[MIRROR] Fix gas overlays (#10944)

Co-authored-by: ShadowLarkens <shadowlarkens@gmail.com>
Co-authored-by: Cameron Lennox <killer65311@gmail.com>

code/modules/xgm/xgm_gas_data.dm

@@ -1,4 +1,4 @@
-/var/datum/xgm_gas_data/gas_data
+GLOBAL_DATUM_INIT(gas_data, /datum/xgm_gas_data, new())
 
 /datum/xgm_gas_data
 	//Simple list of all the gas IDs.
@@ -16,6 +16,28 @@
 	//Flags.
 	var/list/flags = list()
 
+/datum/xgm_gas_data/New()
+	. = ..()
+	for(var/p in subtypesof(/decl/xgm_gas))
+		var/decl/xgm_gas/gas = new p //avoid initial() because of potential New() actions
+
+		if(gas.id in gases)
+			error("Duplicate gas id `[gas.id]` in `[p]`")
+
+		gases += gas.id
+		name[gas.id] = gas.name
+		specific_heat[gas.id] = gas.specific_heat
+		molar_mass[gas.id] = gas.molar_mass
+		if(gas.tile_overlay)
+			var/atom/movable/gas_visuals/GV = new(null)
+			GV.icon_state = gas.tile_overlay
+			tile_overlay[gas.id] = GV
+		if(gas.overlay_limit)
+			overlay_limit[gas.id] = gas.overlay_limit
+		flags[gas.id] = gas.flags
+
+	return 1
+
 /decl/xgm_gas
 	var/id = ""
 	var/name = "Unnamed Gas"
@@ -27,40 +49,7 @@
 
 	var/flags = 0
 
-/hook/startup/proc/generateGasData()
-	gas_data = new
-	for(var/p in subtypesof(/decl/xgm_gas))
-		var/decl/xgm_gas/gas = new p //avoid initial() because of potential New() actions
-
-		if(gas.id in gas_data.gases)
-			error("Duplicate gas id `[gas.id]` in `[p]`")
-
-		gas_data.gases += gas.id
-		gas_data.name[gas.id] = gas.name
-		gas_data.specific_heat[gas.id] = gas.specific_heat
-		gas_data.molar_mass[gas.id] = gas.molar_mass
-		if(gas.tile_overlay)
-			gas_data.tile_overlay[gas.id] = gas.tile_overlay // CHOMPEdit
-		if(gas.overlay_limit)
-			gas_data.overlay_limit[gas.id] = gas.overlay_limit
-		gas_data.flags[gas.id] = gas.flags
-
-	return 1
-
-// CHOMPEdit Start
-/obj/effect/gas_overlay
-	name = "gas"
-	desc = "You shouldn't be clicking this."
+/atom/movable/gas_visuals
 	icon = 'icons/effects/tile_effects.dmi'
-	icon_state = "generic"
-	layer = GASFIRE_LAYER
-	appearance_flags = PIXEL_SCALE | RESET_COLOR
 	mouse_opacity = 0
-	var/gas_id
-
-/obj/effect/gas_overlay/Initialize(mapload, gas)
-	. = ..()
-	gas_id = gas
-	if(gas_data.tile_overlay[gas_id])
-		icon_state = gas_data.tile_overlay[gas_id]
-// CHOMPEdit End
+	plane = ABOVE_MOB_PLANE

code/modules/xgm/xgm_gas_mixture.dm

@@ -13,9 +13,7 @@
 	var/group_multiplier = 1
 
 	//List of active tile overlays for this gas_mixture.  Updated by check_tile_graphic()
-	var/list/graphic = list() // CHOMPAdd
-
-	var/list/tile_overlay_cache	// COMPAdd
+	var/list/graphic
 
 /datum/gas_mixture/New(vol = CELL_VOLUME)
 	volume = vol
@@ -42,7 +40,7 @@
 
 	if(moles > 0 && abs(temperature - temp) > MINIMUM_TEMPERATURE_DELTA_TO_CONSIDER)
 		var/self_heat_capacity = heat_capacity()
-		var/giver_heat_capacity = gas_data.specific_heat[gasid] * moles
+		var/giver_heat_capacity = GLOB.gas_data.specific_heat[gasid] * moles
 		var/combined_heat_capacity = giver_heat_capacity + self_heat_capacity
 		if(combined_heat_capacity != 0)
 			temperature = (temp * giver_heat_capacity + temperature * self_heat_capacity) / combined_heat_capacity
@@ -129,7 +127,7 @@
 /datum/gas_mixture/proc/heat_capacity()
 	. = 0
 	for(var/g in gas)
-		. += gas_data.specific_heat[g] * gas[g]
+		. += GLOB.gas_data.specific_heat[g] * gas[g]
 	. *= group_multiplier
 
