make ships orbit their targets

src/lib/ecs/system/ShipSystem.cpp

@@ -343,12 +343,24 @@ entt::entity ShipSystem::spawn(const std::string& schematicId, int level,
 
     if (!weaponChildren.empty())
     {
-        m_admin.addComponent<AttackBehavior>(entity, AttackBehavior{});
+        float maxWeaponRange = 0.0f;
+        for (entt::entity child : weaponChildren)
+        {
+            const float r = m_admin.get<WeaponComponent>(child).range_tiles;
+            if (r > maxWeaponRange) { maxWeaponRange = r; }
+        }
+
+        AttackBehavior attack;
+        attack.orbitRadius_tiles =
+            maxWeaponRange * static_cast<float>(m_config.world.orbitFactor);
+        m_admin.addComponent<AttackBehavior>(entity, attack);
 
         if (!isEnemy)
         {
             RallyBehavior rally;
-            rally.rallyPoint = m_rallyPoint;
+            rally.rallyPoint       = m_rallyPoint;
+            rally.orbitRadius_tiles =
+                static_cast<float>(m_config.world.rallyOrbitRadius_tiles);
             m_admin.addComponent<RallyBehavior>(entity, rally);
         }
     }
@@ -365,6 +377,8 @@ entt::entity ShipSystem::spawn(const std::string& schematicId, int level,
         SalvageScrapBehavior salvage;
         salvage.scrapTarget              = std::nullopt;
         salvage.maxCollectionRange_tiles = maxCollRange;
+        salvage.orbitRadius_tiles =
+            maxCollRange * static_cast<float>(m_config.world.orbitFactor);
         m_admin.addComponent<SalvageScrapBehavior>(entity, salvage);
 
         DeliverScrapBehavior deliver;
@@ -384,6 +398,8 @@ entt::entity ShipSystem::spawn(const std::string& schematicId, int level,
         RepairBehavior repair;
         repair.currentTarget        = std::nullopt;
         repair.maxRepairRange_tiles = maxRepairRange;
+        repair.orbitRadius_tiles =
+            maxRepairRange * static_cast<float>(m_config.world.orbitFactor);
         m_admin.addComponent<RepairBehavior>(entity, repair);
     }
 

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

@@ -5,6 +5,7 @@
 #include "EntityAdmin.h"
 #include "ModuleOwnerComponent.h"
 #include "MovementIntentComponent.h"
+#include "OrbitMath.h"
 #include "PositionComponent.h"
 #include "SelectedBehaviorComponent.h"
 #include "tracing.h"
@@ -28,7 +29,9 @@ void AttackExecutor::execute(EntityAdmin& admin)
             QVector2D dest = pos.value;
             if (admin.isValid(t) && admin.hasAll<PositionComponent>(t))
             {
-                dest = admin.get<PositionComponent>(t).value;
+                const QVector2D targetPos = admin.get<PositionComponent>(t).value;
+                dest = OrbitMath::computeOrbitDestination(pos.value, targetPos,
+                                                          attack.orbitRadius_tiles);
             }
             intent = MovementIntentComponent{true, dest};
         });

src/lib/ecs/system/ai/OrbitMath.h

@@ -0,0 +1,45 @@
+#pragma once
+
+#include <cmath>
+
+#include <QVector2D>
+
+// Orbit movement helper (REQ-SHP-ORBIT). Behaviors that keep a ship circling a
+// target (attack, repair, salvage, rally) feed the result of this function as the
+// movement intent destination instead of the target's center.
+namespace OrbitMath
+{
+    // Lead angle (radians) by which the radial direction is rotated to produce
+    // tangential motion. The fixed positive (counter-clockwise) sense makes the
+    // orbit direction stable for the duration of orbiting a given target.
+    constexpr float kOrbitLeadAngle_rad = 0.6f;
+
+    // Returns a destination on the orbit circle of `radius` around `target`. The
+    // result always lies exactly `radius` from `target`, so steering toward it
+    // both corrects the standoff distance and advances the ship tangentially.
+    // A radius of zero or less falls back to the target center (legacy "approach
+    // the target" behavior), e.g. when the ship has no tool range to orbit at.
+    inline QVector2D computeOrbitDestination(const QVector2D& shipPos,
+                                             const QVector2D& target, float radius)
+    {
+        if (radius <= 0.0f) { return target; }
+
+        QVector2D radial = shipPos - target;
+        float length = radial.length();
+        if (length < 1.0e-4f)
+        {
+            // Ship sits on the target; pick an arbitrary radial direction.
+            radial = QVector2D(1.0f, 0.0f);
+            length = 1.0f;
+        }
+        const QVector2D radialDirection = radial / length;
+
+        const float cosLead = std::cos(kOrbitLeadAngle_rad);
+        const float sinLead = std::sin(kOrbitLeadAngle_rad);
+        const QVector2D leadDirection(
+            radialDirection.x() * cosLead - radialDirection.y() * sinLead,
+            radialDirection.x() * sinLead + radialDirection.y() * cosLead);
+
+        return target + radius * leadDirection;
+    }
+}

