Allow usage of prerender and postrender on raster imageries

[hy31337]

.

[hy31337]

    this.baseLayers.forEach((base) => {
      base.on("prerender", (event) => {
        let vectorContext = getVectorContext(event);
        let ctx = event.context;
        ctx.save();
        vectorContext.drawFeature(clipFeature, style); // 可以对边界设置一个样式
        event.context.globalCompositeOperation = "source-over";
        ctx.clip();
      });
      base.on("postrender", (event) => {
        let ctx = event.context;
        ctx.restore();
      });
      base.setExtent(clipFeature.getGeometry().getExtent());
    });

[gberaudo]

Hi @hy31337, what you are trying to do is not supported right now.
Can you give an example about how it should display?