One fix and one enhancement to AI shield behavior

code/ai/ai.h

@@ -330,7 +330,7 @@ typedef struct ai_info {
 	float	time_enemy_near;					//	SUSHI: amount of time enemy continuously "near" the player
 	fix		last_attack_time;					//	Missiontime of last time this ship attacked its enemy.
 	fix		last_hit_time;						//	Missiontime of last time this ship was hit by anyone.
-	int		last_hit_quadrant;				//	Shield section of last hit.
+	int		danger_shield_quadrant;				//	Shield section AI will prefer to prioritize for recharging, it if possible.
 	fix		last_hit_target_time;			//	Missiontime of last time this ship successfully hit target.
 	int		hitter_objnum;						//	Object index of ship that hit this ship last time.
 	int		hitter_signature;					//	Signature of hitter.  Prevents stupidity if hitter gets killed.

code/ai/ai_flags.h

@@ -172,6 +172,8 @@ namespace AI {
 		Guards_ignore_protected_attackers,
 		Standard_strafe_used_more,
 		Unify_usage_ai_shield_manage_delay,
+		Fix_AI_shield_management_bug,
+		AI_balances_shields_when_attacked,
 		Disable_ai_transferring_energy,
 		Freespace_1_missile_behavior,
 		ETS_uses_power_output,

code/ai/ai_profiles.cpp

@@ -699,6 +699,10 @@ void parse_ai_profiles_tbl(const char *filename)
 
 				set_flag(profile, "$unify usage of AI Shield Manage Delay:", AI::Profile_Flags::Unify_usage_ai_shield_manage_delay);
 
+				set_flag(profile, "$fix AI shield management bug:", AI::Profile_Flags::Fix_AI_shield_management_bug);
+
+				set_flag(profile, "$AI balances shields instead of directs when attacked:", AI::Profile_Flags::AI_balances_shields_when_attacked);
+
 				set_flag(profile, "$disable AI transferring energy:", AI::Profile_Flags::Disable_ai_transferring_energy);
 
 				set_flag(profile, "$enable freespace 1 style missile behavior:", AI::Profile_Flags::Freespace_1_missile_behavior);

code/ai/aicode.cpp

@@ -924,6 +924,8 @@ void parse_ai_class()
 	set_aic_flag(aicp, "$use actual primary range:", AI::Profile_Flags::Use_actual_primary_range);
 
 	set_aic_flag(aicp, "$firing requires exact los:", AI::Profile_Flags::Require_exact_los);
+
+	set_aic_flag(aicp, "$AI balances shields instead of directs when attacked:", AI::Profile_Flags::AI_balances_shields_when_attacked);
 }
 
 void reset_ai_class_names()
@@ -13320,8 +13322,8 @@ void ai_manage_shield(object *objp, ai_info *aip)
 		aip->shield_manage_timestamp = timestamp((int) (delay * 1000.0f));
 
 		if (sip->is_small_ship() || (aip->ai_profile_flags[AI::Profile_Flags::All_ships_manage_shields])) {
-			if (Missiontime - aip->last_hit_time < F1_0*10)
-				ai_transfer_shield(objp, aip->last_hit_quadrant);
+			if ((Missiontime - aip->last_hit_time < F1_0 * 10) && !((aip->ai_profile_flags[AI::Profile_Flags::AI_balances_shields_when_attacked])))
+				ai_transfer_shield(objp, aip->danger_shield_quadrant);
 			else
 				ai_balance_shield(objp);
 		}
@@ -15559,7 +15561,7 @@ void init_ai_object(int objnum)
 	aip->time_enemy_near = 0.0f;
 	aip->last_attack_time = 0;
 	aip->last_hit_time = 0;
-	aip->last_hit_quadrant = 0;
+	aip->danger_shield_quadrant = 0;
 	aip->hitter_objnum = -1;
 	aip->hitter_signature = -1;
 	aip->resume_goal_time = -1;

code/object/collideshipweapon.cpp

@@ -446,6 +446,12 @@ static int ship_weapon_check_collision(object *ship_objp, object *weapon_objp, f
 
 		// make sure that the shield is active in that quadrant
 		if (shipp->flags[Ship::Ship_Flags::Dying] || !ship_is_shield_up(ship_objp, quadrant_num)) {
+			// if the shield is down in the quadrant we still want the AI to record that the shield was hit here
+			// so that the AI can put energy torwards repairing that shield segement (but put behind a flag)
+			// --wookieejedi
+			if (The_mission.ai_profile->flags[AI::Profile_Flags::Fix_AI_shield_management_bug] && SCP_vector_inbounds(ship_objp->shield_quadrant, quadrant_num)) {
+				Ai_info[Ships[ship_objp->instance].ai_index].danger_shield_quadrant = quadrant_num;
+			}
 			quadrant_num = -1;
 			shield_collision = 0;
 		}

code/object/objectshield.cpp

@@ -204,7 +204,7 @@ float shield_apply_damage(object *objp, int quadrant_num, float damage)
 
 	if (objp->type != OBJ_SHIP && objp->type != OBJ_START)
 		return damage;
-	Ai_info[Ships[objp->instance].ai_index].last_hit_quadrant = quadrant_num;
+	Ai_info[Ships[objp->instance].ai_index].danger_shield_quadrant = quadrant_num;
 
 	remaining_damage = damage - objp->shield_quadrant[quadrant_num];
 	if (remaining_damage > 0.0f) {