make repair ships not retreat if someone needs help

src/lib/ecs/system/ai/RetreatEvaluator.cpp

@@ -6,10 +6,12 @@
 
 #include "AttackBehavior.h"
 #include "BehaviorScores.h"
+#include "BehaviorTargeting.h"
 #include "EntityAdmin.h"
 #include "FactionComponent.h"
 #include "HealthComponent.h"
 #include "PositionComponent.h"
+#include "RepairBehavior.h"
 #include "RetreatBehavior.h"
 #include "SensorRangeComponent.h"
 #include "ShipIdentityComponent.h"
@@ -28,9 +30,15 @@ void RetreatEvaluator::evaluate(EntityAdmin& admin)
             if (f.isEnemy) { enemyShips.push_back(pos.value); }
         });
 
-    admin.forEach<RetreatBehavior, PositionComponent, HealthComponent, SensorRangeComponent>(
+    // Snapshot repairables so weaponless repair ships can decide whether there is
+    // still a damaged ally worth holding ground for.
+    const std::vector<RepairableInfo> repairables = buildRepairables(admin);
+
+    admin.forEach<RetreatBehavior, PositionComponent, HealthComponent,
+                  SensorRangeComponent, FactionComponent>(
         [&](entt::entity e, RetreatBehavior& retreat, const PositionComponent& pos,
-            const HealthComponent& health, const SensorRangeComponent& sensor)
+            const HealthComponent& health, const SensorRangeComponent& sensor,
+            const FactionComponent& faction)
         {
             const bool lowHp = (health.maxHp > 0.0f)
                 && (health.hp / health.maxHp < retreat.retreatHpFraction);
@@ -39,14 +47,36 @@ void RetreatEvaluator::evaluate(EntityAdmin& admin)
             const bool hasWeapons = admin.hasAll<AttackBehavior>(e);
             if (!hasWeapons)
             {
+                bool enemyInRange = false;
                 for (const QVector2D& enemy : enemyShips)
                 {
                     if ((enemy - pos.value).length() <= sensor.value_tiles)
                     {
-                        threatened = true;
+                        enemyInRange = true;
                         break;
                     }
                 }
+
+                // A weaponless ship with a repair tool holds its ground while a
+                // damaged ally remains within sensor range; it only flees once
+                // there is nothing left to repair.
+                bool repairTargetInRange = false;
+                if (enemyInRange && admin.hasAll<RepairBehavior>(e))
+                {
+                    for (const RepairableInfo& r : repairables)
+                    {
+                        if (r.entity == e) { continue; }
+                        if (r.isEnemy != faction.isEnemy) { continue; }
+                        if (r.hp <= 0.0f || r.hp >= r.maxHp) { continue; }
+                        if ((r.position - pos.value).length() <= sensor.value_tiles)
+                        {
+                            repairTargetInRange = true;
+                            break;
+                        }
+                    }
+                }
+
+                threatened = enemyInRange && !repairTargetInRange;
             }
 
             retreat.score = (lowHp || threatened)