added camera shake to ob (#3658)

# About the pull request

Added a camera shake and stun feature based on the user's distance to
the OB. This is a copy of an existing branch that I somehow managed to
mess up -> #3605

# Explain why it's good for the game

OBs should feel like OBs, and adding this feature just helps make OBs
feel like an actual large explosion.

# Changelog

:cl:
add: added camera shake and stun to OB.
/:cl:

code/__DEFINES/conflict.dm

@@ -232,6 +232,7 @@
 //OB timings
 #define OB_TRAVEL_TIMING 12 SECONDS
 #define OB_CRASHING_DOWN 1 SECONDS
+#define OB_CLUSTER_DURATION 45 SECONDS
 //=================================================
 
 //Health of various items

code/modules/admin/tabs/event_tab.dm

@@ -830,7 +830,6 @@
 			if(isnull(OBShell.double_explosion_delay)) return
 			statsmessage = "Custom HE OB ([OBShell.name]) Stats from [key_name(usr)]: Clear Power: [OBShell.clear_power], Clear Falloff: [OBShell.clear_falloff], Clear Delay: [OBShell.clear_delay], Blast Power: [OBShell.standard_power], Blast Falloff: [OBShell.standard_falloff], Blast Delay: [OBShell.double_explosion_delay]."
 			warhead = OBShell
-			qdel(OBShell)
 		if("Custom Cluster")
 			var/obj/structure/ob_ammo/warhead/cluster/OBShell = new
 			OBShell.name = input("What name should the warhead have?", "Set name", "Cluster orbital warhead")
@@ -847,7 +846,6 @@
 			if(isnull(OBShell.explosion_falloff)) return
 			statsmessage = "Custom Cluster OB ([OBShell.name]) Stats from [key_name(usr)]: Salvos: [OBShell.total_amount], Shot per Salvo: [OBShell.instant_amount], Explosion Power: [OBShell.explosion_power], Explosion Falloff: [OBShell.explosion_falloff]."
 			warhead = OBShell
-			qdel(OBShell)
 		if("Custom Incendiary")
 			var/obj/structure/ob_ammo/warhead/incendiary/OBShell = new
 			OBShell.name = input("What name should the warhead have?", "Set name", "Incendiary orbital warhead")
@@ -876,19 +874,28 @@
 				if(isnull(OBShell.fire_color)) return
 			statsmessage = "Custom Incendiary OB ([OBShell.name]) Stats from [key_name(usr)]: Clear Power: [OBShell.clear_power], Clear Falloff: [OBShell.clear_falloff], Clear Delay: [OBShell.clear_delay], Fire Distance: [OBShell.distance], Fire Duration: [OBShell.fire_level], Fire Strength: [OBShell.burn_level]."
 			warhead = OBShell
-			qdel(OBShell)
 
 	if(custom)
-		if(alert(usr, statsmessage, "Confirm Stats", "Yes", "No") != "Yes") return
+		if(alert(usr, statsmessage, "Confirm Stats", "Yes", "No") != "Yes")
+			qdel(warhead)
+			return
 		message_admins(statsmessage)
 
 	var/turf/target = get_turf(usr.loc)
 
 	if(alert(usr, "Fire or Spawn Warhead?", "Mode", "Fire", "Spawn") == "Fire")
-		if(alert("Are you SURE you want to do this? It will create an OB explosion!",, "Yes", "No") != "Yes") return
+		if(alert("Are you SURE you want to do this? It will create an OB explosion!",, "Yes", "No") != "Yes")
+			qdel(warhead)
+			return
+
 		message_admins("[key_name(usr)] has fired \an [warhead.name] at ([target.x],[target.y],[target.z]).")
 		warhead.warhead_impact(target)
-		QDEL_IN(warhead, OB_CRASHING_DOWN)
+
+		if(istype(warhead, /obj/structure/ob_ammo/warhead/cluster))
+		// so the user's screen can shake for the duration of the cluster, otherwise we get a runtime.
+			QDEL_IN(warhead, OB_CLUSTER_DURATION)
+		else
+			QDEL_IN(warhead, OB_CRASHING_DOWN)
 	else
 		warhead.loc = target
 

code/modules/cm_marines/orbital_cannon.dm

@@ -353,6 +353,9 @@ var/list/ob_type_fuel_requirements
 /obj/structure/ob_ammo/warhead
 	name = "theoretical orbital ammo"
 	var/warhead_kind
+	var/shake_frequency
+	var/max_shake_factor
+	var/max_knockdown_time
 
 /obj/structure/ob_ammo/warhead/proc/warhead_impact(turf/target)
 	// make damn sure everyone hears it
@@ -398,10 +401,37 @@ var/list/ob_type_fuel_requirements
 		return TRUE
 	return FALSE
 
