Ports Tau Ceti's welding animation! (#67725)

add: welding now has an animation!

code/game/objects/items.dm

@@ -1,4 +1,5 @@
 GLOBAL_DATUM_INIT(fire_overlay, /mutable_appearance, mutable_appearance('icons/effects/fire.dmi', "fire"))
+GLOBAL_DATUM_INIT(welding_sparks, /mutable_appearance, mutable_appearance('icons/effects/welding_effect.dmi', "welding_sparks", GASFIRE_LAYER, ABOVE_LIGHTING_PLANE))
 
 /// Anything you can pick up and hold.
 /obj/item

code/game/objects/items/tools/weldingtool.dm

@@ -120,6 +120,11 @@
 	dyn_explosion(src, plasmaAmount/5, explosion_cause = src) // 20 plasma in a standard welder has a 4 power explosion. no breaches, but enough to kill/dismember holder
 	qdel(src)
 
+/obj/item/weldingtool/use_tool(atom/target, mob/living/user, delay, amount, volume, datum/callback/extra_checks)
+	target.add_overlay(GLOB.welding_sparks)
+	. = ..()
+	target.cut_overlay(GLOB.welding_sparks)
+
 /obj/item/weldingtool/attack(mob/living/carbon/human/attacked_humanoid, mob/living/user)
 	if(!istype(attacked_humanoid))
 		return ..()

code/modules/projectiles/guns/energy/special.dm

@@ -167,8 +167,11 @@
 	return (!QDELETED(cell) && cell.use(amount ? amount * charge_weld : charge_weld))
 
 /obj/item/gun/energy/plasmacutter/use_tool(atom/target, mob/living/user, delay, amount=1, volume=0, datum/callback/extra_checks)
+
 	if(amount)
+		target.add_overlay(GLOB.welding_sparks)
 		. = ..()
+		target.cut_overlay(GLOB.welding_sparks)
 	else
 		. = ..(amount=1)