Mobile game development is one of the fastest-growing fields in the current gaming industry. Many developers are using the Unity engine to create 2D mobile games, and effectively utilizing touch input is a crucial factor in making a successful game. In this article, I will explain in detail how to develop 2D games using Unity and how to build a touch input system.
1. Setting Up the 2D Game Development Environment
Before starting game development, you need to set up the Unity environment. Here are the steps to set up a Unity 2D project.
- Install Unity: Download and install Unity Hub. Then install the desired version of Unity.
- Create a New Project: Click “New Project” in Unity Hub and select the 2D template. Set the name and location of the project.
- Understand the Unity Editor: It is important to understand the basic components of the Unity editor (Hierarchy, Inspector, Game View, etc.).
2. Understanding Touch Input
On mobile devices, users provide input by touching the screen. In Unity, the Input.touchCount and Input.GetTouch methods are used to handle touch input. These methods provide the number of touch inputs and information about each touch.
2.1 Handling Touch Input
using UnityEngine;
public class TouchInput : MonoBehaviour
{
void Update()
{
// Get the number of touch inputs
if (Input.touchCount > 0)
{
for (int i = 0; i < Input.touchCount; i++)
{
Touch touch = Input.GetTouch(i);
ProcessTouch(touch);
}
}
}
private void ProcessTouch(Touch touch)
{
if (touch.phase == TouchPhase.Began)
{
// Touch began
Debug.Log("Touch began at: " + touch.position);
}
else if (touch.phase == TouchPhase.Moved)
{
// Touch moved
Debug.Log("Touch moved at: " + touch.position);
}
else if (touch.phase == TouchPhase.Ended)
{
// Touch ended
Debug.Log("Touch ended at: " + touch.position);
}
}
}
3. Utilizing Touch Input in Mobile Games
Touch input is mainly used for character movement, UI manipulation, and game interactions. Here, I will explain how to utilize touch input through a simple character movement implementation.
3.1 Writing the Character Movement Script
using UnityEngine;
public class PlayerController : MonoBehaviour
{
public float moveSpeed = 5f;
void Update()
{
if (Input.touchCount > 0)
{
Touch touch = Input.GetTouch(0);
Vector2 touchPos = Camera.main.ScreenToWorldPoint(touch.position);
if (touch.phase == TouchPhase.Moved)
{
// Move the character
Vector2 targetPosition = new Vector2(touchPos.x, transform.position.y);
transform.position = Vector2.MoveTowards(transform.position, targetPosition, moveSpeed * Time.deltaTime);
}
}
}
}
4. UI and Touch Input
UI also plays an important role in games. Unity's UI system is designed to allow player interaction through touch input.
4.1 Creating a UI Button
- Create a UI Canvas: Right-click in the Hierarchy and select UI > Canvas.
- Add a Button: Right-click on the Canvas and select UI > Button to add a button.
- Edit Button Text: Modify the Text component of the button to add text that will be shown to the user.
4.2 Handling Button Click Events
using UnityEngine;
using UnityEngine.UI;
public class UIButtonHandler : MonoBehaviour
{
public Button myButton;
void Start()
{
myButton.onClick.AddListener(OnButtonClick);
}
void OnButtonClick()
{
Debug.Log("Button has been clicked!");
// Implement additional actions upon button click
}
}
5. Application Example of Touch Input: Jumping Character
Now, let's create a jumping character using touch input. This character can jump based on where the screen is touched.
5.1 Writing the Jump Script
using UnityEngine;
public class JumpingCharacter : MonoBehaviour
{
public float jumpForce = 10f;
private bool isGrounded;
void Update()
{
if (Input.touchCount > 0 && isGrounded)
{
Touch touch = Input.GetTouch(0);
if (touch.phase == TouchPhase.Began)
{
Jump();
}
}
}
void Jump()
{
GetComponent().AddForce(new Vector2(0, jumpForce), ForceMode2D.Impulse);
isGrounded = false; // Remains false until touching the ground
}
private void OnCollisionEnter2D(Collision2D collision)
{
if (collision.gameObject.CompareTag("Ground"))
{
isGrounded = true; // Becomes true when touching the ground
}
}
}
6. Final Project: Touch-Based 2D Platform Game
Let's combine all the elements above to create a simple 2D platform game. In this game, the player can move and jump by touching the screen.
6.1 Complete Scripts
- PlayerController.cs: Integrates the movement script explained above with jumping functionality.
- UIButtonHandler.cs: Implements various functions including handling of UI button clicks.
6.2 Integrating Scripts
using UnityEngine;
public class PlatformerCharacter : MonoBehaviour
{
public float moveSpeed = 5f;
public float jumpForce = 10f;
private bool isGrounded;
void Update()
{
HandleMovement();
HandleJump();
}
void HandleMovement()
{
if (Input.touchCount > 0)
{
Touch touch = Input.GetTouch(0);
Vector2 targetPosition = Camera.main.ScreenToWorldPoint(touch.position);
transform.position = Vector2.MoveTowards(transform.position, new Vector2(targetPosition.x, transform.position.y), moveSpeed * Time.deltaTime);
}
}
void HandleJump()
{
if (Input.touchCount > 0 && isGrounded)
{
Touch touch = Input.GetTouch(0);
if (touch.phase == TouchPhase.Began)
{
Jump();
}
}
}
void Jump()
{
GetComponent().AddForce(new Vector2(0, jumpForce), ForceMode2D.Impulse);
isGrounded = false;
}
private void OnCollisionEnter2D(Collision2D collision)
{
if (collision.gameObject.CompareTag("Ground"))
{
isGrounded = true;
}
}
}
7. Conclusion
Now you have learned how to create a 2D mobile game that handles touch input using Unity. Touch input is an essential element in many mobile game developments. Based on this tutorial, unleash your creativity and add various features and fun gameplay to create your own game.
Additionally, if you encounter any problems or have questions during the game development process, you can seek help through Unity forums or developer communities. Keep progressing based on what you learned in this tutorial!