Polaris/code/game/objects/items/weapons/shields.dm

//** Shield Helpers
//These are shared by various items that have shield-like behaviour

//bad_arc is the ABSOLUTE arc of directions from which we cannot block. If you want to fix it to e.g. the user's facing you will need to rotate the dirs yourself.
/proc/check_shield_arc(mob/user, var/bad_arc, atom/damage_source = null, mob/attacker = null)
	//check attack direction
	var/attack_dir = 0 //direction from the user to the source of the attack
	if(istype(damage_source, /obj/item/projectile))
		var/obj/item/projectile/P = damage_source
		attack_dir = get_dir(get_turf(user), P.starting)
	else if(attacker)
		attack_dir = get_dir(get_turf(user), get_turf(attacker))
	else if(damage_source)
		attack_dir = get_dir(get_turf(user), get_turf(damage_source))

	if(!(attack_dir && (attack_dir & bad_arc)))
		return 1
	return 0

/proc/default_parry_check(mob/user, mob/attacker, atom/damage_source)
	//parry only melee attacks
	if(istype(damage_source, /obj/item/projectile) || (attacker && get_dist(user, attacker) > 1) || user.incapacitated())
		return 0

	//block as long as they are not directly behind us
	var/bad_arc = reverse_direction(user.dir) //arc of directions from which we cannot block
	if(!check_shield_arc(user, bad_arc, damage_source, attacker))
		return 0

	return 1

/obj/item/weapon/shield
	name = "shield"
	var/base_block_chance = 50
	item_icons = list(
				slot_l_hand_str = 'icons/mob/items/lefthand_melee.dmi',
				slot_r_hand_str = 'icons/mob/items/righthand_melee.dmi',
				)

/obj/item/weapon/shield/handle_shield(mob/user, var/damage, atom/damage_source = null, mob/attacker = null, var/def_zone = null, var/attack_text = "the attack")
	if(user.incapacitated())
		return 0

	//block as long as they are not directly behind us
	var/bad_arc = reverse_direction(user.dir) //arc of directions from which we cannot block
	if(check_shield_arc(user, bad_arc, damage_source, attacker))
		if(prob(get_block_chance(user, damage, damage_source, attacker)))
			user.visible_message("<span class='danger'>\The [user] blocks [attack_text] with \the [src]!</span>")
			return 1
	return 0

/obj/item/weapon/shield/proc/get_block_chance(mob/user, var/damage, atom/damage_source = null, mob/attacker = null)
	return base_block_chance

/obj/item/weapon/shield/riot
	name = "riot shield"
	desc = "A shield adept for close quarters engagement.  It's also capable of protecting from less powerful projectiles."
	icon = 'icons/obj/weapons.dmi'
	icon_state = "riot"
	flags = CONDUCT
	slot_flags = SLOT_BACK
	force = 5.0
	throwforce = 5.0
	throw_speed = 1
	throw_range = 4
	w_class = ITEMSIZE_LARGE
	origin_tech = list(TECH_MATERIAL = 2)
	matter = list("glass" = 7500, DEFAULT_WALL_MATERIAL = 1000)
	attack_verb = list("shoved", "bashed")
	var/cooldown = 0 //shield bash cooldown. based on world.time

/obj/item/weapon/shield/riot/handle_shield(mob/user, var/damage, atom/damage_source = null, mob/attacker = null, var/def_zone = null, var/attack_text = "the attack")
	if(user.incapacitated())
		return 0

	//block as long as they are not directly behind us
	var/bad_arc = reverse_direction(user.dir) //arc of directions from which we cannot block
	if(check_shield_arc(user, bad_arc, damage_source, attacker))
		if(prob(get_block_chance(user, damage, damage_source, attacker)))
			//At this point, we succeeded in our roll for a block attempt, however these kinds of shields struggle to stand up
			//to strong bullets and lasers.  They still do fine to pistol rounds of all kinds, however.
			if(istype(damage_source, /obj/item/projectile))
				var/obj/item/projectile/P = damage_source
				if((is_sharp(P) && P.armor_penetration >= 10) || istype(P, /obj/item/projectile/beam))
					//If we're at this point, the bullet/beam is going to go through the shield, however it will hit for less damage.
					//Bullets get slowed down, while beams are diffused as they hit the shield, so these shields are not /completely/
					//useless.  Extremely penetrating projectiles will go through the shield without less damage.
					user.visible_message("<span class='danger'>\The [user]'s [src.name] is pierced by [attack_text]!</span>")
					if(P.armor_penetration < 30) //PTR bullets and x-rays will bypass this entirely.
						P.damage = P.damage / 2
					return 0
			//Otherwise, if we're here, we're gonna stop the attack entirely.
			user.visible_message("<span class='danger'>\The [user] blocks [attack_text] with \the [src]!</span>")
			playsound(user.loc, 'sound/weapons/Genhit.ogg', 50, 1)
			return 1
	return 0

