Implement more types of heuristics

Signed-off-by: Chris Cromer <chris@cromer.cl>

gradle/wrapper/gradle-wrapper.properties

@@ -12,8 +12,6 @@
 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #
 #
-
-#Sat Oct 26 13:11:28 CLST 2019
 distributionUrl=https\://services.gradle.org/distributions/gradle-5.2.1-all.zip
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists

src/main/java/cl/cromer/azaraka/Constants.java

@@ -34,6 +34,10 @@ public interface Constants {
 	 * The name of the game
 	 */
 	String TITLE = "La Aventura de Azaraka";
+	/**
+	 * The heuristic to use in the AI distance calculations
+	 */
+	AIHeuristic aIHeuristic = AIHeuristic.MANHATTAN;
 	/**
 	 * Which type of AI to use
 	 */
@@ -186,6 +190,24 @@ public interface Constants {
 		}
 	}
 
+	/**
+	 * The different heuristics that the AI uses to calculate distance
+	 */
+	enum AIHeuristic {
+		/**
+		 * Used for 4 direction movements
+		 */
+		MANHATTAN,
+		/**
+		 * Used for 8 direction movements
+		 */
+		DIAGONAL,
+		/**
+		 * Used for distance between 2 points
+		 */
+		EUCLIDEAN
+	}
+
 	/**
 	 * The different AI that can be used by the player
 	 */

src/main/java/cl/cromer/azaraka/ai/PlayerAI.java

@@ -22,6 +22,7 @@ import cl.cromer.azaraka.object.Portal;
 import cl.cromer.azaraka.sprite.Animation;
 
 import java.awt.event.KeyEvent;
+import java.awt.geom.Point2D;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -52,17 +53,17 @@ public interface PlayerAI extends Runnable, Constants {
 
 	/**
 	 * The heuristic to get the distance between the start state and the end state
-	 *
+	 * <p>
 	 * Manhattan Distance
 	 * Used for 4 direction movements
 	 * h = abs (current_cell.x – goal.x) +
 	 * abs (current_cell.y – goal.y)
-	 *
+	 * <p>
 	 * Diagonal Distance
 	 * Used for 8 direction movements
 	 * h = max { abs(current_cell.x – goal.x),
 	 * abs(current_cell.y – goal.y) }
-	 *
+	 * <p>
 	 * Euclidean Distance
 	 * Used for distance between 2 points
 	 * h = sqrt ( (current_cell.x – goal.x)2 +
@@ -73,8 +74,16 @@ public interface PlayerAI extends Runnable, Constants {
 	 * @return Returns the distance between the states
 	 */
 	default double heuristic(State start, State goal) {
+		switch (aIHeuristic) {
+			case DIAGONAL:
+				return Math.max(Math.abs(start.getX() - goal.getX()), Math.abs(start.getY() - goal.getY()));
+			case EUCLIDEAN:
+				return Point2D.distance(start.getX(), start.getY(), goal.getX(), goal.getY());
+			case MANHATTAN:
+			default:
 				return Math.abs(start.getX() - goal.getX()) + Math.abs(start.getY() - goal.getY());
 		}
+	}
 
 	/**
 	 * Sort the destinations based on importance and distance