fxgl-racing

name	fxgl-racing
description	Build a top-down racing game in FXGL — implement vehicle physics with forward thrust, steering, friction, and drift, create a circuit track with ordered checkpoint gates for lap counting, add AI opponents following a predefined racing line with waypoints, handle car-wall collisions with bounce-back, add power-up pickups on track (boost, shield, attack), track race position (1st/2nd/3rd), display lap timer and best lap, and implement a ghost replay system for time trials. Use this skill when building a top-down racer, kart racer, circuit racing game, or any vehicle-control game with lap-based competition.
triggers	["racing","top-down racing","car physics","lap counter","checkpoint","racing line","AI racer","drift","kart","circuit","ghost replay","race position"]
compatibility	Java 17+, FXGL 21.x
category	fxgl/game-types
tags	["fxgl","java","javafx","game-types","racing"]
metadata	{"author":"fxgl-skills","version":"1.0","fxgl-version":"21.1"}
allowed-tools	["Read","Write","Edit","Bash"]

FXGL Top-Down Racing

Vehicle Physics Component

public class VehicleComponent extends Component {
    private PhysicsComponent physics;

    // Tuning parameters
    private static final double ACCELERATION     = 300.0;  // px/s²
    private static final double MAX_SPEED        = 350.0;  // px/s
    private static final double TURN_SPEED       = 3.0;    // radians/s at full speed
    private static final double FRICTION         = 0.85;   // velocity multiplier per frame
    private static final double DRIFT_FRICTION   = 0.95;   // less grip when drifting

    private double speed    = 0;
    private       ;   
        ;

    
       {
           isHeld(KeyCode.W) || isHeld(KeyCode.UP);
              isHeld(KeyCode.S) || isHeld(KeyCode.DOWN);
               isHeld(KeyCode.A) || isHeld(KeyCode.LEFT);
              isHeld(KeyCode.D) || isHeld(KeyCode.RIGHT);
        drifting         = isHeld(KeyCode.SHIFT) && Math.abs(speed) > ;

        
         (throttle) speed = Math.min(MAX_SPEED, speed + ACCELERATION * tpf);
          (brake) speed = Math.max(-MAX_SPEED * , speed - ACCELERATION *  * tpf);

        
           drifting ? DRIFT_FRICTION : FRICTION;
         (!throttle && !brake) speed *= Math.pow(friction, tpf * );

        
         (Math.abs(speed) > ) {
               TURN_SPEED * tpf * (speed / MAX_SPEED);
             (left)  angle -= steerAmount;
             (right) angle += steerAmount;
        }

        
           Math.cos(angle) * speed;
           Math.sin(angle) * speed;

        
           drifting ?  : ;
        physics.setVelocityX(vx * ( - lateralFriction) + physics.getVelocityX() * lateralFriction);
        physics.setVelocityY(vy * ( - lateralFriction) + physics.getVelocityY() * lateralFriction);

        entity.setRotation(Math.toDegrees(angle));
    }

       {
           MAX_SPEED * ;
        speed = boostSpeed;
        runOnce(() -> {}, Duration.seconds(duration));  
    }

       {
         getInput().isHeld(key);
    }
}