photosynth component for traits and species (#17712)

code/datums/components/traits/photosynth.dm

@@ -0,0 +1,28 @@
+// If a mob has this component, every life tick it will gain nutrition if it's standing in light up to nutrition_max.
+// Extremely good tutorial component if you need an example with no special bells and whistles, and no "gotcha" behaviors.
+/datum/component/photosynth
+	var/mob/living/owner
+	var/nutrition_max = 1000
+
+/datum/component/photosynth/Initialize()
+	if(!isliving(parent))
+		return COMPONENT_INCOMPATIBLE
+	owner = parent
+	RegisterSignal(owner, COMSIG_LIVING_LIFE, PROC_REF(process_component))
+
+/datum/component/photosynth/proc/process_component()
+	if(QDELETED(parent))
+		return
+	if(owner.stat == DEAD)
+		return
+	if(!isturf(owner.loc))
+		return
+	if(owner.nutrition >= nutrition_max)
+		return
+	var/turf/T = owner.loc
+	owner.adjust_nutrition(T.get_lumcount() / 10)
+
+/datum/component/photosynth/Destroy(force = FALSE)
+	UnregisterSignal(owner, COMSIG_LIVING_LIFE)
+	owner = null
+	. = ..()