/
vtk.go
169 lines (160 loc) · 5.94 KB
/
vtk.go
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package main
// Support for vtk 4.2 file output
// Author: Rémy Lassalle-Balier
// Modified by Arne Vansteenkiste, 2012, 2013.
// Modified by Mykola Dvornik, 2013
import (
"bytes"
"encoding/base64"
"encoding/binary"
"fmt"
"io"
"log"
"github.com/mumax/3/data"
)
func dumpVTK(out io.Writer, q *data.Slice, meta data.Meta, dataformat string) (err error) {
err = writeVTKHeader(out, q)
err = writeVTKCellData(out, q, meta, dataformat)
err = writeVTKPoints(out, q, dataformat, meta)
err = writeVTKFooter(out)
return
}
func writeVTKHeader(out io.Writer, q *data.Slice) (err error) {
gridsize := q.Size()
_, err = fmt.Fprintln(out, "<?xml version=\"1.0\"?>")
_, err = fmt.Fprintln(out, "<VTKFile type=\"StructuredGrid\" version=\"0.1\" byte_order=\"LittleEndian\">")
_, err = fmt.Fprintf(out, "\t<StructuredGrid WholeExtent=\"0 %d 0 %d 0 %d\">\n", gridsize[0]-1, gridsize[1]-1, gridsize[2]-1)
_, err = fmt.Fprintf(out, "\t\t<Piece Extent=\"0 %d 0 %d 0 %d\">\n", gridsize[0]-1, gridsize[1]-1, gridsize[2]-1)
return
}
func writeVTKPoints(out io.Writer, q *data.Slice, dataformat string, info data.Meta) (err error) {
_, err = fmt.Fprintln(out, "\t\t\t<Points>")
fmt.Fprintf(out, "\t\t\t\t<DataArray type=\"Float32\" NumberOfComponents=\"3\" format=\"%s\">\n\t\t\t\t\t", dataformat)
gridsize := q.Size()
cellsize := info.CellSize
switch dataformat {
case "ascii":
for k := 0; k < gridsize[2]; k++ {
for j := 0; j < gridsize[1]; j++ {
for i := 0; i < gridsize[0]; i++ {
x := (float32)(i) * (float32)(cellsize[0])
y := (float32)(j) * (float32)(cellsize[1])
z := (float32)(k) * (float32)(cellsize[2])
_, err = fmt.Fprint(out, x, " ", y, " ", z, " ")
}
}
}
case "binary":
buffer := new(bytes.Buffer)
for k := 0; k < gridsize[2]; k++ {
for j := 0; j < gridsize[1]; j++ {
for i := 0; i < gridsize[0]; i++ {
x := (float32)(i) * (float32)(cellsize[0])
y := (float32)(j) * (float32)(cellsize[1])
z := (float32)(k) * (float32)(cellsize[2])
binary.Write(buffer, binary.LittleEndian, x)
binary.Write(buffer, binary.LittleEndian, y)
binary.Write(buffer, binary.LittleEndian, z)
}
}
}
b64len := uint32(len(buffer.Bytes()))
bufLen := new(bytes.Buffer)
binary.Write(bufLen, binary.LittleEndian, b64len)
base64out := base64.NewEncoder(base64.StdEncoding, out)
base64out.Write(bufLen.Bytes())
base64out.Write(buffer.Bytes())
base64out.Close()
default:
log.Fatalf("Illegal VTK data format: %v. Options are: ascii, binary", dataformat)
}
_, err = fmt.Fprintln(out, "\n\t\t\t\t</DataArray>")
_, err = fmt.Fprintln(out, "\t\t\t</Points>")
return
}
func writeVTKCellData(out io.Writer, q *data.Slice, meta data.Meta, dataformat string) (err error) {
N := q.NComp()
data := q.Tensors()
switch N {
case 1:
fmt.Fprintf(out, "\t\t\t<PointData Scalars=\"%s\">\n", meta.Name)
fmt.Fprintf(out, "\t\t\t\t<DataArray type=\"Float32\" Name=\"%s\" NumberOfComponents=\"%d\" format=\"%s\">\n\t\t\t\t\t", meta.Name, N, dataformat)
case 3:
fmt.Fprintf(out, "\t\t\t<PointData Vectors=\"%s\">\n", meta.Name)
fmt.Fprintf(out, "\t\t\t\t<DataArray type=\"Float32\" Name=\"%s\" NumberOfComponents=\"%d\" format=\"%s\">\n\t\t\t\t\t", meta.Name, N, dataformat)
case 6, 9:
fmt.Fprintf(out, "\t\t\t<PointData Tensors=\"%s\">\n", meta.Name)
fmt.Fprintf(out, "\t\t\t\t<DataArray type=\"Float32\" Name=\"%s\" NumberOfComponents=\"%d\" format=\"%s\">\n\t\t\t\t\t", meta.Name, 9, dataformat) // must be 9!
