Partial tower implementation

game/systems/s_entity.c

@@ -310,6 +310,75 @@ void updateBuildingRecruitment(ecs_iter_t *it) {
     }
 }
 
+void updateTower(ecs_iter_t *it) {
+    Game *game = ecs_singleton_get_mut(ECS, Game);
+    Owner *owner = ecs_field(it, Owner, 1);
+    Tower *tower = ecs_field(it, Tower, 2);
+    Position *position = ecs_field(it, Position, 3);
+    Size *size = ecs_field(it, Size, 4);
+
+    f32 dt = GetFrameTime();
+
+    for (i32 i = 0; i < it->count; i++) {
+        tower[i].fireElapsed += dt;
+        if (tower[i].fireElapsed < tower[i].fireCooldown)
+            continue;
+
+        Vector2 center = {
+                position[i].x + size[i].x * 0.5f,
+                position[i].y - size[i].y * 0.5f,
+        };
+        f32 range = tower[i].range;
+        Rectangle bounds = {
+                center.x - range,
+                center.y - range,
+                range * 2,
+                range * 2,
+        };
+        BzSpatialGridIter spatialIt = bzSpatialGridIter(game->entityGrid,
+                                                 bounds.x, bounds.y,
+                                                 bounds.width, bounds.height);
+
+        ecs_entity_t target = 0;
+        Vector2 targetPos = Vector2Zero();
+        f32 targetDst = INFINITY;
+        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);
+            if (owner[i].player == otherOwner.player)
+                continue;
+            if (other == it->entities[i]) continue;
+            Position otherPos;
+            Rectangle otherBounds;
+            if (!entityGetHitBox(other, &otherPos, &otherBounds))
+                continue;
+            Vector2 otherCenter = {
+                    otherBounds.x + otherBounds.width * 0.5f,
+                    otherBounds.y - otherBounds.height * 0.5f
+            };
+            f32 dst = Vector2Distance(center, otherCenter);
+            if (dst > range)
+                continue;
+            if (targetDst == INFINITY || dst < targetDst) {
+                target = other;
+                targetPos = otherCenter;
+                targetDst = dst;
+            }
+        }
+
+        if (target == 0) continue;
+
+
+
+        tower[i].fireElapsed = 0.0f;
+
+        bzLogInfo("FIRE!");
+    }
+
+}
+
 void renderHealthBar(ecs_iter_t *it) {
     Position *pos = ecs_field(it, Position, 1);
     HitBox *hitbox = ecs_field(it, HitBox, 2);

game/systems/systems.c

@@ -90,6 +90,16 @@ ECS_MOVE(Building, dst, src, {
     *src = (Building) {.type = 0};
 })
 
+ECS_DTOR(AttachedEntity, attacked, {
+    if (ecs_is_alive(ECS, attacked->entity))
+        ecs_delete(ECS,  attacked->entity);
+    attacked->entity = 0;
+})
+ECS_MOVE(AttachedEntity, dst, src, {
+    *dst = *src;
+    src->entity = 0;
+})
+
 void delayDeleteUpdate(ecs_iter_t *it) {
     DelayDelete *delay = ecs_field(it, DelayDelete, 1);
 
@@ -117,6 +127,10 @@ void setupSystems() {
         .dtor = ecs_dtor(Building),
         .move_dtor = ecs_move(Building)
     });
+    ecs_set_hooks(ECS, AttachedEntity, {
+        .dtor = ecs_dtor(AttachedEntity),
+        .move_dtor = ecs_move(AttachedEntity)
+    });
 
     ECS_OBSERVER(ECS, entityPathRemove, EcsOnRemove, Path);
 
@@ -140,6 +154,8 @@ void setupSystems() {
     ECS_SYSTEM(ECS, resetHarvestCount, EcsOnUpdate, Harvestable);
     ECS_SYSTEM(ECS, updateAISystem, EcsOnUpdate, BzBTState);
 
+    ECS_SYSTEM(ECS, updateTower, EcsOnUpdate, Owner, Tower, Position, Size);
+
     ECS_SYSTEM(ECS, updateAnimationState, EcsOnUpdate, Animation, TextureRegion);
     ECS_SYSTEM(ECS, updateAnimation, EcsOnUpdate, Animation, TextureRegion);
     ECS_SYSTEM(ECS, updateEasingSystem, EcsOnUpdate, Easing, Position, HitBox, Rotation);

game/systems/systems.h

@@ -157,6 +157,15 @@ void entityFollowPath(ecs_iter_t *it);
  */
 void updateBuildingRecruitment(ecs_iter_t *it);
 
+/*
+ * 0: Game (singleton for querying entities)
+ * 1: Owner
+ * 2: Tower
+ * 3: Position
+ * 4: Size
+ */
+void updateTower(ecs_iter_t *it);
+
 /*
  * 1: Position
  * 2: HitBox