Vehicle autofire (#4959)

# About the pull request

Convert vehicle hardpoints from using their bespoke firing system to one
structured closely on handheld guns and deployables such as the M2C. Now
using the `autofire` component. Much like handheld weapons it is capable
of different firemodes (semi/burst/auto) and changing targets during
fire.

Hardpoints were converted to match their old effectiveness as closely as
possible; this is intended as a quality of life improvement, not a
rebalance. Damage, AP, range, ammo, etc were not touched.

Fire rates were copied over directly. Single-fire weapons with long
delays were made semi-auto (e.g. LTB), and those with short delays were
made full-auto (e.g. autocannon). Burst-fire weapons with significant
extra delays after the burst remained burst-fire (cupola, smokescreen),
and the rest were converted to full-auto (e.g. dual cannon). While
changing firemodes is easily implemented, no weapon seemed a good
candidate for more than one firemode and so that is omitted for now.

Scatter was approximated. The existing `accuracy` functioned as a
percent chance the shot would stray one tile from the target. Gun-style
`scatter` is instead a cone of fire in degrees. No direct conversion is
possible, so scatter values are roughly set such that firing at a tile
at the edge of the screen should "feel" about as accurate. Closer ranges
would experience less spread than before, longer ranges more.

The buffing weapon sensor module was adjusted to work with the new
firing system, and effects hardpoint scatter angle and firing rate.
Vehicle buffs still use multipliers instead of adding/subtracting as
handheld guns do, as a flat +/- adjustment to fire delay would have a
significantly different effect on slow firing weapons (e.g. LTB) vs fast
firing (e.g. autocannon). One major difference is that burstfire delays
are effected and buffs increases the burst density. Before, there was a
single cooldown initiated at the start of the burst, and only that
cooldown was modified by the buff. Now, since the inter-burst delay is
needed by the `autofire` component both the inter-burst delay and the
after-burst delay are modified by buffs.

Activating non-selected hardpoints was removed as not compatible. The
issue is that tracking a single click's modifiers is no longer
sufficient, it has to track through the whole mousedown-to-mouseup
period and the user can change multiple click modifiers in that time. I
could not find a method that was satisfactory without a much bigger
overhaul of vehicle controls than I'd like to take on in a PR not meant
for it. I'm sure it can be done, but that brings up the question of if
that's even the control scheme we'd want, in a PR that was never meant
to ask that question let alone answer it.

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# Explain why it's good for the game

Vehicle weapons using `gun`-like code makes them easier and more
familiar to use, and more code commonality makes maintenance just a
little bit easier.
# Testing Photographs and Procedure
<details>
<summary>Screenshots & Videos</summary>

Put screenshots and videos here with an empty line between the
screenshots and the `<details>` tags.

</details>


# Changelog
:cl:
refactor: vehicle weapons can fire full-auto
del: no more controls for firing vehicle non-selected weapons
/:cl:

code/modules/vehicles/hardpoints/holder/holder.dm

@@ -43,10 +43,21 @@
 	for(var/obj/item/hardpoint/H in hardpoints)
 		H.take_damage(damage)
 
-/obj/item/hardpoint/holder/on_install(obj/vehicle/multitile/V)
-	for(var/obj/item/hardpoint/HP in hardpoints)
-		HP.owner = V
-	return
+/obj/item/hardpoint/holder/on_install(obj/vehicle/multitile/vehicle)
+	..()
+	if(!vehicle) //in loose holder
+		return
+	for(var/obj/item/hardpoint/hardpoint in hardpoints)
+		hardpoint.owner = vehicle
+		hardpoint.on_install(vehicle)
+
+/obj/item/hardpoint/holder/on_uninstall(obj/vehicle/multitile/vehicle)
+	if(!vehicle) //in loose holder
+		return
+	for(var/obj/item/hardpoint/hardpoint in hardpoints)
+		hardpoint.on_uninstall(vehicle)
+		hardpoint.owner = null
+	..()
 
