openlayers-5 - OpenLayers 5：平滑移动标记

Question

我使用 https://openlayers.org/en/latest/examples/feature-move-animation.html

代码片段：

// This long string is placed here due to jsFiddle limitations.
// It is usually loaded with AJAX.
var polyline = [
  'hldhx@lnau`BCG_EaC??cFjAwDjF??uBlKMd@}@z@??aC^yk@z_@se@b[wFdE??wFfE}N',
  'fIoGxB_I\\gG}@eHoCyTmPqGaBaHOoD\\??yVrGotA|N??o[N_STiwAtEmHGeHcAkiA}^',
  'aMyBiHOkFNoI`CcVvM??gG^gF_@iJwC??eCcA]OoL}DwFyCaCgCcCwDcGwHsSoX??wI_E',
  'kUFmq@hBiOqBgTwS??iYse@gYq\\cp@ce@{vA}s@csJqaE}{@iRaqE{lBeRoIwd@_T{]_',
  'Ngn@{PmhEwaA{SeF_u@kQuyAw]wQeEgtAsZ}LiCarAkVwI}D??_}RcjEinPspDwSqCgs@',
  'sPua@_OkXaMeT_Nwk@ob@gV}TiYs[uTwXoNmT{Uyb@wNg]{Nqa@oDgNeJu_@_G}YsFw]k',
  'DuZyDmm@i_@uyIJe~@jCg|@nGiv@zUi_BfNqaAvIow@dEed@dCcf@r@qz@Egs@{Acu@mC',
  'um@yIey@gGig@cK_m@aSku@qRil@we@{mAeTej@}Tkz@cLgr@aHko@qOmcEaJw~C{w@ka',
  'i@qBchBq@kmBS{kDnBscBnFu_Dbc@_~QHeU`IuyDrC_}@bByp@fCyoA?qMbD}{AIkeAgB',
  'k_A_A{UsDke@gFej@qH{o@qGgb@qH{`@mMgm@uQus@kL{_@yOmd@ymBgwE}x@ouBwtA__',
  'DuhEgaKuWct@gp@cnBii@mlBa_@}|Asj@qrCg^eaC}L{dAaJ_aAiOyjByH{nAuYu`GsAw',
  'Xyn@ywMyOyqD{_@cfIcDe}@y@aeBJmwA`CkiAbFkhBlTgdDdPyiB`W}xDnSa}DbJyhCrX',
  'itAhT}x@bE}Z_@qW_Kwv@qKaaAiBgXvIm}A~JovAxCqW~WanB`XewBbK{_A`K}fBvAmi@',
  'xBycBeCauBoF}}@qJioAww@gjHaPopA_NurAyJku@uGmi@cDs[eRaiBkQstAsQkcByNma',
  'CsK_uBcJgbEw@gkB_@ypEqDoqSm@eZcDwjBoGw`BoMegBaU_`Ce_@_uBqb@ytBwkFqiT_',
  'fAqfEwe@mfCka@_eC_UmlB}MmaBeWkkDeHwqAoX}~DcBsZmLcxBqOwqE_DkyAuJmrJ\\o',
  '~CfIewG|YibQxBssB?es@qGciA}RorAoVajA_nAodD{[y`AgPqp@mKwr@ms@umEaW{dAm',
  'b@umAw|@ojBwzDaaJsmBwbEgdCsrFqhAihDquAi`Fux@}_Dui@_eB_u@guCuyAuiHukA_',
  'lKszAu|OmaA{wKm}@clHs_A_rEahCssKo\\sgBsSglAqk@yvDcS_wAyTwpBmPc|BwZknF',
  'oFscB_GsaDiZmyMyLgtHgQonHqT{hKaPg}Dqq@m~Hym@c`EuiBudIabB{hF{pWifx@snA',
  'w`GkFyVqf@y~BkoAi}Lel@wtc@}`@oaXi_C}pZsi@eqGsSuqJ|Lqeb@e]kgPcaAu}SkDw',
  'zGhn@gjYh\\qlNZovJieBqja@ed@siO{[ol\\kCmjMe\\isHorCmec@uLebB}EqiBaCg}',
  '@m@qwHrT_vFps@kkI`uAszIrpHuzYxx@e{Crw@kpDhN{wBtQarDy@knFgP_yCu\\wyCwy',
  'A{kHo~@omEoYmoDaEcPiuAosDagD}rO{{AsyEihCayFilLaiUqm@_bAumFo}DgqA_uByi',
  '@swC~AkzDlhA}xEvcBa}Cxk@ql@`rAo|@~bBq{@``Bye@djDww@z_C_cAtn@ye@nfC_eC',
  '|gGahH~s@w}@``Fi~FpnAooC|u@wlEaEedRlYkrPvKerBfYs}Arg@m}AtrCkzElw@gjBb',
  'h@woBhR{gCwGkgCc[wtCuOapAcFoh@uBy[yBgr@c@iq@o@wvEv@sp@`FajBfCaq@fIipA',
  'dy@ewJlUc`ExGuaBdEmbBpBssArAuqBBg}@s@g{AkB{bBif@_bYmC}r@kDgm@sPq_BuJ_',
  's@{X_{AsK_d@eM{d@wVgx@oWcu@??aDmOkNia@wFoSmDyMyCkPiBePwAob@XcQ|@oNdCo',
  'SfFwXhEmOnLi\\lbAulB`X_d@|k@au@bc@oc@bqC}{BhwDgcD`l@ed@??bL{G|a@eTje@',
  'oS~]cLr~Bgh@|b@}Jv}EieAlv@sPluD{z@nzA_]`|KchCtd@sPvb@wSb{@ko@f`RooQ~e',
  '[upZbuIolI|gFafFzu@iq@nMmJ|OeJn^{Qjh@yQhc@uJ~j@iGdd@kAp~BkBxO{@|QsAfY',
  'gEtYiGd]}Jpd@wRhVoNzNeK`j@ce@vgK}cJnSoSzQkVvUm^rSgc@`Uql@xIq\\vIgg@~k',
  'Dyq[nIir@jNoq@xNwc@fYik@tk@su@neB}uBhqEesFjoGeyHtCoD|D}Ed|@ctAbIuOzqB',
  '_}D~NgY`\\um@v[gm@v{Cw`G`w@o{AdjAwzBh{C}`Gpp@ypAxn@}mAfz@{bBbNia@??jI',
  'ab@`CuOlC}YnAcV`@_^m@aeB}@yk@YuTuBg^uCkZiGk\\yGeY}Lu_@oOsZiTe[uWi[sl@',
  'mo@soAauAsrBgzBqgAglAyd@ig@asAcyAklA}qAwHkGi{@s~@goAmsAyDeEirB_{B}IsJ',
  'uEeFymAssAkdAmhAyTcVkFeEoKiH}l@kp@wg@sj@ku@ey@uh@kj@}EsFmG}Jk^_r@_f@m',
  '~@ym@yjA??a@cFd@kBrCgDbAUnAcBhAyAdk@et@??kF}D??OL'
].join('');

