Assistance with unity 2d melee attack

Question

I'm making a 2D platform fighter but I've looked all over the internet and I'm not sure i can find what I'm looking for. I'm trying to make a melee attack to when you hit R-click on the mouse it dashes in the direction you are walking.

Ill try and figure out knock-back or dmg later. Any help with the movement of the script?

I'll list my current movement code below.

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

namespace NinjaController {

[RequireComponent(typeof(Rigidbody2D))]
[RequireComponent(typeof(Collider2D))]
public class NinjaController : MonoBehaviour {

private Rigidbody2D RBody { get; set; }

[SerializeField]
private PhysicsParams physicsParams;

public Vector2 Velocity { get { return(RBody.velocity); } }

public Vector2 VelocityRelativeGround { get { return(Velocity / PhysicsParams.onGroundMaxVelHorizontal); } }

private float timeRealLastGroundCollision = 0;
private float timeRealLastWallLeftCollision = 0;
private float timeRealLastWallRightCollision = 0;

public bool IsOnGround {
  get {
    return GetIsColliding(timeRealLastGroundCollision);
  }
}

public bool IsOnWallLeft {
  get {
    return GetIsColliding(timeRealLastWallLeftCollision);
  }
}

public bool IsOnWallRight {
  get {
    return GetIsColliding(timeRealLastWallRightCollision);
  }
}

public bool IsInAir { get { return isPlayerInAir; } }

private bool GetIsColliding(float timeLastCollision) {
  return(Time.realtimeSinceStartup < timeLastCollision + 0.05f);
}

private Vector2 currentVelocity = Vector2.zero;
private Vector2 currentForce = Vector2.zero;

private float EntityMass { get { return(PhysicsParams.playerMass); } }

private bool isPlayerInAir = false;
private bool keyJumpRetrigger = false;
private bool keyJumpPressed = false;
private bool isPlayerOnWall = false;

public PhysicsParams PhysicsParams {
  get { return physicsParams; }
  set { physicsParams = value; }
}

public Vector2 CurrentForce { get { return currentForce; } }

public bool IsOnWall { get { return isPlayerOnWall; } }

private List<Renderer> allRenderers;

public List<Renderer> AllRenderers { get { return allRenderers; } }

public Vector3 Position {
  get {
    return transform.position;
  }
  set {
    transform.position = value;
  }
}

public Vector2 Position2D {
  get {
    return transform.position;
  }
  set {
    transform.position = value;
  }
}

public void Awake() {
  RBody = GetComponent<Rigidbody2D>();
  allRenderers = new List<Renderer>(GetComponentsInChildren<Renderer>(true));
}

public void Update() {

  //let's reset forces to 0 and then add regular gravitation
  SimResetForce();
  SimAddForce(new Vector2(0, PhysicsParams.gameGravity) * EntityMass);

  //process key input (like jumping key pressed, etc...)
  ProcessInput();

  //simulate position and velocity based on all acting forces
  ComputeVelocity(Time.deltaTime);

  //collision detection with static world
  isPlayerOnWall = IsOnWallLeft || IsOnWallRight;
  isPlayerInAir = IsOnGround == false;
}

private void SimResetForce() {
  currentForce = Vector2.zero;
}

private void SimAddForce(Vector2 force) {
  currentForce += force;
}

private void ComputeVelocity(float dt) {

  currentVelocity += (currentForce / EntityMass) * dt;

  //let's cap the speed in case its higher than the max
  if (isPlayerInAir) {
    currentVelocity.x = Mathf.Clamp(currentVelocity.x, -PhysicsParams.inAirMaxVelHorizontal, PhysicsParams.inAirMaxVelHorizontal);
  } else {
    currentVelocity.x = Mathf.Clamp(currentVelocity.x, -PhysicsParams.onGroundMaxVelHorizontal, PhysicsParams.onGroundMaxVelHorizontal);
  }

  RBody.velocity = currentVelocity;
}

private void ProcessInput() {

  bool isKeyDownJump = Input.GetButton("Jump");
  float inputAxisX = Input.GetAxisRaw("Horizontal");
  bool isKeyDownLeft = inputAxisX < -0.5f;
  bool isKeyDownRight = inputAxisX > 0.5f;

  //-----------------
  //JUMPING LOGIC:
  //player is on ground
  if (isPlayerInAir == false) {
    //in case the player is on ground and does not press the jump key, he
    //should be allowed to jump
    if (isKeyDownJump == false) {
      keyJumpRetrigger = true;
    }

