unsafe void UnsafeRead(ReadOnlySpan <byte> all)
{
var _uint32 = sizeof(UInt32);
var header = all.Slice(0, sizeof(sbyte) * 80);
var triangles = all.Slice(sizeof(sbyte) * 80, sizeof(uint));
var text = Utf8ReadOnlySpanHelper.GetString(header);
if (!Utf8Parser.TryParse(triangles, out UInt32 value, out var _))
{
throw new Exception("Can't read float");
}
}
unsafe void UnsafeRead(ReadOnlySpan <byte> all)
{
var groupname = "noname";
var current = GeometryCache.CreatePart(groupname);
var floats = new float[3];
var vertices = new OBJVertex[4];
var triangleFan = new OBJVertex[6];
while (!all.IsEmpty)
{
var endLine = all.IndexOf(LFChars);
int separatorLenght = LFChars.Length;
if (endLine == -1)
{
endLine = all.Length;
separatorLenght = 0;
}
if (endLine == 0) //has only CR_LF, ignore then
{
all = all.Slice(separatorLenght);
continue;
}
int cr = 0;
if (all[endLine - 1] == CRChars) //check 'CR LF'
{
cr = 1;
}
var line = all.Slice(0, endLine - cr);//ignore CR_LF or LF
all = all.Slice(endLine + separatorLenght);
if (line.StartsWith(commentChars) || IsWhiteSpace(line))
{
continue;
}
//lenth 2 is default for OBJ format keys, just use it as a const
var part = line.Slice(2, line.Length - 2).Trim(space);
if (line.StartsWith(groupChars))
{
var names = Utf8ReadOnlySpanHelper.GetString(part).Trim().SplitOnWhitespace();
groupname = string.Join(" ", names);//clean up group name from extra space
current = GeometryCache.CreatePart(groupname);
}
else if (line.StartsWith(textureChars))
{
//vt u v w
// u is the value for the horizontal direction of the texture.
// v is an optional argument.
// v is the value for the vertical direction of the texture.The default is 0.
// w is an optional argument.
// w is a value for the depth of the texture.The default is 0.
SplitVertex(ref part, floats, 2);
var v = new Vector2(floats[0], 1 - floats[1]); // '1 - ' specific fot OBJ format
current.AddTextureCoor(ref v);
}
else if (line.StartsWith(normalChars))
{
SplitVertex(ref part, floats);
var v = new Vector3(floats[0], floats[1], floats[2]);
current.AddNormal(ref v);
}
else if (line.StartsWith(vectorChars))
{
SplitVertex(ref part, floats);
var v = new Vector3(floats[0], floats[1], floats[2]);
current.AddPosition(ref v);
if (!part.IsEmpty) //format 'v' line with colors
//example: v -2.503583 6.779097 -5.350025 0.0 128.0 0.0
{
SplitVertex(ref part, floats);
v = new Vector3(floats[0], floats[1], floats[2]);
current.AddColor(ref v);
}
if (!part.IsEmpty)
{
throw new NotSupportedException("Unexpected vertex format.");
}
}
else if (line.StartsWith(faceChars))
{
var topo = SplitFace(part, vertices);
current.AddVertices(vertices, topo);
}
else if (line.StartsWith(materialChars))
{
//mtllib filename.mat
var end = line.IndexOf(space);
var filename = line.Slice(end + 1, line.Length - end - 1);
LoadMaterial(filename);
}
}
}