var route = /** @type {module:ol/geom/LineString~LineString} */ (new ol.format.Polyline({
  factor: 1e6
}).readGeometry(polyline, {
  dataProjection: 'EPSG:4326',
  featureProjection: 'EPSG:3857'
}));

var routeCoords = route.getCoordinates();
var routeLength = routeCoords.length;

var routeFeature = new ol.Feature({
  type: 'route',
  geometry: route
});
var geoMarker = new ol.Feature({
  type: 'geoMarker',
  geometry: new ol.geom.Point(routeCoords[0])
});
var startMarker = new ol.Feature({
  type: 'icon',
  geometry: new ol.geom.Point(routeCoords[0])
});
var endMarker = new ol.Feature({
  type: 'icon',
  geometry: new ol.geom.Point(routeCoords[routeLength - 1])
});

var styles = {
  'route': new ol.style.Style({
    stroke: new ol.style.Stroke({
      width: 6,
      color: [237, 212, 0, 0.8]
    })
  }),
  'icon': new ol.style.Style({
    image: new ol.style.Icon({
      anchor: [0.5, 1],
      src: 'https://openlayers.org/en/v4.6.5/examples/data/icon.png'
    })
  }),
  'geoMarker': new ol.style.Style({
    image: new ol.style.Circle({ // CircleStyle({
      radius: 7,
      snapToPixel: false,
      fill: new ol.style.Fill({
        color: 'black'
      }),
      stroke: new ol.style.Stroke({
        color: 'white',
        width: 2
      })
    })
  })
};

var animating = false;
var speed, now;
var speedInput = document.getElementById('speed');
var startButton = document.getElementById('start-animation');

