private void ParseFaces(Span <string> lineParts, string group, int vertexCounter, TriangleMesh mesh)
{
var normalCounter = 0;
if (lineParts.Length > 4)
{
FanTriangulation(lineParts.Slice(1, lineParts.Length - 1), vertexCounter, group, mesh);
}
else
{
if (lineParts[1].Contains('/'))
{
var faceVertex1 = BuildFace(lineParts[1].Split('/'));
var faceVertex2 = BuildFace(lineParts[2].Split('/'));
var faceVertex3 = BuildFace(lineParts[3].Split('/'));
if (faceVertex1.VertexIndex < 1)
{
mesh.AddTriangle(BuildTiangle(group, vertexCounter, normalCounter, faceVertex1, faceVertex2, faceVertex3));
}
else
{
mesh.AddTriangle(BuildTiangle(group, 0, 0, faceVertex1, faceVertex2, faceVertex3));
}
}
else
{
if (Convert.ToInt32(lineParts[1]) < 1)
{
mesh.AddTriangle(
vertexCounter + Convert.ToInt32(lineParts[1]),
vertexCounter + Convert.ToInt32(lineParts[2]),
vertexCounter + Convert.ToInt32(lineParts[3]), group);
}
else
{
mesh.AddTriangle(Convert.ToInt32(lineParts[1]), Convert.ToInt32(lineParts[2]), Convert.ToInt32(lineParts[3]), group);
}
}
}
}
private void FanTriangulation(Span <string> lineParts, int vertexCounter, string group, TriangleMesh mesh)
{
var normalCounter = 0;
for (int index = 1; index < lineParts.Length - 1; index++)
{
if (lineParts[0].Contains('/'))
{
var faceVertex1 = BuildFace(lineParts[0].Split('/'));
var faceVertex2 = BuildFace(lineParts[index].Split('/'));
var faceVertex3 = BuildFace(lineParts[index + 1].Split('/'));
if (faceVertex1.VertexIndex < 1)
{
mesh.AddTriangle(BuildTiangle(group, vertexCounter, normalCounter, faceVertex1, faceVertex2, faceVertex3));
}
else
{
mesh.AddTriangle(BuildTiangle(group, 0, 0, faceVertex1, faceVertex2, faceVertex3));
}
}
else
{
if (Convert.ToInt32(lineParts[1]) < 1)
{
mesh.AddTriangle(
vertexCounter + Convert.ToInt32(lineParts[0]),
vertexCounter + Convert.ToInt32(lineParts[index]),
vertexCounter + Convert.ToInt32(lineParts[index + 1]), group);
}
else
{
mesh.AddTriangle(Convert.ToInt32(lineParts[0]), Convert.ToInt32(lineParts[index]), Convert.ToInt32(lineParts[index + 1]), group);
}
}
}
}
