Merge pull request #6032 from Walter0o/low_pressure_fix

fixes #6005 and broken ancient human low/high pressure code.

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

@@ -33,6 +33,8 @@
 
 
 /mob/living/carbon/human/Life()
+
+
 	set invisibility = 0
 	set background = 1
 
@@ -128,38 +130,52 @@
 	for(var/obj/item/weapon/grab/G in src)
 		G.process()
 
+// Calculate how vulnerable the human is to under- and overpressure.
+// Returns 0 (equals 0 %) if sealed in an undamaged suit, 1 if unprotected (equals 100%).
+// Suitdamage can modifiy this in 10% steps.
+/mob/living/carbon/human/proc/get_pressure_weakness()
 
-//Much like get_heat_protection(), this returns a 0 - 1 value, which corresponds to the percentage of protection based on what you're wearing and what you're exposed to.
-/mob/living/carbon/human/proc/get_pressure_protection()
-	var/pressure_adjustment_coefficient = 1	//Determins how much the clothing you are wearing protects you in percent.
+	var/pressure_adjustment_coefficient = 1 // Assume no protection at first.
 
-	if(head && (head.flags & STOPSPRESSUREDMAGE))
-		pressure_adjustment_coefficient -= PRESSURE_HEAD_REDUCTION_COEFFICIENT
+	if(wear_suit && (wear_suit.flags & STOPSPRESSUREDMAGE) && head && (head.flags & STOPSPRESSUREDMAGE)) // Complete set of pressure-proof suit worn, assume fully sealed.
+		pressure_adjustment_coefficient = 0
 
-	if(wear_suit && (wear_suit.flags & STOPSPRESSUREDMAGE))
-		pressure_adjustment_coefficient -= PRESSURE_SUIT_REDUCTION_COEFFICIENT
-
-		//Handles breaches in your space suit. 10 suit damage equals a 100% loss of pressure reduction.
+		// Handles breaches in your space suit. 10 suit damage equals a 100% loss of pressure protection.
 		if(istype(wear_suit,/obj/item/clothing/suit/space))
 			var/obj/item/clothing/suit/space/S = wear_suit
 			if(S.can_breach && S.damage)
-				var/pressure_loss = S.damage * 0.1
-				pressure_adjustment_coefficient += pressure_loss
+				pressure_adjustment_coefficient += S.damage * 0.1
 
-	pressure_adjustment_coefficient = min(1,max(pressure_adjustment_coefficient,0)) //So it isn't less than 0 or larger than 1.
+	pressure_adjustment_coefficient = min(1,max(pressure_adjustment_coefficient,0)) // So it isn't less than 0 or larger than 1.
 
-	return 1 - pressure_adjustment_coefficient	//want 0 to be bad protection, 1 to be good protection
+	return pressure_adjustment_coefficient
 
+// Calculate how much of the enviroment pressure-difference affects the human.
 /mob/living/carbon/human/calculate_affecting_pressure(var/pressure)
-	..()
-	var/pressure_difference = abs( pressure - ONE_ATMOSPHERE )
+	var/pressure_difference
 
-	pressure_difference = pressure_difference * (1 - get_pressure_protection())
+	// First get the absolute pressure difference.
+	if(pressure < ONE_ATMOSPHERE) // We are in an underpressure.
+		pressure_difference = ONE_ATMOSPHERE - pressure
+
+	else //We are in an overpressure or standard atmosphere.
+		pressure_difference = pressure - ONE_ATMOSPHERE
+
+	if(pressure_difference < 5) // If the difference is small, don't bother calculating the fraction.
+		pressure_difference = 0
 
-	if(pressure > ONE_ATMOSPHERE)
-		return ONE_ATMOSPHERE + pressure_difference
 	else
+		// Otherwise calculate how much of that absolute pressure difference affects us, can be 0 to 1 (equals 0% to 100%).
+		// This is our relative difference.
+		pressure_difference *= get_pressure_weakness()
+
+	// The difference is always positive to avoid extra calculations.
+	// Apply the relative difference on a standard atmosphere to get the final result.
+	// The return value will be the adjusted_pressure of the human that is the basis of pressure warnings and damage.
+	if(pressure < ONE_ATMOSPHERE)
 		return ONE_ATMOSPHERE - pressure_difference
+	else
+		return ONE_ATMOSPHERE + pressure_difference
 
 /mob/living/carbon/human
 	proc/handle_disabilities()

code/modules/mob/living/carbon/monkey/life.dm

@@ -80,11 +80,6 @@
 			emote(pick("scratch","jump","roll","tail"))
 	updatehealth()
 
-
-/mob/living/carbon/monkey/calculate_affecting_pressure(var/pressure)
-	..()
-	return pressure
-
 /mob/living/carbon/monkey
 
 	proc/handle_disabilities()
@@ -401,9 +396,7 @@
 
 		//Moved these vars here for use in the fuck-it-skip-processing check.
 		var/pressure = environment.return_pressure()
-		var/adjusted_pressure = calculate_affecting_pressure(pressure) //Returns how much pressure actually affects the mob.
-
-		if(adjusted_pressure < WARNING_HIGH_PRESSURE && adjusted_pressure > WARNING_LOW_PRESSURE && abs(environment.temperature - 293.15) < 20 && abs(bodytemperature - 310.14) < 0.5 && environment.phoron < MOLES_PHORON_VISIBLE)
+		if(pressure < WARNING_HIGH_PRESSURE && pressure > WARNING_LOW_PRESSURE && abs(environment.temperature - 293.15) < 20 && abs(bodytemperature - 310.14) < 0.5 && environment.phoron < MOLES_PHORON_VISIBLE)
 
 			//Hopefully should fix the walk-inside-still-pressure-warning issue.
 			if(pressure_alert)
@@ -425,9 +418,9 @@
 			bodytemperature += 0.1*(environment.temperature - bodytemperature)*environment_heat_capacity/(environment_heat_capacity + 270000)
 
 		//Account for massive pressure differences
-		switch(adjusted_pressure)
+		switch(pressure)
 			if(HAZARD_HIGH_PRESSURE to INFINITY)
-				adjustBruteLoss( min( ( (adjusted_pressure / HAZARD_HIGH_PRESSURE) -1 )*PRESSURE_DAMAGE_COEFFICIENT , MAX_HIGH_PRESSURE_DAMAGE) )
+				adjustBruteLoss( min( ( (pressure / HAZARD_HIGH_PRESSURE) -1 )*PRESSURE_DAMAGE_COEFFICIENT , MAX_HIGH_PRESSURE_DAMAGE) )
 				pressure_alert = 2
 			if(WARNING_HIGH_PRESSURE to HAZARD_HIGH_PRESSURE)
 				pressure_alert = 1

code/modules/mob/living/living.dm

@@ -18,7 +18,7 @@
 //This proc is used for mobs which are affected by pressure to calculate the amount of pressure that actually
 //affects them once clothing is factored in. ~Errorage
 /mob/living/proc/calculate_affecting_pressure(var/pressure)
-	return 0
+	return
 
 
 //sort of a legacy burn method for /electrocute, /shock, and the e_chair