metal-examples-tutorials/particles/particle2.playground/Sources/MetalViewDelegate.swift

96 lines
4.1 KiB
Swift

import MetalKit
public class MetalViewDelegate: NSObject, MTKViewDelegate {
public var device: MTLDevice!
var queue: MTLCommandQueue!
var pipelineState: MTLRenderPipelineState!
var model: MTKMesh!
var particles: [Particle]!
var particlesBuffer: MTLBuffer!
var timer: Float = 0
struct Particle {
var initialMatrix = matrix_identity_float4x4
var matrix = matrix_identity_float4x4
var color = float4()
}
override public init() {
super.init()
initializeMetal()
}
func initializeBuffers() {
particles = [Particle](repeatElement(Particle(), count: 1000))
particlesBuffer = device.makeBuffer(length: particles.count * MemoryLayout<Particle>.stride, options: [])!
var pointer = particlesBuffer.contents().bindMemory(to: Particle.self, capacity: particles.count)
for _ in particles {
pointer.pointee.initialMatrix = translate(by: [Float(drand48()) / 10, Float(drand48()) * 10, 0])
pointer.pointee.color = float4(0.2, 0.6, 0.9, 1)
pointer = pointer.advanced(by: 1)
}
let allocator = MTKMeshBufferAllocator(device: device)
let sphere = MDLMesh(sphereWithExtent: [0.01, 0.01, 0.01], segments: [8, 8], inwardNormals: false, geometryType: .triangles, allocator: allocator)
do { model = try MTKMesh(mesh: sphere, device: device) }
catch let e { print(e) }
}
func initializeMetal() {
device = MTLCreateSystemDefaultDevice()
queue = device.makeCommandQueue()
initializeBuffers()
let library: MTLLibrary
do {
let path = Bundle.main.path(forResource: "Shaders", ofType: "metal")
let source = try String(contentsOfFile: path!, encoding: .utf8)
library = try device.makeLibrary(source: source, options: nil)
let descriptor = MTLRenderPipelineDescriptor()
descriptor.colorAttachments[0].pixelFormat = .bgra8Unorm
descriptor.vertexFunction = library.makeFunction(name: "vertex_main")
descriptor.fragmentFunction = library.makeFunction(name: "fragment_main")
descriptor.vertexDescriptor = MTKMetalVertexDescriptorFromModelIO(model.vertexDescriptor)
pipelineState = try device.makeRenderPipelineState(descriptor: descriptor)
} catch let error as NSError {
fatalError("library error: " + error.description)
}
}
func translate(by: float3) -> float4x4 {
return float4x4(columns: (
float4( 1, 0, 0, 0),
float4( 0, 1, 0, 0),
float4( 0, 0, 1, 0),
float4( by.x, by.y, by.z, 1)
))
}
func update() {
timer += 0.01
var pointer = particlesBuffer.contents().bindMemory(to: Particle.self, capacity: particles.count)
for _ in particles {
pointer.pointee.matrix = translate(by: [0, -3 * timer, 0]) * pointer.pointee.initialMatrix
pointer = pointer.advanced(by: 1)
}
}
public func mtkView(_ view: MTKView, drawableSizeWillChange size: CGSize) { }
public func draw(in view: MTKView) {
update()
guard let commandBuffer = queue.makeCommandBuffer(),
let descriptor = view.currentRenderPassDescriptor,
let commandEncoder = commandBuffer.makeRenderCommandEncoder(descriptor: descriptor),
let drawable = view.currentDrawable else { fatalError() }
let submesh = model.submeshes[0]
commandEncoder.setRenderPipelineState(pipelineState)
commandEncoder.setVertexBuffer(model.vertexBuffers[0].buffer, offset: 0, index: 0)
commandEncoder.setVertexBuffer(particlesBuffer, offset: 0, index: 1)
commandEncoder.drawIndexedPrimitives(type: .triangle, indexCount: submesh.indexCount, indexType: submesh.indexType, indexBuffer: submesh.indexBuffer.buffer, indexBufferOffset: 0, instanceCount: particles.count)
commandEncoder.endEncoding()
commandBuffer.present(drawable)
commandBuffer.commit()
}
}