Triangle mesh in Metal - swift

Question

I'm trying to create triangle 2D mesh using SwiftUI & Metal. I have lists of vertices[929 items] and indices[1750 items] to draw a mesh. I have used method .drawIndexedPrimitives, but it isn't correct for this purpose. I think this problem should be solved by using MTKMesh, but I don't know how to apply this to 2D mesh with lists of vertices and indices. Please suggest/give some ideas to solve this problem
The code of Renderer Class below
import Foundation
import MetalKit
class Renderer: NSObject, MTKViewDelegate {
var parent: MetalViewComponent
var metalDevice: MTLDevice!
var metalCommandQueue: MTLCommandQueue!
let pipelineState: MTLRenderPipelineState
let vertexBuffer: MTLBuffer?
// let mesh = MTKMesh(mesh: <#T##MDLMesh#>, device: <#T##MTLDevice#>)
let indexBuffer: MTLBuffer?
init(_ parent: MetalViewComponent) {
self.parent = parent
if let metalDevice = MTLCreateSystemDefaultDevice() {
self.metalDevice = metalDevice
}
self.metalCommandQueue = metalDevice.makeCommandQueue()
let pipelineDescriptor = MTLRenderPipelineDescriptor()
let library = metalDevice.makeDefaultLibrary()
pipelineDescriptor.vertexFunction = library?.makeFunction(name: "vertexShader")
pipelineDescriptor.fragmentFunction = library?.makeFunction(name: "fragmentShader")
pipelineDescriptor.colorAttachments[0].pixelFormat = .bgra8Unorm
do {
try pipelineState = metalDevice.makeRenderPipelineState(descriptor: pipelineDescriptor)
} catch {
fatalError()
}
let vertices = [Vertex(position: [-3.49195e-17, -0.570297], color: [0, 1, 1, 1]),
Vertex(position: [-0.245024, -0.578218], color: [0, 1, 1, 1]),
Vertex(position: [-0.529488, -0.52307], color: [0, 1, 1, 1]),...
let indices: [UInt32] = [470,469,433,
433,469,432,
470,433,434,
506,469,507,
469,470,507, // from 1 to 928
vertexBuffer = metalDevice.makeBuffer(bytes: vertices, length: vertices.count * MemoryLayout<Vertex>.stride, options: [])!
indexBuffer = metalDevice.makeBuffer(bytes: indices, length: indices.count * MemoryLayout<UInt16>.size, options: [])
super.init()
print("Число вертексов: \(vertices.count)")
}
func mtkView(_ view: MTKView, drawableSizeWillChange size: CGSize) {
}
func draw(in view: MTKView) {
guard let drawable = view.currentDrawable else {
return
}
let commandBuffer = metalCommandQueue.makeCommandBuffer()
let renderPassDescriptor = view.currentRenderPassDescriptor
renderPassDescriptor?.colorAttachments[0].clearColor = MTLClearColorMake(0, 0, 0, 1.0)
renderPassDescriptor?.colorAttachments[0].loadAction = .clear
renderPassDescriptor?.colorAttachments[0].storeAction = .store
let renderEncoder = commandBuffer?.makeRenderCommandEncoder(descriptor: renderPassDescriptor!)
renderEncoder?.setRenderPipelineState(pipelineState)
renderEncoder?.setVertexBuffer(vertexBuffer, offset: 0, index: 0)
renderEncoder?.drawIndexedPrimitives(type: .lineStrip, indexCount: 1750, indexType: .uint32, indexBuffer: indexBuffer!, indexBufferOffset: 0)
renderEncoder?.endEncoding()
commandBuffer?.present(drawable)
commandBuffer?.commit()
}
}//
This is what's drawing for now
this is what I expect