RenderCache缓存无法命中

[re-ovo]

问题

Debug的时候发现RenderPipeline一直在创建，看了下RenderCache, copy了描述符以后又更新了描述符，导致缓存无法命中

// RenderCache.ts
createRenderPipeline(descriptor: RenderPipelineDescriptor): RenderPipeline {
    let renderPipeline = this.renderPipelinesCache.get(descriptor);
    if (renderPipeline === null) {
      const descriptorCopy = renderPipelineDescriptorCopy(descriptor);
      // 这里更新了descriptorCopy，导致缓存实际上无法命中
      descriptorCopy.colorAttachmentFormats =
        descriptorCopy.colorAttachmentFormats.filter((f) => f); 
      renderPipeline = this.device.createRenderPipeline(descriptorCopy);
      this.renderPipelinesCache.add(descriptorCopy, renderPipeline);
    }
    return renderPipeline;
  }