DartStick.ts

/**
 * Handles dart sticking to the score board on collision.
 * Works with GrabbableObject and MatchTransform system.
 * Add this component to dart objects.
 */
@component
export class DartStick extends BaseScriptComponent {
  @input
  @hint("The score board object to stick to")
  scoreBoard: SceneObject

  @input
  @hint("Sound to play when dart sticks to board")
  hitSound: AudioComponent

  @input
  @hint("Sound to play when dart bounces off board")
  bounceSound: AudioComponent

  //@input
  //@hint("Maximum angle in degrees for a successful stick (default: 66)")
  private maxStickAngle: number = 170.0

  @input
  @hint("Offset for tip positioning (default: -0.66)")
  tipOffset: number = -0.66

  private bodyComponent: BodyComponent | null = null
  private hasStuck: boolean = false
  private scoreBoardTransform: Transform | null = null

  onAwake() {
    // Get the body component
    this.bodyComponent = this.getSceneObject().getComponent("Physics.BodyComponent")

    if (!this.bodyComponent) {
      print("DartStick: Physics.BodyComponent is required!")
      return
    }

    // Set up audio for low latency
    if (this.hitSound) {
      this.hitSound.playbackMode = Audio.PlaybackMode.LowLatency
    }
    if (this.bounceSound) {
      this.bounceSound.playbackMode = Audio.PlaybackMode.LowLatency
    }

    // Get score board transform
    if (this.scoreBoard) {
      this.scoreBoardTransform = this.scoreBoard.getTransform()
    }

    // Set up collision event
    this.bodyComponent.onCollisionEnter.add(this.onCollisionEnter.bind(this))
  }

  /**
   * Called when dart collides with something
   */
  private onCollisionEnter(e: CollisionEnterEventArgs) {
    if (this.hasStuck) return

    const collision = e.collision

    // Check if we hit the score board
    const hitObject = collision.collider.getSceneObject()
    const isDartBoardHit = hitObject.name === "DartBoard" || hitObject === this.scoreBoard

    if (!isDartBoardHit) {
      // Hit something else, just bounce
      if (this.bounceSound) {
        this.bounceSound.play(1)
      }
      return
    }

    // Get current transform
    const myTransform = this.getSceneObject().getTransform()
    const touchPoint = myTransform.getWorldPosition()
    const touchRotation = myTransform.getWorldRotation()
    const touchScale = myTransform.getWorldScale()

    // Check if this is a straight hit (good angle)
    if (this.isStraightHit(touchRotation)) {
      print(`DartStick: Straight hit detected! Sticking to board.`)

      // Stop physics
      this.bodyComponent.dynamic = false
      this.bodyComponent.velocity = vec3.zero()

      // Adjust position to account for dart tip
      const childLocalPosition = new vec3(0, 0, this.tipOffset)
      const parentWorldPosition = touchPoint.sub(touchRotation.multiplyVec3(childLocalPosition.mult(touchScale)))

      // Parent to the score board
      this.getSceneObject().setParent(hitObject)

      // Set final transform
      myTransform.setWorldPosition(parentWorldPosition)
      myTransform.setWorldRotation(touchRotation)
      myTransform.setWorldScale(touchScale)

      this.hasStuck = true

      // Play hit sound
      if (this.hitSound) {
        this.hitSound.play(1)
      }

      print(`DartStick: Dart stuck to board at ${parentWorldPosition}`)
    } else {
      // Not a straight hit, bounce off
      print(`DartStick: Bounce - hit angle too steep`)

      if (this.bounceSound) {
        this.bounceSound.play(1)
      }
    }
  }

  /**
   * Check if the dart hit at a good angle (straight enough to stick)
   */
  private isStraightHit(dartRotation: quat): boolean {
    if (!this.scoreBoardTransform) return false

    // Get the board's forward direction
    const boardForward = this.scoreBoardTransform.forward

    // Get the dart's UP direction (because we rotate 90° on X, up becomes the pointing direction)
    // The dart model's forward becomes up after the 90° X rotation
    const dartPointingDirection = dartRotation.multiplyVec3(vec3.up())

    // Calculate angle between board forward and where dart is pointing
    const angle = boardForward.angleTo(dartPointingDirection) * MathUtils.RadToDeg

    // Check if angle is within acceptable range
    const isGoodAngle = angle < this.maxStickAngle && angle > 0

    print(
      `DartStick: Hit angle: ${angle.toFixed(1)}° (max: ${this.maxStickAngle}°) - ${isGoodAngle ? "STICK!" : "BOUNCE"}`
    )

    return isGoodAngle
  }
}