MetalByTutorials/18-rendering-with-rays/starter/Clouds.playground/Pages/4. Clouds.xcplaygroundpage/Sources/Renderer.swift

49 lines
1.6 KiB
Swift

import MetalKit
public class Renderer: NSObject, MTKViewDelegate {
public var device: MTLDevice!
var queue: MTLCommandQueue!
var pipelineState: MTLComputePipelineState!
var time: Float = 0
override public init() {
super.init()
initializeMetal()
}
func initializeMetal() {
device = MTLCreateSystemDefaultDevice()
queue = device!.makeCommandQueue()
do {
let library = device.makeDefaultLibrary()!
guard let kernel = library.makeFunction(name: "compute") else { fatalError() }
pipelineState = try device.makeComputePipelineState(function: kernel)
} catch {
print(error)
}
}
public func mtkView(_ view: MTKView, drawableSizeWillChange size: CGSize) {}
public func draw(in view: MTKView) {
time += 0.01
guard let commandBuffer = queue.makeCommandBuffer(),
let commandEncoder = commandBuffer.makeComputeCommandEncoder(),
let drawable = view.currentDrawable else { fatalError() }
commandEncoder.setComputePipelineState(pipelineState)
commandEncoder.setTexture(drawable.texture, index: 0)
commandEncoder.setBytes(&time, length: MemoryLayout<Float>.size, index: 0)
let w = pipelineState.threadExecutionWidth
let h = pipelineState.maxTotalThreadsPerThreadgroup / w
let threadsPerGroup = MTLSizeMake(w, h, 1)
let threadsPerGrid = MTLSizeMake(Int(view.drawableSize.width),
Int(view.drawableSize.height), 1)
commandEncoder.dispatchThreads(threadsPerGrid, threadsPerThreadgroup: threadsPerGroup)
commandEncoder.endEncoding()
commandBuffer.present(drawable)
commandBuffer.commit()
}
}