default:
log.Fatalf("vtk: cannot handle %v components", N)
}
gridsize := q.Size()
switch dataformat {
case "ascii":
for k := 0; k < gridsize[2]; k++ {
for j := 0; j < gridsize[1]; j++ {
for i := 0; i < gridsize[0]; i++ {
// if symmetric tensor manage it appart to write the full 9 components
if N == 6 {
fmt.Fprint(out, data[0][k][j][i], " ")
fmt.Fprint(out, data[1][k][j][i], " ")
fmt.Fprint(out, data[2][k][j][i], " ")
fmt.Fprint(out, data[1][k][j][i], " ")
fmt.Fprint(out, data[3][k][j][i], " ")
fmt.Fprint(out, data[4][k][j][i], " ")
fmt.Fprint(out, data[2][k][j][i], " ")
fmt.Fprint(out, data[4][k][j][i], " ")
fmt.Fprint(out, data[5][k][j][i], " ")
} else {
for c := 0; c < N; c++ {
fmt.Fprint(out, data[c][k][j][i], " ")
}
}
}
}
}
case "binary":
// Inlined for performance, terabytes of data will pass here...
buffer := new(bytes.Buffer)
for k := 0; k < gridsize[2]; k++ {
for j := 0; j < gridsize[1]; j++ {
for i := 0; i < gridsize[0]; i++ {
// if symmetric tensor manage it appart to write the full 9 components
if N == 6 {
binary.Write(buffer, binary.LittleEndian, data[0][k][j][i])
binary.Write(buffer, binary.LittleEndian, data[1][k][j][i])
binary.Write(buffer, binary.LittleEndian, data[2][k][j][i])
binary.Write(buffer, binary.LittleEndian, data[1][k][j][i])
binary.Write(buffer, binary.LittleEndian, data[3][k][j][i])
binary.Write(buffer, binary.LittleEndian, data[4][k][j][i])
binary.Write(buffer, binary.LittleEndian, data[2][k][j][i])
binary.Write(buffer, binary.LittleEndian, data[4][k][j][i])
binary.Write(buffer, binary.LittleEndian, data[5][k][j][i])
} else {
for c := 0; c < N; c++ {
binary.Write(buffer, binary.LittleEndian, data[c][k][j][i])
}
}
}
}
}
b64len := uint32(len(buffer.Bytes()))
bufLen := new(bytes.Buffer)
binary.Write(bufLen, binary.LittleEndian, b64len)
base64out := base64.NewEncoder(base64.StdEncoding, out)
base64out.Write(bufLen.Bytes())
base64out.Write(buffer.Bytes())
base64out.Close()
default:
panic(fmt.Errorf("vtk: illegal data format " + dataformat + ". Options are: ascii, binary"))
}
fmt.Fprintln(out, "\n\t\t\t\t</DataArray>")
fmt.Fprintln(out, "\t\t\t</PointData>")
return
}
func writeVTKFooter(out io.Writer) (err error) {
_, err = fmt.Fprintln(out, "\t\t</Piece>")
_, err = fmt.Fprintln(out, "\t</StructuredGrid>")
_, err = fmt.Fprintln(out, "</VTKFile>")
return
}