版本记录

前言

源码

1. Swift

OpenGL源码

首先看下工程组织结构

接着看一下sb文件

下面就是源码了

1. Array+Helpers.swift

import Foundation

//
// MARK: - Array Helpers
//

/// Array extension to help with size/memory calculations when working with OpenGL.
extension Array {
  //
  // MARK: - Instance Methods
  //
  
  /// Returns the memory size/footprint (in bytes) of a given array.
  ///
  /// - Returns: Integer value representing the memory size the array.
  func size() -> Int {
    return count * MemoryLayout.size(ofValue: self[0])
  }
}

2. Vertex.swift

import GLKit

//
// MARK: - Vertex
//

/// Structure to hold a vertex's position and color data.
struct Vertex {
  /// Stores the X coordinate of a vertex.
  var x: GLfloat
  /// Stores the Y coordinate of a vertex.
  var y: GLfloat
  /// Stores the Z coordinate of a vertex.
  var z: GLfloat
  /// Stores the red color value of a vertex.
  var r: GLfloat
  /// Stores the green color value of a vertex.
  var g: GLfloat
  /// Stores the blue color value of a vertex.
  var b: GLfloat
  /// Stores the alpha value of a vertex.
  var a: GLfloat
}

3. ViewController.swift

import GLKit

final class ViewController: GLKViewController {
  var Vertices = [
    Vertex(x:  1, y: -1, z: 0, r: 1, g: 0, b: 0, a: 1),
    Vertex(x:  1, y:  1, z: 0, r: 0, g: 1, b: 0, a: 1),
    Vertex(x: -1, y:  1, z: 0, r: 0, g: 0, b: 1, a: 1),
    Vertex(x: -1, y: -1, z: 0, r: 0, g: 0, b: 0, a: 1),
    ]
  
  var Indices: [GLubyte] = [0, 1, 2, 2, 3, 0]
  
  private var context: EAGLContext?
  private var effect = GLKBaseEffect()
  private var rotation: Float = 0.0
  private var ebo = GLuint()
  private var vbo = GLuint()
  private var vao = GLuint()
  
  deinit {
    tearDownGL()
  }
  
  private func setupGL() {
    context = EAGLContext(api: .openGLES3)
    EAGLContext.setCurrent(context)
    
    if let view = view as? GLKView, let context = context {
      view.context = context
      delegate = self
    }
    
    // Helper variables to identify the position and color attributes for OpenGL calls.
    let vertexAttribColor = GLuint(GLKVertexAttrib.color.rawValue)
    let vertexAttribPosition = GLuint(GLKVertexAttrib.position.rawValue)
    
    // The size, in memory, of a Vertex structure.
    let vertexSize = MemoryLayout<Vertex>.stride
    let colorOffset = MemoryLayout<GLfloat>.stride * 3
    let colorOffsetPointer = UnsafeRawPointer(bitPattern: colorOffset)
    
    // VAO
    
    // Generate and bind a vertex array object.
    glGenVertexArraysOES(1, &vao)
    glBindVertexArrayOES(vao)
    
    // VBO
    glGenBuffers(1, &vbo)
    glBindBuffer(GLenum(GL_ARRAY_BUFFER), vbo)
    glBufferData(GLenum(GL_ARRAY_BUFFER), Vertices.size(), Vertices, GLenum(GL_STATIC_DRAW))
    glEnableVertexAttribArray(vertexAttribPosition)
    glVertexAttribPointer(vertexAttribPosition, 3, GLenum(GL_FLOAT), GLboolean(UInt8(GL_FALSE)), GLsizei(vertexSize), nil)
    
    // Enable the colors vertex attribute to then specify information about how the color of a vertex is stored.
    glEnableVertexAttribArray(vertexAttribColor)
    glVertexAttribPointer(vertexAttribColor, 4, GLenum(GL_FLOAT), GLboolean(UInt8(GL_FALSE)), GLsizei(vertexSize), colorOffsetPointer)
    
    // EBO
    glGenBuffers(1, &ebo)
    glBindBuffer(GLenum(GL_ELEMENT_ARRAY_BUFFER), ebo)
    glBufferData(GLenum(GL_ELEMENT_ARRAY_BUFFER), Indices.size(), Indices, GLenum(GL_STATIC_DRAW))
    glBindBuffer(GLenum(GL_ARRAY_BUFFER), 0)
    glBindVertexArrayOES(0)
  }
  
