init dump

Sources/JolkEngine/Loaders/ObjLoader.swift

@@ -0,0 +1,92 @@
+import Foundation
+import OrderedCollections
+
+
+/*
+extension ObjMaterial
+{
+	func convert() -> Material
+	{
+		var m = Material()
+		m.diffuse = self.diffuse.setAlpha(self.alpha)
+		if ![ .colour, .lambert, .shadowOnly ].contains(self.model)
+		{
+			m.specular = self.specular
+			m.specularExp = self.specularExp
+		}
+		return m
+	}
+}
+*/
+
+public struct ObjLoader: LoaderProtocol
+{
+	public typealias T = Mesh
+
+	public init() {}
+
+	public func load(url: URL) -> T?
+	{
+		try? Self.read(url: url)
+	}
+
+	private static func read(url: URL) throws -> Mesh
+	{
+		return try read(model: try ObjReader.read(url: url))
+	}
+
+	public static func read(model: ObjModel) throws -> Mesh
+	{
+		var subMeshes: OrderedDictionary<String, Mesh.SubMesh> = .init()
+		var vertices = [Mesh.Vertex]()
+		var indices = [UInt16]()
+
+		let readIndex =
+		{ (v: ObjModel.Index) -> UInt16 in
+			let vertex = Mesh.Vertex(
+				position: model.positions[v.p],
+				normal: model.normals[v.n],
+				texCoord: model.texCoords[v.t])
+			if let index = vertices.firstIndex(of: vertex)
+			{
+				indices.append(UInt16(index))
+				return UInt16(index)
+			}
+			else
+			{
+				let index = UInt16(vertices.count)
+				indices.append(index)
+				vertices.append(vertex)
+				return index
+			}
+		}
+
+		for mesh in model.objects
+		{
+			let start = indices.count
+			for face: ObjModel.Face in mesh.value.faces
+			{
+				switch face
+				{
+				case .triangle(let v1, let v2, let v3):
+					for v in [ v1, v2, v3 ] { _ = readIndex(v) }
+				case .quad(let v1, let v2, let v3, let v4):
+					let n1 = readIndex(v1)
+					_ = readIndex(v2)
+					indices.append(readIndex(v3))
+					_ = readIndex(v4)
+					indices.append(n1)
+				case .ngon(_): fallthrough
+				default: break
+				}
+			}
+			let length = indices.count - start
+			if length > 0
+			{
+				subMeshes[mesh.key] = .init(start: start, length: length)
+			}
+		}
+
+		return Mesh(vertices: vertices, indices: indices, subMeshes: subMeshes)
+	}
+}