[MIRROR] Freon Cold Fire [MDB IGNORE] (#12773)

* Freon Cold Fire (#65392)

Adds the visual effect of fire to freon burn reaction.
Freon burn reaction now produces coldspots and cold cyan fires

* Freon Cold Fire

Co-authored-by: Ghilker <42839747+Ghilker@users.noreply.github.com>

code/__DEFINES/atmospherics/atmos_core.dm

@@ -138,6 +138,9 @@
 ///Helper for small fires to grow
 #define FIRE_GROWTH_RATE 40000
 
+///Multiplier for the temperature shared to other turfs
+#define COLD_FIRE_SPREAD_RADIOSITY_SCALE 0.95
+
 ///moles in a 2.5 m^3 cell at 101.325 Pa and 20 degC (103 or so)
 #define MOLES_CELLSTANDARD (ONE_ATMOSPHERE*CELL_VOLUME/(T20C*R_IDEAL_GAS_EQUATION))
 ///compared against for superconductivity

code/__DEFINES/reactions.dm

@@ -96,8 +96,10 @@
 // - Freon:
 /// The maximum temperature freon can combust at.
 #define FREON_MAXIMUM_BURN_TEMPERATURE 283
-/// The minimum temperature freon can combust at.
+///Minimum temperature allowed for the burn to go at max speed, we would have negative pressure otherwise
 #define FREON_LOWER_TEMPERATURE 60
+///Terminal temperature after wich we stop the reaction
+#define FREON_TERMINAL_TEMPERATURE 20
 /// Multiplier for freonfire with O2 moles * FREON_OXYGEN_FULLBURN for the maximum fuel consumption
 #define FREON_OXYGEN_FULLBURN 10
 /// The maximum fraction of the freon in a mix that can combust each reaction tick.

code/modules/atmospherics/environmental/LINDA_fire.dm

@@ -41,6 +41,8 @@
 	var/trit = . ? .[MOLES] : 0
 	. = air_gases[/datum/gas/hydrogen]
 	var/h2 = . ? .[MOLES] : 0
+	. = air_gases[/datum/gas/freon]
+	var/freon = . ? .[MOLES] : 0
 	if(active_hotspot)
 		if(soh)
 			if(plas > 0.5 || trit > 0.5 || h2 > 0.5)
@@ -48,9 +50,15 @@
 					active_hotspot.temperature = exposed_temperature
 				if(active_hotspot.volume < exposed_volume)
 					active_hotspot.volume = exposed_volume
+			else if(freon > 0.5)
+				if(active_hotspot.temperature > exposed_temperature)
+					active_hotspot.temperature = exposed_temperature
+				if(active_hotspot.volume < exposed_volume)
+					active_hotspot.volume = exposed_volume
 		return
 
-	if((exposed_temperature > FIRE_MINIMUM_TEMPERATURE_TO_EXIST) && (plas > 0.5 || trit > 0.5 || h2 > 0.5))
+	if(((exposed_temperature > PLASMA_MINIMUM_BURN_TEMPERATURE) && (plas > 0.5 || trit > 0.5 || h2 > 0.5)) || \
+		((exposed_temperature < FREON_MAXIMUM_BURN_TEMPERATURE) && (freon > 0.5)))
 
 		active_hotspot = new /obj/effect/hotspot(src, exposed_volume*25, exposed_temperature)
 
@@ -58,7 +66,6 @@
 			//remove just_spawned protection if no longer processing this cell
 		SSair.add_to_active(src)
 
-
 /**
  * Hotspot objects interfaces with the temperature of turf gasmixtures while also providing visual effects.
  * One important thing to note about hotspots are that they can roughly be divided into two categories based on the bypassing variable.
@@ -89,6 +96,8 @@
 	/// Whether the hotspot becomes passive and follows the gasmix temp instead of changing it.
 	var/bypassing = FALSE
 	var/visual_update_tick = 0
+	///Are we burning freon?
+	var/cold_fire = FALSE
 
