Refactors projectile ricochets (#25764)

* same taste, twice the speed

* pulls proc/handle_ricochet() to the atom level. adds var/flags_ricochet and related defines.

* space indentation sneaks its way in yet again

---------

Co-authored-by: Luc <89928798+lewcc@users.noreply.github.com>

code/modules/events/blob/blob_structures/strong_blob.dm

@@ -61,16 +61,4 @@
 	brute_resist = 0.5
 	explosion_block = 2
 	point_return = 9
-	flags_2 = CHECK_RICOCHET_2
-
-/obj/structure/blob/shield/reflective/handle_ricochet(obj/item/projectile/P)
-	var/turf/p_turf = get_turf(P)
-	var/face_direction = get_dir(src, p_turf)
-	var/face_angle = dir2angle(face_direction)
-	var/incidence_s = GET_ANGLE_OF_INCIDENCE(face_angle, (P.Angle + 180))
-	if(abs(incidence_s) > 90 && abs(incidence_s) < 270)
-		return FALSE
-	var/new_angle_s = SIMPLIFY_DEGREES(face_angle + incidence_s)
-	P.set_angle(new_angle_s)
-	visible_message("<span class='warning'>[P] reflects off [src]!</span>")
-	return TRUE
+	flags_ricochet = RICOCHET_SHINY

code/modules/projectiles/projectile_base.dm

@@ -66,9 +66,6 @@
 	var/immolate = 0
 	var/dismemberment = 0 //The higher the number, the greater the bonus to dismembering. 0 will not dismember at all.
 	var/impact_effect_type //what type of impact effect to show when hitting something
-	var/ricochets = 0
-	var/ricochets_max = 2
-	var/ricochet_chance = 30
 
 	var/log_override = FALSE //whether print to admin attack logs or just keep it in the diary
 
@@ -114,6 +111,27 @@
 	var/impact_light_color_override
 	var/hitscan_duration = 0.3 SECONDS
 
+	/// how many times we've ricochet'd so far (instance variable, not a stat)
+	var/ricochets = 0
+	/// how many times we can ricochet max
+	var/ricochets_max = 0
+	/// how many times we have to ricochet min (unless we hit an atom we can ricochet off)
+	var/min_ricochets = 0
+	/// 0-100 (or more, I guess), the base chance of ricocheting, before being modified by the atom we shoot and our chance decay
+	var/ricochet_chance = 0
+	/// 0-1 (or more, I guess) multiplier, the ricochet_chance is modified by multiplying this after each ricochet
+	var/ricochet_decay_chance = 0.7
+	/// 0-1 (or more, I guess) multiplier, the projectile's damage is modified by multiplying this after each ricochet
+	var/ricochet_decay_damage = 0.7
+	/// On ricochet, if nonzero, we consider all mobs within this range of our projectile at the time of ricochet to home in on like Revolver Ocelot, as governed by ricochet_auto_aim_angle
+	var/ricochet_auto_aim_range = 0
+	/// On ricochet, if ricochet_auto_aim_range is nonzero, we'll consider any mobs within this range of the normal angle of incidence to home in on, higher = more auto aim
+	var/ricochet_auto_aim_angle = 30
+	/// the angle of impact must be within this many degrees of the struck surface, set to 0 to allow any angle
+	var/ricochet_incidence_leeway = 40
+	/// Can our ricochet autoaim hit our firer?
+	var/ricochet_shoots_firer = TRUE
+
 /obj/item/projectile/New()
 	return ..()
 
@@ -429,7 +447,21 @@
 
 
 /obj/item/projectile/proc/on_ricochet(atom/A)
-	return
+	if(!ricochet_auto_aim_angle || !ricochet_auto_aim_range)
+		return
+
+	var/mob/living/unlucky_sob
+	var/best_angle = ricochet_auto_aim_angle
+	for(var/mob/living/L in range(ricochet_auto_aim_range, src.loc))
+		if(L.stat == DEAD || !isInSight(src, L) || (!ricochet_shoots_firer && L == firer))
+			continue
+		var/our_angle = abs(closer_angle_difference(Angle, get_angle(src.loc, L.loc)))
+		if(our_angle < best_angle)
+			best_angle = our_angle
+			unlucky_sob = L
+
+	if(unlucky_sob)
+		set_angle(get_angle(src, unlucky_sob.loc))
 
 /obj/item/projectile/proc/check_ricochet()
 	if(prob(ricochet_chance))
@@ -437,8 +469,12 @@
 	return FALSE
 
 /obj/item/projectile/proc/check_ricochet_flag(atom/A)
-	if(A.flags_2 & CHECK_RICOCHET_2)
+	if((flag in list(ENERGY, LASER)) && (A.flags_ricochet & RICOCHET_SHINY))
 		return TRUE
+
+	if((flag in list(BOMB, BULLET)) && (A.flags_ricochet & RICOCHET_HARD))
+		return TRUE
+
 	return FALSE
 
 /obj/item/projectile/set_angle(new_angle)