#[repr(u32)]
pub enum VtkElementType {
TRIANGLE = 5,
QUAD = 9,
TETRA = 10,
HEXAHEDRON = 12,
WEDGE = 13,
PYRAMID = 14,
}
pub fn write_vtk_points<T>(
file: &mut std::fs::File,
name: &str,
vtx2xyz: &[T],
ndim: usize,
) -> std::io::Result<()>
where
T: std::fmt::Display,
{
use std::io::Write;
let np = vtx2xyz.len() / ndim;
writeln!(file, "# vtk DataFile Version 2.0")?;
writeln!(file, "{name}")?;
writeln!(file, "ASCII")?;
writeln!(file, "DATASET UNSTRUCTURED_GRID")?;
writeln!(file, "POINTS {np} float")?;
if ndim == 3 {
for xyz in vtx2xyz.chunks(3) {
writeln!(file, "{} {} {}", xyz[0], xyz[1], xyz[2])?;
}
} else if ndim == 2 {
for xy in vtx2xyz.chunks(2) {
writeln!(file, "{} {}", xy[0], xy[1])?;
}
} else {
panic!();
}
Ok(())
}
pub fn write_vtk_cells(
file: &mut std::fs::File,
vtk_elem_type: VtkElementType,
elem2vtx: &[usize],
) -> std::io::Result<()> {
let num_node = match vtk_elem_type {
VtkElementType::TRIANGLE => 3,
VtkElementType::QUAD => 4,
VtkElementType::TETRA => 4,
VtkElementType::HEXAHEDRON => 8,
VtkElementType::PYRAMID => 5,
VtkElementType::WEDGE => 6,
};
let num_elem = elem2vtx.len() / num_node;
assert_eq!(elem2vtx.len(), num_elem * num_node);
use std::io::Write;
let mut writer = std::io::BufWriter::new(file);
writeln!(writer, "CELLS {} {}", num_elem, num_elem * (num_node + 1))?;
for av in elem2vtx.chunks(num_node) {
write!(writer, "{num_node}")?;
for v in av {
write!(writer, " {v}")?;
}
writeln!(writer)?;
}
writeln!(writer, "CELL_TYPES {num_elem}")?;
{
let id_elem = vtk_elem_type as usize;
for _ in 0..num_elem {
writeln!(writer, "{id_elem}")?;
}
}
Ok(())
}
pub fn write_vtk_cells_mix<IDX>(
file: &mut std::fs::File,
tet2vtx: &[IDX],
pyramid2vtx: &[IDX],
prism2vtx: &[IDX],
) -> std::io::Result<()>
where
IDX: num_traits::PrimInt + std::fmt::Display,
{
let num_tet = tet2vtx.len() / 4;
let num_pyramid = pyramid2vtx.len() / 5;
let num_prism = prism2vtx.len() / 6;
let num_elem = num_tet + num_pyramid + num_prism;
let num_idx = 5 * num_tet + 6 * num_pyramid + 7 * num_prism;
use std::io::Write;
let mut writer = std::io::BufWriter::new(file);
writeln!(writer, "CELLS {num_elem} {num_idx}")?;
for av in tet2vtx.chunks(4) {
write!(writer, "4")?;
av.iter().for_each(|v| write!(writer, " {v}").unwrap());
writeln!(writer)?;
}
for av in pyramid2vtx.chunks(5) {
write!(writer, "5")?;
av.iter().for_each(|v| write!(writer, " {v}").unwrap());
writeln!(writer)?;
}
for av in prism2vtx.chunks(6) {
write!(writer, "6")?;
writeln!(
writer,
" {} {} {} {} {} {}",
av[0], av[2], av[1], av[3], av[5], av[4]
)
.unwrap();
}
writeln!(writer, "CELL_TYPES {num_elem}")?;
for _ in 0..num_tet {
writeln!(writer, "{}", VtkElementType::TETRA as u32).unwrap();
}
for _ in 0..num_pyramid {
writeln!(writer, "{}", VtkElementType::PYRAMID as u32).unwrap();
}
for _ in 0..num_prism {
writeln!(writer, "{}", VtkElementType::WEDGE as u32).unwrap();
}
Ok(())
}
pub fn write_vtk_data_point_scalar<T>(
file: &mut std::fs::File,
vtx2data: &[T],
num_vtx: usize,
num_stride: usize,
) -> std::io::Result<()>
where
T: std::fmt::Display,
{
use std::io::Write;
writeln!(file, "SCALARS pointvalue float 1")?;
writeln!(file, "LOOKUP_TABLE default")?;
for ip in 0..num_vtx {
writeln!(file, "{}", vtx2data[ip * num_stride])?;
}
Ok(())
}
#[cfg(test)]
mod test {
use crate::io_vtk::VtkElementType;
#[test]
fn trimesh3_scalardata() {
let (tri2vtx, vtx2xyz) = crate::trimesh3_primitive::hemisphere_zup::<f64>(1., 16, 32);
let mut file = std::fs::File::create("../target/trimesh3.vtk").expect("file not found.");
crate::io_vtk::write_vtk_points(&mut file, "hoge", &vtx2xyz, 3).unwrap();
crate::io_vtk::write_vtk_cells(&mut file, VtkElementType::TRIANGLE, &tri2vtx).unwrap();
let vtx2data = {
let mut vtx2data = Vec::<f64>::with_capacity(vtx2xyz.len() / 3);
for i_vtx in 0..vtx2xyz.len() / 3 {
let z = vtx2xyz[i_vtx * 3 + 2];
vtx2data.push(z.powi(3));
}
vtx2data
};
use std::io::Write;
let _ = writeln!(file, "POINT_DATA {}", vtx2xyz.len() / 3);
let _ =
crate::io_vtk::write_vtk_data_point_scalar(&mut file, &vtx2data, vtx2xyz.len() / 3, 1);
}
}