Adds shield generators.

Kinda WIP but it functions ATM.

code/modules/mob/_modifiers/modifiers.dm

@@ -64,6 +64,10 @@
 	var/siemens_coefficient = null		// Similar to above two vars but 0 = full protection, to be consistant with siemens numbers everywhere else.
 
 	var/vision_flags					// Vision flags to add to the mob. SEE_MOB, SEE_OBJ, etc.
+	var/energy_based					// Sees if the modifier is based on something electronic based.
+	var/energy_cost						// How much the modifier uses per action/special effect blocked. For base values.
+	var/energy_modifier					// How much energy is used when numbers are involed. For values, such as taking damage. Ex: (Damage*energy_modifier)
+	var/obj/item/weapon/cell/energy_source = null	// The source of the above.
 
 /datum/modifier/New(var/new_holder, var/new_origin)
 	holder = new_holder

code/modules/mob/_modifiers/modifiers_vr.dm

@@ -30,4 +30,70 @@
 		if(water_floor.depth < 1) //You're not in deep enough water anymore.
 			expire(silent = FALSE)
 	else
-		expire(silent = FALSE)
+		expire(silent = FALSE)
+
+
+
+
+
+
+
+
+
+/datum/modifier/shield_projection
+	name = "Shield Projection"
+	desc = "You are currently protected by a shield, rendering nigh impossible to hit you through conventional means."
+
+	on_created_text = "<span class='notice'>Your shield generator buzzes on.</span>"
+	on_expired_text = "<span class='warning'>Your shield generator buzzes off.</span>"
+	mob_overlay_state = "repel_missiles" 	//Looks alright, I guess. Placeholder.
+	stacks = MODIFIER_STACK_FORBID //No stacking shields. If you put one one your belt and backpack it won't work.
+
+	siemens_coefficient = 2 //Stun weapons drain 100% charge per damage. They're good at blocking lasers and bullets but not good at blocking stun beams!
+	incoming_brute_damage_percent = 0
+	incoming_fire_damage_percent = 0
+	incoming_hal_damage_percent = 0
+	energy_based = 1
+	energy_cost = 99999 //This is changed to the shield_genertor's energy_cost.
+	energy_modifier = 50 //This is how much battery is used per damage unit absorbed. Higher damage means higher charge use per damage absorbed. Changed below!
+	var/obj/item/device/personal_shield_generator/shield_generator //This is the shield generator you're wearing!
+
+
+/datum/modifier/shield_projection/on_applied()
+	return
+
+/datum/modifier/shield_projection/on_expire()
+	return
+
+/datum/modifier/shield_projection/check_if_valid() //Let's check to make sure you got the stuff and set the vars.
+	if(ishuman(holder)) //Only humans can use this!
+		var/mob/living/carbon/human/H = holder
+		if(istype(H.get_equipped_item(slot_back), /obj/item/device/personal_shield_generator))
+			shield_generator = H.get_equipped_item(slot_back) //Sets the var on the modifier that the shield gen is their back shield gen.
+			energy_source = shield_generator.bcell
+			energy_cost = shield_generator.generator_hit_cost
+			energy_modifier = shield_generator.energy_modifier
+		else if(istype(H.get_equipped_item(slot_belt), /obj/item/device/personal_shield_generator))
+			shield_generator = H.get_equipped_item(slot_belt) //No need for other checks. If they got hit by this, they just turned it on.
+			energy_source = shield_generator.bcell
+			energy_cost = shield_generator.generator_hit_cost
+			energy_modifier = shield_generator.energy_modifier
+		else if(istype(H.get_equipped_item(slot_s_store), /obj/item/device/personal_shield_generator) ) //Rigsuits.
+			shield_generator = H.get_equipped_item(slot_s_store)
+			energy_source = shield_generator.bcell
+			energy_cost = shield_generator.generator_hit_cost
+			energy_modifier = shield_generator.energy_modifier
+		else
+			expire(silent = TRUE)
+	else
+		expire(silent = TRUE)
+
+/datum/modifier/shield_projection/tick() //When the shield generator runs out of charge, it'll remove this naturally.
+	if(holder.stat == DEAD)
+		expire(silent = TRUE) //If you're dead the generator stops protecting you but keeps running.
+	if(!shield_generator || !shield_generator.slot_check()) //No shield to begin with/shield is not on them any longer.
+		expire(silent = FALSE)
+	var/shield_efficiency = 1-(energy_source.charge/energy_source.maxcharge) //0 = complete resistance. 1 = no resistance.
+	incoming_brute_damage_percent = shield_efficiency //Less charge means less resistance!
+	incoming_fire_damage_percent = shield_efficiency
+	incoming_hal_damage_percent = shield_efficiency