var vectorLayer = new ol.layer.Vector({ // VectorLayer({
  source: new ol.source.Vector({ // VectorSource({
    features: [routeFeature, geoMarker, startMarker, endMarker]
  }),
  style: function(feature) {
    // hide geoMarker if animation is active
    if (animating && feature.get('type') === 'geoMarker') {
      return null;
    }
    return styles[feature.get('type')];
  }
});

var center = [-5639523.95, -3501274.52];
var map = new ol.Map({
  target: document.getElementById('map'),
  loadTilesWhileAnimating: true,
  view: new ol.View({
    center: center,
    zoom: 9,
    minZoom: 2,
    maxZoom: 19
  }),
  layers: [
    new ol.layer.Tile({ // TileLayer({
      source: new ol.source.OSM()
    }),
    vectorLayer
  ]
});

var moveFeature = function(event) {
  var vectorContext = event.vectorContext;
  var frameState = event.frameState;

  if (animating) {
    var elapsedTime = frameState.time - now;
    // here the trick to increase speed is to jump some indexes
    // on lineString coordinates
    var index = Math.round(speed * elapsedTime / 1000);

    if (index >= routeLength) {
      stopAnimation(true);
      return;
    }

    var currentPoint = new ol.geom.Point(routeCoords[index]);
    var feature = new ol.Feature(currentPoint);
    vectorContext.drawFeature(feature, styles.geoMarker);
  }
  // tell OpenLayers to continue the postcompose animation
  map.render();
};

function startAnimation() {
  if (animating) {
    stopAnimation(false);
  } else {
    animating = true;
    now = new Date().getTime();
    speed = speedInput.value;
    startButton.textContent = 'Cancel Animation';
    // hide geoMarker
    geoMarker.setStyle(null);
    // just in case you pan somewhere else
    map.getView().setCenter(center);
    map.on('postcompose', moveFeature);
    map.render();
  }
}


/**
 * @param {boolean} ended end of animation.
 */
function stopAnimation(ended) {
  animating = false;
  startButton.textContent = 'Start Animation';

  // if animation cancelled set the marker at the beginning
  var coord = ended ? routeCoords[routeLength - 1] : routeCoords[0];
  /** @type {module:ol/geom/Point~Point} */
  (geoMarker.getGeometry())
  .setCoordinates(coord);
  //remove listener
  map.un('postcompose', moveFeature);
}

startButton.addEventListener('click', startAnimation, false);

html,
body {
  height: 100%;
  width: 100%;
  padding: 0px;
  margin: 0px;
}

.map {
  height: 90%;
  width: 100%;
}

<script src="https://cdn.rawgit.com/openlayers/openlayers.github.io/master/en/v5.1.3/build/ol.js"></script>
<div id="map" class="map"></div>
<label for="speed">
      speed:&nbsp;
      <input id="speed" type="range" min="10" max="999" step="10" value="60">
    </label>
<button id="start-animation">Start Animation</button>

但我需要在两点（或多点）之间平滑移动标记

score 2 · Accepted Answer

参见ol-ext : featureAnimation

该库文档中的示例

代码片段（OpenLayers 文档中使用 ol-ext 的示例）：

// use window.onload so can move encoded polyline definition to bottom
window.onload = function() {
  var route = /** @type {module:ol/geom/LineString~LineString} */ (new ol.format.Polyline({
    factor: 1e6
  }).readGeometry(polyline, {
    dataProjection: 'EPSG:4326',
    featureProjection: 'EPSG:3857'
  }));

  var routeCoords = route.getCoordinates();
  var routeLength = routeCoords.length;

  var routePts = new ol.Feature({
    type: 'route',
    geometry: new ol.geom.MultiPoint(routeCoords)
  });

  var routeFeature = new ol.Feature({
    type: 'route',
    geometry: route
  });
  var geoMarker = new ol.Feature({
    type: 'geoMarker',
    geometry: new ol.geom.Point(routeCoords[0])
  });
  var startMarker = new ol.Feature({
    type: 'icon',
    geometry: new ol.geom.Point(routeCoords[0])
  });
  var endMarker = new ol.Feature({
    type: 'icon',
    geometry: new ol.geom.Point(routeCoords[routeLength - 1])
  });

