buffertransition.js

Tily.BufferTransition = (function(_super) {
  "use strict";
  Tily.utility.__extends(BufferTransition, _super);

  /**
   * Represents a buffer transition for fading from one buffer to another.
   * @class
   * @extends Tily.Transition
   * @memberof Tily
   * @param {Tily.Buffer} start The starting buffer.
   * @param {Tily.Buffer} finish The finishing buffer.
   * @param {TransitionOptions} [options] An optional options object for configuring the
   * transition.
   */
  function BufferTransition(start, finish, options) {
    _super.call(this, start, finish, options);
  }

  /**
   * Update the transition.
   * @name update
   * @function
   * @instance
   * @memberof Tily.BufferTransition
   * @param {number} elapsedTime The number of seconds that have elapsed since the last update.
   * @returns {number} An interpolated alpha value between 0 and 1.
   */
  BufferTransition.prototype.update = function(elapsedTime) {
    this.currentTime += elapsedTime;

    // If transition is currently in progress, ease from start to finish value
    if (this.currentTime < this.totalTime) {
      return this.easeFunction(0, 1, this.amount);
    }

    // Otherwise, transition has finished
    if (this.finishedCallback && !this.finished) {
      this.finishedCallback(this.start, this.finish);
    }
    this.finished = true;
    return 1;
  };
  return BufferTransition;
}(Tily.Transition));