Code clean up and optimization

.gitignore

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+/target/

scopviz/src/main/java/de/tu_darmstadt/informatik/tk/scopviz/main/AuxilFunctions.java

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+package de.tu_darmstadt.informatik.tk.scopviz.main;
+
+import java.util.Iterator;
+
+import org.graphstream.algorithm.Toolkit;
+import org.graphstream.graph.Edge;
+import org.graphstream.graph.Node;
+import org.graphstream.ui.geom.Point3;
+import org.graphstream.ui.view.Camera;
+
+/**
+ * This class contains helpful static functions.
+ * 
+ * @author Matthias Wilhelm
+ *
+ */
+public class AuxilFunctions {
+	/**
+	 * Width in pixel for which the edge selection triggers
+	 */
+	private static final int EDGE_SELECTION_WIDTH = 5;
+	/**
+	 * Recalculates pi / 2
+	 */
+	private static final double HALF_PI = Math.PI / 2;
+
+	/**
+	 * Returns the closest Edge in the current Graph to a given position. It
+	 * allows for an inaccuracy of around {@value #EDGE_SELECTION_WIDTH}px
+	 * 
+	 * @param pos
+	 *            The position. Expects a <b>Point3</b>, but only uses the x and
+	 *            y coordinates
+	 * @return the closest Edge if a valid Edge exists, returns <b>null</b>
+	 *         otherwise
+	 */
+	public static Edge getClosestEdge(Point3 pos) {
+		Camera cam = Main.getInstance().getGraphManager().getView().getCamera();
+
+		Point3 min = cam.transformPxToGu(0, 0);
+		Point3 max = cam.transformPxToGu(EDGE_SELECTION_WIDTH, EDGE_SELECTION_WIDTH);
+
+		double dist = Math.max(Math.abs(max.x - min.x), Math.abs(max.y - min.y));
+
+		return getClosestEdge(pos, dist);
+	}
+
+	/**
+	 * Returns the closest Edge in the current Graph to a given position within
+	 * the given maxDistance
+	 * 
+	 * @param pos
+	 *            The position. Expects a <b>Point3</b>, but only uses the x and
+	 *            y coordinates
+	 * @param maxDistance
+	 *            the maximum distance (in gu) the edge may be away from the
+	 *            position to be considered as a valid edge
+	 * @return the closest Edge if a valid Edge exists, returns <b>null</b>
+	 *         otherwise
+	 */
+	public static Edge getClosestEdge(Point3 pos, double maxDistance) {
+		double x0 = pos.x;
+		double y0 = pos.y;
+		double dist = maxDistance;
+
+		Edge result = null;
+		GraphManager gm = Main.getInstance().getGraphManager();
+
+		for (Iterator<Edge> iterator = gm.getGraph().getEdgeIterator(); iterator.hasNext();) {
+			Edge edge = (Edge) iterator.next();
+
+			double[] n1 = Toolkit.nodePosition(edge.getNode0());
+			double[] n2 = Toolkit.nodePosition(edge.getNode1());
+
+			double x1 = n1[0];
+			double y1 = n1[1];
+			double x2 = n2[0];
+			double y2 = n2[1];
+
+			double a = distance(x0, y0, x2, y2);
+			double b = distance(x0, y0, x1, y1);
+			double c = distance(x1, y1, x2, y2);
+
+			double b2 = b * b;
+			double a2 = a * a;
+			double c2 = c * c;
+
+			double cdist = Math.abs((y2 - y1) * x0 - (x2 - x1) * y0 + x2 * y1 - y2 * x1) / c;
+			double alpha = Math.acos((b2 + c2 - a2) / (2 * b * c));
+			double beta = Math.acos((a2 + c2 - b2) / (2 * a * c));
+
+			if (cdist < dist && alpha <= HALF_PI && beta <= HALF_PI) {
+				dist = cdist;
+				result = edge;
+			}
+		}
+		return result;
+	}
+
+	/**
+	 * Calculates the distance between two given Nodes
+	 * 
+	 * @param a
+	 *            Node 1
+	 * @param b
+	 *            Node 2
+	 * @return the distance between the two Nodes as a double
+	 */
+	public static double distance(Node a, Node b) {
+		double[] n1 = Toolkit.nodePosition(a);
+		double[] n2 = Toolkit.nodePosition(b);
+
+		return distance(n1[0], n1[1], n2[0], n2[1]);
+	}
+
+	/**
+	 * Calculates the distance between a x,y position and a Node
+	 * 
+	 * @param x0
+	 *            x cord of the position
+	 * @param y0
+	 *            y cord of the position
+	 * @param a
+	 *            the Node
+	 * @return the distance between the position and the Node as a double
+	 */
+	public static double distance(double x0, double y0, Node a) {
+		double[] n1 = Toolkit.nodePosition(a);
+
+		return distance(x0, y0, n1[0], n1[1]);
+	}
+
+	/**
+	 * Calculates the distance between two x,y positions
+	 * 
+	 * @param x0
+	 *            x cord of the first position
+	 * @param y0
+	 *            y cord of the first position
+	 * @param x1
+	 *            x cord of the second position
+	 * @param y1
+	 *            y cord of the second position
+	 * @return the distance between the two positions as a double
+	 */
+	public static double distance(double x0, double y0, double x1, double y1) {
+		return Math.sqrt(Math.pow(y0 - y1, 2) + Math.pow(x0 - x1, 2));
+	}
+
+}