  var styles = {
    'route': new ol.style.Style({
      stroke: new ol.style.Stroke({
        width: 6,
        color: [237, 212, 0, 0.8]
      }),
      image: new ol.style.Circle({
        radius: 1,
        snapToPixel: false,
        fill: new ol.style.Fill({
          color: 'red'
        })
      })
    }),
    'icon': new ol.style.Style({
      image: new ol.style.Icon({
        anchor: [0.5, 1],
        src: 'https://openlayers.org/en/v4.6.5/examples/data/icon.png'
      })
    }),
    'geoMarker': new ol.style.Style({
      image: new ol.style.Circle({ // CircleStyle({
        radius: 7,
        snapToPixel: false,
        fill: new ol.style.Fill({
          color: 'black'
        }),
        stroke: new ol.style.Stroke({
          color: 'white',
          width: 2
        })
      })
    })
  };

  var animating = false;
  var speed, now;
  var speedInput = document.getElementById('speed');
  var startButton = document.getElementById('start-animation');

  var vectorLayer = new ol.layer.Vector({ // VectorLayer({
    source: new ol.source.Vector({ // VectorSource({
      features: [routePts, routeFeature, geoMarker, startMarker, endMarker]
    }),
    style: function(feature) {
      return styles[feature.get('type')];
    }
  });

  var center = [-5639523.95, -3501274.52];
  var map = new ol.Map({
    target: document.getElementById('map'),
    loadTilesWhileAnimating: true,
    view: new ol.View({
      center: center,
      zoom: 9,
      minZoom: 2,
      maxZoom: 19
    }),
    layers: [
      new ol.layer.Tile({ // TileLayer({
        source: new ol.source.OSM()
      }),
      vectorLayer
    ]
  });
  console.log("init speed=" + speedInput.value / 100);

  function startAnimation() {
    if (animating) animating.stop();
    console.log("update speed=" + Number(speedInput.value) / 100);
    // anim.set("speed", Number(speedInput.value)/10);
    var anim = new ol.featureAnimation.Path({
      path: route,
      easing: ol.easing.linear,
      speed: Number(speedInput.value) / 100
    });

    animating = vectorLayer.animateFeature(geoMarker, anim);
  }
  geoMarker.on('change', function() {
    map.getView().setCenter(geoMarker.getGeometry().getCoordinates());
  });

