謎に重い自作関数

function entityHeadVec(e: entity) :: vector:
    set {_vec} to vector from {_e}'s head to location 1 meter infront of {_e}'s head
    return {_vec}

function mobShootGun(entity: entity,dmg: number, prc: number, kb: number, speed: number, spread: number):
    # 雪玉発射
    make {_entity} shoot snowball at speed 0
    # 変数設定
    set {_projectile} to last shot projectile
    # 重力消去
    set gravity of {_projectile} to false
    # 射撃者設定
    set shooter of {_projectile} to {_entity}
    # 弾のばらつきを作るためのランダムなvector生成
    set {_spreadVec} to vector randNum(-1,1),randNum(-1,1),randNum(-1,1)
    # 弾の直進vector生成
    set {_shootVec}  to entityHeadVec({_entity})
    # spreadVecの強さをランダムで再設定
    set normal length of {_spreadVec} to randNum(0,{_spread})*0.1
    # velocityを消去
    delete velocity of {_projectile}
    # 再push
    push {_projectile} {_shootVec}
    push {_projectile} {_spreadVec}
    # 弾速をspeedに基づいて再設定
    set normal length of velocity of {_projectile} to {_speed}
    #broadcast "%{_dmg}, {_prc}, {_spread}%"
    # metadataで性能を保存
    set metadata value "damage"   of {_projectile} to {_dmg}
    set metadata value "piercing" of {_projectile} to {_prc}
    set metadata value "kb"       of {_projectile} to {_kb}

function entityHeadVec(e: entity) :: vector:
    set {_vec} to vector from {_e}'s head to location 1 meter infront of {_e}'s head
    return {_vec}

function mobShootGun(entity: entity,dmg: number, prc: number, kb: number, speed: number, spread: number):
    # 雪玉発射
    make {_entity} shoot snowball at speed 0
    # 変数設定
    set {_projectile} to last shot projectile
    # 重力消去
    set gravity of {_projectile} to false
    # 射撃者設定
    set shooter of {_projectile} to {_entity}
    # 弾のばらつきを作るためのランダムなvector生成
    set {_spreadVec} to vector randNum(-1,1),randNum(-1,1),randNum(-1,1)
    # 弾の直進vector生成
    set {_shootVec}  to entityHeadVec({_entity})
    # spreadVecの強さをランダムで再設定
    set normal length of {_spreadVec} to randNum(0,{_spread})*0.1
    # velocityを消去
    delete velocity of {_projectile}
    # 再push
    push {_projectile} {_shootVec}
    push {_projectile} {_spreadVec}
    # 弾速をspeedに基づいて再設定
    set normal length of velocity of {_projectile} to {_speed}
    #broadcast "%{_dmg}, {_prc}, {_spread}%"
    # metadataで性能を保存
    set metadata value "damage"   of {_projectile} to {_dmg}
    set metadata value "piercing" of {_projectile} to {_prc}
    set metadata value "kb"       of {_projectile} to {_kb}