Cómo hacer un juego de serpientes en Unity
En esta publicación, mostraré cómo crear un Juego de serpientes clásico en Unity.
Unity versión utilizada en este tutorial: Unity 2018.3.0f2 (64 bits)
Paso 1: crea el guión
Al ser un "One Script Game", este tutorial solo requiere 1 script:
SC_SnakeGameGenerator.cs
//You are free to use this script in Free or Commercial projects
//sharpcoderblog.com @2019
using System.Collections.Generic;
using UnityEngine;
public class SC_SnakeGameGenerator : MonoBehaviour
{
//Game area resolution, the higher number means more blocks
public int areaResolution = 22;
//Snake movement speed
public float snakeSpeed = 10f;
//Main Camera
public Camera mainCamera;
//Materials
public Material groundMaterial;
public Material snakeMaterial;
public Material headMaterial;
public Material fruitMaterial;
//Grid system
Renderer[] gameBlocks;
//Snake coordenates
List<int> snakeCoordinates = new List<int>();
enum Direction { Up, Down, Left, Right };
Direction snakeDirection = Direction.Right;
float timeTmp = 0;
//Block where the fruit is placed
int fruitBlockIndex = -1;
//Total accumulated points
int totalPoints = 0;
//Game status
bool gameStarted = false;
bool gameOver = false;
//Camera scaling
Bounds targetBounds;
//Text styling
GUIStyle mainStyle = new GUIStyle();
// Start is called before the first frame update
void Start()
{
//Generate play area
gameBlocks = new Renderer[areaResolution * areaResolution];
for (int x = 0; x < areaResolution; x++)
{
for (int y = 0; y < areaResolution; y++)
{
GameObject quadPrimitive = GameObject.CreatePrimitive(PrimitiveType.Quad);
quadPrimitive.transform.position = new Vector3(x, 0, y);
Destroy(quadPrimitive.GetComponent<Collider>());
quadPrimitive.transform.localEulerAngles = new Vector3(90, 0, 0);
quadPrimitive.transform.SetParent(transform);
gameBlocks[(x * areaResolution) + y] = quadPrimitive.GetComponent<Renderer>();
targetBounds.Encapsulate(gameBlocks[(x * areaResolution) + y].bounds);
}
}
//Scale the MainCamera to fit the game blocks
mainCamera.transform.eulerAngles = new Vector3(90, 0, 0);
mainCamera.orthographic = true;
float screenRatio = (float)Screen.width / (float)Screen.height;
float targetRatio = targetBounds.size.x / targetBounds.size.y;
if (screenRatio >= targetRatio)
{
mainCamera.orthographicSize = targetBounds.size.y / 2;
}
else
{
float differenceInSize = targetRatio / screenRatio;
mainCamera.orthographicSize = targetBounds.size.y / 2 * differenceInSize;
}
mainCamera.transform.position = new Vector3(targetBounds.center.x, targetBounds.center.y + 1, targetBounds.center.z);
//Generate the Snake with 3 blocks
InitializeSnake();
ApplyMaterials();
mainStyle.fontSize = 24;
mainStyle.alignment = TextAnchor.MiddleCenter;
mainStyle.normal.textColor = Color.white;
}
void InitializeSnake()
{
snakeCoordinates.Clear();
int firstlock = Random.Range(0, areaResolution - 1) + (areaResolution * 3);
snakeCoordinates.Add(firstlock);
snakeCoordinates.Add(firstlock - areaResolution);
snakeCoordinates.Add(firstlock - (areaResolution * 2));
gameBlocks[snakeCoordinates[0]].transform.localEulerAngles = new Vector3(90, 90, 0);
fruitBlockIndex = -1;
timeTmp = 1;
snakeDirection = Direction.Right;
totalPoints = 0;
}
// Update is called once per frame
void Update()
{
if (!gameStarted)
{
if (Input.anyKeyDown)
{
gameStarted = true;
}
return;
}
if (gameOver)
{
//Flicker the snake blocks
if (timeTmp < 0.44f)
{
timeTmp += Time.deltaTime;