  startButton.addEventListener('click', startAnimation, false);
}
// This long string is placed here due to jsFiddle limitations.
// It is usually loaded with AJAX.
var polyline = [
  'hldhx@lnau`BCG_EaC??cFjAwDjF??uBlKMd@}@z@??aC^yk@z_@se@b[wFdE??wFfE}N',
  'fIoGxB_I\\gG}@eHoCyTmPqGaBaHOoD\\??yVrGotA|N??o[N_STiwAtEmHGeHcAkiA}^',
  'aMyBiHOkFNoI`CcVvM??gG^gF_@iJwC??eCcA]OoL}DwFyCaCgCcCwDcGwHsSoX??wI_E',
  'kUFmq@hBiOqBgTwS??iYse@gYq\\cp@ce@{vA}s@csJqaE}{@iRaqE{lBeRoIwd@_T{]_',
  'Ngn@{PmhEwaA{SeF_u@kQuyAw]wQeEgtAsZ}LiCarAkVwI}D??_}RcjEinPspDwSqCgs@',
  'sPua@_OkXaMeT_Nwk@ob@gV}TiYs[uTwXoNmT{Uyb@wNg]{Nqa@oDgNeJu_@_G}YsFw]k',
  'DuZyDmm@i_@uyIJe~@jCg|@nGiv@zUi_BfNqaAvIow@dEed@dCcf@r@qz@Egs@{Acu@mC',
  'um@yIey@gGig@cK_m@aSku@qRil@we@{mAeTej@}Tkz@cLgr@aHko@qOmcEaJw~C{w@ka',
  'i@qBchBq@kmBS{kDnBscBnFu_Dbc@_~QHeU`IuyDrC_}@bByp@fCyoA?qMbD}{AIkeAgB',
  'k_A_A{UsDke@gFej@qH{o@qGgb@qH{`@mMgm@uQus@kL{_@yOmd@ymBgwE}x@ouBwtA__',
  'DuhEgaKuWct@gp@cnBii@mlBa_@}|Asj@qrCg^eaC}L{dAaJ_aAiOyjByH{nAuYu`GsAw',
  'Xyn@ywMyOyqD{_@cfIcDe}@y@aeBJmwA`CkiAbFkhBlTgdDdPyiB`W}xDnSa}DbJyhCrX',
  'itAhT}x@bE}Z_@qW_Kwv@qKaaAiBgXvIm}A~JovAxCqW~WanB`XewBbK{_A`K}fBvAmi@',
  'xBycBeCauBoF}}@qJioAww@gjHaPopA_NurAyJku@uGmi@cDs[eRaiBkQstAsQkcByNma',
  'CsK_uBcJgbEw@gkB_@ypEqDoqSm@eZcDwjBoGw`BoMegBaU_`Ce_@_uBqb@ytBwkFqiT_',
  'fAqfEwe@mfCka@_eC_UmlB}MmaBeWkkDeHwqAoX}~DcBsZmLcxBqOwqE_DkyAuJmrJ\\o',
  '~CfIewG|YibQxBssB?es@qGciA}RorAoVajA_nAodD{[y`AgPqp@mKwr@ms@umEaW{dAm',
  'b@umAw|@ojBwzDaaJsmBwbEgdCsrFqhAihDquAi`Fux@}_Dui@_eB_u@guCuyAuiHukA_',
  'lKszAu|OmaA{wKm}@clHs_A_rEahCssKo\\sgBsSglAqk@yvDcS_wAyTwpBmPc|BwZknF',
  'oFscB_GsaDiZmyMyLgtHgQonHqT{hKaPg}Dqq@m~Hym@c`EuiBudIabB{hF{pWifx@snA',
  'w`GkFyVqf@y~BkoAi}Lel@wtc@}`@oaXi_C}pZsi@eqGsSuqJ|Lqeb@e]kgPcaAu}SkDw',
  'zGhn@gjYh\\qlNZovJieBqja@ed@siO{[ol\\kCmjMe\\isHorCmec@uLebB}EqiBaCg}',
  '@m@qwHrT_vFps@kkI`uAszIrpHuzYxx@e{Crw@kpDhN{wBtQarDy@knFgP_yCu\\wyCwy',
  'A{kHo~@omEoYmoDaEcPiuAosDagD}rO{{AsyEihCayFilLaiUqm@_bAumFo}DgqA_uByi',
  '@swC~AkzDlhA}xEvcBa}Cxk@ql@`rAo|@~bBq{@``Bye@djDww@z_C_cAtn@ye@nfC_eC',
  '|gGahH~s@w}@``Fi~FpnAooC|u@wlEaEedRlYkrPvKerBfYs}Arg@m}AtrCkzElw@gjBb',
  'h@woBhR{gCwGkgCc[wtCuOapAcFoh@uBy[yBgr@c@iq@o@wvEv@sp@`FajBfCaq@fIipA',
  'dy@ewJlUc`ExGuaBdEmbBpBssArAuqBBg}@s@g{AkB{bBif@_bYmC}r@kDgm@sPq_BuJ_',
  's@{X_{AsK_d@eM{d@wVgx@oWcu@??aDmOkNia@wFoSmDyMyCkPiBePwAob@XcQ|@oNdCo',
  'SfFwXhEmOnLi\\lbAulB`X_d@|k@au@bc@oc@bqC}{BhwDgcD`l@ed@??bL{G|a@eTje@',
  'oS~]cLr~Bgh@|b@}Jv}EieAlv@sPluD{z@nzA_]`|KchCtd@sPvb@wSb{@ko@f`RooQ~e',
  '[upZbuIolI|gFafFzu@iq@nMmJ|OeJn^{Qjh@yQhc@uJ~j@iGdd@kAp~BkBxO{@|QsAfY',
  'gEtYiGd]}Jpd@wRhVoNzNeK`j@ce@vgK}cJnSoSzQkVvUm^rSgc@`Uql@xIq\\vIgg@~k',
  'Dyq[nIir@jNoq@xNwc@fYik@tk@su@neB}uBhqEesFjoGeyHtCoD|D}Ed|@ctAbIuOzqB',
  '_}D~NgY`\\um@v[gm@v{Cw`G`w@o{AdjAwzBh{C}`Gpp@ypAxn@}mAfz@{bBbNia@??jI',
  'ab@`CuOlC}YnAcV`@_^m@aeB}@yk@YuTuBg^uCkZiGk\\yGeY}Lu_@oOsZiTe[uWi[sl@',
  'mo@soAauAsrBgzBqgAglAyd@ig@asAcyAklA}qAwHkGi{@s~@goAmsAyDeEirB_{B}IsJ',
  'uEeFymAssAkdAmhAyTcVkFeEoKiH}l@kp@wg@sj@ku@ey@uh@kj@}EsFmG}Jk^_r@_f@m',
  '~@ym@yjA??a@cFd@kBrCgDbAUnAcBhAyAdk@et@??kF}D??OL'
].join('');