 /obj/item/hardpoint/holder/proc/can_install(obj/item/hardpoint/H)
 	// Can only have 1 hardpoint of each slot type
@@ -121,16 +132,17 @@
 	H.forceMove(src)
 	LAZYADD(hardpoints, H)
 
+	H.on_install(owner)
 	H.rotate(turning_angle(H.dir, dir))
 
 /obj/item/hardpoint/holder/proc/remove_hardpoint(obj/item/hardpoint/H, turf/uninstall_to)
 	if(!hardpoints)
 		return
-	hardpoints -= H
 	H.forceMove(uninstall_to ? uninstall_to : get_turf(src))
 
+	H.on_uninstall(owner)
 	H.reset_rotation()
-
+	hardpoints -= H
 	H.owner = null
 
 	if(H.health <= 0)

code/modules/vehicles/hardpoints/holder/tank_turret.dm

@@ -13,8 +13,6 @@
 	density = TRUE //come on, it's huge
 
 	activatable = TRUE
-	cooldown = 150
-	accuracy = 0.8
 
 	ammo = new /obj/item/ammo_magazine/hardpoint/turret_smoke
 	max_clips = 2
@@ -60,6 +58,15 @@
 	// Used during the windup
 	var/rotating = FALSE
 
+	scatter = 4
+	gun_firemode = GUN_FIREMODE_BURSTFIRE
+	gun_firemode_list = list(
+		GUN_FIREMODE_BURSTFIRE,
+	)
+	burst_amount = 2
+	burst_delay = 1.0 SECONDS
+	extra_delay = 13.0 SECONDS
+
 /obj/item/hardpoint/holder/tank_turret/update_icon()
 	var/broken = (health <= 0)
 	icon_state = "tank_turret_[broken]"
@@ -182,12 +189,7 @@
 					user.client.pixel_x = -1 * AM.view_tile_offset * 32
 					user.client.pixel_y = 0
 
-/obj/item/hardpoint/holder/tank_turret/fire(mob/user, atom/A)
-	if(ammo.current_rounds <= 0)
-		return
-
-	next_use = world.time + cooldown
-
+/obj/item/hardpoint/holder/tank_turret/try_fire(atom/target, mob/living/user, params)
 	var/turf/L
 	var/turf/R
 	switch(owner.dir)
@@ -204,26 +206,14 @@
 			L = locate(owner.x - 4, owner.y + 2, owner.z)
 			R = locate(owner.x - 4, owner.y - 2, owner.z)
 
-	if(LAZYLEN(activation_sounds))
-		playsound(get_turf(src), pick(activation_sounds), 60, 1)
-	fire_projectile(user, L)
+	if(shots_fired)
+		target = R
+	else
+		target = L
 
-	sleep(10)
+	return ..()
 
-	if(LAZYLEN(activation_sounds))
-		playsound(get_turf(src), pick(activation_sounds), 60, 1)
-	fire_projectile(user, R)
-
-	to_chat(user, SPAN_WARNING("Smoke Screen uses left: <b>[SPAN_HELPFUL(ammo ? ammo.current_rounds / 2 : 0)]/[SPAN_HELPFUL(ammo ? ammo.max_rounds / 2 : 0)]</b> | Mags: <b>[SPAN_HELPFUL(LAZYLEN(backup_clips))]/[SPAN_HELPFUL(max_clips)]</b>"))
-
-/obj/item/hardpoint/holder/tank_turret/fire_projectile(mob/user, atom/A)
-	set waitfor = 0
-
-	var/turf/origin_turf = get_turf(src)
-	origin_turf = locate(origin_turf.x + origins[1], origin_turf.y + origins[2], origin_turf.z)
+/obj/item/hardpoint/holder/tank_turret/get_origin_turf()
+	var/origin_turf = ..()
 	origin_turf = get_step(get_step(origin_turf, owner.dir), owner.dir) //this should get us tile in front of tank to prevent grenade being stuck under us.
-
-	var/obj/projectile/P = generate_bullet(user, origin_turf)
-	SEND_SIGNAL(P, COMSIG_BULLET_USER_EFFECTS, owner.seats[VEHICLE_GUNNER])
-	P.fire_at(A, owner.seats[VEHICLE_GUNNER], src, get_dist(origin_turf, A) + 1, P.ammo.shell_speed)
-	ammo.current_rounds--
+	return origin_turf