}
else
{
timeTmp = 0;
for (int i = 0; i < snakeCoordinates.Count; i++)
{
if (gameBlocks[snakeCoordinates[i]].sharedMaterial == groundMaterial)
{
gameBlocks[snakeCoordinates[i]].sharedMaterial = (i == 0 ? headMaterial : snakeMaterial);
}
else
{
gameBlocks[snakeCoordinates[i]].sharedMaterial = groundMaterial;
}
}
}
if (Input.GetKeyDown(KeyCode.Space))
{
InitializeSnake();
ApplyMaterials();
gameOver = false;
gameStarted = false;
}
}
else
{
if (timeTmp < 1)
{
timeTmp += Time.deltaTime * snakeSpeed;
}
else
{
timeTmp = 0;
if (snakeDirection == Direction.Right || snakeDirection == Direction.Left)
{
//Detect if the Snake hit the sides
if (snakeDirection == Direction.Left && snakeCoordinates[0] < areaResolution)
{
gameOver = true;
return;
}
else if (snakeDirection == Direction.Right && snakeCoordinates[0] >= (gameBlocks.Length - areaResolution))
{
gameOver = true;
return;
}
int newCoordinate = snakeCoordinates[0] + (snakeDirection == Direction.Left ? -areaResolution : areaResolution);
//Snake has ran into itself, game over
if (snakeCoordinates.Contains(newCoordinate))
{
gameOver = true;
return;
}
if (newCoordinate < gameBlocks.Length)
{
for (int i = snakeCoordinates.Count - 1; i > 0; i--)
{
snakeCoordinates[i] = snakeCoordinates[i - 1];
}
snakeCoordinates[0] = newCoordinate;
gameBlocks[snakeCoordinates[0]].transform.localEulerAngles = new Vector3(90, (snakeDirection == Direction.Left ? -90 : 90), 0);
}
}
else if (snakeDirection == Direction.Up || snakeDirection == Direction.Down)
{
//Detect if snake hits the top or bottom
if (snakeDirection == Direction.Up && (snakeCoordinates[0] + 1) % areaResolution == 0)
{
gameOver = true;
return;
}
else if (snakeDirection == Direction.Down && (snakeCoordinates[0] + 1) % areaResolution == 1)
{
gameOver = true;
return;
}
int newCoordinate = snakeCoordinates[0] + (snakeDirection == Direction.Down ? -1 : 1);
//Snake has ran into itself, game over
if (snakeCoordinates.Contains(newCoordinate))
{
gameOver = true;
return;
}
if (newCoordinate < gameBlocks.Length)
{
for (int i = snakeCoordinates.Count - 1; i > 0; i--)
{
snakeCoordinates[i] = snakeCoordinates[i - 1];
}
snakeCoordinates[0] = newCoordinate;
gameBlocks[snakeCoordinates[0]].transform.localEulerAngles = new Vector3(90, (snakeDirection == Direction.Down ? 180 : 0), 0);
}
}
ApplyMaterials();
}
if (Input.GetKeyDown(KeyCode.RightArrow))
{
int newCoordinate = snakeCoordinates[0] + areaResolution;
if (!ContainsCoordinate(newCoordinate))
{
snakeDirection = Direction.Right;
}
}
if (Input.GetKeyDown(KeyCode.LeftArrow))
{
int newCoordinate = snakeCoordinates[0] - areaResolution;
if (!ContainsCoordinate(newCoordinate))
{
snakeDirection = Direction.Left;
}
}
if (Input.GetKeyDown(KeyCode.UpArrow))
{
int newCoordinate = snakeCoordinates[0] + 1;
if (!ContainsCoordinate(newCoordinate))
{
snakeDirection = Direction.Up;
}
}
if (Input.GetKeyDown(KeyCode.DownArrow))
{
int newCoordinate = snakeCoordinates[0] - 1;
if (!ContainsCoordinate(newCoordinate))
{
snakeDirection = Direction.Down;
}
}
}
if (fruitBlockIndex < 0)
{
//Place a fruit block
int indexTmp = Random.Range(0, gameBlocks.Length - 1);
//Check if the block is not occupied with a snake block
for (int i = 0; i < snakeCoordinates.Count; i++)
{
if (snakeCoordinates[i] == indexTmp)
{
indexTmp = -1;
break;
}
}
fruitBlockIndex = indexTmp;
}
}
void ApplyMaterials()
{
//Apply Snake material
for (int i = 0; i < gameBlocks.Length; i++)
{
