make ships orbit their targets

src/test/BehaviorSystemTest.cpp

@@ -1,5 +1,6 @@
 #include "catch.hpp"
 
+#include <cmath>
 #include <random>
 
 #include <QPoint>
@@ -25,6 +26,7 @@
 #include "MovementIntentComponent.h"
 #include "MovementIntentSystem.h"
 #include "PositionComponent.h"
+#include "RallyBehavior.h"
 #include "RepairBehavior.h"
 #include "RepairSystem.h"
 #include "RepairToolComponent.h"
@@ -440,7 +442,7 @@ TEST_CASE("BehaviorSystem: advancing ship falls back to enemy HQ, then off-world
 // RepairBehavior
 // ---------------------------------------------------------------------------
 
-TEST_CASE("BehaviorSystem: repair ship moves toward damaged friendly ship",
+TEST_CASE("BehaviorSystem: repair ship orbits damaged friendly ship",
           "[behavior]")
 {
     Fixture f;
@@ -455,7 +457,13 @@ TEST_CASE("BehaviorSystem: repair ship moves toward damaged friendly ship",
 
     REQUIRE(winnerOf(f.admin, repairShip) == BehaviorKind::Repair);
     REQUIRE(intent(f.admin, repairShip).active);
-    REQUIRE(intent(f.admin, repairShip).target.x() == Approx(5.0f));
+
+    // Orbit at orbit_factor * max repair range (REQ-SHP-ORBIT): the movement
+    // destination lies exactly the orbit radius from the target's center.
+    const float orbitRadius = f.admin.get<RepairBehavior>(repairShip).orbitRadius_tiles;
+    REQUIRE(orbitRadius > 0.0f);
+    REQUIRE((intent(f.admin, repairShip).target - pos(f.admin, friendly).value).length()
+            == Approx(orbitRadius));
 }
 
 TEST_CASE("BehaviorSystem: repair ship heals damaged ally within repair range",
@@ -703,7 +711,7 @@ TEST_CASE("RepairSystem: does not crash when a tool's owner is not a repair ship
 // SalvageScrapBehavior / DeliverScrapBehavior
 // ---------------------------------------------------------------------------
 
-TEST_CASE("BehaviorSystem: salvage ship moves toward nearest scrap", "[behavior]")
+TEST_CASE("BehaviorSystem: salvage ship orbits nearest scrap", "[behavior]")
 {
     Fixture f;
     const ShipLayoutConfig salvageLayout = makeSingleModuleLayout("salvager");
@@ -717,7 +725,11 @@ TEST_CASE("BehaviorSystem: salvage ship moves toward nearest scrap", "[behavior]
 
     REQUIRE(winnerOf(f.admin, ship) == BehaviorKind::SalvageScrap);
     REQUIRE(intent(f.admin, ship).active);
-    REQUIRE(intent(f.admin, ship).target.x() == Approx(scrapPos.x()));
+
+    // Orbit at orbit_factor * max collection range (REQ-SHP-ORBIT).
+    const float orbitRadius = f.admin.get<SalvageScrapBehavior>(ship).orbitRadius_tiles;
+    REQUIRE(orbitRadius > 0.0f);
+    REQUIRE((intent(f.admin, ship).target - scrapPos).length() == Approx(orbitRadius));
 }
 
