我应该如何在Metal中渲染文本？

import Metal
import MetalKit

// 创建字体纹理（简化示例）
func createFontTexture(for text: String) -> MTLTexture {
    // 这里应该包含创建字体纹理的逻辑，例如使用Core Text生成字形并上传到GPU。
    // 为简化，假设我们已经有了一个纹理。
    let textureDescriptor = MTLTextureDescriptor.texture2DDescriptor(
        pixelFormat: .rgba8Unorm,
        width: 512,
        height: 512,
        mipmapped: false)
    let texture = device.makeTexture(descriptor: textureDescriptor)!
    // 填充纹理数据...
    return texture
}

// 设置渲染管线状态
let library = device.makeDefaultLibrary()!
let vertexFunction = library.makeFunction(name: "vertexShader")
let fragmentFunction = library.makeFunction(name: "fragmentShader")

let pipelineDescriptor = MTLRenderPipelineDescriptor()
pipelineDescriptor.vertexFunction = vertexFunction
pipelineDescriptor.fragmentFunction = fragmentFunction
pipelineDescriptor.colorAttachments[0].pixelFormat = .bgra8Unorm

let pipelineState = try! device.makeRenderPipelineState(descriptor: pipelineDescriptor)

// 渲染文本
func renderText(_ text: String, to texture: MTLTexture) {
    let commandBuffer = commandQueue.makeCommandBuffer()!
    let renderPassDescriptor = MTLRenderPassDescriptor()
    renderPassDescriptor.colorAttachments[0].texture = texture
    renderPassDescriptor.colorAttachments[0].loadAction = .clear
    renderPassDescriptor.colorAttachments[0].clearColor = MTLClearColor(red: 0.0, green: 0.0, blue: 0.0, alpha: 1.0)

    let renderEncoder = commandBuffer.makeRenderCommandEncoder(descriptor: renderPassDescriptor)!
    renderEncoder.setRenderPipelineState(pipelineState)
    // 设置顶点和纹理坐标...
    renderEncoder.drawPrimitives(type: .triangleStrip, vertexStart: 0, vertexCount: 4)
    renderEncoder.endEncoding()

    commandBuffer.present(drawable)
    commandBuffer.commit()
}

// 假设我们已经有了一个MTKView和它的drawable
let texture = createFontTexture(for: "Hello, Metal!")
renderText("Hello, Metal!", to: texture)