fxgl-tower-defense

name	fxgl-tower-defense
description	Build a tower defense game in FXGL — implement waypoint-following enemies with WaypointMoveComponent, create a boolean grid for tower placement that excludes path cells, implement tower targeting logic (nearest/strongest/first enemy in range), fire projectiles from towers at enemies, build a wave-based enemy spawning system with configurable intervals, add gold rewards on enemy kills, deduct player lives when enemies reach the exit, implement tower sell/upgrade mechanics, preview tower range with a circle overlay, and support multiple tower types (basic, slow, splash, chain). Use this skill when building a tower defense game, lane defense, or any game where the player places defensive structures against waves of path-following enemies.
triggers	["tower defense","waypoint enemy","tower placement","wave system","tower range","enemy path","tower targeting","splash tower","slow tower","buy tower","sell tower"]
compatibility	Java 17+, FXGL 21.x
category	fxgl/game-types
tags	["fxgl","java","javafx","game-types","tower","defense"]
metadata	{"author":"fxgl-skills","version":"1.0","fxgl-version":"21.1"}
allowed-tools	["Read","Write","Edit","Bash"]

FXGL Tower Defense

Grid Setup

private static final int TILE = 48;
private static final int COLS = 20;
private static final int ROWS = 12;

// Grid: true = occupied (path or tower), false = buildable
private boolean[][] occupied = new boolean[COLS][ROWS];

// Mark path cells as occupied (read from Tiled or define manually)
private List<Point2D> waypointPixels;

@Override
protected void initGame() {
    setLevelFromMap("td_level.tmx");
    // Read waypoints from Tiled object layer
    waypointPixels = getGameWorld()
            .getEntitiesByType(EntityType.WAYPOINT)
            .stream()
            .sorted(Comparator.comparingInt(e -> e.getInt("order")))
            .map(Entity::getPosition)
            .toList();

    // Mark path tiles as occupied using Tiled tile type
    getGameWorld().getEntitiesByType(EntityType.PATH).forEach(e -> {
        occupied[(int)(e.getX() / TILE)][(int)(e.getY() / TILE)] = true;
    });
}

Enemy with WaypointMoveComponent

@Spawns("enemy")
public Entity newEnemy {
        ();
    waypointMove.setSpeed(data.getOrDefault(, ));
    waypointMove.setLooping();
    waypointPixels.forEach(waypointMove::addWaypoint);

    
    waypointMove.setOnLastWaypointReached(() -> {
        entity.removeFromWorld();
        inc(, -);
         (geti() <= ) showGameOver();
    });

     entityBuilder(data)
            .type(EntityType.ENEMY)
            .view()
            .bbox(BoundingShape.circle())
            .with(waypointMove)
            .with( (data.getOrDefault(, )))
            .with( ())
            .build();
}