// mesh and loader based on work by JTalton; http://www.opentk.com/node/642

public class MeshLoader

{

public bool Load(MeshGroup mesh, string fileName)

{

try

{

using (StreamReader streamReader = new StreamReader(fileName))

{

filepath = fileName.Substring(0,fileName.LastIndexOf("/")+1);

Load(mesh, streamReader);

streamReader.Close();

return true;

}

}

catch { return false; }

}

string filepath;

bool ignoreMaterials = false;

int uiCurMaterial = 1;

Dictionary<string, Texture> Materials;

char[] splitCharacters = new char[] { ' ' };

List<Vector3> vertices;

List<Vector3> normals;

List<Vector2> texCoords;

List<Mesh.ObjVertex> objVertices;

List<Mesh.ObjTriangle> objTriangles;

List<Mesh.ObjQuad> objQuads;

void LoadMTLFile(string mtl)

{

mtl = filepath + mtl;

if (!File.Exists(mtl))

{

ignoreMaterials = true;

return;

}

Console.WriteLine(mtl);

TextReader textReader = new StreamReader(mtl);

Materials = new Dictionary<string, Texture>();

string currentMaterialName = "";

string line;

while((line = textReader.ReadLine()) != null)

{

line = line.Trim(splitCharacters);

line = line.Replace(" ", " ");

string[] parameters = line.Split(splitCharacters);

switch (parameters[0])

{

case "newmtl":

currentMaterialName = parameters[1];

if (!Materials.ContainsKey(currentMaterialName))

Materials[currentMaterialName] = null;

else

throw new ArgumentException(currentMaterialName);

break;

case "map_Kd":

string Kd = parameters[1];

for (int i = 2; i < parameters.Length; i++)

Kd += " " + parameters[i];

if (File.Exists(filepath + Kd))

{

Materials[currentMaterialName] = new Texture(filepath + Kd);

Console.WriteLine(filepath + Kd);

}

else

Materials[currentMaterialName] = Game.defaultTexture;

break;

}

}

}

void Load(MeshGroup meshgroup, TextReader textReader)

{

Mesh mesh = new Mesh(null, null, null, 0);

vertices = new List<Vector3>();

normals = new List<Vector3>();

texCoords = new List<Vector2>();

objVertices = new List<Mesh.ObjVertex>();

objTriangles = new List<Mesh.ObjTriangle>();

objQuads = new List<Mesh.ObjQuad>();

int firsto = 0;

string line;

while ((line = textReader.ReadLine()) != null)

{

line = line.Trim(splitCharacters);

line = line.Replace(" ", " ");

string[] parameters = line.Split(splitCharacters);

switch (parameters[0])

{

case "p": // point

break;

case "v": // vertex

float x = float.Parse(parameters[1]);

float y = float.Parse(parameters[2]);

float z = float.Parse(parameters[3]);

vertices.Add(new Vector3(x, y, z));

break;

case "vt": // texCoord

float u = float.Parse(parameters[1]);

float v = float.Parse(parameters[2]);

texCoords.Add(new Vector2(u, v));

break;

case "vn": // normal

float nx = float.Parse(parameters[1]);

float ny = float.Parse(parameters[2]);

float nz = float.Parse(parameters[3]);

normals.Add(new Vector3(nx, ny, nz));

break;

case "f":

switch (parameters.Length)

{

case 4:

Mesh.ObjTriangle objTriangle = new Mesh.ObjTriangle();

objTriangle.Index0 = ParseFaceParameter(parameters[1]);

objTriangle.Index1 = ParseFaceParameter(parameters[2]);

objTriangle.Index2 = ParseFaceParameter(parameters[3]);

objTriangles.Add(objTriangle);

break;

case 5:

Mesh.ObjQuad objQuad = new Mesh.ObjQuad();

objQuad.Index0 = ParseFaceParameter(parameters[1]);

objQuad.Index1 = ParseFaceParameter(parameters[2]);

objQuad.Index2 = ParseFaceParameter(parameters[3]);

objQuad.Index3 = ParseFaceParameter(parameters[4]);

break;

}

break;

case "mtllib":

string mtl = parameters[1];

for (int i = 2; i < parameters.Length; i++)

mtl += " " + parameters[i];

LoadMTLFile(mtl);

break;

case "usemtl":

string umtl = "";

for (int i = 1; i < parameters.Length; i++)

umtl += parameters[i];

if (ignoreMaterials)

uiCurMaterial = 1;

else

uiCurMaterial = Materials[umtl].id;

break;

case "o":

Console.WriteLine(parameters[1]);

if (firsto > 0)

{

mesh.vertices = objVertices.ToArray();

mesh.triangles = objTriangles.ToArray();

mesh.quads = objQuads.ToArray();

mesh.texture = uiCurMaterial;

meshgroup.AddMesh(mesh);

}

mesh = new Mesh(null, null, null, 0);

firsto++;

//vertices = new List<Vector3>();

//normals = new List<Vector3>();

//texCoords = new List<Vector2>();

objVertices = new List<Mesh.ObjVertex>();

objTriangles = new List<Mesh.ObjTriangle>();

objQuads = new List<Mesh.ObjQuad>();

break;

}

}

Console.WriteLine();

mesh.vertices = objVertices.ToArray();

mesh.triangles = objTriangles.ToArray();

mesh.quads = objQuads.ToArray();

mesh.texture = uiCurMaterial;

meshgroup.AddMesh(mesh);

vertices = null;

normals = null;

texCoords = null;

objVertices = null;

objTriangles = null;

objQuads = null;

}

char[] faceParamaterSplitter = new char[] { '/' };

int ParseFaceParameter(string faceParameter)

{

Vector3 vertex = new Vector3();

Vector2 texCoord = new Vector2();

Vector3 normal = new Vector3();

string[] parameters = faceParameter.Split(faceParamaterSplitter);

int vertexIndex = int.Parse(parameters[0]);

if (vertexIndex < 0) vertexIndex = vertices.Count + vertexIndex;

else vertexIndex = vertexIndex - 1;

vertex = vertices[vertexIndex];

if (parameters.Length > 1) if (parameters[1] != "")

{

int texCoordIndex = int.Parse(parameters[1]);

if (texCoordIndex < 0) texCoordIndex = texCoords.Count + texCoordIndex;

else texCoordIndex = texCoordIndex - 1;

texCoord = texCoords[texCoordIndex];

}

if (parameters.Length > 2)

{

int normalIndex = int.Parse(parameters[2]);

if (normalIndex < 0) normalIndex = normals.Count + normalIndex;

else normalIndex = normalIndex - 1;

normal = normals[normalIndex];

}

return AddObjVertex(ref vertex, ref texCoord, ref normal);

}

int AddObjVertex(ref Vector3 vertex, ref Vector2 texCoord, ref Vector3 normal)

{

Mesh.ObjVertex newObjVertex = new Mesh.ObjVertex();

newObjVertex.Vertex = vertex;

newObjVertex.TexCoord = texCoord;

newObjVertex.Normal = normal;

objVertices.Add(newObjVertex);

return objVertices.Count - 1;

}

}