 
 /obj/effect/hotspot/Initialize(mapload, starting_volume, starting_temperature)
@@ -130,7 +139,7 @@
 	bypassing = !just_spawned && (volume > CELL_VOLUME*0.95)
 
 	//Passive mode
-	if(bypassing)
+	if(bypassing || cold_fire)
 		reference = location.air // Our color and volume will depend on the turf's gasmix
 	//Active mode
 	else
@@ -150,6 +159,8 @@
 		temperature = reference.temperature
 
 	// Handles the burning of atoms.
+	if(cold_fire)
+		return
 	for(var/A in location)
 		var/atom/AT = A
 		if(!QDELETED(AT) && AT != src)
@@ -171,7 +182,12 @@
 	var/heat_a = 255
 	var/greyscale_fire = 1 //This determines how greyscaled the fire is.
 
-	if(temperature < 5000) //This is where fire is very orange, we turn it into the normal fire texture here.
+	if(cold_fire)
+		heat_r = 0
+		heat_g = LERP(255, temperature, 1.2)
+		heat_b = LERP(255, temperature, 0.9)
+		heat_a = 100
+	else if(temperature < 5000) //This is where fire is very orange, we turn it into the normal fire texture here.
 		var/normal_amt = gauss_lerp(temperature, 1000, 3000)
 		heat_r = LERP(heat_r,255,normal_amt)
 		heat_g = LERP(heat_g,255,normal_amt)
@@ -237,12 +253,16 @@
 	if(location.excited_group)
 		location.excited_group.reset_cooldowns()
 
-	if((temperature < FIRE_MINIMUM_TEMPERATURE_TO_EXIST) || (volume <= 1))
+	cold_fire = FALSE
+	if(temperature <= FREON_MAXIMUM_BURN_TEMPERATURE)
+		cold_fire = TRUE
+
+	if((temperature < FIRE_MINIMUM_TEMPERATURE_TO_EXIST && !cold_fire) || (volume <= 1))
 		qdel(src)
 		return
 
 	//Not enough / nothing to burn
-	if(!location.air || (INSUFFICIENT(/datum/gas/plasma) && INSUFFICIENT(/datum/gas/tritium) && INSUFFICIENT(/datum/gas/hydrogen)) || INSUFFICIENT(/datum/gas/oxygen))
+	if(!location.air || (INSUFFICIENT(/datum/gas/plasma) && INSUFFICIENT(/datum/gas/tritium) && INSUFFICIENT(/datum/gas/hydrogen) && INSUFFICIENT(/datum/gas/freon)) || INSUFFICIENT(/datum/gas/oxygen))
 		qdel(src)
 		return
 
@@ -250,11 +270,14 @@
 
 	if(bypassing)
 		icon_state = "3"
-		location.burn_tile()
+		if(!cold_fire)
+			location.burn_tile()
 
 		//Possible spread due to radiated heat.
-		if(location.air.temperature > FIRE_MINIMUM_TEMPERATURE_TO_SPREAD)
+		if(location.air.temperature > FIRE_MINIMUM_TEMPERATURE_TO_SPREAD || cold_fire)
 			var/radiated_temperature = location.air.temperature*FIRE_SPREAD_RADIOSITY_SCALE
+			if(cold_fire)
+				radiated_temperature = location.air.temperature * COLD_FIRE_SPREAD_RADIOSITY_SCALE
 			for(var/t in location.atmos_adjacent_turfs)
 				var/turf/open/T = t
 				if(!T.active_hotspot)
@@ -280,7 +303,7 @@
 
