I am trying to create a increase in movement using shift key, but I don't know how to

Question

Being new to coding, I am building a game.
I would like to make the Shift key increase the character speed.

var FirstPersonMovement = pc.createScript('firstPersonMovement');

FirstPersonMovement.attributes.add('camera', {
    type: 'entity',
    description: 'Optional, assign a camera entity, otherwise one is created'
});

FirstPersonMovement.attributes.add('power', {
    type: 'number',
    default: 2500,
    description: 'Adjusts the speed of player movement'
});

FirstPersonMovement.attributes.add('lookSpeed', {
    type: 'number',
    default: 0.25,
    description: 'Adjusts the sensitivity of looking'
});

// initialize code called once per entity
FirstPersonMovement.prototype.initialize = function() {
    this.force = new pc.Vec3();
    this.eulers = new pc.Vec3();

    var app = this.app;

    // Listen for mouse move events
    app.mouse.on("mousemove", this._onMouseMove, this);

    // when the mouse is clicked hide the cursor
    app.mouse.on("mousedown", function () {
        app.mouse.enablePointerLock();
    }, this);

    // Check for required components
    if (!this.entity.collision) {
        console.error("First Person Movement script needs to have a 'collision' component");
    }

    if (!this.entity.rigidbody || this.entity.rigidbody.type !== pc.BODYTYPE_DYNAMIC) {
        console.error("First Person Movement script needs to have a DYNAMIC 'rigidbody' component");
    }
};

// update code called every frame
FirstPersonMovement.prototype.update = function(dt) {
    // If a camera isn't assigned from the Editor, create one
    if (!this.camera) {
        this._createCamera();
    }

    var force = this.force;
    var app = this.app;

    // Get camera directions to determine movement directions
    var forward = this.camera.forward;
    var right = this.camera.right;


    // movement
    var x = 0;
    var z = 0;

    // Use W-A-S-D and SHIFT keys to move player
    // Check for key presses
    if (app.keyboard.isPressed(pc.KEY_A) || app.keyboard.isPressed(pc.KEY_Q)) {
        x -= right.x;
        z -= right.z;
    }

    if (app.keyboard.isPressed(pc.KEY_D)) {
        x += right.x;
        z += right.z;
    }

    if (app.keyboard.isPressed(pc.KEY_W)) {
        x += forward.x;
        z += forward.z;
    }
        
    if (app.keyboard.isPressed(pc.KEY_S))  {
        x -= forward.x;
        z -= forward.z;
    }
    if (app.keyboard.isPressed(pc.KEY_SHIFT)) {
        x += forward.x;
        z += forward.z;
    }

    // use direction from keypresses to apply a force to the character
    if (x !== 0 && z !== 0) {
        force.set(x, 0, z).normalize().scale(this.power);
        this.entity.rigidbody.applyForce(force);
    }

    // update camera angle from mouse events
    this.camera.setLocalEulerAngles(this.eulers.y, this.eulers.x, 0);
};

FirstPersonMovement.prototype._onMouseMove = function (e) {
    // If pointer is disabled
    // If the left mouse button is down update the camera from mouse movement
    if (pc.Mouse.isPointerLocked() || e.buttons[0]) {
        this.eulers.x -= this.lookSpeed * e.dx;
        this.eulers.y -= this.lookSpeed * e.dy;
    }
};

FirstPersonMovement.prototype._createCamera = function () {
    // If user hasn't assigned a camera, create a new one
    this.camera = new pc.Entity();
    this.camera.setName("First Person Camera");
    this.camera.addComponent("camera");
    this.entity.addChild(this.camera);
    this.camera.translateLocal(0, 0.5, 0);
};

I have already created a Shift movement (for character movement) but it required a lot of code. That code can found here at PlayCanvas

Answer 1

Before moving in any direction, check if the shift key is pressed. Then based on if it is pressed or not, change the amount of movement that occurs.

You can change the movement by adding 0 to any direction by default, and a different number, like 5 in the example, whenever the shift key is pressed.

let extraVelocity = 0;

if (app.keyboard.isPressed(pc.KEY_SHIFT)) {
  extraVelocity = 5;
}

if (app.keyboard.isPressed(pc.KEY_A) || app.keyboard.isPressed(pc.KEY_Q)) {
  x -= (right.x + extraVelocity);
  z -= (right.z + extraVelocity);
}

if (app.keyboard.isPressed(pc.KEY_D)) {
  x += (right.x + extraVelocity);
  z += (right.z + extraVelocity);
}

if (app.keyboard.isPressed(pc.KEY_W)) {
  x += (forward.x + extraVelocity);
  z += (forward.z + extraVelocity);
}

if (app.keyboard.isPressed(pc.KEY_S)) {
  x -= (forward.x + extraVelocity);
  z -= (forward.z + extraVelocity);
}