Dash

Purpose

This feature allows the Player to dash in the direction they are facing.

How it works

The dash is given an initial direction of "Right"

private String direction = "Right";

This is changed depending on which direction the player moves with direction being set as "Left" or "Right" to inform the program which way the player last moved:

case Keys.A:
        walkDirection.add(Vector2Utils.LEFT);
        direction = "Left";
        triggerWalkEvent();
        return true;
 case Keys.D:
        walkDirection.add(Vector2Utils.RIGHT);
        direction = "Right";
        triggerWalkEvent();
        return true;

From this when the dash key 'L' is pressed, a horizontal vector is applied in the given direction of the direction the player last moved.

case Keys.L:
    if (direction.equals("Left")) {
    dashDirection.add(Vector2Utils.LEFT); // Adds to the x vector to the left
    } else {
    dashDirection.add(Vector2Utils.RIGHT); // Adds to the x vector to the right
    }
    triggerDashEvent();
    dashed = true;
    return true;

The triggerDashEvent() function then sends this direction through the events system:

private void triggerDashEvent() {
    // Player has an x velocity in the direction they last went or are going
    entity.getEvents().trigger("dash", dashDirection);
    dashDirection.x = 0;
    dashed = false;
  }

This triggers the dash event and passes dashDirection to the listener for this event:

entity.getEvents().addListener("dash", this::dash);

Applying the Dash

The dash creates an impulse vector by scaling the dash direction by dashspeed then the linear impulse vector is applied to the player's body.

void dash(Vector2 direction) {
  Body body = physicsComponent.getBody();
  Vector2 impulse = direction.cpy().scl(dashspeed);
  body.applyLinearImpulse(impulse, body.getWorldCenter(), true);
}