 TEST_CASE("BehaviorSystem: salvage ship collects scrap on arrival", "[behavior]")
@@ -1038,3 +1050,76 @@ TEST_CASE("SensorRange: salvage ship ignores scrap beyond sensor range", "[senso
     REQUIRE_FALSE(f.admin.get<SalvageScrapBehavior>(ship).scrapTarget.has_value());
     REQUIRE(intent(f.admin, ship).target.x() > pos(f.admin, ship).value.x());
 }
+
+// ---------------------------------------------------------------------------
+// Orbit movement (REQ-SHP-ORBIT)
+// ---------------------------------------------------------------------------
+
+TEST_CASE("Orbit: combat ship aims at a point on the orbit circle around its target",
+          "[orbit]")
+{
+    Fixture f;
+    const entt::entity player = f.ships.spawn("interceptor", 1, QVector2D(0.0f, 0.0f));
+    const entt::entity enemy  = f.ships.spawn("interceptor", 1, QVector2D(10.0f, 0.0f),
+                                               /*isEnemy=*/true);
+
+    f.decide();
+
+    REQUIRE(winnerOf(f.admin, player) == BehaviorKind::Attack);
+    const float orbitRadius = f.admin.get<AttackBehavior>(player).orbitRadius_tiles;
+    REQUIRE(orbitRadius > 0.0f);
+    // The movement destination lies exactly the orbit radius from the enemy center.
+    REQUIRE((intent(f.admin, player).target - pos(f.admin, enemy).value).length()
+            == Approx(orbitRadius));
+}
+
+TEST_CASE("Orbit: rally ship orbits the rally point at the configured rally radius",
+          "[orbit]")
+{
+    Fixture f;
+    const QVector2D rallyPoint(-50.0f, 0.0f);
+    f.ships.setRallyPoint(rallyPoint);
+    const entt::entity player = f.ships.spawn("interceptor", 1, QVector2D(0.0f, 0.0f));
+
+    f.decide();
+
+    REQUIRE(winnerOf(f.admin, player) == BehaviorKind::Rally);
+    const float orbitRadius = f.admin.get<RallyBehavior>(player).orbitRadius_tiles;
+    REQUIRE(orbitRadius == Approx(static_cast<float>(f.cfg.world.rallyOrbitRadius_tiles)));
+    REQUIRE((intent(f.admin, player).target - rallyPoint).length() == Approx(orbitRadius));
+}
+
+TEST_CASE("Orbit: combat ship settles near the orbit radius and circles a stationary target",
+          "[orbit]")
+{
+    Fixture f;
+    const QVector2D enemyPos(80.0f, 0.0f);
+    const entt::entity player = f.ships.spawn("interceptor", 1, QVector2D(0.0f, 0.0f));
+    const entt::entity enemy  = f.ships.spawn("interceptor", 1, enemyPos, /*isEnemy=*/true);
+
+    const float orbitRadius = f.admin.get<AttackBehavior>(player).orbitRadius_tiles;
+    REQUIRE(orbitRadius > 0.0f);
+    REQUIRE(orbitRadius < enemyPos.x());  // ship must close in to reach the orbit
+
+    // Run many full ticks, pinning the enemy in place so it is a stationary target.
+    float angleBefore = 0.0f;
+    for (int i = 0; i < 1200; ++i)
+    {
+        f.admin.get<PositionComponent>(enemy).value = enemyPos;       // keep target fixed
+        f.admin.get<DynamicBodyComponent>(enemy).velocity_tpt = QVector2D(0.0f, 0.0f);
+        if (i == 800)
+        {
+            angleBefore = std::atan2(pos(f.admin, player).value.y() - enemyPos.y(),
+                                     pos(f.admin, player).value.x() - enemyPos.x());
+        }
+        f.runBehaviorTick();
+    }
+    const float angleAfter = std::atan2(pos(f.admin, player).value.y() - enemyPos.y(),
+                                        pos(f.admin, player).value.x() - enemyPos.x());
+
+    // Settled close to the orbit radius (chasing a moving lead point oscillates a bit).
+    const float dist = (pos(f.admin, player).value - enemyPos).length();
+    REQUIRE(dist == Approx(orbitRadius).margin(0.35f * orbitRadius));
+    // The ship is circling: its angular position around the target has moved.
+    REQUIRE(std::abs(angleAfter - angleBefore) > 0.05f);
+}

src/test/ConfigLoaderTest.cpp

@@ -76,6 +76,8 @@ TEST_CASE("ConfigLoader loads the committed bin/config/ configs end-to-end", "[c
     REQUIRE(cfg.world.regions.enemyBufferWidth_tiles == 15);
     REQUIRE(cfg.world.expansion.columnsPerExpansion_tiles == 10);
     REQUIRE(cfg.world.push.bossAdvanceSeconds == Approx(60.0));
+    REQUIRE(cfg.world.orbitFactor == Approx(0.8));
+    REQUIRE(cfg.world.rallyOrbitRadius_tiles == Approx(5.0));
 
     // Spot-check that a config-derived formula computes as expected.
     // threat_rate_formula = "x": evaluates to the input value.
@@ -163,6 +165,8 @@ belt_speed_mps = 20
 starting_building_blocks = 100
 tunnel_max_distance_tiles = 10
 departure_interval_seconds = 20
+orbit_factor = 0.8
+rally_orbit_radius_tiles = 5.0
 
 [regions]
 asteroid_width_tiles = 40
@@ -211,6 +215,8 @@ belt_speed_mps = 20
 starting_building_blocks = 100
 tunnel_max_distance_tiles = 10
 departure_interval_seconds = 20
+orbit_factor = 0.8
+rally_orbit_radius_tiles = 5.0
 
 [regions]
 asteroid_width_tiles = 40