protected void Start()
{
    contactFilter.useTriggers = false;
    contactFilter.SetLayerMask(Physics2D.GetLayerCollisionMask(gameObject.layer));
    contactFilter.useLayerMask = true;
}

protected void FixedUpdate()
{
    velocity += gravityModifier * Physics2D.gravity * Time.deltaTime;
    velocity.x = targetVelocity.x + impulse.x;

    if (impulse.x > 0) impulse.x = Mathf.Max(0, impulse.x - 10 * Time.deltaTime);
    else if (impulse.x < 0) impulse.x = Mathf.Min(0, impulse.x + 10 * Time.deltaTime);

    grounded = false;

    Vector2 moveAlongGround = new Vector2(groundNormal.y, -groundNormal.x);
    Vector2 deltaPosition = velocity * Time.deltaTime;

    Vector2 move = moveAlongGround * deltaPosition;
    Movement(move, false);

    move = Vector2.up * deltaPosition.y;
    Movement(move, true);
}

void Movement(Vector2 move, bool yMovement)
{
    float distance = move.magnitude;

    if (distance > minMoveDistance)
    {
        int count = rb2d.Cast(move, contactFilter, hitBuffer, distance + shellRadius);
        hitBufferList.Clear();

        for (int i = 0; i < count; i++)
        {
            hitBufferList.Add(hitBuffer[i]);
        }

        for (int i = 0; i < hitBufferList.Count; i++)
        {
            Vector2 currentNormal = hitBufferList[i].normal;

            if (currentNormal.y > minGroundNormalY)
            {
                grounded = true;
                if (yMovement)
                {
                    groundNormal = currentNormal;
                    currentNormal.x = 0;
                }
            }

            float projection = Vector2.Dot(velocity, currentNormal);

            if (projection < 0)
            {
                velocity = velocity - projection * currentNormal;
            }


            float modifiedDistance = hitBufferList[i].distance - shellRadius;
            distance = modifiedDistance < distance ? modifiedDistance : distance;
        }
    }

    if (distance > 0.01F) rb2d.position += move.normalized * distance;
}