implement waves

src/lib/sim/CombatSystem.h

@@ -0,0 +1,61 @@
+#pragma once
+
+#include <optional>
+#include <vector>
+
+#include <QVector2D>
+
+#include "Building.h"
+#include "EntityId.h"
+#include "FireEvent.h"
+#include "GameConfig.h"
+#include "Ship.h"
+#include "Tick.h"
+
+class BuildingSystem;
+class ShipSystem;
+
+// Resolves all weapon fire for ships and defence stations (tick-order step 8).
+// REQ-SHP-FIRING, REQ-DEF-PLAYER-FIRE, REQ-DEF-ENEMY-FIRE.
+class CombatSystem
+{
+public:
+    explicit CombatSystem(const GameConfig& config);
+
+    // Advance weapon cooldowns, acquire targets for stations, fire when ready,
+    // apply damage, and append FireEvents. Damage is applied immediately via
+    // ShipSystem::damageShip and BuildingSystem::damageBuilding; step 9
+    // removes entities whose HP dropped to zero or below.
+    void tick(Tick currentTick,
+              ShipSystem& ships,
+              BuildingSystem& buildings,
+              std::vector<FireEvent>& outFireEvents);
+
+private:
+    // Process one ship's weapon for this tick.
+    void resolveShipWeapon(Ship& ship, Tick currentTick,
+                           ShipSystem& ships,
+                           BuildingSystem& buildings,
+                           std::vector<FireEvent>& out);
+
+    // Process one defence-station's weapon for this tick.
+    void resolveStationWeapon(Building& station, Tick currentTick,
+                              ShipSystem& ships,
+                              BuildingSystem& buildings,
+                              std::vector<FireEvent>& out);
+
+    // Find the nearest valid target for a defence station within its range.
+    // Enemy stations target player ships + HQ + PlayerDefenceStation.
+    // Player stations target enemy ships only.
+    std::optional<EntityId> acquireStationTarget(
+        const Building& station, bool stationIsEnemy,
+        const ShipSystem& ships,
+        const BuildingSystem& buildings) const;
+
+    // Return the world position of the entity, or nullopt if it no longer exists.
+    std::optional<QVector2D> targetPosition(EntityId id,
+                                            const ShipSystem& ships,
+                                            const BuildingSystem& buildings) const;
+
+    const GameConfig& m_config;
+};