  /// Perform cleanup, and delete buffers and memory.
  private func tearDownGL() {
    EAGLContext.setCurrent(context)
    
    glDeleteBuffers(1, &vao)
    glDeleteBuffers(1, &vbo)
    glDeleteBuffers(1, &ebo)
    
    EAGLContext.setCurrent(nil)
    context = nil
  }
  
  override func viewDidLoad() {
    super.viewDidLoad()
    
    setupGL()
  }
}

extension ViewController: GLKViewControllerDelegate {
  func glkViewControllerUpdate(_ controller: GLKViewController) {
    let aspect = fabsf(Float(view.bounds.size.width) / Float(view.bounds.size.height))
    let projectionMatrix = GLKMatrix4MakePerspective(GLKMathDegreesToRadians(65.0), aspect, 4.0, 10.0)
    effect.transform.projectionMatrix = projectionMatrix
    
    var modelViewMatrix = GLKMatrix4MakeTranslation(0.0, 0.0, -6.0)
    rotation += 90 * Float(timeSinceLastUpdate)
    modelViewMatrix = GLKMatrix4Rotate(modelViewMatrix, GLKMathDegreesToRadians(rotation), 0, 0, 1)
    effect.transform.modelviewMatrix = modelViewMatrix
  }

  override func glkView(_ view: GLKView, drawIn rect: CGRect) {
    glClearColor(0.85, 0.85, 0.85, 1.0)
    glClear(GLbitfield(GL_COLOR_BUFFER_BIT))
    
    effect.prepareToDraw()
    glBindVertexArrayOES(vao)
    glDrawElements(GLenum(GL_TRIANGLES), GLsizei(Indices.count), GLenum(GL_UNSIGNED_BYTE), nil)
    glBindVertexArrayOES(0)
  }
}

下面看一下实现效果

Metal源码

首先还是看下工程组织结构

接着看sb中的内容

下面就是源码了

1. Array+Helpers.swift

import Foundation

// MARK: - Array Helpers

/// Array extension to help with size/memory calculations when working with OpenGL.
extension Array {
  // MARK: - Instance Methods
  
  /// Returns the memory size/footprint (in bytes) of a given array.
  ///
  /// - Returns: Integer value representing the memory size the array.
  func size() -> Int {
    return count * MemoryLayout.size(ofValue: self[0])
  }
}

2. Vertex.swift

import GLKit

//
// MARK: - Vertex
//

/// Structure to hold a vertex's position and color data.
struct Vertex {
  /// Stores the X coordinate of a vertex.
  var x: GLfloat
  /// Stores the Y coordinate of a vertex.
  var y: GLfloat
  /// Stores the Z coordinate of a vertex.
  var z: GLfloat
  /// Stores the red color value of a vertex.
  var r: GLfloat
  /// Stores the green color value of a vertex.
  var g: GLfloat
  /// Stores the blue color value of a vertex.
  var b: GLfloat
  /// Stores the alpha value of a vertex.
  var a: GLfloat
}

struct SceneMatrices {
  var projectionMatrix: GLKMatrix4 = GLKMatrix4Identity
  var modelviewMatrix: GLKMatrix4 = GLKMatrix4Identity
}

3. ViewController.swift

import GLKit
import MetalKit
final class ViewController: UIViewController {
  @IBOutlet weak var metalView: MTKView!

  private var vertexBuffer: MTLBuffer!
  private var indicesBuffer: MTLBuffer!
  private var metalDevice: MTLDevice!
  private var metalCommandQueue: MTLCommandQueue!
  private var pipelineState: MTLRenderPipelineState!

  var Vertices = [
    Vertex(x:  1, y: -1, z: 0, r: 1, g: 0, b: 0, a: 1),
    Vertex(x:  1, y:  1, z: 0, r: 0, g: 1, b: 0, a: 1),
    Vertex(x: -1, y:  1, z: 0, r: 0, g: 0, b: 1, a: 1),
    Vertex(x: -1, y: -1, z: 0, r: 0, g: 0, b: 0, a: 1),
    ]
  
  var Indices: [UInt32] = [0, 1, 2, 2, 3, 0]
  
  private var rotation: Float = 0.0
  private var ebo = GLuint()
  private var vbo = GLuint()
  private var vao = GLuint()

  private var sceneMatrices = SceneMatrices()
  private var uniformBuffer: MTLBuffer!
  private var lastUpdateDate = Date()
  
