Projectile piercing fix (#22157)

Fixes the fact that no projectiles could pierce.
Uses the bitflags introduced in the projectile refactor.
Only some heavy rifle bullets and most ship weapons will pierce.
This also indirectly fixes how anemic all the non-explosive ship weapons
were.

This should probably also check armour piercing, the armor on a mob and
have some values tweaked for some weapons, but I wanted to keep this a
pure bugfix, so the numbers are exactly as they were before this was
broken.

Lore people might want to check their weapons to decide what they should
pierce, how much and how often.



https://github.com/user-attachments/assets/538a3a21-a796-4a81-ba53-6f91addd6785

code/modules/overmap/ship_weaponry/_ship_ammunition.dm

@@ -224,6 +224,7 @@
 	anti_materiel_potential = 3
 	impact_sounds = list(BULLET_IMPACT_MEAT = SOUNDS_BULLET_MEAT, BULLET_IMPACT_METAL = SOUNDS_BULLET_METAL)
 	accuracy = 100
+	projectile_piercing = PASSMOB|PASSDOORS|PASSGLASS|PASSCLOSEDTURF|PASSWINDOW|PASSMACHINE|PASSBLOB|PASSFLAPS|PASSVEHICLE //It's a ship weapon let it try to penetrate everything.
 	var/obj/item/ship_ammunition/ammo
 	var/primed = FALSE
 	var/hit_target = FALSE //First target we hit. Used to report if a hit was successful.

code/modules/projectiles/projectile.dm

@@ -74,7 +74,10 @@
 	var/projectile_piercing = NONE
 	/// Number of times we've pierced something. Incremented BEFORE bullet_act and on_hit proc!
 	var/pierces = 0
-
+	///The base chance that a projectile capable of piercing will actually pierce.
+	var/pierce_chance = 0
+	///Used to determine whether or not to apply embed chances on hit.
+	var/last_hit_pierced = FALSE
 	/// If objects are below this layer, we pass through them.
 	var/hit_threshhold = PROJECTILE_HIT_THRESHHOLD_LAYER
 
@@ -234,7 +237,7 @@
 
 	var/reflected = FALSE
 
-	/// If greater than zero, the projectile will pass through dense objects as specified by on_penetrate()
+	/// If greater than zero, the projectile will pass through dense objects as specified by prehit_pierce()
 	var/penetrating = 0
 
 	/// For KAs, really.
@@ -647,11 +650,17 @@
 	if((projectile_phasing & A.pass_flags_self) && (phasing_ignore_direct_target || original != A))
 		return PROJECTILE_PIERCE_PHASE
 	if(projectile_piercing & A.pass_flags_self)
-		return PROJECTILE_PIERCE_HIT
+		if (penetrating > pierces)
+			if(damage > 20 && prob(pierce_chance + damage))
+				penetrating--
+				last_hit_pierced = TRUE
+				return PROJECTILE_PIERCE_HIT
+
 	if(ismovable(A))
 		var/atom/movable/AM = A
 		if(AM.throwing)
 			return (projectile_phasing & LETPASSTHROW) ? PROJECTILE_PIERCE_PHASE : ((projectile_piercing & LETPASSTHROW)? PROJECTILE_PIERCE_HIT : PROJECTILE_PIERCE_NONE)
+	last_hit_pierced = FALSE
 	return PROJECTILE_PIERCE_NONE
 
 /obj/projectile/proc/check_ricochet(atom/A)
@@ -1137,6 +1146,9 @@
 /// Checks if the projectile is eligible for embedding. Not that it necessarily will.
 /obj/projectile/proc/can_embed()
 	//embed must be enabled and damage type must be brute
+	if (projectile_piercing & PASSMOB) //If the shot passes through you it can't embed.
+		if (last_hit_pierced)
+			return FALSE
 	if(!embed || damage_type != DAMAGE_BRUTE)
 		return FALSE
 	return TRUE

code/modules/projectiles/projectile/bullets.dm

@@ -8,7 +8,7 @@
 	embed = TRUE
 	sharp = TRUE
 	shrapnel_type = /obj/item/material/shard/shrapnel
-	var/mob_passthrough_check = 0
+	projectile_piercing = PASSMOB|PASSFLAPS|PASSGRILLE //These are the things it can piece, a number of times up to 'penetrating', if it actually does pierce is decided by projectile/prehit_pierce()
 
 	muzzle_type = /obj/effect/projectile/muzzle/bullet
 
@@ -16,17 +16,6 @@
 	if(isliving(target) && (..(target, blocked, def_zone) == BULLET_ACT_HIT))
 		var/mob/living/L = target
 		shake_camera(L, 3, 2)
-
-	if(penetrating > 0 && damage > 20 && prob(damage))
-		mob_passthrough_check = 1
-	else
-		mob_passthrough_check = 0
-	return ..()
-
-/obj/projectile/bullet/can_embed()
-	//prevent embedding if the projectile is passing through the mob
-	if(mob_passthrough_check)
-		return 0
 	return ..()
 
 /**
@@ -276,11 +265,12 @@
 	damage = 40
 	armor_penetration = 15
 	penetrating = FALSE
+	projectile_piercing = PASSMOB|PASSFLAPS|PASSGRILLE|PASSDOORS|PASSDOORHATCH|PASSCLOSEDTURF|PASSWINDOW|PASSGLASS|PASSMACHINE
 
 /obj/projectile/bullet/rifle/a762
 	damage = 35
 	armor_penetration = 22
-	penetrating = TRUE
+	penetrating = 1
 
 /obj/projectile/bullet/rifle/a556
 	damage = 30
@@ -290,7 +280,7 @@
 /obj/projectile/bullet/rifle/a556/ap
 	damage = 25
 	armor_penetration = 45
-	penetrating = TRUE
+	penetrating = 1
 
 /obj/projectile/bullet/rifle/a556/polymer
 	damage = 25
@@ -312,7 +302,7 @@
 	name = "Z33s Tamparii bullet"
 	damage = 30
 	armor_penetration = 30
-	penetrating = TRUE
+	penetrating = 1
 
 /obj/projectile/bullet/rifle/a145
 	damage = 80
@@ -327,13 +317,13 @@
 /obj/projectile/bullet/rifle/kumar_super
 	damage = 40
 	armor_penetration = 30
-	penetrating = TRUE
+	penetrating = 1
 
 /obj/projectile/bullet/rifle/vintage
 	name = ".30-06 Govt. bullet"
 	damage = 50
 	weaken = 1
-	penetrating = TRUE
+	penetrating = 1
 
 /obj/projectile/bullet/rifle/govt
 	name = ".40-70 Govt. bullet"
@@ -459,6 +449,8 @@
 	embed = 1
 	sharp = 1
 	penetrating = 1
+	projectile_piercing = PASSMOB|PASSFLAPS|PASSGRILLE|PASSDOORS|PASSDOORHATCH|PASSCLOSEDTURF|PASSWINDOW|PASSGLASS|PASSMACHINE
+
 
 	muzzle_type = /obj/effect/projectile/muzzle/pulse
 
@@ -559,6 +551,7 @@
 	anti_materiel_potential = 6
 	embed = FALSE
 	penetrating = 1
+	projectile_piercing = PASSMOB|PASSDOORS|PASSGLASS|PASSCLOSEDTURF|PASSWINDOW|PASSMACHINE|PASSBLOB|PASSFLAPS|PASSVEHICLE //It's designed to penetrate mechs.
 
 	var/devastation_range = -1
 	var/heavy_impact_range = -1