+/// proc designed for handling ob camera shakes, takes the target location as input and calculates camera shake based off user location.
+/obj/structure/ob_ammo/warhead/proc/handle_ob_shake(turf/epicenter)
+
+	var/radius_size = 30
+
+	for(var/mob/living/user in urange(radius_size, epicenter))
+
+		var/distance = get_accurate_dist(get_turf(user), epicenter)
+		var/distance_percent = ((radius_size - distance) / radius_size)
+		var/total_shake_factor = abs(max_shake_factor * distance_percent)
+
+		// it's of type cluster.
+		if(!max_knockdown_time)
+			shake_camera(user, 0.5, total_shake_factor, shake_frequency)
+			continue
+
+		shake_camera(user, 3, total_shake_factor, shake_frequency)
+		user.KnockDown(rand(max_knockdown_time * distance_percent, (max_knockdown_time * distance_percent + 1)))
+
+		if(!user.knocked_down)
+			continue
+		to_chat(user, SPAN_WARNING("You are thrown off balance and fall to the ground!"))
+
 /obj/structure/ob_ammo/warhead/explosive
 	name = "\improper HE orbital warhead"
 	warhead_kind = "explosive"
 	icon_state = "ob_warhead_1"
+	shake_frequency = 3
+	max_shake_factor = 15
+	max_knockdown_time = 6
+
 	var/clear_power = 1200
 	var/clear_falloff = 400
 	var/standard_power = 600
@@ -419,16 +449,20 @@ var/list/ob_type_fuel_requirements
 	var/datum/cause_data/cause_data = create_cause_data(initial(name), source_mob)
 	cell_explosion(target, clear_power, clear_falloff, EXPLOSION_FALLOFF_SHAPE_LINEAR, null, cause_data) //break shit around
 	sleep(clear_delay)
-	//ACTUALLY BLOW SHIT UP
+
+	// Explosion if turf is not a wall.
 	if(!target.density)
 		cell_explosion(target, standard_power, standard_falloff, EXPLOSION_FALLOFF_SHAPE_LINEAR, null, cause_data)
+		handle_ob_shake(target)
 		sleep(double_explosion_delay)
 		cell_explosion(target, standard_power, standard_falloff, EXPLOSION_FALLOFF_SHAPE_LINEAR, null, cause_data)
 		return
 
+	// Checks turf around the target
 	for(var/turf/T in range(2, target))
 		if(!T.density)
 			cell_explosion(target, standard_power, standard_falloff, EXPLOSION_FALLOFF_SHAPE_LINEAR, null, cause_data)
+			handle_ob_shake(target)
 			sleep(double_explosion_delay)
 			cell_explosion(target, standard_power, standard_falloff, EXPLOSION_FALLOFF_SHAPE_LINEAR, null, cause_data)
 			return
@@ -437,6 +471,9 @@ var/list/ob_type_fuel_requirements
 	name = "\improper Incendiary orbital warhead"
 	warhead_kind = "incendiary"
 	icon_state = "ob_warhead_2"
+	shake_frequency = 1
+	max_shake_factor = 8
+	max_knockdown_time = 3
 	var/clear_power = 1200
 	var/clear_falloff = 400
 	var/clear_delay = 3
@@ -457,13 +494,18 @@ var/list/ob_type_fuel_requirements
 	sleep(10)
 	var/datum/cause_data/cause_data = create_cause_data(initial(name), source_mob)
 	cell_explosion(target, clear_power, clear_falloff, EXPLOSION_FALLOFF_SHAPE_LINEAR, null, cause_data) //break shit around
+	handle_ob_shake(target)
+
 	sleep(clear_delay)
 	fire_spread(target, cause_data, distance, fire_level, burn_level, fire_color, fire_type, TURF_PROTECTION_OB)
 
 /obj/structure/ob_ammo/warhead/cluster
 	name = "\improper Cluster orbital warhead"
 	warhead_kind = "cluster"
 	icon_state = "ob_warhead_3"
+	shake_frequency = 2
+	max_shake_factor = 1
+
 	var/total_amount = 75 // how many times will the shell fire?
 	var/instant_amount = 3 // how many explosions per time it fires?
 	var/explosion_power = 350
@@ -492,11 +534,13 @@ var/list/ob_type_fuel_requirements
 			if(protected_by_pylon(TURF_PROTECTION_OB, U)) //If the turf somehow gained OB protection while the cluster was firing
 				continue
 			fire_in_a_hole(U)
+
 		sleep(delay_between_clusters)
 
 /obj/structure/ob_ammo/warhead/cluster/proc/fire_in_a_hole(turf/loc)
 	new /obj/effect/overlay/temp/blinking_laser (loc)
 	addtimer(CALLBACK(GLOBAL_PROC, GLOBAL_PROC_REF(cell_explosion), loc, explosion_power, explosion_falloff, EXPLOSION_FALLOFF_SHAPE_LINEAR, null, create_cause_data(initial(name), source_mob)), 1 SECONDS)
+	addtimer(CALLBACK(src, PROC_REF(handle_ob_shake), loc), 1 SECONDS)
 
 /obj/structure/ob_ammo/ob_fuel
 	name = "solid fuel"
@@ -607,3 +651,4 @@ var/list/ob_type_fuel_requirements
 		return TRUE
 
 	tgui_interact(user)
+