html,
body {
  height: 100%;
  width: 100%;
  padding: 0px;
  margin: 0px;
}

.map {
  height: 90%;
  width: 100%;
}

<script src="https://cdn.rawgit.com/openlayers/openlayers.github.io/master/en/v5.1.3/build/ol.js"></script>
<script src="https://cdn.rawgit.com/Viglino/ol-ext/master/dist/ol-ext.js"></script>
<button id="start-animation">Start Animation</button>
<label for="speed">
      speed:&nbsp;
      <input id="speed" type="range" min="10" max="4999" step="10" value="500">
    </label>
<div id="map" class="map"></div>

score 0 · Accepted Answer

OpenLayers 示例移动不顺畅，因为它使用的唯一坐标是线串改变方向的点。因此，长直道的穿越速度比弯曲部分快得多。ol-ext 方法将线串分成等长的小段，但它似乎正在为视图设置动画以跟上标记，而不是简单地为标记设置动画。通过重用此问题答案第二部分中的 splitLineString 函数https://gis.stackexchange.com/questions/306976/add-image-along-the-linestring精细划分线串并根据基于计时器的索引仅设置一种图标样式，可以实现独立于视图的平滑移动（最好在全屏窗口中看到），并且还允许图标与方向保持对齐旅行。

// This long string is placed here due to jsFiddle limitations.
// It is usually loaded with AJAX.
var polyline = [
  'hldhx@lnau`BCG_EaC??cFjAwDjF??uBlKMd@}@z@??aC^yk@z_@se@b[wFdE??wFfE}N',
  'fIoGxB_I\\gG}@eHoCyTmPqGaBaHOoD\\??yVrGotA|N??o[N_STiwAtEmHGeHcAkiA}^',
  'aMyBiHOkFNoI`CcVvM??gG^gF_@iJwC??eCcA]OoL}DwFyCaCgCcCwDcGwHsSoX??wI_E',
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].join('');


function splitLineString(geometry, minSegmentLength, options) {

  function calculatePointsDistance(coord1, coord2) {
var dx = coord1[0] - coord2[0];
var dy = coord1[1] - coord2[1];
return Math.sqrt(dx * dx + dy * dy);
  };

  function calculateSplitPointCoords(startNode, nextNode, distanceBetweenNodes, distanceToSplitPoint) {
var d = distanceToSplitPoint / distanceBetweenNodes;
var x = nextNode[0] + (startNode[0] - nextNode[0]) * d;
var y = nextNode[1] + (startNode[1] - nextNode[1]) * d;
return [x, y];
  };

  function calculateAngle(startNode, nextNode, alwaysUp) {
var x = (startNode[0] - nextNode[0]);
var y = (startNode[1] - nextNode[1]);
var angle = Math.atan(x/y);
if (!alwaysUp) {
   angle = y > 0 ? angle + Math.PI : x < 0 ? angle + Math.PI*2 : angle;
}
return angle;
  };

  var splitPoints = [];
  var coords = geometry.getCoordinates();

  var coordIndex = 0;
  var startPoint = coords[coordIndex];
  var nextPoint = coords[coordIndex + 1];
  var angle = calculateAngle(startPoint, nextPoint, options.alwaysUp);

  var n = Math.ceil(geometry.getLength()/minSegmentLength);
  var segmentLength = geometry.getLength() / n;
  var currentSegmentLength = options.midPoints ? segmentLength/2 : segmentLength;
 
  for (var i = 0; i <= n; i++) {

var distanceBetweenPoints = calculatePointsDistance(startPoint, nextPoint);
currentSegmentLength += distanceBetweenPoints;

