay/cryotheum/six
+	icon_state = "cryotheum6"
+
 /datum/gas/radon
 	id = GAS_RADON
 	name = "Radon"

code/modules/ZAS/Zone.dm

@@ -49,8 +49,11 @@ Class Procs:
 	var/list/edges = list()
 	var/datum/gas_mixture/air = new
 
-	var/list/graphic_add = list()
-	var/list/graphic_remove = list()
+	//Flags of active tile overlays for this zone.  Updated by check_tile_graphic()
+	var/graphic = 0
+
+	var/graphic_add = 0
+	var/graphic_remove = 0
 
 	#ifdef ZAS_COLOR
 	var/turf_color
@@ -80,7 +83,7 @@ Class Procs:
 	air.merge(turf_air)
 	T.zone = src
 	contents += T
-	T.update_graphic(air.graphic)
+	T.update_graphic(graphic)
 	#ifdef ZAS_COLOR
 	T.color = turf_color
 	#endif
@@ -100,7 +103,7 @@ Class Procs:
 	air.volume -= turf_air.volume
 	air.update_values()
 	contents -= T
-	T.update_graphic(graphic_remove = air.graphic)
+	T.update_graphic(graphic_remove = graphic)
 	#ifdef ZAS_COLOR
 	T.color = null
 	#endif
@@ -117,7 +120,7 @@ Class Procs:
 #endif
 	c_invalidate()
 	for(var/turf/simulated/T in contents)
-		T.update_graphic(graphic_remove = air.graphic)
+		T.update_graphic(graphic_remove = graphic)
 		into.add(T)
 		#ifdef ZASDBG
 		T.dbg(merged)
@@ -145,7 +148,7 @@ Class Procs:
 		return //Short circuit for explosions where rebuild is called many times over.
 	c_invalidate()
 	for(var/turf/simulated/T in contents)
-		T.update_graphic(graphic_remove = air.graphic) //we need to remove the overlays so they're not doubled when the zone is rebuilt
+		T.update_graphic(graphic_remove = graphic) //we need to remove the overlays so they're not doubled when the zone is rebuilt
 		#ifdef ZAS_COLOR
 		T.color = null
 		#endif
@@ -171,16 +174,38 @@ Class Procs:
 /zone/proc/tick()
 	check_for_events()
 	air.reaction_tick()
-	if(air.check_tile_graphic(graphic_add, graphic_remove))
+	if(check_tile_graphic())
 		for(var/turf/simulated/T in contents)
 			T.update_graphic(graphic_add, graphic_remove)
-		graphic_add.len = 0
-		graphic_remove.len = 0
+		graphic_add = 0
+		graphic_remove = 0
 
 	for(var/connection_edge/E in edges)
 		if(E.sleeping)
 			E.recheck()
 
+//Rechecks the gas_mixture and adjusts the graphic list if needed.
+/zone/proc/check_tile_graphic()
+	for(var/g in XGM.overlay_limit)
+		if(g in gas2show)
+			if(graphic & gas2show[g])
+				//Overlay is already applied for this gas, check if it's still valid.
+				if(air.molar_density(g) <= XGM.overlay_limit[g])
+					graphic_remove |= gas2show[g]
+			else
+				//Overlay isn't applied for this gas, check if it's valid and needs to be added.
+				if(air.molar_density(g) > XGM.overlay_limit[g])
+					graphic_add |= gas2show[g]
+
+	. = 0
+	//Apply changes
+	if(graphic_add)
+		graphic |= graphic_add
+		. = 1
+	if(graphic_remove)
+		graphic &= ~graphic_remove
+		. = 1
+
 /zone/proc/dbg_data(mob/M)
 	to_chat(M, name)
 	to_chat(M, "O2: [air[GAS_OXYGEN]] N2: [air[GAS_NITROGEN]] CO2: [air[GAS_CARBON]] P: [air[GAS_PLASMA]]")

code/modules/ZAS/_gas_mixture.dm

@@ -17,9 +17,6 @@
 
 	var/temperature = 0 //in Kelvin
 
-	//List of active tile overlays for this gas_mixture.  Updated by check_tile_graphic()
-	var/list/graphic = list()
-
 	var/pressure = 0
 
 	var/tmp/fuel_burnt = 0
@@ -307,32 +304,6 @@
 //Procedures used for very specific events//
 ////////////////////////////////////////////
 
-//Rechecks the gas_mixture and adjusts the graphic list if needed.
-//Two lists can be passed by reference if you need know specifically which graphics were added and removed.
-/datum/gas_mixture/proc/check_tile_graphic(list/graphic_add = null, list/graphic_remove = null)
-	for(var/g in XGM.overlay_limit)
-		if(graphic.Find(XGM.tile_overlay[g]))
-			//Overlay is already applied for this gas, check if it's still valid.
-			if(molar_density(g) <= XGM.overlay_limit[g])
-				if(!graphic_remove)
-					graphic_remove = list()
-				graphic_remove += XGM.tile_overlay[g]
-		else
-			//Overlay isn't applied for this gas, check if it's valid and needs to be added.
-			if(molar_density(g) > XGM.overlay_limit[g])
-				if(!graphic_add)
-					graphic_add = list()
-				graphic_add += XGM.tile_overlay[g]
-
-	. = 0
-	//Apply changes
-	if(graphic_add && graphic_add.len)
-		graphic += graphic_add
-		. = 1
-	if(graphic_remove && graphic_remove.len)
-		graphic -= graphic_remove
-		. = 1
-
 /datum/gas_mixture/proc/react(atom/dump_location)
 	//Purpose: Calculating if it is possible for a fire to occur in the airmix
 	//Called by: Air mixes updating?