Added Mod Loader

New Mod Loader class that will search for jars in the mods folder and
execute the constructor on the class with the same name as the jar file.
Jar classes will have access to everything in the game, but there isn't
a Mod API or useful functions for adding levels yet. See Test.jar and
Test.java for brief example.

saveGame.fd

@@ -1,5 +1,5 @@
 true
 true
 4
+13
 12
-9

src/Test.java

@@ -0,0 +1,11 @@
+import edu.ncsu.feddgame.GameInstance;
+import edu.ncsu.feddgame.level.Level2;
+
+public class Test {
+
+	public Test(){
+		//System.out.println("Test loaded");
+		GameInstance.scenes.add(new Level2());
+	}
+
+}

src/edu/ncsu/feddgame/GameInstance.java

@@ -78,9 +78,6 @@ public class GameInstance {
 		add(new Level8());
 		add(new Level9());
 		add(new Level10());
-		if (demoMode)
-			add(new DemoLevel());
-		add(new GameComplete());
 	}};
 
 	public static int levNum = 0; // Start with 0
@@ -108,6 +105,7 @@ public GameInstance() {
 	 */
 	private void setup() {
 		SaveData.readData();
+		new ModLoader();
 		objectManager = new ObjectManager();
 
 		// If glfw fails to initialize, throw exception 
@@ -120,6 +118,10 @@ private void setup() {
 		glfwWindowHint(GLFW_STENCIL_BITS, 4);
 
 		window = new Window(800, 800, "Laser Amazer", false);
+
+		if (demoMode)
+			scenes.add(new DemoLevel());
+		scenes.add(new GameComplete());
 	}
 
 	/**
@@ -159,7 +161,7 @@ private void renderLoop() {
 		//
 			setLevel(0); // Set the starting level
 		//
-
+			
 		new Thread(() -> logicLoop()).start(); // Run the logic in a separate thread
 
 		glfwSetWindowSize(window.window, 1200, 800);

src/edu/ncsu/feddgame/ModLoader.java

@@ -0,0 +1,76 @@
+package edu.ncsu.feddgame;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.Hashtable;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+
+public class ModLoader extends ClassLoader{
+	private String jarPath = "mods/";
+	private ArrayList<String> jars = new ArrayList<String>();
+	@SuppressWarnings("rawtypes")
+	private Hashtable<String, Class> classes = new Hashtable<String, Class>();
+
+	public ModLoader(){
+		super(ModLoader.class.getClassLoader());
+		loadMods();
+	}
+
+	public void loadMods(){
+		File folder = new File(jarPath);
+		File[] jarFiles = folder.listFiles();
+		for (int i = 0; i < jarFiles.length; i++){
+			if (jarFiles[i].isFile()){
+				jars.add(jarFiles[i].getName());
+			}
+		}
+		for (String s : jars){
+			try {
+				loadClass(s.substring(0, s.length()-4),jarPath + s).newInstance(); 	//Loads the class by the same name as the jar and constructs it
+			} catch (Exception e) {}
+		}
+	}
+
+	@SuppressWarnings("rawtypes")
+	public Class loadClass(String className, String jarFile){
+		try{
+			return findClass(className, jarFile);
+		}catch (Exception e){
+			return null;
+		}
+	}
+
+	@SuppressWarnings("rawtypes")
+	public Class findClass(String className, String jarFile) {
+        byte classByte[];
+        Class result = null;
+        JarFile jar = null;
+        try {
+            jar = new JarFile(jarFile);
+            JarEntry entry = jar.getJarEntry(className + ".class");
+            InputStream is = jar.getInputStream(entry);
+            ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
+            int nextValue = is.read();
+            while (-1 != nextValue) {
+                byteStream.write(nextValue);
+                nextValue = is.read();
+            }
+
+            classByte = byteStream.toByteArray();
+            result = defineClass(className, classByte, 0, classByte.length, null);
+            classes.put(className, result);
+            return result;
+        } catch (Exception e) {
+            return null;
+        }finally {
+        	try {
+				jar.close();
+			} catch (IOException e) {
+			}
+        }
+    }
+}