    //did player press down the jump button?
    if (isKeyDownJump == true && keyJumpRetrigger == true) {
      keyJumpPressed = true;
      keyJumpRetrigger = false;

      //when pressing jump on ground we set the upwards velocity directly
      currentVelocity = new Vector2(currentVelocity.x, PhysicsParams.jumpUpVel);
    }
  } else if (isPlayerOnWall == true) {
    //let's allow jumping again in case of being on the wall
    if (isKeyDownJump == false) {
      keyJumpRetrigger = true;
    }
    if (currentVelocity.y < 0) {//apply friction when moving downwards
      SimAddForce(new Vector2(0, PhysicsParams.wallFriction) * EntityMass);
    }
    if (currentVelocity.y < PhysicsParams.wallFrictionStrongVelThreshold) {//apply even more friction when moving downwards fast
      SimAddForce(new Vector2(0, PhysicsParams.wallFrictionStrong) * EntityMass);
    }
    if (isKeyDownJump == true && keyJumpRetrigger == true) {
      keyJumpPressed = true;
      keyJumpRetrigger = false;

      //in case we are moving down -> let's set the velocity directly
      //in case we are moving up -> sum up velocity
      if (IsOnWallLeft == true) {
        if (currentVelocity.y <= 0) {
          currentVelocity = new Vector2(PhysicsParams.jumpWallVelHorizontal, PhysicsParams.jumpWallVelVertical);
        } else {
          currentVelocity = new Vector2(PhysicsParams.jumpWallVelHorizontal, currentVelocity.y + PhysicsParams.jumpWallVelVertical);
        }
      } else if (IsOnWallRight == true) {
        if (currentVelocity.y <= 0)
          currentVelocity = new Vector2(-PhysicsParams.jumpWallVelHorizontal, PhysicsParams.jumpWallVelVertical);
        else
          currentVelocity = new Vector2(-PhysicsParams.jumpWallVelHorizontal, currentVelocity.y + PhysicsParams.jumpWallVelVertical);
      }
    }
  }
  //did player lift the jump button?
  if (isKeyDownJump == false) {
    keyJumpPressed = false;
  }

  //let's apply force in case we are holding the jump key during a jump.
  if (keyJumpPressed == true) {
    SimAddForce(new Vector2(0, PhysicsParams.jumpUpForce) * EntityMass);
  }
  //however let's stop doing that as soon as we fall down after the up-phase.
  if (keyJumpPressed == true && currentVelocity.y <= 0) {
    keyJumpPressed = false;
  }

  //let's apply additional gravity in case we're in air moving up but not holding the jump button
  if (keyJumpPressed == false && isPlayerInAir == true && currentVelocity.y > 0) {
    SimAddForce(new Vector2(0, PhysicsParams.jumpGravity) * EntityMass);
  }

  //-----------------
  //IN AIR SIDEWAYS:
  if (isPlayerInAir == true) {
    //steering into moving direction (slow accel)
    if (isKeyDownLeft == true && currentVelocity.x <= 0)
      SimAddForce(new Vector2(-PhysicsParams.inAirMoveHorizontalForce, 0) * EntityMass);
    else if (isKeyDownRight == true && currentVelocity.x >= 0)
      SimAddForce(new Vector2(PhysicsParams.inAirMoveHorizontalForce, 0) * EntityMass);
    //steering against moving direction (fast reverse accel)
    else if (isKeyDownLeft == true && currentVelocity.x >= 0)
      SimAddForce(new Vector2(-PhysicsParams.inAirMoveHorizontalForceReverse, 0) * EntityMass);
    else if (isKeyDownRight == true && currentVelocity.x <= 0)
      SimAddForce(new Vector2(PhysicsParams.inAirMoveHorizontalForceReverse, 0) * EntityMass);
  }

  //-----------------
  //ON GROUND SIDEWAYS:
  if (isPlayerInAir == false) {
    //steering into moving direction (slow accel)
    if (isKeyDownLeft == true && currentVelocity.x <= 0)
      SimAddForce(new Vector2(-PhysicsParams.onGroundMoveHorizontalForce, 0) * EntityMass);
    else if (isKeyDownRight == true && currentVelocity.x >= 0)
      SimAddForce(new Vector2(PhysicsParams.onGroundMoveHorizontalForce, 0) * EntityMass);
    //steering against moving direction (fast reverse accel)
    else if (isKeyDownLeft == true && currentVelocity.x >= 0)
      SimAddForce(new Vector2(-PhysicsParams.onGroundMoveHorizontalForceReverse, 0) * EntityMass);
    else if (isKeyDownRight == true && currentVelocity.x <= 0)
      SimAddForce(new Vector2(PhysicsParams.onGroundMoveHorizontalForceReverse, 0) * EntityMass);
    //not steering -> brake due to friction.
    else if (isKeyDownLeft != true && isKeyDownRight != true && currentVelocity.x > 0)
      SimAddForce(new Vector2(-PhysicsParams.groundFriction, 0) * EntityMass);
    else if (isKeyDownLeft != true && isKeyDownRight != true && currentVelocity.x < 0)
      SimAddForce(new Vector2(PhysicsParams.groundFriction, 0) * EntityMass);

