Busier Rows

Lesson 12 of 20 in Coddy's Unity Game: Sky Lanes course.

One obstacle a row is easy: the other two lanes are always free. Later in the run, rows should hold two or three. made already counts the pieces, so it can set how busy a row may be:

int busy = Mathf.Min(3, 1 + made / 12);
int count = Random.Range(1, busy + 1);

Two obstacles must not share a lane. Keep the free lanes in a list and take each one out once it is used. And three walls in a row would leave no way past, so at two walls pick a barrier or a bar instead.

List<int> lanes = new List<int> { -1, 0, 1 };
int pick = Random.Range(0, lanes.Count);
int lane = lanes[pick];
lanes.RemoveAt(pick);

Challenge

Medium

In Fill, work out busy and count as above.
Place count obstacles, each in a lane taken out of lanes.
Count the walls; when kind == 2 and there are already two, pick Random.Range(0, 2) instead.

Try it yourself

using UnityEngine;

public class Runner : MonoBehaviour
{
    public float laneWidth = 2.5f;
    public float laneSpeed = 16f;
    public float jumpHeight = 1.6f;
    public float gravity = -40f;
    public float slideTime = 0.7f;

    public int lane;

    private CharacterController controller;
    private GameManager game;
    private float fallSpeed;
    private float slide;

    void Start()
    {
        controller = GetComponent<CharacterController>();
        game = FindFirstObjectByType<GameManager>();
    }

    void Update()
    {
        if (!game.over)
        {
            if (Input.GetKeyDown(KeyCode.A) || Input.GetKeyDown(KeyCode.LeftArrow)) lane = Mathf.Max(-1, lane - 1);
            if (Input.GetKeyDown(KeyCode.D) || Input.GetKeyDown(KeyCode.RightArrow)) lane = Mathf.Min(1, lane + 1);
            bool jump = Input.GetKeyDown(KeyCode.W) || Input.GetKeyDown(KeyCode.UpArrow) || Input.GetKeyDown(KeyCode.Space);
            if (jump && controller.isGrounded)
            {
                fallSpeed = Mathf.Sqrt(jumpHeight * -2f * gravity);
                StopSlide();
            }
            if ((Input.GetKeyDown(KeyCode.S) || Input.GetKeyDown(KeyCode.DownArrow)) && controller.isGrounded)
            {
                slide = slideTime;
                Resize(0.5f);
            }
        }

        if (slide > 0f)
        {
            slide -= Time.deltaTime;
            if (slide <= 0f) StopSlide();
        }

        if (controller.isGrounded && fallSpeed < 0f) fallSpeed = -2f;
        fallSpeed += gravity * Time.deltaTime;

        float targetX = lane * laneWidth;
        float x = Mathf.MoveTowards(transform.position.x, targetX, laneSpeed * Time.deltaTime);
        Vector3 move = new Vector3(x - transform.position.x, fallSpeed * Time.deltaTime, 0f);
        controller.Move(move);
    }

    void StopSlide()
    {
        if (transform.localScale.y < 1f) Resize(1f);
        slide = 0f;
    }

    void Resize(float height)
    {
        controller.enabled = false;
        transform.position += Vector3.up * (height - transform.localScale.y);
        transform.localScale = new Vector3(1f, height, 1f);
        controller.enabled = true;
    }

    void OnTriggerEnter(Collider other)
    {
        if (game.over) return;
        if (other.CompareTag("Obstacle"))
        {
            game.GameOver();
        }
    }
}