HullUtil.java

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package eu.mihosoft.vrl.v3d.ext.quickhull3d;
 
import eu.mihosoft.vrl.v3d.CSG;
import eu.mihosoft.vrl.v3d.Vector3d;
import eu.mihosoft.vrl.v3d.Polygon;
import eu.mihosoft.vrl.v3d.PropertyStorage;
import java.util.ArrayList;
import java.util.List;
 
public class HullUtil {
 
    private HullUtil() {
        throw new AssertionError("Don't instantiate me!", null);
    }
 
    public static CSG hull(List<?> points) {
        List<Vector3d> plist = new ArrayList<>();
        if (Vector3d.class.isInstance(points.get(0))) {
            points.stream().forEach((pobj) -> plist.add((Vector3d) pobj));
            return hull(plist, new PropertyStorage());
        }
        if (CSG.class.isInstance(points.get(0))) {
            for (Object csg : points)
                ((CSG) csg).getPolygons().forEach((p) -> p.vertices.forEach((v) -> plist.add(v.pos)));
 
            return hull(plist, new PropertyStorage());
        }
        throw new RuntimeException("Objects in list are of unknown type: " + points.get(0).getClass().getName()+"\r\nExpected CSG or Vector3d ");
    }
 
    public static CSG hull(List<Vector3d> points, PropertyStorage storage) {
 
        Point3d[] hullPoints = points.stream().map((vec) -> new Point3d(vec.x, vec.y, vec.z)).toArray(Point3d[]::new);
 
        QuickHull3D hull = new QuickHull3D();
        hull.build(hullPoints);
        hull.triangulate();
 
        int[][] faces = hull.getFaces();
 
        List<Polygon> polygons = new ArrayList<>();
 
        List<Vector3d> vertices = new ArrayList<>();
 
        for (int[] verts : faces) {
 
            for (int i : verts) {
                vertices.add(points.get(hull.getVertexPointIndices()[i]));
            }
 
            polygons.add(Polygon.fromPoints(vertices, storage));
 
            vertices.clear();
        }
 
        return CSG.fromPolygons(polygons);
    }
 
    public static CSG hull(CSG csg, PropertyStorage storage) {
 
        List<Vector3d> points = new ArrayList<>(csg.getPolygons().size() * 3);
 
        csg.getPolygons().forEach((p) -> p.vertices.forEach((v) -> points.add(v.pos)));
 
        return hull(points, storage);
    }
 
    public static CSG hull(CSG... csgList) {
 
        List<Vector3d> points = new ArrayList<>();
        for (CSG csg : csgList)
            csg.getPolygons().forEach((p) -> p.vertices.forEach((v) -> points.add(v.pos)));
 
        return hull(points, new PropertyStorage());
    }
}