// Close the input file and throw an ExceptionParseError exception.
void parse_error()
{
const size_t line_number = m_lexer.get_line_number();
m_lexer.close();
throw ExceptionParseError(line_number);
}
void parse_f_statement()
{
clear_keep_memory(m_face_vertex_indices);
clear_keep_memory(m_face_tex_coord_indices);
clear_keep_memory(m_face_normal_indices);
while (true)
{
m_lexer.eat_blanks();
if (m_lexer.is_eol())
break;
//
// Recognized (epsilon)
// Accept n
//
{
const long n = m_lexer.accept_long();
const size_t v = fix_index(n, m_vertices.size());
m_face_vertex_indices.push_back(v);
}
//
// Recognized n
// Accept (epsilon), /
//
{
const unsigned char c = m_lexer.get_char();
if (m_lexer.is_space(c))
continue;
else if (c == '/')
m_lexer.next_char();
else parse_error();
}
//
// Recognized n/
// Accept /, n
//
{
const unsigned char c = m_lexer.get_char();
if (c == '/')
{
m_lexer.next_char();
goto skip;
}
else
{
const long n = m_lexer.accept_long();
const size_t vt = fix_index(n, m_tex_coords.size());
m_face_tex_coord_indices.push_back(vt);
}
}
//
// Recognized n/n
// Accept (epsilon), /
//
{
const unsigned char c = m_lexer.get_char();
if (m_lexer.is_space(c))
continue;
else if (c == '/')
m_lexer.next_char();
else parse_error();
}
skip:
//
// Recognized n//, n/n/
// Accept (epsilon), n
//
{
const unsigned char c = m_lexer.get_char();
if (m_lexer.is_space(c))
continue;
else
{
const long n = m_lexer.accept_long();
const size_t vn = fix_index(n, m_normals.size());
m_face_normal_indices.push_back(vn);
}
}
}
// Check whether the face is well-formed.
const size_t vc = m_face_vertex_indices.size();
const size_t tc = m_face_tex_coord_indices.size();
const size_t nc = m_face_normal_indices.size();
const bool well_formed =
vc >= 3
&& (tc == 0 || tc == vc)
&& (nc == 0 || nc == vc);
if (well_formed)
{
// The face is well-formed, insert it into the mesh.
insert_face_into_mesh();
}
else
{
// The face is ill-formed, ignore it or abort parsing.
if (m_options & StopOnInvalidFaceDef)
throw ExceptionInvalidFaceDef(m_lexer.get_line_number());
}
}