if (currentSegmentLength < segmentLength) {
  coordIndex++;
  if(coordIndex < coords.length - 1) {
    startPoint = coords[coordIndex];
    nextPoint = coords[coordIndex + 1];
    angle = calculateAngle(startPoint, nextPoint, options.alwaysUp);
    i--;
    continue;
  } else {
    if (!options.midPoints) {
      var splitPointCoords = nextPoint;
      splitPointCoords.push(angle);
      splitPoints.push(splitPointCoords);
    }
    break;
  }
} else {
  var distanceToSplitPoint = currentSegmentLength - segmentLength;
  var splitPointCoords = calculateSplitPointCoords(startPoint, nextPoint, distanceBetweenPoints, distanceToSplitPoint);
  startPoint = splitPointCoords.slice();
  splitPointCoords.push(angle);
  splitPoints.push(splitPointCoords);
  currentSegmentLength = 0;
}
  }

  return splitPoints;
};

var route = new ol.format.Polyline({
  factor: 1e6
}).readGeometry(polyline, {
  dataProjection: 'EPSG:4326',
  featureProjection: 'EPSG:3857'
});

var routeCoords = route.getCoordinates();
var routeLength = routeCoords.length;

var routeFeature = new ol.Feature({
  type: 'route',
  geometry: route
});
var startMarker = new ol.Feature({
  type: 'icon',
  geometry: new ol.geom.Point(routeCoords[0])
});
var endMarker = new ol.Feature({
  type: 'icon',
  geometry: new ol.geom.Point(routeCoords[routeLength - 1])
});

var raster = new ol.layer.Tile({
  source:  new ol.source.OSM() 
});

var repeat = false;
var timer = -1;

var style = function(feature, resolution) {

  if (feature.get('type') == 'route') {

var styles = [
  new ol.style.Style({
    stroke: new ol.style.Stroke({
      width: 6,
      color: [237, 212, 0, 0.8],
    })
  })
];

if (timer < 0) {
  feature.unset('splitPoints', true);
} else {
  var splitPoints = feature.get('splitPoints');
  if (!splitPoints) {
    splitPoints = splitLineString(feature.getGeometry(), 2 * resolution, {alwaysUp: false, midPoints: true});
    feature.set('splitPoints', splitPoints, true);
  }
  if (!repeat && timer >= splitPoints.length) {
    stopAnimation(true);
  } else {
    var index = timer % splitPoints.length;
    var point = splitPoints[index];
    styles.push(
      new ol.style.Style({
        geometry: new ol.geom.Point([point[0],point[1]]),
        image: new ol.style.Icon({
          src: 'https://cdn1.iconfinder.com/data/icons/basic-ui-elements-color-round/3/19-32.png',
          rotation: point[2]
        }),
        zIndex: 1
      })
    );
  }
}
return styles;

  } else {

return [
  new ol.style.Style({
    image: new ol.style.Icon({
      anchor: [0.5, 1],
      src: 'https://openlayers.org/en/v4.6.5/examples/data/icon.png',
    })
  })
];

  }

}

var vector = new ol.layer.Vector({
  source: new ol.source.Vector({
features: [routeFeature, startMarker, endMarker]
  }),
  style: style
});

var map = new ol.Map({
  layers: [raster, vector],
  target: 'map',
  view: new ol.View({
center: [-5639523.95, -3501274.52],
zoom: 10
  })
});


var animating = false;
var token;
var speedInput = document.getElementById('speed');
var startButton = document.getElementById('start-animation');

function startAnimation() {

  if (animating) {
stopAnimation(false);
  } else {

animating = true;
startButton.textContent = 'Cancel Animation';
token = setInterval( function(){
  timer++;
  vector.setStyle(style);
}, 6000/speedInput.value);

  }
}

function stopAnimation(ended) {
  animating = false;
  startButton.textContent = 'Start Animation';
  clearInterval(token);
  timer = -1;
  if (!ended) {
vector.setStyle(style);
  }
}

startButton.addEventListener('click', startAnimation, false);

html,
body {
  height: 100%;
  width: 100%;
  padding: 0px;
  margin: 0px;
}

.map {
  height: 90%;
  width: 100%;
}

<link rel="stylesheet" href="https://cdn.rawgit.com/openlayers/openlayers.github.io/master/en/v5.3.0/css/ol.css" type="text/css">
<script src="https://cdn.rawgit.com/openlayers/openlayers.github.io/master/en/v5.3.0/build/ol.js"></script>
<div id="map" class="map"></div>
<label for="speed">
      speed:&nbsp;
      <input id="speed" type="range" min="10" max="999" step="10" value="200">
    </label>
<button id="start-animation">Start Animation</button>

openlayers-5 - OpenLayers 5：平滑移动标记

2 回答 2

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