gimm-platformer-project/Assets/Scripts/tetrominoUserControl.cs

using UnityEngine;
using UnityEngine.SceneManagement;

public class tetrominoUserControl : MonoBehaviour
{
    public GameObject activeTetromino;
    
    // Update is called once per frame
    void Update()
    {
        if (Input.GetButtonDown("tetrisMoveLeft") && activeTetromino != null)
        {
            if (!checkMoveCollisions(Vector2.left))
            {
                activeTetromino.gameObject.transform.position += Vector3.left * 1.0f;
                GetComponent<AudioSource>().Play();
            }
        }
        
        if (Input.GetButtonDown("tetrisMoveRight") && activeTetromino != null)
        {
            if (!checkMoveCollisions(Vector2.right))
            {
                activeTetromino.gameObject.transform.position += Vector3.right * 1.0f;
                GetComponent<AudioSource>().Play();
            }
        }

        if (Input.GetButtonDown("tetrisDrop") && activeTetromino != null)
        {
            if (!checkMoveCollisions(Vector2.down))
            {
                activeTetromino.gameObject.transform.position += Vector3.down * 1.0f;
                GetComponent<AudioSource>().Play();
            }
        }

        if (Input.GetButtonDown("tetrisRotateLeft") && activeTetromino != null)
        {
            checkRotateCollisions(90);
            GetComponent<AudioSource>().Play();
        }
        
        if (Input.GetButtonDown("tetrisRotateRight") && activeTetromino != null)
        {
            checkRotateCollisions(90);
            GetComponent<AudioSource>().Play();
        }

        if (Input.GetButtonDown("Quit"))
        {
            SceneManager.LoadScene("titleScreen");
        }
    }

    public void setActiveTetromino(GameObject tetromino)
    {
        activeTetromino = tetromino;
    }

    public void unsetActiveTetromino()
    {
        activeTetromino = null;
    }

    private bool checkMoveCollisions(Vector2 direction)
    {
        bool wouldCollide = false;
        
        foreach (Transform child in activeTetromino.transform)
        {
            RaycastHit2D collision = Physics2D.Raycast(child.position, direction, 1.0f);
            if (collision.collider != null && collision.collider.transform.parent != child.parent)
            {
                wouldCollide = true;
            }

        }

        if (wouldCollide)
        {
            return true;
        }
        else
        {
            return false;
        }
    }

    private void checkRotateCollisions(int degrees)
    {
        bool wouldCollide = false;
        Collider2D[] results = new Collider2D[10];
        
        //Perform the rotation (will undo later if there's a collision).
        activeTetromino.gameObject.transform.Rotate(0,0,degrees,Space.World);

        foreach (Transform child in activeTetromino.transform)
        {
            //Store any overlapping colliders in the results array.
            child.GetComponent<BoxCollider2D>().OverlapCollider(new ContactFilter2D().NoFilter(), results);
            //If there are collisions...
            foreach (Collider2D a in results)
            {
                //and IF they aren't an extra null item in the array...
                if (a != null)
                {
                    //Only act if the overlap is not with another part of this tetromino.
                    if (a.gameObject.transform.parent != child.parent)
                    {
                        Debug.Log("Collision detected with " + a.gameObject.name);
                        wouldCollide = true;
                    }
                }
            }
        }
        //If we collided, undo the rotation.
        if (wouldCollide)
        {
            activeTetromino.gameObject.transform.Rotate(0,0,degrees * -1,Space.World);
        }
    }
}