Enemy swarm movement

game/systems/s_entity.c

@@ -256,6 +256,110 @@ void entityMoveToTarget(ecs_iter_t *it) {
     }
 }
 
+void entityMoveSwarm(ecs_iter_t *it) {
+    Game *game = ecs_singleton_get_mut(ECS, Game);
+    Position *pos = ecs_field(it, Position, 1);
+    Velocity *vel = ecs_field(it, Velocity, 2);
+    HitBox   *hb  = ecs_field(it, HitBox, 3);
+    Swarm    *swarm = ecs_field(it, Swarm, 4);
+    Owner    *owner = ecs_field(it, Owner, 5);
+    Steering *steer = ecs_field(it, Steering, 6);
+
+    for (i32 i = 0; i < it->count; i++) {
+
+        // Vector2 align = Vector2Zero(); // Alignment (match velocity)
+        Vector2 avoid = Vector2Zero(); // Separation
+        Vector2 target = Vector2Zero();
+        Vector2 cohesion = Vector2Zero(); // Cohesion (move towards center)
+
+        const f32 FRIEND_RADIUS = 22.0f;
+        const f32 ENEMY_RADIUS = 52.0f;
+
+        const Vector2 center = entityGetCenter(pos[i], hb[i]);
+
+        const f32 RANGE = BZ_MAX(FRIEND_RADIUS, ENEMY_RADIUS);
+        BzSpatialGridIter spatialIt = bzSpatialGridIter(game->entityGrid,
+                                                        center.x - RANGE, center.y - RANGE,
+                                                        RANGE * 2.0f, RANGE * 2.0f);
+
+        i32 numFriends = 0;
+        while (bzSpatialGridQueryNext(&spatialIt)) {
+            ecs_entity_t other = *(ecs_entity_t *) spatialIt.data;
+            if (!ecs_has(ECS, other, Owner))
+                continue;
+            Owner otherOwner = *ecs_get(ECS, other, Owner);
+            bool isFriend = owner[i].player == otherOwner.player;
+
+            if (!ecs_has(ECS, other, Position) || !ecs_has(ECS, other, HitBox))
+                continue;
+            Position otherPos = *ecs_get(ECS, other, Position);
+            Rectangle otherHB = *ecs_get(ECS, other, HitBox);;
+            Vector2 otherCenter = entityGetCenter(otherPos, otherHB);
+            f32 dst = Vector2Distance(center, otherCenter);
+            const f32 MIN_AVOID_DST = 18.0f;
+            const f32 MIN_ENEMY_DST = ENEMY_RADIUS;
+            if (isFriend) {
+                if (dst < MIN_AVOID_DST) {
+                    Vector2 dif = Vector2Subtract(center, otherCenter);
+                    dif = Vector2Scale(Vector2Normalize(dif), MIN_AVOID_DST - dst);
+                    avoid = Vector2Add(avoid, dif);
+                }
+                Vector2Add(cohesion, otherCenter);
+                numFriends++;
+            } else {
+                if (dst < MIN_ENEMY_DST) {
+                    //DrawCircleV(otherCenter, 2.0f, RED);
+                    Vector2 dif = Vector2Subtract(otherCenter, center);
+                    dif = Vector2Scale(Vector2Normalize(dif), MIN_ENEMY_DST - dst);
+                    target = Vector2Add(target, dif);
+                }
+            }
+        }
+
+        if (numFriends > 0) {
+            cohesion = Vector2Divide(cohesion, (Vector2) { numFriends, numFriends });
+            cohesion = Vector2Subtract(cohesion, center);
+        }
+
+
+        //bzLogInfo("%d %d", numFriends, numEnemies);
+
+        const f32 noiseRange = 10.0f;
+        Vector2 noise = {
+                randFloatRange(-noiseRange, noiseRange),
+                randFloatRange(-noiseRange, noiseRange)
+        };
+        Vector2 followWaypoint = Vector2Zero();
+        if (swarm[i].currWaypoint < game->swamNumWaypoints) {
+            Vector2 waypoint = game->swarmWaypoints[swarm[i].currWaypoint];
+            Vector2 waypointDir = Vector2Subtract(waypoint, center);
+            followWaypoint = waypointDir;
+
+            f32 dst = Vector2Distance(center, waypoint);
+            const f32 WAYPOINT_THRESHOLD = 54.0f;
+            if (dst < WAYPOINT_THRESHOLD) {
+                swarm[i].currWaypoint++;
+            }
+        }
+        const f32 AVOID_FACTOR = 1.0f;
+        const f32 TARGET_FACTOR = 2.2f;
+        const f32 COHESION_FACTOR = 0.10f;
+        const f32 WAYPOINT_FACTOR = 0.45f;
+        const f32 NOISE_FACTOR = 0.2f;
+        Vector2 move = Vector2Zero();
+        move = Vector2Add(move, Vector2Scale(avoid, AVOID_FACTOR));
+        move = Vector2Add(move, Vector2Scale(target, TARGET_FACTOR));
+        //move = Vector2Add(move, Vector2Scale(cohesion, COHESION_FACTOR));
+        move = Vector2Add(move, Vector2Scale(followWaypoint, WAYPOINT_FACTOR));
+        move = Vector2Add(move, Vector2Scale(noise, NOISE_FACTOR));
+
+        //bzLogInfo("%.2f %.2f", move.x, move.y);
+        //DrawLineV(center, Vector2Add(center, Vector2Scale(Vector2Normalize(avoid), 100)), ORANGE);
+
+        steer[i] = move;
+    }
+}
+
 void entityFollowPath(ecs_iter_t *it) {
     const Game *game = ecs_singleton_get(ECS, Game);
 
@@ -307,7 +411,7 @@ void updateBuildingRecruitment(ecs_iter_t *it) {
                 slot->elapsed = 0;
                 PlayerResources *playerRes = &game->playerResources[player];
                 playerRes->pop--;
-                entityRecruit(slot->entityType, placePos, player, game);
+                entityCreate(slot->entityType, placePos, player, game);
                 slot->numRecruiting--;
             }
         }