void AppendIndex(int index, ObjLine line)
{
string[] indices = line.Tokens[index].Split('/');
// Required: Position
int positionIndex = int.Parse(indices[0], CultureInfo.InvariantCulture) - positionsIndexOffset;
int texCoordIndex = -1;
int normalIndex = -1;
// Optional: Texture coordinate
if (indices.Length > 1 && indices[1].Equals(string.Empty) == false)
{
texCoordIndex = int.Parse(indices[1]) - textureCoordinatesIndexOffset;
}
// Optional: Normal
if (indices.Length > 2 && indices[2].Equals(string.Empty) == false)
{
normalIndex = int.Parse(indices[2]) - normalsIndexOffset;
}
// Build vertex
var vertex = new PositionNormalTextured {
Position = positions[positionIndex]
};
if (texCoordIndex >= 0)
{
vertex.TextureCoordinates = textureCoordinates[texCoordIndex];
}
if (normalIndex >= 0)
{
vertex.Normal = normals[normalIndex];
}
// check if the vertex does not already exists
string hash = vertex.ToString();
int vertexIndex;
if (!registeredVertices.TryGetValue(hash, out vertexIndex))
{
stagingVertices.Add(vertex);
vertexIndex = stagingVertices.Count - 1;
registeredVertices.Add(hash, vertexIndex);
}
stagingIndices.Add(vertexIndex);
}
