eu.mihosoft.jcsg.ext.imagej.STLLoader Maven / Gradle / Ivy
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Java implementation of BSP based CSG (Constructive Solid Geometry)
package eu.mihosoft.jcsg.ext.imagej;
/**
* Fork of
* https://github.com/fiji/fiji/blob/master/src-plugins/3D_Viewer/src/main/java/customnode/STLLoader.java
*
* TODO: license unclear
*/
import eu.mihosoft.vvecmath.ModifiableVector3d;
import eu.mihosoft.vvecmath.Vector3d;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.text.DecimalFormat;
import java.text.ParseException;
import java.util.ArrayList;
public class STLLoader {
// /**
// * Load the specified stl file and returns the result as a hash map, mapping
// * the object names to the corresponding CustomMesh objects.
// */
// public static Map load(String stlfile)
// throws IOException {
// STLLoader sl = new STLLoader();
// try {
// sl.parse(stlfile);
// } catch (RuntimeException e) {
// System.out.println("error reading " + sl.name);
// throw e;
// }
// return sl.meshes;
// }
//
// private HashMap meshes;
public STLLoader() {
}
String line;
BufferedReader in;
// attributes of the currently read mesh
private ArrayList vertices = new ArrayList<>();
private final ModifiableVector3d normal = Vector3d.zero().asModifiable(); //to be used for file checking
private FileInputStream fis;
private int triangles;
// private DecimalFormat decimalFormat = new DecimalFormat("0.0E0");
public ArrayList parse(File f) throws IOException {
vertices.clear();
// determine if this is a binary or ASCII STL
// and send to the appropriate parsing method
// Hypothesis 1: this is an ASCII STL
BufferedReader br = new BufferedReader(new FileReader(f));
String line = br.readLine();
String[] words = line.trim().split("\\s+");
if (line.indexOf('\0') < 0 && words[0].equalsIgnoreCase("solid")) {
System.out.println("Looks like an ASCII STL");
parseAscii(f);
return vertices;
}
// Hypothesis 2: this is a binary STL
FileInputStream fs = new FileInputStream(f);
// bytes 80, 81, 82 and 83 form a little-endian int
// that contains the number of triangles
byte[] buffer = new byte[84];
fs.read(buffer, 0, 84);
triangles = (int) (((buffer[83] & 0xff) << 24)
| ((buffer[82] & 0xff) << 16) | ((buffer[81] & 0xff) << 8) | (buffer[80] & 0xff));
if (((f.length() - 84) / 50) == triangles) {
System.out.println("Looks like a binary STL");
parseBinary(f);
return vertices;
}
System.err.println("File is not a valid STL");
return vertices;
}
private void parseAscii(File f) {
try {
in = new BufferedReader(new FileReader(f));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
vertices = new ArrayList<>();
try {
while ((line = in.readLine()) != null) {
String[] numbers = line.trim().split("\\s+");
if (numbers[0].equals("vertex")) {
float x = parseFloat(numbers[1]);
float y = parseFloat(numbers[2]);
float z = parseFloat(numbers[3]);
Vector3d vertex = Vector3d.xyz(x, y, z);
vertices.add(vertex);
} else if (numbers[0].equals("facet") && numbers[1].equals("normal")) {
normal.setX(parseFloat(numbers[2]));
normal.setY(parseFloat(numbers[3]));
normal.setZ(parseFloat(numbers[4]));
}
}
in.close();
} catch (IOException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
}
}
private void parseBinary(File f) {
vertices = new ArrayList();
try {
fis = new FileInputStream(f);
for (int h = 0; h < 84; h++) {
fis.read();// skip the header bytes
}
for (int t = 0; t < triangles; t++) {
byte[] tri = new byte[50];
for (int tb = 0; tb < 50; tb++) {
tri[tb] = (byte) fis.read();
}
normal.setX(leBytesToFloat(tri[0], tri[1], tri[2], tri[3]));
normal.setY(leBytesToFloat(tri[4], tri[5], tri[6], tri[7]));
normal.setZ(leBytesToFloat(tri[8], tri[9], tri[10], tri[11]));
for (int i = 0; i < 3; i++) {
final int j = i * 12 + 12;
float px = leBytesToFloat(tri[j], tri[j + 1], tri[j + 2],
tri[j + 3]);
float py = leBytesToFloat(tri[j + 4], tri[j + 5],
tri[j + 6], tri[j + 7]);
float pz = leBytesToFloat(tri[j + 8], tri[j + 9],
tri[j + 10], tri[j + 11]);
Vector3d p = Vector3d.xyz(px, py, pz);
vertices.add(p);
}
}
fis.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
// private float parseFloat(String string) throws ParseException {
// //E+05 -> E05, e+05 -> E05
// string = string.replaceFirst("[eE]\\+", "E");
// //E-05 -> E-05, e-05 -> E-05
// string = string.replaceFirst("e\\-", "E-");
// return decimalFormat.parse(string).floatValue();
// }
private float parseFloat(String string) throws ParseException {
return Float.parseFloat(string);
}
private float leBytesToFloat(byte b0, byte b1, byte b2, byte b3) {
return Float.intBitsToFloat((((b3 & 0xff) << 24) | ((b2 & 0xff) << 16)
| ((b1 & 0xff) << 8) | (b0 & 0xff)));
}
}