Controls of vehicle in "Micro-Machines"-like racing game

[zeastarr]

Hi everyone,

I'm new in Java Game Development and would like to create a "Micro-Machine"-like racing game. Just simple with a fixed size fullscreen-track without scrolling and in bird's eye view. My recent problem is the realization of the control.

Every direction in this kind of game is only relative to the actual direction of the car. E.g. if the car moves from east to west on the screen and there is no bend then i just press the cursor-up key to accelerate. If there is a bend at the end of the screen which leads the track from south to north I have to press cursor right + cursor up and so on...   It wouldn't be a problem for me if the up/down would steer the y-movement and the left/right would take control of the x-movement like in games like Boulder Dash for example...

I think I have to work with angles but I don't have much ideas how to do that. I also could add an y-acceleration to a x-acceleration, but how can i determine the current direction of my car?

Do you have any clues for me?  Thanks alot and if I got this working I gonna post the code in here.

Cheers,

Sascha   

[SimonH]

Your car has a location (x,y) a direction angle in radians (a) and a speed (s).
To move the car forward;

1   2

x+=(int)(s*Math.cos(a));  y+=(int)(s*Math.sin(a));

To turn the car change a, to speed up or slow down the car change s (or make s less than 0 to reverse).

[zeastarr]

thanks alot! that helped me!   

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[Eli Delventhal]

You can also give the car a velocity, and then apply acceleration in the correct direction (as posted above). That way you can have drifting and whatnot.

[Del]

how would you apply velocity, my math is terrible, before reading this post my attempt at moving a car "micro-machine"-like was

 if ((upPressed) && (!downPressed)) {
                accelerateY = 1;
                    if (ySpeed <51){
                        ySpeed = (ySpeed+1);
                    }
                } else accelerateY = 0;
               
                if (accelerateY == 0){
                ySpeed=(ySpeed-1);
                }
            }
 if (ySpeed < 1){
            ySpeed = (ySpeed+1);
            }
            if ((ySpeed >1) && (ySpeed < 10)){
            carYaxisPosition = (carYaxisPosition -1);
            }
            if ((ySpeed >10) && (ySpeed < 20)){
            carYaxisPosition = (carYaxisPosition -2);
            }
             if ((ySpeed >20) && (ySpeed < 30)){
            carYaxisPosition = (carYaxisPosition -3);
            }
            if ((ySpeed >30) && (ySpeed < 40)){
            carYaxisPosition = (carYaxisPosition -4);
            }
            if (ySpeed >50){
            carYaxisPosition = (carYaxisPosition -5);
            }
and that was just forward motion

[Eli Delventhal]

To apply velocity all you do is add the acceleration! It's also good to have a maximum value.