实现轮播效果时，如果使用blob方式加载图像，16次后webgl会崩溃

[xmsuperman]

出现 WARNING: Too many active WebGL contexts. Oldest context will be lost.

然后出现 TypeError: Cannot read properties of null (reading 'createShader')

at createProgram (index.js:1122:1) at new plot (index.js:1334:1) at TIFFImageryProvider.eval (index.js:2156:1) at Generator.next () at fulfilled (index.js:22:1)

`let i = 0; window.setInterval(async () => {

      that.viewer.imageryLayers.remove(baseImagelayer);
      baseProvider.destroy();

      imageBlob = null;

      imageBlob = await axios.get('http://localhost/api/file/export/734615026031136768.TIF', {
        responseType: "blob"
      });

      baseProvider = new TIFFImageryProvider({            
        url: imageBlob.data,
        renderOptions: {
          nodata: -999,
          single: {
            colorScale: "jet",
            //colorScaleImage: image,
            domain: [0, 80],
          }
        }, 
        enablePickFeatures: true,
        //resampleMethod: 'bilinear',
      });
      baseImagelayer = new Cesium.ImageryLayer(baseProvider); 
      that.viewer.imageryLayers.add(baseImagelayer);

      i++;
      console.log(i);
    },2000);`

[xmsuperman]

可以确认内置的plot组件存在内存泄露

[xmsuperman]

通过修改原码，可以极大的延缓内存溢出的时间，但是经测试300+以后还是会内存溢出。

1327行 将OffscreenCanvas对象全局化， this.offscreenCanvas = new OffscreenCanvas(512, 512);

1331行 创建create3DContext使用全局化的offscreenCanvas if (create3DContext(this.offscreenCanvas, { premultipliedAlpha: false }) !== null) {

在destory方法中增加以下代码 if(this.ctx){ this.ctx.clearRect(0, 0, this.canvas.width, this.canvas.height); }

    this.gl = null;
    this.offscreenCanvas = null;
    this.ctx = null;

    this.canvas = null;
    this._source = null;

[xmsuperman]

将TIFFImageryProvider的destory增加 this._workerFarm = null; this.plot = null;
将WorkerFarm的destory方法增加 this.worker = null;

[xmsuperman]

元凶找到，按照作者的指导，修改 1331行 原 if (create3DContext(new OffscreenCanvas(512, 512), { premultipliedAlpha: false }) !== null) { const gl = create3DContext(this.canvas, { premultipliedAlpha: false }); 新 const gl = create3DContext(this.canvas, { premultipliedAlpha: false }); if (gl!==null) {

彻底解决问题