如何在MTKView中使用多重采样?

我正试着用多重取样法 MTKView . 我有一个 sampleCount rasterSampleCount 设置为4,并使用它生成渲染管道状态,我在渲染时使用该状态。

在代表的 draw(in:) 方法,通过获取视图的当前渲染过程描述符并设置 storeAction multisampleResolve . 我也试过了 storeAndMultisampleResolve 无济于事。

我已经为渲染过程描述符创建了一个resolve纹理,它的宽度和高度与视图相同,像素格式也相同。

我需要做什么才能让渲染进入屏幕?

下面是如何设置视图、管道状态和“解析纹理”(resolve texture):

    metalView = newMetalView
    metalView.sampleCount = 4
    metalView.clearColor = MTLClearColor(red: 0.0, green: 0.0, blue: 0.0, alpha: 0.0)
    device = newMetalView.device!

    let metalLibrary = device.makeDefaultLibrary()!
    let vertexFunction =  metalLibrary.makeFunction(name: "vertexShader")
    let fragmentFunction = metalLibrary.makeFunction(name: "fragmentShader")

    let pipelineStateDescriptor = MTLRenderPipelineDescriptor.init()
    pipelineStateDescriptor.label = "Particle Renderer"
    pipelineStateDescriptor.vertexFunction = vertexFunction
    pipelineStateDescriptor.fragmentFunction = fragmentFunction
    pipelineStateDescriptor.colorAttachments [ 0 ].pixelFormat = metalView.colorPixelFormat
    pipelineStateDescriptor.rasterSampleCount = 4

    do {
        try pipelineState = device.makeRenderPipelineState(descriptor: pipelineStateDescriptor)
    } catch {
        NSLog("Unable to create pipeline state")
        pipelineState = nil
    }

    let textureDescriptor = MTLTextureDescriptor.texture2DDescriptor(pixelFormat: metalView.colorPixelFormat, width: Int(metalView.bounds.width), height: Int(metalView.bounds.height), mipmapped: false)
    resolveTexture = device.makeTexture(descriptor: textureDescriptor)!

我是这样画的:

    let commandBuffer = commandQueue.makeCommandBuffer()
    commandBuffer?.label = "Partcle Command Buffer"
    let renderPassDescriptor = metalView.currentRenderPassDescriptor
    renderPassDescriptor?.colorAttachments[0].clearColor = MTLClearColorMake(0.0, 0.0, 0.0, 0.0)
    renderPassDescriptor?.colorAttachments[0].loadAction = MTLLoadAction.clear
    renderPassDescriptor?.colorAttachments[0].storeAction = MTLStoreAction.multisampleResolve
    renderPassDescriptor?.colorAttachments[0].resolveTexture = resolveTexture

    let renderEncoder = commandBuffer?.makeRenderCommandEncoder(descriptor: renderPassDescriptor!)
    renderEncoder?.label = "Particle Render Encoder"
    renderEncoder?.setViewport(MTLViewport(originX: 0.0, originY: 0.0, width: Double(viewportSize.x), height: Double(viewportSize.y), znear: -1.0, zfar: 1.0))
    renderEncoder?.setRenderPipelineState(pipelineState!);

    renderEncoder?.endEncoding()
    commandBuffer?.present(metalView.currentDrawable!)
    commandBuffer?.commit()

以下是调试器在我的纹理中显示的内容:

奇怪的是,在进行调试时,我意外地隐藏了Xcode,对于1帧,视图显示了正确的纹理。