AnimatingWobblingPlane.swift

var sceneConstants: SceneConstants = ...

public func draw(in view: MTKView) {
    guard let drawable = view.currentDrawable else { return }
    
    ...
    let deltaTime = 1 / Float(view.preferredFramesPerSecond)
    sceneConstants.t += deltaTime
    
    commandEncoder.setVertexBytes(&sceneConstants,
                                  length: MemoryLayout<SceneConstants>.stride,
                                  index: 2)
    
    ...
    
    commandEncoder.endEncoding()
    
    commandBuffer.present(drawable)
    commandBuffer.commit()
}