  private func setupMetal() {
    metalDevice = MTLCreateSystemDefaultDevice()  // 1
    metalCommandQueue = metalDevice.makeCommandQueue()  // 2
    metalView.device = metalDevice // 3
    metalView.delegate = self // 4

    let vertexBufferSize = Vertices.size()
    vertexBuffer = metalDevice.makeBuffer(bytes: &Vertices, length: vertexBufferSize, options: .storageModeShared)

    let indicesBufferSize = Indices.size()
    indicesBuffer = metalDevice.makeBuffer(bytes: &Indices, length: indicesBufferSize, options: .storageModeShared)

    let defaultLibrary = metalDevice.makeDefaultLibrary()!
    let fragmentProgram = defaultLibrary.makeFunction(name: "basic_fragment")
    let vertexProgram = defaultLibrary.makeFunction(name: "basic_vertex") // 1

    let pipelineStateDescriptor = MTLRenderPipelineDescriptor()
    pipelineStateDescriptor.vertexFunction = vertexProgram
    pipelineStateDescriptor.fragmentFunction = fragmentProgram
    pipelineStateDescriptor.colorAttachments[0].pixelFormat = .bgra8Unorm // 2

    pipelineState = try! metalDevice.makeRenderPipelineState(descriptor: pipelineStateDescriptor) // 3
  }
  
  override func viewDidLoad() {
    super.viewDidLoad()
    
    setupMetal()
  }
}

// MARK: - MTKView Delegate Extension
extension ViewController: MTKViewDelegate {
  // 1
  func mtkView(_ view: MTKView, drawableSizeWillChange size: CGSize) {
    let aspect = fabsf(Float(size.width) / Float(size.height))  // 1
    let projectionMatrix = GLKMatrix4MakePerspective(GLKMathDegreesToRadians(65.0), aspect, 4.0, 10.0)  // 2
    sceneMatrices.projectionMatrix = projectionMatrix  // 3
  }

  // 2
  func draw(in view: MTKView) {
    // 1
    guard let drawable = view.currentDrawable else {
      return
    }

    let renderPassDescriptor = MTLRenderPassDescriptor() // 2
    renderPassDescriptor.colorAttachments[0].texture = drawable.texture // 3
    renderPassDescriptor.colorAttachments[0].loadAction = .clear // 4
    renderPassDescriptor.colorAttachments[0].clearColor = MTLClearColor(red: 0.85, green: 0.85, blue: 0.85, alpha: 1.0) // 5

    // 6
    guard let commandBuffer = metalCommandQueue.makeCommandBuffer() else {
      return
    }

    // 7
    guard let renderEncoder = commandBuffer.makeRenderCommandEncoder(descriptor: renderPassDescriptor) else {
      return
    }

    // Frame drawing goes here
    renderEncoder.setVertexBuffer(vertexBuffer, offset: 0, index: 0)  // 1
    // Update logic
    var modelViewMatrix = GLKMatrix4MakeTranslation(0.0, 0.0, -6.0)
    let timeSinceLastUpdate = lastUpdateDate.timeIntervalSince(Date())
    rotation += 90 * Float(timeSinceLastUpdate) // 1
    modelViewMatrix = GLKMatrix4Rotate(modelViewMatrix, GLKMathDegreesToRadians(rotation), 0, 0, 1)  // 2
    sceneMatrices.modelviewMatrix = modelViewMatrix

    // Set uniform buffer
    let uniformBufferSize = MemoryLayout.size(ofValue: sceneMatrices)
    uniformBuffer = metalDevice.makeBuffer(bytes: &sceneMatrices, length: uniformBufferSize, options: .storageModeShared) // 2
    renderEncoder.setVertexBuffer(uniformBuffer, offset: 0, index: 1)  // 3

    renderEncoder.setRenderPipelineState(pipelineState)
    renderEncoder.drawIndexedPrimitives(type: .triangle, indexCount: Indices.count, indexType: .uint32, indexBuffer: indicesBuffer, indexBufferOffset: 0) // 2

    renderEncoder.endEncoding() // 8
    commandBuffer.addCompletedHandler { _ in
      self.lastUpdateDate = Date()
    }
    commandBuffer.present(drawable) // 9
     // 10
  }
}

具体效果同OpenGL一样，这里就不展示了。

后记

本篇主要讲述了将项目从OpenGL转化到Metal，感兴趣的给个赞或者关注~~~