I tried using iOS Metal in a simple app but when i call the device.newDefaultLibrary() function then I get an error in runtime:
/BuildRoot/Library/Caches/com.apple.xbs/Sources/Metal/Metal-56.7/Framework/MTLLibrary.mm:1842: failed assertion `Metal default library not found'
Has anyone any idea what cloud be the problem? I followed this tutorial: https://www.raywenderlich.com/77488/ios-8-metal-tutorial-swift-getting-started The code is a little old but with tiny changes it work. Here is my viewController code:
import UIKit
import Metal
import QuartzCore
class ViewController: UIViewController {
//11A
var device: MTLDevice! = nil
//11B
var metalLayer: CAMetalLayer! = nil
//11C
let vertexData:[Float] = [
0.0, 1.0, 0.0,
-1.0, -1.0, 0.0,
1.0, -1.0, 0.0]
var vertexBuffer: MTLBuffer! = nil
//11F
var pipelineState: MTLRenderPipelineState! = nil
//11G
var commandQueue: MTLCommandQueue! = nil
//12A
var timer: CADisplayLink! = nil
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
//11A
device = MTLCreateSystemDefaultDevice()
//11B
metalLayer = CAMetalLayer() // 1
metalLayer.device = device // 2
metalLayer.pixelFormat = .BGRA8Unorm // 3
metalLayer.framebufferOnly = true // 4
metalLayer.frame = view.layer.frame // 5
view.layer.addSublayer(metalLayer) // 6
//11C
let dataSize = vertexData.count * sizeofValue(vertexData[0]) // 1
vertexBuffer = device.newBufferWithBytes(vertexData, length: dataSize, options: MTLResourceOptions.CPUCacheModeDefaultCache) // 2
//11F
// 1
let defaultLibrary = device.newDefaultLibrary() //The error is generating here
let fragmentProgram = defaultLibrary!.newFunctionWithName("basic_fragment")
let vertexProgram = defaultLibrary!.newFunctionWithName("basic_vertex")
// 2
let pipelineStateDescriptor = MTLRenderPipelineDescriptor()
pipelineStateDescriptor.vertexFunction = vertexProgram
pipelineStateDescriptor.fragmentFunction = fragmentProgram
pipelineStateDescriptor.colorAttachments[0].pixelFormat = .BGRA8Unorm
// 3
do {
try pipelineState = device.newRenderPipelineStateWithDescriptor(pipelineStateDescriptor)
} catch _ {
print("Failed to create pipeline state, error")
}
//11G
commandQueue = device.newCommandQueue()
//12A
timer = CADisplayLink(target: self, selector: Selector("gameloop"))
timer.addToRunLoop(NSRunLoop.mainRunLoop(), forMode: NSDefaultRunLoopMode)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
//MARK: Custom Methodes
//12A
func render() {
//12C
let commandBuffer = commandQueue.commandBuffer()
//12B
let drawable = metalLayer.nextDrawable()
let renderPassDescriptor = MTLRenderPassDescriptor()
renderPassDescriptor.colorAttachments[0].texture = drawable!.texture
renderPassDescriptor.colorAttachments[0].loadAction = .Clear
renderPassDescriptor.colorAttachments[0].clearColor = MTLClearColor(red: 0.0, green: 104.0/255.0, blue: 5.0/255.0, alpha: 1.0)
//12D
let renderEncoderOpt = commandBuffer.renderCommandEncoderWithDescriptor(renderPassDescriptor)
renderEncoderOpt.setRenderPipelineState(pipelineState)
renderEncoderOpt.setVertexBuffer(vertexBuffer, offset: 0, atIndex: 0)
renderEncoderOpt.drawPrimitives(.Triangle, vertexStart: 0, vertexCount: 3, instanceCount: 1)
renderEncoderOpt.endEncoding()
//12E
commandBuffer.presentDrawable(drawable!)
commandBuffer.commit()
}
func gameloop() {
autoreleasepool {
self.render()
}
}
}
I use an iPhone 5s device with iOS 9.3 for testing.
The default library is only included in your app when you have at least one .metal
file in your app target's Compile Sources build phase. I assume you've followed the steps of the tutorial where you created the Metal shader source file and added the vertex and fragment functions, so you simply need to use the +
icon in the build phases setting to add that file to your compilation phase:
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