/// <summary>
/// If the incoming vertex does already exist in the vertex collection of the meshObject it returns the index of the already existing item.
/// Else it adds the incoming vertex to the collection and returns its current index.
/// </summary>
/// <param name="index"></param>
/// <param name="vertex"></param>
/// <returns></returns>
private int AddVertex(int index, PositionNormalTextureVertex vertex)
{
// TODO PERFORMANCE LEAK for large meshes
//if (_mesh_object_file.Vertices.Contains(vertex))
//{
// return _mesh_object_file.Vertices.IndexOf(vertex);
//}
//else
{
_mesh_object_file.Vertices.Add(vertex);
return _mesh_object_file.Vertices.Count - 1;
}
}
/// <summary>
/// Dispatcher for the geometry file.
/// Formats: f int int int | f int/int int/int int/int | f int/int/int int/int/int int/int/int
/// Collects the data from the temporary lists and assign them to the mesh.
/// Faces are stored as series of three vertices in clockwise order. Vertices are described by their
/// position, optional texture coordinate, and optional normal, encoded as indices into the respective
/// temporary component list.
/// </summary>
/// <param name="splitted"></param>
private void AddFaces(string[] splitted)
{
if (splitted.Length >= 4)
{
int index_position = 0, index_texcoord, index_normal;
int vertex_in_face, first_index;
int[] index_helper = new int[4];
PositionNormalTextureVertex vertex = new PositionNormalTextureVertex();
if (splitted[1] == string.Empty)
{
// more than 1 space distance
int old_length = splitted.Length;
// remove additional spacings
List<String> tmp_space_split = new List<string>();
for (int i = 0; i < old_length; i++)
{
if (splitted[i] != string.Empty)
{
tmp_space_split.Add(splitted[i]);
}
}
splitted = tmp_space_split.ToArray();
}
vertex_in_face = splitted.Length - 1;
for (int index_face = 0; index_face < vertex_in_face; index_face++)
{
// get indices for position, texcoords and normals out of the file and get with them the values from the according normal, position or texcoords list
// for a single vertice
string[] vertice_series = splitted[1 + index_face].Split('/');
if (vertice_series.Length >= 1)
{
// is in format: f int int int
index_position = Int32.Parse(vertice_series[0]);
vertex.Position = _tmp_positions[index_position - 1];
}
if (vertice_series.Length >= 2)
{
// format: f int/int int/int int/int
if (!String.IsNullOrEmpty(vertice_series[1]))
{
index_texcoord = Int32.Parse(vertice_series[1]);
vertex.TextureCoordinate = _tmp_tex_coords[index_texcoord - 1];
}
}
if (vertice_series.Length >= 3)
{
// format: int/int/int ..
index_normal = Int32.Parse(vertice_series[2]);
vertex.Normal = _tmp_normals[index_normal - 1];
}
// if a duplicate vertex doesn't exist, add this vertex to the vertices list and store the index in the indices list.
// after the fileinput these data eventually become the vertex buffer and index buffer for the mesh.
int index = AddVertex(index_position, vertex);
// faces helper for four faces -> f 1 2 3 4
if(vertex_in_face == 4 && index_face >= 0 && index_face < 4)
{
index_helper[index_face] = index;
}
if(index_face < 3)
{
_mesh_object_file.Indices.Add(index);
}
else
{
_mesh_object_file.Attributes.Add(_current_material_subset_index);
// add new trianglestrip
//for (int i = 2; i >= 0; i--)
// _mesh_object_file.Indices.Add(index_helper[i]);
_mesh_object_file.Indices.Add(index_helper[0]);
_mesh_object_file.Indices.Add(index_helper[2]);
_mesh_object_file.Indices.Add(index_helper[3]);
_mesh_object_file.Attributes.Add(_current_material_subset_index);
}
}
if (vertex_in_face < 4)
_mesh_object_file.Attributes.Add(_current_material_subset_index);
}
}
