--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dwtx/draw2d/graph/Segment.d	Sun Aug 03 00:52:14 2008 +0200
@@ -0,0 +1,116 @@
+/*******************************************************************************
+ * Copyright (c) 2004, 2005 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ * IBM Corporation - initial API and implementation
+ * Port to the D programming language:
+ *     Frank Benoit <benoit@tionex.de>
+ *******************************************************************************/
+module dwtx.draw2d.graph.Segment;
+
+import dwt.dwthelper.utils;
+import tango.text.convert.Format;
+
+import dwtx.draw2d.geometry.Geometry;
+import dwtx.draw2d.geometry.Point;
+import dwtx.draw2d.graph.Vertex;
+
+/**
+ * A Segment representation for the ShortestPathRouting. A segment is a line between
+ * two vertices.
+ *
+ * This class is for internal use only
+ * @author Whitney Sorenson
+ * @since 3.0
+ */
+class Segment {
+
+Vertex start, end;
+
+/**
+ * Creates a segment between the given start and end points.
+ * @param start the start vertex
+ * @param end the end vertex
+ */
+this(Vertex start, Vertex end) {
+    this.start = start;
+    this.end = end;
+}
+
+/**
+ * Returns the cosine of the made between this segment and the given segment
+ * @param otherSegment the other segment
+ * @return cosine value (not arc-cos)
+ */
+double cosine(Segment otherSegment) {
+    double cos = (((start.x - end.x) * (otherSegment.end.x - otherSegment.start.x))
+            + ((start.y - end.y) * (otherSegment.end.y - otherSegment.start.y)))
+                / (getLength() * otherSegment.getLength());
+    double sin = (((start.x - end.x) * (otherSegment.end.y - otherSegment.start.y))
+            - ((start.y - end.y) * (otherSegment.end.x - otherSegment.start.x)));
+    if (sin < 0.0)
+        return (1 + cos);
+
+    return -(1 + cos);
+}
+
+/**
+ * Returns the cross product of this segment and the given segment
+ * @param otherSegment the other segment
+ * @return the cross product
+ */
+long crossProduct(Segment otherSegment) {
+    return (((start.x - end.x) * (otherSegment.end.y - end.y))
+            - ((start.y - end.y) * (otherSegment.end.x - end.x)));
+}
+
+private double getLength() {
+    return (end.getDistance(start));
+}
+
+/**
+ * Returns a number that represents the sign of the slope of this segment. It does
+ * not return the actual slope.
+ * @return number representing sign of the slope
+ */
+double getSlope() {
+    if (end.x - start.x >= 0)
+        return (end.y - start.y);
+    else
+        return -(end.y - start.y);
+}
+
+/**
+ * Returns true if the given segment intersects this segment.
+ * @param sx start x
+ * @param sy start y
+ * @param tx end x
+ * @param ty end y
+ * @return true if the segments intersect
+ */
+bool intersects(int sx, int sy, int tx, int ty) {
+    return Geometry.linesIntersect(start.x, start.y, end.x, end.y, sx, sy, tx, ty);
+}
+
+/**
+ * Return true if the segment represented by the points intersects this segment.
+ * @param s start point
+ * @param t end point
+ * @return true if the segments intersect
+ */
+bool intersects(Point s, Point t) {
+    return intersects(s.x, s.y, t.x, t.y);
+}
+
+/**
+ * @see java.lang.Object#toString()
+ */
+public String toString() {
+    return Format( "{}---{}", start, end ); //$NON-NLS-1$
+}
+
+}