code/modules/vehicles/hardpoints/primary/autocannon.dm

@@ -8,8 +8,6 @@
 	activation_sounds = list('sound/weapons/vehicles/autocannon_fire.ogg')
 
 	health = 500
-	cooldown = 7
-	accuracy = 0.98
 	firing_arc = 60
 
 	origins = list(0, -3)
@@ -23,3 +21,10 @@
 		"4" = list(32, 0),
 		"8" = list(-32, 0)
 	)
+
+	scatter = 1
+	gun_firemode = GUN_FIREMODE_AUTOMATIC
+	gun_firemode_list = list(
+		GUN_FIREMODE_AUTOMATIC,
+	)
+	fire_delay = 0.7 SECONDS

code/modules/vehicles/hardpoints/primary/dual_cannon.dm

@@ -12,10 +12,7 @@
 	damage_multiplier = 0.2
 
 	health = 500
-	cooldown = 7
-	accuracy = 0.98
 	firing_arc = 60
-	var/burst_amount = 2
 
 	origins = list(0, -2)
 
@@ -33,27 +30,15 @@
 		"8" = list(14, 9)
 	)
 
+	scatter = 1
+	gun_firemode = GUN_FIREMODE_AUTOMATIC
+	gun_firemode_list = list(
+		GUN_FIREMODE_AUTOMATIC,
+	)
+	fire_delay = 0.3 SECONDS
+
 /obj/item/hardpoint/primary/dualcannon/set_bullet_traits()
 	..()
 	LAZYADD(traits_to_give, list(
 		BULLET_TRAIT_ENTRY(/datum/element/bullet_trait_iff)
 	))
-
-/obj/item/hardpoint/primary/dualcannon/fire(mob/user, atom/A)
-	if(ammo.current_rounds <= 0)
-		return
-
-	next_use = world.time + cooldown * owner.misc_multipliers["cooldown"]
-
-	for(var/bullets_fired = 1, bullets_fired <= burst_amount, bullets_fired++)
-		var/atom/T = A
-		if(!prob((accuracy * 100) / owner.misc_multipliers["accuracy"]))
-			T = get_step(get_turf(A), pick(GLOB.cardinals))
-		if(LAZYLEN(activation_sounds))
-			playsound(get_turf(src), pick(activation_sounds), 60, 1)
-		fire_projectile(user, T)
-		if(ammo.current_rounds <= 0)
-			break
-		if(bullets_fired < burst_amount) //we need to sleep only if there are more bullets to shoot in the burst
-			sleep(3)
-	to_chat(user, SPAN_WARNING("[src] Ammo: <b>[SPAN_HELPFUL(ammo ? ammo.current_rounds : 0)]/[SPAN_HELPFUL(ammo ? ammo.max_rounds : 0)]</b> | Mags: <b>[SPAN_HELPFUL(LAZYLEN(backup_clips))]/[SPAN_HELPFUL(max_clips)]</b>"))

code/modules/vehicles/hardpoints/primary/flamer.dm

@@ -8,8 +8,6 @@
 	activation_sounds = list('sound/weapons/vehicles/flamethrower.ogg')
 
 	health = 400
-	cooldown = 20
-	accuracy = 0.75
 	firing_arc = 90
 
 	origins = list(0, -3)
@@ -26,36 +24,19 @@
 
 	use_muzzle_flash = FALSE
 
+	scatter = 5
+	fire_delay = 2.0 SECONDS
+
 /obj/item/hardpoint/primary/flamer/set_bullet_traits()
 	..()
 	LAZYADD(traits_to_give, list(
 		BULLET_TRAIT_ENTRY(/datum/element/bullet_trait_iff)
 	))
 