    //in case the velocity is close to 0 and no keys are pressed we should make the the player stop.
    //to do this let's first undo the prior friction force, and then set the velocity to 0.
    if (isKeyDownLeft != true && isKeyDownRight != true && currentVelocity.x > 0 && currentVelocity.x < PhysicsParams.groundFrictionEpsilon) {
      SimAddForce(new Vector2(PhysicsParams.groundFriction, 0) * EntityMass);
      currentVelocity.x = 0;
    } else if (isKeyDownLeft != true && isKeyDownRight != true && currentVelocity.x < 0 && currentVelocity.x > -PhysicsParams.groundFrictionEpsilon) {
      SimAddForce(new Vector2(-PhysicsParams.groundFriction, 0) * EntityMass);
      currentVelocity.x = 0;
    }
  }
}

public void ResetVelocity() {
  currentVelocity = Vector2.zero;
}

public void OnCollisionStay2D(Collision2D collision) {

  foreach (ContactPoint2D contactPoint in collision.contacts) {
    if (GetIsVectorClose(new Vector2(0, 1), contactPoint.normal)) {
      timeRealLastGroundCollision = Time.realtimeSinceStartup;
      currentVelocity.y = Mathf.Clamp(currentVelocity.y, 0, Mathf.Abs(currentVelocity.y));
    }
    if (GetIsVectorClose(new Vector2(1, 0), contactPoint.normal)) {
      timeRealLastWallLeftCollision = Time.realtimeSinceStartup;
      currentVelocity.x = Mathf.Clamp(currentVelocity.x, 0, Mathf.Abs(currentVelocity.x));
    }
    if (GetIsVectorClose(new Vector2(-1, 0), contactPoint.normal)) {
      timeRealLastWallRightCollision = Time.realtimeSinceStartup;
      currentVelocity.x = Mathf.Clamp(currentVelocity.x, -Mathf.Abs(currentVelocity.x), 0);
    }
    if(GetIsVectorClose(Vector2.down, contactPoint.normal)) {
      currentVelocity.y = Mathf.Clamp(currentVelocity.y, -Mathf.Abs(currentVelocity.y), 0);
    }
  }
}

private bool GetIsVectorClose(Vector2 vectorA, Vector2 vectorB) {
  return(Mathf.Approximately(0, Vector2.Distance(vectorA, vectorB)));
}

public void OnLifeChanged (int life, Vector2 contactVector) {
  const float forceEnemyCollision = 15.0f;
  currentVelocity = contactVector.normalized * forceEnemyCollision;
}

public void ResetPlayer() {
  currentVelocity = Vector2.zero;
}
}
}

Answer 1

For dashing, it will be something along the line of:

bool isDashing;
float currentDashTime = 0; // How long in seconds since the dash started.
float dashTime = 1f; // How long in seconds will the dash be.
float dashSpeed = 10f;

private void Update()
{
    if (Input.GetMouseButtonDown(1)) // Right click
    {
        if (!isDashing) StartCoroutine(Dash());
    }
}

private IEnumerator Dash()
{
    isDashing = true;
    currentDashTime = 0;
    Vector2 facingDirection = new Vector2(transform.right.x, transform.right.y)
    rb2d.AddForce(facingDirection * dashSpeed);

    while (currentDashTime < dashTime)
    {
        currentDashTime += Time.deltaTime;
        yield return null;
    }

    // If you want the character to stop after dashing ends.
    // rb.velocity = Vector2.zero;

    isDashing = false;
}

As for melee attacks, I'll recommend looking into 2D Raycasts, provided your enemies have colliders on them. You can raycast before you start dashing so you know what you will collide with during the dash beforehand.

RaycastHit2D hit = Physics2D.Raycast(transform.position, facingDirection);
if (hit.collider != null)
{
    // Check for enemy, damage the enemy... etc.
}

Use Physics2D.RaycastAll if you want to get all enemies hit along a line. Physics2D.RayCast only returns the first collider hit.