fxgl-bullet-hell

name	fxgl-bullet-hell
description	Build a bullet hell (danmaku) game in FXGL — create a tiny precise hitbox independent of the player sprite, add a graze sensor for near-miss scoring, script spiral and circular aimed bullet patterns, implement phase-based boss attack scripting, add a screen- clearing bomb that removes all enemy bullets, handle invincibility frames on hit, accelerate and decelerate bullets mid-flight, create homing bullets with delayed lock- on, and efficiently manage 1000+ simultaneous bullets on screen. Use this skill when building a danmaku shooter, pattern-based boss, or any game requiring dense bullet patterns and precise hitbox design.
triggers	["bullet hell","danmaku","spiral pattern","bullet pattern","graze","bomb","hitbox smaller than sprite","homing bullet","1000 bullets","dense bullets","boss pattern"]
compatibility	Java 17+, FXGL 21.x
category	fxgl/game-types
tags	["fxgl","java","javafx","game-types","bullet","hell"]
metadata	{"author":"fxgl-skills","version":"1.0","fxgl-version":"21.1"}
allowed-tools	["Read","Write","Edit","Bash"]

FXGL Bullet Hell

Player: Tiny Hitbox + Graze Sensor

@Spawns("player")
public Entity newPlayer(SpawnData data) {
    // Actual hitbox — very small, centered on sprite
    PhysicsComponent hitboxPhysics = new PhysicsComponent();
    hitboxPhysics.setBodyType(BodyType.DYNAMIC);
    hitboxPhysics.setFixedRotation(true);

    FixtureDef hitFD = new FixtureDef();
    hitFD.setFriction(0);
    hitFD.setDensity(1);
    hitboxPhysics.addFixtureDef(hitFD);

    Entity player = entityBuilder(data)
            .type(EntityType.PLAYER)
            .view("player_ship.png")                     // 48×48 sprite
            .bbox(BoundingShape.circle(4))               // only 4px radius hitbox!
            .with(hitboxPhysics)
            .with(new CollidableComponent(true))
            .with(new BulletHellPlayerComponent())
            .build();

    return player;
}

// Separate graze sensor entity attached nearby:
private Entity grazeEntity;

@Override
protected void initGame() {
    // ... spawn player ...
    grazeEntity = entityBuilder()
            .type(EntityType.GRAZE_SENSOR)
            .at(player.getX(), player.getY())
            .bbox(BoundingShape.circle(18))              
            .with( ())
            .buildAndAttach();
}


   {
    
    grazeEntity.setPosition(player.getPosition());
}