Acceleration problems

Question

Im trying to make a car game, but i cannot get the acceleration code right. With this code:

        if(gas){
        speed += 3;
    }else if(break_ && !(speed < 6)){
        speed -= 3;
    }else if(!break_ && !gas && !(speed < 6)){
        speed -= 0.3;
    }else{
        speed = 6;
    }

it is up on 1000 within 5 secounds. I tried multiplying it with smaller numbers, but it still doesnt work(in fact it got worse). So, how can this be improved so it has reasonable parameters? Asof the maximum speed, i can implement that on my own.

Answer 1

Try adding in a Velocity variable. But more importantly, you need to keep track of your deltaTime, which is the time that elapsed since your last frame.

More than likely the framework you are using has this, if not you will need to implement one.

float Velocity;
float Speed = 3;     //Your speed could vary here

if(gas){
   Velocity += Speed * deltaTime;     //when gas is pressed, speed up
}
else if (brake && (Velocity > 6)) {
   Velocity -= Speed * deltaTime;      //When brakes are pressed, slow down
} 
else if(!brake && !gas && (Velocity > 6)){
   Velocity -= Speed * deltaTime;     //friction should be a different value than Speed
}
else {
    Velocity = 6;
}


//Update the position
Position.Axis += Velocity;