text: /*
    Copyright (c) 2016-2018 Jean-Marc VIGLINO, 
    released under the CeCILL license (http://www.cecill.info/).
    
  */
  
  import ol_ext_inherits from '../util/ext'
  import ol_featureAnimation from './FeatureAnimation'
  
  /** Path animation: feature follow a path
   * @constructor
   * @extends {ol.featureAnimation}
   * @param {ol.featureAnimationPathOptions} options extend ol.featureAnimation options
   *  @param {Number} options.speed speed of the feature, if 0 the duration parameter will be used instead, default 0
   *  @param {Number|boolean} options.rotate rotate the symbol when following the path, true or the initial rotation, default false
   *  @param {ol.geom.LineString|ol.Feature} options.path the path to follow
   */
  var ol_featureAnimation_Path = function(options){
    options = options || {};
    ol_featureAnimation.call(this, options);
    this.speed_ = options.speed || 0;
    this.path_ = options.path;
    switch (options.rotate) {
      case true: 
      case 0:
        this.rotate_ = 0;
        break;
      default:
        this.rotate_ = options.rotate || false;
        break;
    }
    if (this.path_ && this.path_.getGeometry) this.path_ = this.path_.getGeometry();
    if (this.path_ && this.path_.getLineString) this.path_ = this.path_.getLineString();
    if (this.path_.getLength) {
      this.dist_ = this.path_.getLength()
      if (this.path_ && this.path_.getCoordinates) this.path_ = this.path_.getCoordinates();
    } else {
      this.dist_ = 0;
    }
    if (this.speed_>0) this.duration_ = this.dist_/this.speed_;
  }
  ol_ext_inherits(ol_featureAnimation_Path, ol_featureAnimation);
  
  /** Animate
  * @param {ol_featureAnimationEvent} e
  */
  ol_featureAnimation_Path.prototype.animate = function (e) {
    // First time 
    if (!e.time) {
      if (!this.dist_) return false;
    }
    var dmax = this.dist_*this.easing_(e.elapsed);
    var p0, p, s, dx,dy, dl, d = 0;
    p = this.path_[0];
    // Linear interpol
    for (var i = 1; i<this.path_.length; i++) {
      p0 = p;
      p = this.path_[i];
      dx = p[0]-p0[0];
      dy = p[1]-p0[1];
      dl = Math.sqrt(dx*dx+dy*dy);
      if (dl && d+dl>=dmax) {
        s = (dmax-d)/dl;
        p = [ p0[0] + (p[0]-p0[0])*s, p0[1] + (p[1]-p0[1])*s];
        break;
      }
      d += dl;
    }
    // Rotate symbols
    var style = e.style;
    e.rotation = Math.PI/2 + Math.atan2(p0[1] - p[1], p0[0] - p[0]);
    if (this.rotate_!==false) {
      var st = []
      var angle = this.rotate_ - e.rotation + e.frameState.viewState.rotation;
      e.rotation = Math.PI/2 + Math.atan2(p0[1] - p[1], p0[0] - p[0]);
      for (var k=0; s=e.style[k]; k++) {
        if (s.getImage()) {
          //s = s.clone();
          s.getImage().setRotation(angle);
        }
        st.push(s);
      }
      // Rotated style
      e.style = st;
    }
    e.geom.setCoordinates(p);
    // Animate
    this.drawGeom_(e, e.geom);
    // restore style (if modify by rotation)
    e.style = style;
    
    return (e.time <= this.duration_);
  }
  
  export default ol_featureAnimation_Path
  