 /obj/effect/hotspot/proc/on_entered(datum/source, atom/movable/arrived, atom/old_loc, list/atom/old_locs)
 	SIGNAL_HANDLER
-	if(isliving(arrived))
+	if(isliving(arrived) && !cold_fire)
 		var/mob/living/immolated = arrived
 		immolated.fire_act(temperature, volume)
 

code/modules/atmospherics/gasmixtures/reactions.dm

@@ -58,12 +58,12 @@
 	/// A short string describing this reaction.
 	var/desc
 	/** REACTION FACTORS
-	 * 
+	 *
 	 * Describe (to a human) factors influencing this reaction in an assoc list format.
 	 * Also include gases formed by the reaction
 	 * Implement various interaction for different keys under subsystem/air/proc/atmos_handbook_init()
-	 * 
-	 * E.G. 
+	 *
+	 * E.G.
 	 * factor["Temperature"] = "Minimum temperature of 20 kelvins, maximum temperature of 100 kelvins"
 	 * factor["o2"] = "Minimum oxygen amount of 20 moles, more oxygen increases reaction rate up to 150 moles"
 	 */
@@ -379,13 +379,14 @@
 	priority_group = PRIORITY_FIRE
 	name = "Freon Combustion"
 	id = "freonfire"
+	expands_hotspot = TRUE
 	desc = "Reaction between oxygen and freon that consumes a huge amount of energy and can cool things significantly. Also able to produce hot ice."
 
 /datum/gas_reaction/freonfire/init_reqs()
 	requirements = list(
 		/datum/gas/oxygen = MINIMUM_MOLE_COUNT,
 		/datum/gas/freon = MINIMUM_MOLE_COUNT,
-		"MIN_TEMP" = FREON_LOWER_TEMPERATURE,
+		"MIN_TEMP" = FREON_TERMINAL_TEMPERATURE,
 		"MAX_TEMP" = FREON_MAXIMUM_BURN_TEMPERATURE,
 	)
 
@@ -395,10 +396,12 @@
 
 	var/temperature = air.temperature
 	var/temperature_scale
-	if(temperature < FREON_LOWER_TEMPERATURE) //stop the reaction when too cold
+	if(temperature < FREON_TERMINAL_TEMPERATURE) //stop the reaction when too cold
 		temperature_scale = 0
+	else if(temperature < FREON_LOWER_TEMPERATURE)
+		temperature_scale = 0.5
 	else
-		temperature_scale = (FREON_MAXIMUM_BURN_TEMPERATURE - temperature) / (FREON_MAXIMUM_BURN_TEMPERATURE - FREON_LOWER_TEMPERATURE) //calculate the scale based on the temperature
+		temperature_scale = (FREON_MAXIMUM_BURN_TEMPERATURE - temperature) / (FREON_MAXIMUM_BURN_TEMPERATURE - FREON_TERMINAL_TEMPERATURE) //calculate the scale based on the temperature
 	if (temperature_scale <= 0)
 		return NO_REACTION
 
@@ -427,7 +430,13 @@
 	var/energy_consumed = FIRE_FREON_ENERGY_CONSUMED * freon_burn_rate
 	var/new_heat_capacity = air.heat_capacity()
 	if(new_heat_capacity > MINIMUM_HEAT_CAPACITY)
-		air.temperature = (temperature * old_heat_capacity - energy_consumed) / new_heat_capacity
+		air.temperature = max((temperature * old_heat_capacity - energy_consumed) / new_heat_capacity, TCMB)
+
+	var/turf/open/location = holder
+	if(istype(location))
+		temperature = air.temperature
+		if(temperature < FREON_MAXIMUM_BURN_TEMPERATURE)
+			location.hotspot_expose(temperature, CELL_VOLUME)
 
 	return REACTING
 
@@ -544,7 +553,7 @@
 	var/list/cached_gases = air.gases
 	var/pressure = air.return_pressure()
 	// This slows down in relation to pressure, very quickly. Please don't expect it to be anything more then a snail
-	
+
 	// Bigger is better for these two values.
 	var/pressure_efficiency = (0.1 * ONE_ATMOSPHERE) / pressure // More pressure = more bad
 	var/ratio_efficiency = min(cached_gases[/datum/gas/nitrous_oxide][MOLES] / cached_gases[/datum/gas/plasma][MOLES], 1) // Malus to production if more plasma than n2o.