import { Object3D } from './Object3D'
import { Matrix4 } from './Matrix4'
import { Frustum } from './Frustum'

/**
 * Constructs a camera object. Can be extended to calculate projection matrices.
 */
export class Camera extends Object3D {
  /**
   * A projection matrix. Useful for projecting transforms.
   */
  readonly projectionMatrix = new Matrix4()
  /**
   * A view matrix. Useful for aligning transforms with the camera.
   */
  readonly viewMatrix = new Matrix4()
  /**
   * A projection-view matrix. Used internally for checking whether objects are in view.
   */
  readonly projectionViewMatrix = new Matrix4()
  /**
   * Frustum clipping planes. Used to calculate a frustum representation.
   */
  readonly frustum = new Frustum()

  updateMatrix(): void {
    super.updateMatrix()
    if (this.matrixAutoUpdate) this.viewMatrix.copy(this.matrix).invert()
  }
}