/// <summary>
/// http://en.wikipedia.org/wiki/Wavefront_.obj_file
/// </summary>
/// <param name="filename"></param>
/// <returns></returns>
public static Mesh LoadObjFile(string filename)
{
var file = Filepaths.GetModelFileInfo(filename);
if (!file.Exists)
throw new ModelException(StandardExceptions.NewFileNotFound(file));
string src;
using (var s = new StreamReader(file.FullName))
{
src = s.ReadToEnd();
}
var lines = src.Split('\n').Where(s => !s.StartsWith("#")).ToList();
var vertexs = new List<Vector3>();
var vertexTextures = new List<Vector2>();
var vertexNormals = new List<Vector3>();
foreach (
var xyzw in
lines.Where(s => s.StartsWith("v "))
.Select(s => s.Substring(s.IndexOf(' ') + 1).Split(' '))
.ToList())
{
string x = "", y = "", z = "", w = "";
if (xyzw.Length >= 1)
x = xyzw[0];
if (xyzw.Length >= 2)
y = xyzw[1];
if (xyzw.Length >= 3)
z = xyzw[2];
if (xyzw.Length == 4)
w = xyzw[3];
// TODO: Vertex4 for position in the Vertex class
vertexs.Add(new Vector3(float.Parse(x), float.Parse(y), float.Parse(z)));
}
// TODO: .mtl and that stuff
foreach (
var uvw in
lines.Where(s => s.StartsWith("vt "))
.Select(s => s.Substring(s.IndexOf(' ') + 1).Split(' '))
.ToList())
{
string u = "", v = "", w = "";
if (uvw.Length >= 1)
u = uvw[0];
if (uvw.Length >= 2)
v = uvw[1];
if (uvw.Length == 3)
w = uvw[3];
// TODO: Vertex3 for texture in the Vertex class
vertexTextures.Add(new Vector2(float.Parse(u), float.Parse(v)));
}
foreach (
var xyz in
lines.Where(s => s.StartsWith("vn "))
.Select(s => s.Substring(s.IndexOf(' ') + 1).Split(' '))
.ToList())
{
string x = "", y = "", z = "";
if (xyz.Length >= 1)
x = xyz[0];
if (xyz.Length >= 2)
y = xyz[1];
if (xyz.Length >= 3)
z = xyz[2];
vertexNormals.Add(new Vector3(float.Parse(x), float.Parse(y), float.Parse(z)).Normalized());
}
// TODO: lines starting with vp
var vertices = new List<Vertex>();
var indices = new List<int>();
foreach (
var face in
lines.Where(s => s.StartsWith("f "))
.Select(s => s.Substring(s.IndexOf(' ') + 1).Split(' '))
.ToList())
{
for (int i = 0; i < face.Length - 2; i++)
{
for (int j = 0; j < 3; j++)
{
string[] vert = face[i + j].Split('/');
int v = 0, t = 0, n = 0;
v = int.Parse(vert[0]);
if (vert.Length >= 2 && vert[1] != string.Empty)
t = int.Parse(vert[1]);
if (vert.Length == 3)
n = int.Parse(vert[2]);
Vector3 position = vertexs[v - 1];
Vector2 texture = Vector2.Zero;
if (t != 0)
texture = vertexTextures[t - 1];
Vector3 normal = Vector3.Zero;
if (n != 0)
normal = vertexNormals[n - 1];
vertices.Add(new Vertex(position, normal, texture));
indices.Add(indices.Count);
}
}
}
var mesh = new Mesh(
BufferLibrary.CreateVertexBuffer(filename, vertices.ToArray()),
BufferLibrary.CreateIndexBuffer(
filename, indices.Select(i => (uint) i).ToArray(), PrimitiveType.Triangles),
indices.Count, PrimitiveType.Triangles);
AddMesh(mesh, filename);
return mesh;
}
private void RenderMesh(Mesh mesh)
{
GL.BindBuffer(BufferTarget.ArrayBuffer, mesh.VboId);
GL.BindBuffer(BufferTarget.ElementArrayBuffer, mesh.IboId);
GL.EnableVertexAttribArray(0);
GL.VertexAttribPointer(0, 3, VertexAttribPointerType.Float, false, Vertex.SizeInBytes, (IntPtr)0);
GL.EnableVertexAttribArray(1);
GL.VertexAttribPointer(1, 3, VertexAttribPointerType.Float, false, Vertex.SizeInBytes, (IntPtr)(sizeof(float) * 3));
GL.EnableVertexAttribArray(2);
GL.VertexAttribPointer(2, 2, VertexAttribPointerType.Float, false, Vertex.SizeInBytes, (IntPtr)(sizeof(float) * 6));
GL.DrawRangeElements(mesh.Mode, 0, mesh.Count, mesh.Count, DrawElementsType.UnsignedInt, IntPtr.Zero);
GL.BindBuffer(BufferTarget.ArrayBuffer, 0);
GL.BindBuffer(BufferTarget.ElementArrayBuffer, 0);
}
public static void AddMesh(Mesh mesh, string name)
{
Meshes[name] = mesh;
}