 
@@ -184,8 +182,8 @@
 		return SPECIFIC_ENTROPY_VACUUM	//that gas isn't here
 
 	//group_multiplier gets divided out in volume/gas[gasid] - also, V/(m*T) = R/(partial pressure)
-	var/molar_mass = gas_data.molar_mass[gasid]
-	var/specific_heat = gas_data.specific_heat[gasid]
+	var/molar_mass = GLOB.gas_data.molar_mass[gasid]
+	var/specific_heat = GLOB.gas_data.specific_heat[gasid]
 	return R_IDEAL_GAS_EQUATION * ( log( (IDEAL_GAS_ENTROPY_CONSTANT*volume/(gas[gasid] * temperature)) * (molar_mass*specific_heat*temperature)**(2/3) + 1 ) +  15 )
 
 	//alternative, simpler equation
@@ -265,13 +263,13 @@
 
 	var/sum = 0
 	for(var/g in gas)
-		if(gas_data.flags[g] & flag)
+		if(GLOB.gas_data.flags[g] & flag)
 			sum += gas[g]
 
 	var/datum/gas_mixture/removed = new
 
 	for(var/g in gas)
-		if(gas_data.flags[g] & flag)
+		if(GLOB.gas_data.flags[g] & flag)
 			removed.gas[g] = QUANTIZE((gas[g] / sum) * amount)
 			gas[g] -= removed.gas[g] / group_multiplier
 
@@ -285,7 +283,7 @@
 /datum/gas_mixture/proc/get_by_flag(flag)
 	. = 0
 	for(var/g in gas)
-		if(gas_data.flags[g] & flag)
+		if(GLOB.gas_data.flags[g] & flag)
 			. += gas[g]
 
 //Copies gas and temperature from another gas_mixture.
@@ -337,34 +335,20 @@
 	zburn(null, force_burn=0, no_check=0) //could probably just call zburn() here with no args but I like being explicit.
 
 
-// CHOMPEdit Start
 //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)
-	// var/list/cur_graphic = graphic // Cache for sanic speed
-
-	for(var/obj/effect/gas_overlay/O in graphic)
-		if(gas[O.gas_id] <= gas_data.overlay_limit[O.gas_id])
-			LAZYADD(graphic_remove, O)
-
-	for(var/g in gas_data.overlay_limit)
-/*
-		if(cur_graphic && cur_graphic.Find(gas_data.tile_overlay[g]))
+	var/list/cur_graphic = graphic // Cache for sanic speed
+	for(var/g in GLOB.gas_data.overlay_limit)
+		if(cur_graphic && cur_graphic.Find(GLOB.gas_data.tile_overlay[g]))
 			//Overlay is already applied for this gas, check if it's still valid.
-			if(gas[g] <= gas_data.overlay_limit[g])
-				LAZYADD(graphic_remove, gas_data.tile_overlay[g])
+			if(gas[g] <= GLOB.gas_data.overlay_limit[g])
+				LAZYADD(graphic_remove, GLOB.gas_data.tile_overlay[g])
 		else
 			//Overlay isn't applied for this gas, check if it's valid and needs to be added.
-			if(gas[g] > gas_data.overlay_limit[g])
-				LAZYADD(graphic_add, gas_data.tile_overlay[g])
-*/
-		if(gas[g] > gas_data.overlay_limit[g])
-			var/tile_overlay = get_tile_overlay(g)
-			if(!(tile_overlay in graphic))
-				LAZYADD(graphic_add, tile_overlay)
+			if(gas[g] > GLOB.gas_data.overlay_limit[g])
+				LAZYADD(graphic_add, GLOB.gas_data.tile_overlay[g])
 
-	. = FALSE
-/*
 	. = 0
 	//Apply changes
 	if(LAZYLEN(graphic_add))
@@ -373,14 +357,7 @@
 	if(LAZYLEN(graphic_remove))
 		LAZYREMOVE(graphic, graphic_remove)
 		. = 1
-*/
-	if(graphic_add && graphic_add.len)
-		graphic |= graphic_add
-		. = TRUE
-	if(graphic_remove && graphic_remove.len)
-		graphic -= graphic_remove
-		. = TRUE
-// CHOMPEdit End
+
 
 //Simpler version of merge(), adjusts gas amounts directly and doesn't account for temperature or group_multiplier.
 /datum/gas_mixture/proc/add(datum/gas_mixture/right_side)
@@ -399,12 +376,6 @@
 	update_values()
 	return 1
 
-// Gets the gas overlay for a given gas, and returns the appropriate overlay. Caches. - CHOMPADD
-/datum/gas_mixture/proc/get_tile_overlay(gas_id)
-	if(!LAZYACCESS(tile_overlay_cache, gas_id))
-		LAZYSET(tile_overlay_cache, gas_id, new/obj/effect/gas_overlay(null, gas_id))
-	return tile_overlay_cache[gas_id]
-
 
 //Multiply all gas amounts by a factor.
 /datum/gas_mixture/proc/multiply(factor)
@@ -518,4 +489,4 @@
 
 /datum/gas_mixture/proc/get_mass()
 	for(var/g in gas)
-		. += gas[g] * gas_data.molar_mass[g] * group_multiplier
+		. += gas[g] * GLOB.gas_data.molar_mass[g] * group_multiplier