addVertex method
Adds a vertex at position carrying the current sticky attributes
and returns its index.
Implementation
int addVertex(Vector3 position) {
if (deduplicate) {
final key = _vertexKey(position);
final existing = _vertexLookup[key];
if (existing != null) return existing;
final index = vertexCount;
_vertexLookup[key] = index;
_appendVertex(position);
return index;
}
final index = vertexCount;
_appendVertex(position);
return index;
}