Top-down car simmulator

Newbie & Debugging Questions
#1

Hello,

I’m trying to write simple Top-down car simulator. Ofc i browse the forum and the internet before and there is massive amount of answers but… nothing works for me that why i created new topic.

Best related-topics:

My car is made up with 4 images(wheels) + 1 image(body). X,Y of images are in the relation to an imaginary center of Car (200,200)

Car class constructor:

	public Car()
	{	
		MiddlePoint.x = 200;
		MiddlePoint.y = 200;
			
	    LwheelU = new Wheels(MiddlePoint.x - 60.5 ,MiddlePoint.y -85);
	    LwheelD = new Wheels(MiddlePoint.x - 60.5, MiddlePoint.y + 65);    
	    RwheelU = new Wheels(MiddlePoint.x + 36.5, MiddlePoint.y -85);
	    RwheelD = new Wheels(MiddlePoint.x + 36.5,MiddlePoint.y + 65);    
	    body = new Body(MiddlePoint.x - 36.5, (MiddlePoint.y - (251/1.9))); 
	}

Global game parameters: [#EDIT 1.0]

	//this variable will decide if the specified car is controlled by a human player or by the computer (in Part II of this tutorial you will learn how to add opponents and this variable will come in handy)
	public	double acceleration = 0.4; 
	//the acceleration variable will add to the speed variable on every enterFrame event (in this case 24 times per second); a higher value translates in a faster acceleration of the car
	public double speedDecay = 0.96; 
	//when the car is not accelerated (the UP Key is released), the car will have to slow down smoothly; the speed will multiply with this value (less than 1); the lower this value is, the faster the car will slow down
	public double rotationStep = 1;
	//this is the number of degrees that will increase or decrease the car's rotation (angle) when the left or right keys are pressed
	public double maxSpeed = 3;
	//this is the speed limit on our track; increase it if you want the car to go faster
	public double backSpeed = 1;
	//this is the speed limit when going backwards
	public double speedx = 0, speedy = 0;
	public double rotation = 0;
    //**********************

Move method [#Edit 1.0]

if(speed < 0.3) 
			speed *= 0.70;  //Friction
		else
			speed = 0;
		  
		  
		if (up && speed < maxSpeed)
		{
			speed -=acceleration;
		}
 		if (down)
		{
			speed += backSpeed;
		}		
		if (left )
		{
			rotation -= rotationStep * (speed/maxSpeed);
		}
		if (right )
		{
			rotation += rotationStep * (speed/maxSpeed);
		}
			
		speedx = Math.sin(Math.toRadians(rotation)) * speed;
		speedy = Math.cos(Math.toRadians(rotation)) * speed;
		
		MiddlePoint.x += speedx;
		MiddlePoint.y += speedy;
			
		carAngle = Math.toRadians(rotation);

I’m drawing all elements like that:


		 AffineTransform at;
		 at = new AffineTransform();	
		 at.translate(MiddlePoint.x - 60.5 ,MiddlePoint.y -85);
		 at.rotate(Math.toRadians(carAngle), MiddlePoint.x, Sr_PKT.y);
		 g2d.drawImage(LwheelU.getImage(),at,null);

I’m using timer to refresh actions on board


    public void paint(Graphics g) 
    {
        super.paint(g);
        Car.paint(g);
     
        Toolkit.getDefaultToolkit().sync();
        g.dispose();
    }

    public void actionPerformed(ActionEvent e) 
    {
    	Car.move();
        repaint();  
    }

At the moment car is moving UP/DOWN but when it comes to UP/DOWN + Right/left it is starting to act very weird. The huge problem is also that elements like wheels/body are ,not connecteted"
look:

Actually i just want the car to move correctly - i dont need any kind of colission , friction.

Thanks in advance for any kind of help

Kamil,

##################################

EDIT 1.0

  • Changed keyboard handling to set Flags TRUE (PRESSED) and FALSE (RELEASED)
  • update move function:
    [list]
    [li]Whole x,y changing is now in move function
  • Go UP/DOWN works fine (Frictions stops the car)
  • LEFT/RIGHT doesn’t work correct (or it does but my drawing function is bugged)

[/li]
[/list]