Writing the Player Script

Verificado com a versão: 5


Dificuldade: Intermediário

This is part 9 of 14 of the 2D Roguelike tutorial in which we write the Player script which will take input and control the player's movement.

Writing the Player Script

Intermediário 2D Roguelike tutorial


Please note that this lesson has been updated to reflect changes to Unity's API. Please refer to the upgrade guide PDF found in your asset package download or available directly here.


Code snippet

using UnityEngine;
using System.Collections;
using UnityEngine.SceneManagement;      //Allows us to use SceneManager

    //Player inherits from MovingObject, our base class for objects that can move, Enemy also inherits from this.
    public class Player : MovingObject
        public float restartLevelDelay = 1f;        //Delay time in seconds to restart level.
        public int pointsPerFood = 10;              //Number of points to add to player food points when picking up a food object.
        public int pointsPerSoda = 20;              //Number of points to add to player food points when picking up a soda object.
        public int wallDamage = 1;                  //How much damage a player does to a wall when chopping it.
        private Animator animator;                  //Used to store a reference to the Player's animator component.
        private int food;                           //Used to store player food points total during level.
        //Start overrides the Start function of MovingObject
        protected override void Start ()
            //Get a component reference to the Player's animator component
            animator = GetComponent<Animator>();
            //Get the current food point total stored in GameManager.instance between levels.
            food = GameManager.instance.playerFoodPoints;
            //Call the Start function of the MovingObject base class.
            base.Start ();
        //This function is called when the behaviour becomes disabled or inactive.
        private void OnDisable ()
            //When Player object is disabled, store the current local food total in the GameManager so it can be re-loaded in next level.
            GameManager.instance.playerFoodPoints = food;
        private void Update ()
            //If it's not the player's turn, exit the function.
            if(!GameManager.instance.playersTurn) return;
            int horizontal = 0;     //Used to store the horizontal move direction.
            int vertical = 0;       //Used to store the vertical move direction.
            //Get input from the input manager, round it to an integer and store in horizontal to set x axis move direction
            horizontal = (int) (Input.GetAxisRaw ("Horizontal"));
            //Get input from the input manager, round it to an integer and store in vertical to set y axis move direction
            vertical = (int) (Input.GetAxisRaw ("Vertical"));
            //Check if moving horizontally, if so set vertical to zero.
            if(horizontal != 0)
                vertical = 0;
            //Check if we have a non-zero value for horizontal or vertical
            if(horizontal != 0 || vertical != 0)
                //Call AttemptMove passing in the generic parameter Wall, since that is what Player may interact with if they encounter one (by attacking it)
                //Pass in horizontal and vertical as parameters to specify the direction to move Player in.
                AttemptMove<Wall> (horizontal, vertical);
        //AttemptMove overrides the AttemptMove function in the base class MovingObject
        //AttemptMove takes a generic parameter T which for Player will be of the type Wall, it also takes integers for x and y direction to move in.
        protected override void AttemptMove <T> (int xDir, int yDir)
            //Every time player moves, subtract from food points total.
            //Call the AttemptMove method of the base class, passing in the component T (in this case Wall) and x and y direction to move.
            base.AttemptMove <T> (xDir, yDir);
            //Hit allows us to reference the result of the Linecast done in Move.
            RaycastHit2D hit;
            //If Move returns true, meaning Player was able to move into an empty space.
            if (Move (xDir, yDir, out hit)) 
                //Call RandomizeSfx of SoundManager to play the move sound, passing in two audio clips to choose from.
            //Since the player has moved and lost food points, check if the game has ended.
            CheckIfGameOver ();
            //Set the playersTurn boolean of GameManager to false now that players turn is over.
            GameManager.instance.playersTurn = false;
        //OnCantMove overrides the abstract function OnCantMove in MovingObject.
        //It takes a generic parameter T which in the case of Player is a Wall which the player can attack and destroy.
        protected override void OnCantMove <T> (T component)
            //Set hitWall to equal the component passed in as a parameter.
            Wall hitWall = component as Wall;
            //Call the DamageWall function of the Wall we are hitting.
            hitWall.DamageWall (wallDamage);
            //Set the attack trigger of the player's animation controller in order to play the player's attack animation.
            animator.SetTrigger ("playerChop");
        //OnTriggerEnter2D is sent when another object enters a trigger collider attached to this object (2D physics only).
        private void OnTriggerEnter2D (Collider2D other)
            //Check if the tag of the trigger collided with is Exit.
            if(other.tag == "Exit")
                //Invoke the Restart function to start the next level with a delay of restartLevelDelay (default 1 second).
                Invoke ("Restart", restartLevelDelay);
                //Disable the player object since level is over.
                enabled = false;
            //Check if the tag of the trigger collided with is Food.
            else if(other.tag == "Food")
                //Add pointsPerFood to the players current food total.
                food += pointsPerFood;
                //Disable the food object the player collided with.
                other.gameObject.SetActive (false);
            //Check if the tag of the trigger collided with is Soda.
            else if(other.tag == "Soda")
                //Add pointsPerSoda to players food points total
                food += pointsPerSoda;
                //Disable the soda object the player collided with.
                other.gameObject.SetActive (false);
        //Restart reloads the scene when called.
        private void Restart ()
            //Load the last scene loaded, in this case Main, the only scene in the game.
            SceneManager.LoadScene (0);
        //LoseFood is called when an enemy attacks the player.
        //It takes a parameter loss which specifies how many points to lose.
        public void LoseFood (int loss)
            //Set the trigger for the player animator to transition to the playerHit animation.
            animator.SetTrigger ("playerHit");
            //Subtract lost food points from the players total.
            food -= loss;
            //Check to see if game has ended.
            CheckIfGameOver ();
        //CheckIfGameOver checks if the player is out of food points and if so, ends the game.
        private void CheckIfGameOver ()
            //Check if food point total is less than or equal to zero.
            if (food <= 0) 
                //Call the GameOver function of GameManager.
                GameManager.instance.GameOver ();

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