Changing Speed in Gameplay Affects GUI

Questions & Answers
1

I am making a Space Sim. Right now, my ship can boost, increase it’s speed, and decrease it’s speed. What I need is a GUI of some sort that shows the increase or decrease of speed. I’m not sure how to do that. Here’s my speed script:

var defaultSpeed = 50.0; // speed to default towards if no keys are pressed
var maxSpeed = 75.0; 
var minSpeed = 25.0;
var maxAcceleration = 5.0; // Controls the acceleration
var currentSpeed = 50.0;

// var Player = transform;  // this line gave me an error and it isn't needed any way

function Update() 
{
    transform.Translate(Vector3.forward * Time.deltaTime * currentSpeed);

    if(Input.GetKey("up"))
    currentSpeed += maxAcceleration * Time.deltaTime;
    else if(Input.GetKey("down"))
    currentSpeed-=maxAcceleration * Time.deltaTime;
    else if (currentSpeed > defaultSpeed){
        currentSpeed -= maxAcceleration * Time.deltaTime;
        currentSpeed = Mathf.Clamp(currentSpeed, defaultSpeed, maxSpeed);
    }
    else {
        currentSpeed += maxAcceleration * Time.deltaTime;
        currentSpeed = Mathf.Clamp(currentSpeed, minSpeed, defaultSpeed);
    }
    currentSpeed = Mathf.Clamp(currentSpeed, minSpeed, maxSpeed);
}

The current speed always updates itself in the inspector when I speed up, or slow down, so the current speed is what I want to show. I’m not sure how to show that in GUI, so help would be greatly appreciated. Thanks in advance.

2

A quick search of the Unity Scripting Refrence will find the GUI class. Inside the GUI class, we find two methods that can do what you are asking for: Horizontal Slider and Vertical Slider. All you have to do is feed your current speed value into the scroll bar, and everything should work.

Just don’t read the speed coming out of the function other wise the user can use that to accelerate/decelerate.

Also, in order for the GUI to appear, you have to have all GUI calls inside a special method called OnGUI() - It’s basically the Update() function for GUIs.

edit: did I say scroll bar? I meant slider >.<

3

You can also make a custom graphic like a frame, with a colored bar inside and then set the pixelInset.width of the bar using your current speed as the driver.

I can post more code if that doesn’t make sense.