grid-based block placement system with touch input

Questions & Answers
1

I created a grid-based block placement system with mouse input like this video:

At the moment I can only place blocks with a click of the mouse at the point I am looking at.
Now I want to place the blocks with touch input on mobile devices.
I am new to Unity so can someone give me hints or even better adjust the code right away?
Here is the code:

`using System.Collections;  
using System.Collections.Generic;  
using UnityEngine;  
public class BuildingSystem : MonoBehaviour  

{

    [SerializeField]
    private Camera playerCamera;

    private bool buildModeOn = true;
    private bool canBuild = true;

    private BlockSystem bSys;

    [SerializeField]
    private LayerMask buildableSurfacesLayer;

    private Vector3 buildPos;

    private GameObject currentTemplateBlock;

    [SerializeField]
    private GameObject blockTemplatePrefab;
    [SerializeField]
    private GameObject blockPrefab;

    [SerializeField]
    private Material templateMaterial;

    private int blockSelectCounter = 0;

    private void Start()
    {
        bSys = GetComponent<BlockSystem>();
    }

    private void Update()
    {
        if (Input.GetKeyDown("e"))
        {
            buildModeOn = !buildModeOn;

            if (buildModeOn)
            {
                Cursor.lockState = CursorLockMode.Locked;
            }
            else
            {
                Cursor.lockState = CursorLockMode.None;
            }
        }

        if (Input.GetKeyDown("r"))
        {
            blockSelectCounter++;
            if (blockSelectCounter >= bSys.allBlocks.Count) blockSelectCounter = 0;
        }

        if (buildModeOn)
        {
            RaycastHit buildPosHit;

            if (Physics.Raycast(playerCamera.ScreenPointToRay(new Vector3(Screen.width / 2, Screen.height / 2, 0)), out buildPosHit, 10, buildableSurfacesLayer))
            {
                Vector3 point = buildPosHit.point;
                buildPos = new Vector3(Mathf.Round(point.x), Mathf.Round(point.y), Mathf.Round(point.z));
                canBuild = true;
            }
            else
            {
                Destroy(currentTemplateBlock.gameObject);
                canBuild = false;
            }
        }

        if (!buildModeOn && currentTemplateBlock != null)
        {
            Destroy(currentTemplateBlock.gameObject);
            canBuild = false;
        }

        if (canBuild && currentTemplateBlock == null)
        {
            currentTemplateBlock = Instantiate(blockTemplatePrefab, buildPos, Quaternion.identity);
            currentTemplateBlock.GetComponent<MeshRenderer>().material = templateMaterial;
        }

        if (canBuild && currentTemplateBlock != null)
        {
            currentTemplateBlock.transform.position = buildPos;

            if (Input.GetMouseButtonDown(0))
            {
                PlaceBlock();
            }
        }
    }

    private void PlaceBlock()
    {
        GameObject newBlock = Instantiate(blockPrefab, buildPos, Quaternion.identity);
        Block tempBlock = bSys.allBlocks[blockSelectCounter];
        newBlock.name = tempBlock.blockName + "-Block";
        newBlock.GetComponent<MeshRenderer>().material = tempBlock.blockMaterial;
    }
}`
2

Unity’s touchscreen input system works a little differently from its normal mouse and keyboard input system, and you’ll have to fine-tune the way it works to your liking. A simple way of replacing a mouse click with the tap of a finger would be like this:

if (Input.touchCount > 0) // if at least one finger is touching the screen
{
    if (Input.touches[0].phase == TouchPhase.Began) // if the first finger (ignoring the rest) just touched the screen
    {
        PlaceBlock();
    }
}