-/obj/item/hardpoint/primary/flamer/can_activate(mob/user, atom/A)
-	if(!..())
-		return FALSE
-
-	var/turf/origin_turf = get_turf(src)
-	origin_turf = locate(origin_turf.x + origins[1], origin_turf.y + origins[2], origin_turf.z)
-	if(origin_turf == get_turf(A))
-		return FALSE
-
-	return TRUE
-
-/obj/item/hardpoint/primary/flamer/fire_projectile(mob/user, atom/A)
-	set waitfor = 0
-
-	var/turf/origin_turf = get_turf(src)
-	origin_turf = locate(origin_turf.x + origins[1], origin_turf.y + origins[2], origin_turf.z)
-
-	var/range = get_dist(origin_turf, A) + 1
-
-	var/obj/projectile/P = generate_bullet(user, origin_turf)
-	SEND_SIGNAL(P, COMSIG_BULLET_USER_EFFECTS, owner.seats[VEHICLE_GUNNER])
-	P.fire_at(A, owner.seats[VEHICLE_GUNNER], src, range < P.ammo.max_range ? range : P.ammo.max_range, P.ammo.shell_speed)
-
-	if(use_muzzle_flash)
-		muzzle_flash(Get_Angle(owner, A))
+/obj/item/hardpoint/primary/flamer/try_fire(target, user, params)
+	var/turf/origin_turf = get_origin_turf()
+	if(origin_turf == get_turf(target))
+		to_chat(user, SPAN_WARNING("The target is too close."))
+		return NONE
 
-	ammo.current_rounds--
+	return ..()

code/modules/vehicles/hardpoints/primary/ltb.dm

@@ -8,8 +8,6 @@
 	activation_sounds = list('sound/weapons/vehicles/cannon_fire1.ogg', 'sound/weapons/vehicles/cannon_fire2.ogg')
 
 	health = 500
-	cooldown = 200
-	accuracy = 0.97
 	firing_arc = 60
 
 	origins = list(0, -3)
@@ -30,3 +28,6 @@
 		"4" = list(89, -4),
 		"8" = list(-89, -4)
 	)
+
+	scatter = 2
+	fire_delay = 20.0 SECONDS

code/modules/vehicles/hardpoints/primary/minigun.dm

@@ -7,8 +7,6 @@
 	disp_icon_state = "ltaaap_minigun"
 
 	health = 350
-	cooldown = 8
-	accuracy = 0.6
 	firing_arc = 90
 
 	origins = list(0, -3)
@@ -30,46 +28,58 @@
 		"8" = list(-77, 0)
 	)
 
-	//changed minigun mechanic so instead of having lowered cooldown with each shot it now has increased burst size.
-	//While it's still spammy, user doesn't have to click as fast as possible anymore and has margin of 2 seconds before minigun will start slowing down
-
-	var/chained_shots = 1 //how many quick succession shots we've fired, 1 by default
-	var/last_shot_time = 0 //when was last shot fired, after 3 seconds we stop barrel
-	var/list/chain_bursts = list(1, 1, 2, 2, 3, 3, 3, 4, 4, 4) //how many shots per click we do
+	scatter = 7
+	gun_firemode = GUN_FIREMODE_AUTOMATIC
+	gun_firemode_list = list(
+		GUN_FIREMODE_AUTOMATIC,
+	)
+	fire_delay = 0.8 SECONDS //base fire rate, modified by stage_delay_mult
 
+	activation_sounds = list('sound/weapons/gun_minigun.ogg')
+	/// Active firing time to reach max spin_stage.
+	var/spinup_time = 8 SECONDS
+	/// Grace period before losing spin_stage.
+	var/spindown_grace_time = 2 SECONDS
+	COOLDOWN_DECLARE(spindown_grace_cooldown)
+	/// Cooldown time to reach min spin_stage.
+	var/spindown_time = 3 SECONDS
+	/// Index of stage_rate.
+	var/spin_stage = 1
+	/// Shots fired per fire_delay at a particular spin_stage.
+	var/list/stage_rate = list(1, 1, 2, 2, 3, 3, 3, 4, 4, 4, 5)
+	/// Fire delay multiplier for current spin_stage.
+	var/stage_delay_mult = 1
+	/// When it was last fired, related to world.time.
+	var/last_fired = 0
 
