What follows is the highlighted source code with comments. You can also download this file directly: PathUtil.java.
/* * Copyright (C) 2012 W. Patrick Hooper <wphooper@gmail.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ package path; import geometry.LineSegment; import java.awt.geom.Rectangle2D; /** * Some useful functions for working with Paths and PolygonalPaths. * * @author W. Patrick Hooper */ public class PathUtil { /** Return the smallest rectangle containing the polygonal path. * Here, the polygonal path is considered to be a sequence of line segments, * rather than paths. */ public static Rectangle2D boundingBox(PolygonalPath p) { double xmin = p.startingPoint().re(); double xmax = p.startingPoint().re(); double ymin = p.startingPoint().im(); double ymax = p.startingPoint().im(); EdgeIterator it = p.iterator(); while (it.hasNext()) { LineSegment s = it.next(); if (s.endingPoint().re() < xmin) { xmin = s.endingPoint().re(); } if (s.endingPoint().re() > xmax) { xmax = s.endingPoint().re(); } if (s.endingPoint().im() < ymin) { ymin = s.endingPoint().im(); } if (s.endingPoint().im() > ymax) { ymax = s.endingPoint().im(); } } return new Rectangle2D.Double(xmin, ymin, xmax-xmin, ymax-ymin); } /** Convert a polygonal path to a string representation. */ public static String toString(PolygonalPath p) { EdgeIterator it=p.iterator(); if (! it.hasNext()) { return "<>"; } // Now we know we have at least one segment. LineSegment seg=it.next(); // A StringBuilder is a useful way to assemble a long string. StringBuilder builder=new StringBuilder(); builder.append("< "); builder.append(seg.startingPoint()); builder.append(", "); builder.append(seg.endingPoint()); while (it.hasNext()) { seg=it.next(); builder.append(", "); builder.append(seg.endingPoint()); } builder.append(">"); return builder.toString(); } public static double distanceFromStartToEnd(Path p) { return p.endingPoint().minus(p.startingPoint()).abs(); } }