implementing Drawing Custom Graphics in NSView on macOS 13.6 Using Metal
This might be a silly question, but I'm trying to configure I'm trying to implement I'm working with a question when trying to render custom graphics within an `NSView` subclass using Metal on macOS 13.6..... I've set up a Metal device and a rendering pipeline, and while my setup works fine for a simple triangle, it's failing to render more complex shapes. Specifically, when I try to draw using vertex buffers with more than three vertices, I get a runtime behavior: `MTLCommandBufferErrorInvalidResource`. This happens on the line where I create a drawable: `guard let drawable = metalLayer?.nextDrawable() else { return }`. I suspect it might be related to how I'm managing the vertex buffers or the render pass descriptor. Here’s a snippet of my rendering code: ```swift class CustomMetalView: NSView { private var device: MTLDevice! private var commandQueue: MTLCommandQueue! private var metalLayer: CAMetalLayer! required init?(coder: NSCoder) { super.init(coder: coder) setupMetal() } private func setupMetal() { device = MTLCreateSystemDefaultDevice() metalLayer = CAMetalLayer(layer: self.layer!) metalLayer.device = device metalLayer.pixelFormat = .bgra8Unorm commandQueue = device.makeCommandQueue() } override func draw(_ dirtyRect: NSRect) { super.draw(dirtyRect) drawFrame() } private func drawFrame() { guard let drawable = metalLayer.nextDrawable() else { return } let renderPassDescriptor = MTLRenderPassDescriptor() renderPassDescriptor.colorAttachments[0].texture = drawable.texture renderPassDescriptor.colorAttachments[0].loadAction = .clear renderPassDescriptor.colorAttachments[0].clearColor = MTLClearColor(red: 0, green: 0, blue: 0, alpha: 1) renderPassDescriptor.colorAttachments[0].storeAction = .store let commandBuffer = commandQueue.makeCommandBuffer() let renderEncoder = commandBuffer?.makeRenderCommandEncoder(descriptor: renderPassDescriptor) // scenario arises here when encoding the draw call renderEncoder?.drawPrimitives(type: .triangle, vertexStart: 0, vertexCount: vertexCount) renderEncoder?.endEncoding() commandBuffer?.present(drawable) commandBuffer?.commit() } } ``` I've verified that my vertex buffer is filled correctly and that `vertexCount` is set appropriately. The question only seems to occur with more complex shapes, leading me to think it might be related to how the resources are being managed or how I'm defining the render pass. Any insights on how to debug this or what might be going wrong with multiple vertices would be greatly appreciated. This is for a application running on Ubuntu 20.04. Hoping someone can shed some light on this. Thanks, I really appreciate it! What am I doing wrong? I'm coming from a different tech stack and learning Swift. I'd really appreciate any guidance on this.