-/obj/item/hardpoint/primary/minigun/fire(mob/user, atom/A)
+/obj/item/hardpoint/primary/minigun/set_fire_delay(value)
+	fire_delay = value
+	SEND_SIGNAL(src, COMSIG_GUN_AUTOFIREDELAY_MODIFIED, fire_delay * stage_delay_mult)
 
-	var/S = 'sound/weapons/vehicles/minigun_stop.ogg'
-	//check how much time since last shot. 2 seconds are grace period before minigun starts to lose rotation momentum
-	var/t = world.time - last_shot_time - 2 SECONDS
-	t = round(t / 10)
-	if(t > 0)
-		chained_shots = max(chained_shots - t * 3, 1) //we lose 3 chained_shots per second
-	else
-		if(chained_shots < 11)
-			chained_shots++
-		S = 'sound/weapons/vehicles/minigun_loop.ogg'
+/obj/item/hardpoint/primary/minigun/set_fire_cooldown()
+	calculate_stage_delay_mult() //needs to check grace_cooldown before refreshed
+	last_fired = world.time
+	COOLDOWN_START(src, spindown_grace_cooldown, spindown_grace_time)
+	COOLDOWN_START(src, fire_cooldown, fire_delay * stage_delay_mult)
 
-	if(chained_shots == 1)
-		playsound(get_turf(src), 'sound/weapons/vehicles/minigun_start.ogg', 40, 1)
+/obj/item/hardpoint/primary/minigun/proc/calculate_stage_delay_mult()
+	var/stage_rate_len = stage_rate.len
+	var/delta_time = world.time - last_fired
 
-	next_use = world.time + cooldown * owner.misc_multipliers["cooldown"]
-
-	//how many rounds we will shoot in this burst
-	if(chained_shots > LAZYLEN(chain_bursts)) //5 shots at maximum rotation
-		t = 5
+	var/old_spin_stage = spin_stage
+	if(auto_firing || burst_firing) //spinup if continuing fire
+		var/delta_stage = delta_time * (stage_rate_len - 1)
+		spin_stage += delta_stage / spinup_time
+	else if(COOLDOWN_FINISHED(src, spindown_grace_cooldown)) //spindown if initiating fire after grace
+		var/delta_stage = (delta_time - spindown_grace_time) * (stage_rate_len - 1)
+		spin_stage -= delta_stage / spindown_time
 	else
-		t = LAZYACCESS(chain_bursts, chained_shots)
-	for(var/i = 1; i <= t; i++)
-		var/atom/T = A
-		if(!prob((accuracy * 100) / owner.misc_multipliers["accuracy"]))
-			T = get_step(get_turf(T), pick(GLOB.cardinals))
-		fire_projectile(user, T)
-		if(ammo.current_rounds <= 0)
-			break
-		sleep(2)
-	to_chat(user, SPAN_WARNING("[src] Ammo: <b>[SPAN_HELPFUL(ammo ? ammo.current_rounds : 0)]/[SPAN_HELPFUL(ammo ? ammo.max_rounds : 0)]</b> | Mags: <b>[SPAN_HELPFUL(LAZYLEN(backup_clips))]/[SPAN_HELPFUL(max_clips)]</b>"))
+		return
+	spin_stage = Clamp(spin_stage, 1, stage_rate_len)
+
+	var/old_stage_rate = stage_rate[Floor(old_spin_stage)]
+	var/new_stage_rate = stage_rate[Floor(spin_stage)]
 
-	playsound(get_turf(src), S, 40, 1)
-	last_shot_time = world.time
+	if(old_stage_rate != new_stage_rate)
+		stage_delay_mult = 1 / new_stage_rate
+		SEND_SIGNAL(src, COMSIG_GUN_AUTOFIREDELAY_MODIFIED, fire_delay * stage_delay_mult)