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

@@ -3,6 +3,8 @@
 #include "BehaviorKind.h"
 #include "EntityAdmin.h"
 #include "MovementIntentComponent.h"
+#include "OrbitMath.h"
+#include "PositionComponent.h"
 #include "RallyBehavior.h"
 #include "SelectedBehaviorComponent.h"
 #include "tracing.h"
@@ -10,11 +12,15 @@
 void RallyExecutor::execute(EntityAdmin& admin)
 {
     TRACE();
-    admin.forEach<RallyBehavior, SelectedBehaviorComponent, MovementIntentComponent>(
+    admin.forEach<RallyBehavior, SelectedBehaviorComponent, PositionComponent,
+                  MovementIntentComponent>(
         [](entt::entity /*e*/, const RallyBehavior& rally,
-           const SelectedBehaviorComponent& selected, MovementIntentComponent& intent)
+           const SelectedBehaviorComponent& selected, const PositionComponent& pos,
+           MovementIntentComponent& intent)
         {
             if (selected.winner != BehaviorKind::Rally) { return; }
-            intent = MovementIntentComponent{true, rally.rallyPoint};
+            const QVector2D dest = OrbitMath::computeOrbitDestination(
+                pos.value, rally.rallyPoint, rally.orbitRadius_tiles);
+            intent = MovementIntentComponent{true, dest};
         });
 }

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

@@ -4,6 +4,7 @@
 #include "EntityAdmin.h"
 #include "ModuleOwnerComponent.h"
 #include "MovementIntentComponent.h"
+#include "OrbitMath.h"
 #include "PositionComponent.h"
 #include "RepairBehavior.h"
 #include "RepairToolComponent.h"
@@ -28,7 +29,9 @@ void RepairExecutor::execute(EntityAdmin& admin)
             QVector2D dest = pos.value;
             if (admin.isValid(t) && admin.hasAll<PositionComponent>(t))
             {
-                dest = admin.get<PositionComponent>(t).value;
+                const QVector2D targetPos = admin.get<PositionComponent>(t).value;
+                dest = OrbitMath::computeOrbitDestination(pos.value, targetPos,
+                                                          repair.orbitRadius_tiles);
             }
             intent = MovementIntentComponent{true, dest};
         });

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

@@ -3,6 +3,8 @@
 #include "BehaviorKind.h"
 #include "EntityAdmin.h"
 #include "MovementIntentComponent.h"
+#include "OrbitMath.h"
+#include "PositionComponent.h"
 #include "SalvageScrapBehavior.h"
 #include "SelectedBehaviorComponent.h"
 #include "tracing.h"
@@ -10,12 +12,16 @@
 void SalvageScrapExecutor::execute(EntityAdmin& admin)
 {
     TRACE();
-    admin.forEach<SalvageScrapBehavior, SelectedBehaviorComponent, MovementIntentComponent>(
+    admin.forEach<SalvageScrapBehavior, SelectedBehaviorComponent, PositionComponent,
+                  MovementIntentComponent>(
         [](entt::entity /*e*/, const SalvageScrapBehavior& salvage,
-           const SelectedBehaviorComponent& selected, MovementIntentComponent& intent)
+           const SelectedBehaviorComponent& selected, const PositionComponent& pos,
+           MovementIntentComponent& intent)
         {
             if (selected.winner != BehaviorKind::SalvageScrap) { return; }
             if (!salvage.scrapTarget) { return; }
-            intent = MovementIntentComponent{true, *salvage.scrapTarget};
+            const QVector2D dest = OrbitMath::computeOrbitDestination(
+                pos.value, *salvage.scrapTarget, salvage.orbitRadius_tiles);
+            intent = MovementIntentComponent{true, dest};
         });
 }