implimentation (#17713)

code/datums/components/traits/nutrition_size_change.dm

@@ -0,0 +1,54 @@
+#define GROWMODE_SHRINK 1
+#define GROWMODE_GROW 2
+
+/datum/component/nutrition_size_change
+	var/mob/living/owner
+	var/grow_mode = 0 // Don't use base component
+
+/datum/component/nutrition_size_change/growing
+	grow_mode = GROWMODE_GROW
+
+/datum/component/nutrition_size_change/shrinking
+	grow_mode = GROWMODE_SHRINK
+
+/datum/component/nutrition_size_change/Initialize()
+	if(!isliving(parent))
+		return COMPONENT_INCOMPATIBLE
+	owner = parent
+	RegisterSignal(owner, COMSIG_LIVING_LIFE, PROC_REF(process_component))
+
+/datum/component/nutrition_size_change/proc/process_component()
+	if(QDELETED(parent))
+		return
+	if(owner.stat == DEAD)
+		return
+	if(owner.nutrition <= 0 && grow_mode == GROWMODE_SHRINK && owner.size_multiplier > RESIZE_TINY)
+		owner.nutrition = 0.1
+	if(owner.nutrition <= 0)
+		return
+	// Species controls hunger rate for humans, otherwise use defaults
+	var/nutrition_reduction = DEFAULT_HUNGER_FACTOR
+	if(ishuman(owner))
+		var/mob/living/carbon/human/H = owner
+		nutrition_reduction = H.species.hunger_factor
+	// Modifiers can increase or decrease nutrition cost
+	for(var/datum/modifier/mod in owner.modifiers)
+		if(!isnull(mod.metabolism_percent))
+			nutrition_reduction *= mod.metabolism_percent
+	// Time to change size!
+	if(owner.nutrition > 1000 && grow_mode == GROWMODE_GROW) //Removing the strict check against normal max/min size to support dorms/VR oversizing
+		nutrition_reduction *= 5
+		owner.resize(owner.size_multiplier+0.01, animate = FALSE, uncapped = owner.has_large_resize_bounds()) //Bringing this code in line with micro and macro shrooms
+	if(owner.nutrition < 50 && grow_mode == GROWMODE_SHRINK)
+		nutrition_reduction *= 0.3
+		owner.resize(owner.size_multiplier-0.01, animate = FALSE, uncapped = owner.has_large_resize_bounds()) //Bringing this code in line with micro and macro shrooms
+	// Apply hunger costs
+	owner.adjust_nutrition(-nutrition_reduction)
+
+/datum/component/nutrition_size_change/Destroy(force = FALSE)
+	UnregisterSignal(owner, COMSIG_LIVING_LIFE)
+	owner = null
+	. = ..()
+
+#undef GROWMODE_SHRINK
+#undef GROWMODE_GROW