openlayers4模拟轨迹运动

1. 切割一段线，返回点数组

function cfLineString(start, end, line) {
  var c = line.getLength() * 100//千米
  var count = Math.round(c);
  var routeCoords = [];
  var startx = start[0];
  var starty = start[1];
  var endx = end[0];
  var endy = end[1];
  var avg_x = (endx - startx) / count;
  var avg_y = (endy - starty) / count;
  routeCoords.push(start);
  var val_x = startx;
  var val_y = starty;
  for (var i = 0; i < count; i++) {
    val_x += avg_x;
    val_y += avg_y;
    var val = [val_x, val_y];
    routeCoords.push(val);
  }
  routeCoords.push(end);
  return routeCoords;
}

2.模拟轨迹

// 开始动画
function startAnimation() {
  if (animating) {
    stopAnimation(false);
  } else {
    animating = true;
    now = new Date().getTime();
    speed = 350;
    geoMarker.setStyle(null);
    map.on('postcompose', moveFeature);
    map.render();
  }
}
// 停止动画
function stopAnimation(ended) {
  animating = false;
  var coord = ended ? cfPoints[routeLength - 1] : cfPoints[0];
  (geoMarker.getGeometry()).setCoordinates(coord);
  map.un('postcompose', moveFeature);
}

// 监听事件
var moveFeature = function (event) {
  var vectorContext = event.vectorContext;
  var frameState = event.frameState;
  if (animating) {
    var elapsedTime = frameState.time - now;
    var index = Math.round(speed * elapsedTime / 1000);
    if (index >= routeLength) {
      stopAnimation(true);
      return;
    }
    var currentPoint = new ol.geom.Point(cfPoints[index]);
    var feature = new ol.Feature(currentPoint);
    vectorContext.drawFeature(feature, markerStyle);
  }
  map.render();
};

标签：轨迹,end,openlayers4,val,routeCoords,start,var,avg,模拟
来源： https://www.cnblogs.com/yyxbot/p/16177445.html