gameBlocks[i].sharedMaterial = groundMaterial;
bool fruitPicked = false;
for (int a = 0; a < snakeCoordinates.Count; a++)
{
if (snakeCoordinates[a] == i)
{
gameBlocks[i].sharedMaterial = (a == 0 ? headMaterial : snakeMaterial);
}
if (snakeCoordinates[a] == fruitBlockIndex)
{
//Pick a fruit
fruitPicked = true;
}
}
if (fruitPicked)
{
fruitBlockIndex = -1;
//Add new block
int snakeBlockRotationY = (int)gameBlocks[snakeCoordinates[snakeCoordinates.Count - 1]].transform.localEulerAngles.y;
//print(snakeBlockRotationY);
if (snakeBlockRotationY == 270)
{
snakeCoordinates.Add(snakeCoordinates[snakeCoordinates.Count - 1] + areaResolution);
}
else if (snakeBlockRotationY == 90)
{
snakeCoordinates.Add(snakeCoordinates[snakeCoordinates.Count - 1] - areaResolution);
}
else if (snakeBlockRotationY == 0)
{
snakeCoordinates.Add(snakeCoordinates[snakeCoordinates.Count - 1] + 1);
}
else if (snakeBlockRotationY == 180)
{
snakeCoordinates.Add(snakeCoordinates[snakeCoordinates.Count - 1] - 1);
}
totalPoints++;
}
if (i == fruitBlockIndex)
{
gameBlocks[i].sharedMaterial = fruitMaterial;
gameBlocks[i].transform.localEulerAngles = new Vector3(90, 0, 0);
}
}
}
bool ContainsCoordinate(int coordinate)
{
for (int i = 0; i < snakeCoordinates.Count; i++)
{
if (snakeCoordinates[i] == coordinate)
{
return true;
}
}
return false;
}
void OnGUI()
{
//Display Player score and other info
if (gameStarted)
{
GUI.Label(new Rect(Screen.width / 2 - 100, 5, 200, 20), totalPoints.ToString(), mainStyle);
}
else
{
GUI.Label(new Rect(Screen.width / 2 - 100, Screen.height / 2 - 10, 200, 20), "Press Any Key to Play\n(Use Arrows to Change Direction)", mainStyle);
}
if (gameOver)
{
GUI.Label(new Rect(Screen.width / 2 - 100, Screen.height / 2 - 20, 200, 40), "Game Over\n(Press 'Space' to Restart)", mainStyle);
}
}
}El guión anterior crea una cuadrícula de quads primitivos, luego cambia sus materiales a uno de los cuatro: un material de fondo, un material de cabeza de serpiente, un material de cuerpo de serpiente o un material de manzana. También coloca automáticamente la cámara directamente encima del sistema de cuadrícula y cambia su tamaño ortográfico para encapsular los límites colectivos de todos los bloques.
Paso 2: Configura el juego de la serpiente
Ahora configuremos el juego Snake usando el script anterior:
- Crear nueva escena
- Cambie la resolución de la vista del juego para que el ancho y el alto sean iguales (por ejemplo, 600 px x 600 px).
- Crea un nuevo GameObject (GameObject -> Crear vacío) y asígnale un nombre "_GameGenerator"
- Adjunte el script SC_SnakeGameGenerator.cs al objeto _GameGenerator
Como notarás, SC_SnakeGameGenerator tiene algunas variables que deben asignarse:
- La variable Cámara principal se explica por sí misma; asigne la cámara principal predeterminada.
- Ahora para los materiales, cree 4 materiales (Clic derecho -> Crear -> Material) y asígneles el nombre respectivamente "ground_material", "snake_material", "head_material" y "fruit_material":
Para el ground_material cambie su Shader a Apagado/Color y cambie el Color Principal a negro:
Para los otros 3 Materiales cambie el Shader a Apagado/Textura y asigne las siguientes texturas:
Para material_serpiente:
Para material_cabeza:
Para material_fruta:
- Asignar los materiales a variables.
Ahora es el momento de presionar Play y probar el juego:
Todo funciona como se esperaba, ahora tienes un juego de serpientes jugable en Unity.