Reduce overtime in relay_render_to_plane

code/_onclick/hud/rendering/render_plate.dm

@@ -64,21 +64,29 @@
  * * relay_plane: plane we are relaying this plane master to
  */
 /atom/movable/screen/plane_master/proc/relay_render_to_plane(mob/mymob, relay_plane)
-	if(relay in mymob.client.screen) //backdrop can be called multiple times
-		return
+	// we may need to regenerate it
 	if(!render_target && generate_render_target)
 		render_target = "*[name]: AUTOGENERATED RENDER TGT"
-	relay = new()
-	relay.render_source = render_target
-	relay.plane = relay_plane
-	relay.layer = (plane + abs(LOWEST_EVER_PLANE))*0.5 //layer must be positive but can be a decimal
+		if(relay && render_target != relay.render_target) // our relay target has changed. this will probably never happen but just in case
+			relay.render_source = render_target
+			// todo: we may actually need to delete and remake this
+	if(mymob.client.render_plates_shown[relay]) //backdrop can be called multiple times
+		return
+	if(!relay) // don't generate a new one just because we cleared our client's screen
+		relay = new()
+		relay.render_source = render_target
+		relay.plane = relay_plane
+		relay.layer = (plane + abs(LOWEST_EVER_PLANE))*0.5 //layer must be positive but can be a decimal
 
-	if(blend_mode_override)
-		relay.blend_mode = blend_mode_override
-	else
-		relay.blend_mode = blend_mode
-	relay.mouse_opacity = mouse_opacity
-	relay.name = render_target
+		if(blend_mode_override)
+			relay.blend_mode = blend_mode_override
+		else
+			relay.blend_mode = blend_mode
+		relay.mouse_opacity = mouse_opacity
+		relay.name = render_target
 	mymob.client.add_to_screen(relay)
+	// this list is used to check if a plane has already had its relay added
+	// this is faster than checking membership in `screen`, ideally
+	mymob.client.render_plates_shown[relay] = TRUE
 	if(blend_mode != BLEND_MULTIPLY)
 		blend_mode = BLEND_DEFAULT

code/modules/client/client_defines.dm

@@ -136,3 +136,8 @@
 	/// If this client has any windows scaling applied
 	var/window_scaling
 
+	/// An alist used to make checks for whether a render plate has been added to a client's screen faster.
+	/// render relay plate -> TRUE
+	/// This must be cleared whenever screen is cleared manually.
+	var/alist/render_plates_shown = alist()
+

code/modules/client/client_procs.dm

@@ -931,6 +931,7 @@ CLIENT_VERB(fix_stat_panel)
 				continue
 
 		remove_from_screen(object)
+	render_plates_shown = alist()
 
 ///opens the particle editor UI for the in_atom object for this client
 /client/proc/open_particle_editor(atom/movable/in_atom)

code/modules/mob/living/brain/brain_item.dm

@@ -30,7 +30,8 @@
 	..()
 	spawn(5)
 		if(brainmob && brainmob.client)
-			brainmob.client.screen.len = null //clear the hud
+			brainmob.client.screen.Cut() //clear the hud
+			brainmob.client.render_plates_shown = alist()
 
 /obj/item/organ/brain/proc/transfer_identity(mob/living/carbon/H)
 	name = "[H]'s brain"

code/modules/mob/living/simple_animal/simple_animal.dm

@@ -85,8 +85,9 @@
 	return ..()
 
 /mob/living/simple_animal/Login()
-	if(src && src.client)
-		src.client.screen = null
+	if(client)
+		client.screen = null
+		client.render_plates_shown = alist()
 	..()
 
 /mob/living/simple_animal/updatehealth()

code/modules/mob/login.dm

@@ -24,6 +24,7 @@
 
 	client.images = null
 	client.screen = null //remove hud items just in case
+	client.render_plates_shown = alist()
 	if(!hud_used)
 		create_hud()
 	if(hud_used)

code/modules/mob/mob_verbs.dm

@@ -143,6 +143,7 @@
 		log_game("[usr.key] AM failed due to disconnect.")
 		return
 	client.screen.Cut()
+	client.render_plates_shown = alist()
 	if(!client)
 		log_game("[usr.key] AM failed due to disconnect.")
 		return

code/modules/organs/limb_objects.dm

@@ -134,7 +134,8 @@
 		overlays += lipstick
 
 	if(brainmob && brainmob.client)
-		brainmob.client.screen.len = null //clear the hud
+		brainmob.client.screen.Cut() //clear the hud
+		brainmob.client.render_plates_shown = alist()
 
 	transfer_identity(H)