From cd62502f3796141c08e6c0e67180156d3e836cba Mon Sep 17 00:00:00 2001
From: joachimschmidt557 <joachim.schmidt557@outlook.com>
Date: Sat, 23 Mar 2019 18:29:14 +0100
Subject: [PATCH] Better graph connection algorithm

---
 Projektgruppe_175/src/base/Graph.java       |  8 ++-
 Projektgruppe_175/src/game/map/GameMap.java | 64 +++++++++++++++++++--
 2 files changed, 65 insertions(+), 7 deletions(-)

diff --git a/Projektgruppe_175/src/base/Graph.java b/Projektgruppe_175/src/base/Graph.java
index c833bb4..dd98ac3 100644
--- a/Projektgruppe_175/src/base/Graph.java
+++ b/Projektgruppe_175/src/base/Graph.java
@@ -19,6 +19,8 @@ import game.map.Castle;
  */
 public class Graph<T> {
 
+	final static boolean DEBUG = true;
+	
     private List<Edge<T>> edges;
     private List<Node<T>> nodes;
 
@@ -166,8 +168,10 @@ public class Graph<T> {
     		    		
     	}
     	
-    	System.out.println(allVisitedNodes.size());
-    	System.out.println(nodes.size());
+    	if (DEBUG) {
+	    	System.out.println(allVisitedNodes.size());
+	    	System.out.println(nodes.size());
+    	}
     	
         return allVisitedNodes.size() == nodes.size();
         
diff --git a/Projektgruppe_175/src/game/map/GameMap.java b/Projektgruppe_175/src/game/map/GameMap.java
index 66da120..6622ba0 100644
--- a/Projektgruppe_175/src/game/map/GameMap.java
+++ b/Projektgruppe_175/src/game/map/GameMap.java
@@ -7,7 +7,9 @@ import gui.Resources;
 import java.awt.*;
 import java.awt.image.BufferedImage;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.stream.Collectors;
 
 /**
@@ -155,20 +157,32 @@ public class GameMap {
 
     	List<Node<Castle>> castleNodes = castleGraph.getNodes();
     	
-    	if (castleNodes.isEmpty())
+    	if (castleNodes.size() < 2)
     		return;
     	
     	// Stage 1
     	List<Node<Castle>> remainingCastles = new ArrayList<Node<Castle>>(castleNodes);
+    	List<Node<Castle>> connectedCastles = new ArrayList<Node<Castle>>();
+    	
     	Node<Castle> castleToConnect = remainingCastles.remove(0);
+    	connectedCastles.add(castleToConnect);
+    	
     	while (!remainingCastles.isEmpty()) {
     		
-    		Node<Castle> nearestCastle = nearestCastle(castleToConnect, remainingCastles);
+    		//Node<Castle> nearestCastle = nearestCastle(castleToConnect, remainingCastles);
     		
-    		castleGraph.addEdge(castleToConnect, nearestCastle);
+    		//castleGraph.addEdge(castleToConnect, nearestCastle);
     		
-    		castleToConnect = nearestCastle;
-    		remainingCastles.remove(castleToConnect);
+    		//castleToConnect = nearestCastle;
+    		//remainingCastles.remove(castleToConnect);
+    		
+    		Map.Entry<Node<Castle>, Node<Castle>> conn = 
+    				nearestCastle(connectedCastles, remainingCastles);
+    		
+    		castleGraph.addEdge(conn.getKey(), conn.getValue());
+    		
+    		remainingCastles.remove(conn.getValue());
+    		connectedCastles.add(conn.getValue());
     		
     	}
 
@@ -182,6 +196,12 @@ public class GameMap {
     
     }
     
+    /**
+     * Returns the nearest castle
+     * @param castle The castle
+     * @param allCastles The castles to choose from
+     * @return The nearest castle
+     */
     private Node<Castle> nearestCastle(Node<Castle> castle, List<Node<Castle>> allCastles) {
     	
     	return allCastles.stream()
@@ -192,6 +212,40 @@ public class GameMap {
     	
     }
     
+    /**
+     * Returns the nearest castle that we can access from a list (1) of castles
+     * @param castles (1) The castles which should connect to the castle
+     * @param allCastles (2) The castles to choose from
+     * @return An edge from a castle from list (1) to the nearest
+     * castle from list (2)
+     */
+    private Map.Entry<Node<Castle>, Node<Castle>> nearestCastle(List<Node<Castle>> castles, List<Node<Castle>> allCastles) {
+    	
+    	// First get all nearest castles one by one
+    	HashMap<Node<Castle>, Node<Castle>> nearestCastles = new HashMap<Node<Castle>, Node<Castle>>();
+    	
+    	for (Node<Castle> castle : castles) {
+    		nearestCastles.put(castle, nearestCastle(castle, allCastles));
+    	}
+    	
+    	// Return the pair with the minimal distance
+    	return
+    	nearestCastles.entrySet().stream()
+    		.min((x, y) -> Double.compare(
+    				x.getValue().getValue().distance(x.getKey().getValue()),
+    				y.getValue().getValue().distance(y.getKey().getValue())))
+    		.get();
+    	
+    }
+    
+    /**
+     * Returns a list of all castles in a predefined
+     * radius
+     * @param castle The castle
+     * @param allCastles The possible castles
+     * @param r The radius
+     * @return All castles in that radius
+     */
     private List<Node<Castle>> allCastlesInRadius(Node<Castle> castle, List<Node<Castle>> allCastles, double r) {
     	
     	return allCastles.stream()