/obj/item/weapon/shield/riot/attackby(obj/item/weapon/W as obj, mob/user as mob)
	if(istype(W, /obj/item/weapon/melee/baton))
		if(cooldown < world.time - 25)
			user.visible_message("<span class='warning'>[user] bashes [src] with [W]!</span>")
			playsound(user.loc, 'sound/effects/shieldbash.ogg', 50, 1)
			cooldown = world.time
	else
		..()

/*
 * Energy Shield
 */

/obj/item/weapon/shield/energy
	name = "energy combat shield"
	desc = "A shield capable of stopping most projectile and melee attacks. It can be retracted, expanded, and stored anywhere."
	icon = 'icons/obj/weapons.dmi'
	icon_state = "eshield0" // eshield1 for expanded
	slot_flags = SLOT_EARS
	flags = CONDUCT
	force = 3.0
	throwforce = 5.0
	throw_speed = 1
	throw_range = 4
	w_class = ITEMSIZE_SMALL
	origin_tech = list(TECH_MATERIAL = 4, TECH_MAGNET = 3, TECH_ILLEGAL = 4)
	attack_verb = list("shoved", "bashed")
	var/active = 0

/obj/item/weapon/shield/energy/handle_shield(mob/user)
	if(!active)
		return 0 //turn it on first!
	. = ..()

	if(.)
		var/datum/effect/effect/system/spark_spread/spark_system = new /datum/effect/effect/system/spark_spread()
		spark_system.set_up(5, 0, user.loc)
		spark_system.start()
		playsound(user.loc, 'sound/weapons/blade1.ogg', 50, 1)

/obj/item/weapon/shield/energy/get_block_chance(mob/user, var/damage, atom/damage_source = null, mob/attacker = null)
	if(istype(damage_source, /obj/item/projectile))
		var/obj/item/projectile/P = damage_source
		if((is_sharp(P) && damage > 10) || istype(P, /obj/item/projectile/beam))
			return (base_block_chance - round(damage / 3)) //block bullets and beams using the old block chance
	return base_block_chance

/obj/item/weapon/shield/energy/attack_self(mob/living/user as mob)
	if ((CLUMSY in user.mutations) && prob(50))
		user << "<span class='warning'>You beat yourself in the head with [src].</span>"
		user.take_organ_damage(5)
	active = !active
	if (active)
		force = 10
		update_icon()
		w_class = ITEMSIZE_LARGE
		slot_flags = null
		playsound(user, 'sound/weapons/saberon.ogg', 50, 1)
		user << "<span class='notice'>\The [src] is now active.</span>"

	else
		force = 3
		update_icon()
		w_class = ITEMSIZE_TINY
		slot_flags = SLOT_EARS
		playsound(user, 'sound/weapons/saberoff.ogg', 50, 1)
		user << "<span class='notice'>\The [src] can now be concealed.</span>"

	if(istype(user,/mob/living/carbon/human))
		var/mob/living/carbon/human/H = user
		H.update_inv_l_hand()
		H.update_inv_r_hand()

	add_fingerprint(user)
	return

/obj/item/weapon/shield/energy/update_icon()
	icon_state = "eshield[active]"
	if(active)
		set_light(1.5, 1.5, "#006AFF")
	else
		set_light(0)

/obj/item/weapon/shield/riot/tele
	name = "telescopic shield"
	desc = "An advanced riot shield made of lightweight materials that collapses for easy storage."
	icon = 'icons/obj/weapons.dmi'
	icon_state = "teleriot0"
	slot_flags = null
	force = 3
	throwforce = 3
	throw_speed = 3
	throw_range = 4
	w_class = ITEMSIZE_NORMAL
	var/active = 0
/*
/obj/item/weapon/shield/energy/IsShield()
	if(active)
		return 1
	else
		return 0
*/
/obj/item/weapon/shield/riot/tele/attack_self(mob/living/user)
	active = !active
	icon_state = "teleriot[active]"
	playsound(src.loc, 'sound/weapons/empty.ogg', 50, 1)

	if(active)
		force = 8
		throwforce = 5
		throw_speed = 2
		w_class = ITEMSIZE_LARGE
		slot_flags = SLOT_BACK
		user << "<span class='notice'>You extend \the [src].</span>"
	else
		force = 3
		throwforce = 3
		throw_speed = 3
		w_class = ITEMSIZE_NORMAL
		slot_flags = null
		user << "<span class='notice'>[src] can now be concealed.</span>"

	if(istype(user,/mob/living/carbon/human))
		var/mob/living/carbon/human/H = user
		H.update_inv_l_hand()
		H.update_inv_r_hand()

	add_fingerprint(user)
	return