From 131dedb22e761bc2ce2887c51f07a5095dc12d71 Mon Sep 17 00:00:00 2001
From: rxbn_ <git@rxbn.de>
Date: Sat, 7 Dec 2019 23:58:50 +0100
Subject: [PATCH] Ball - reflectOnPaddle - structuring and comments

---
 src/break_out/model/Ball.java | 48 ++++++++++++++++++++++-------------
 1 file changed, 31 insertions(+), 17 deletions(-)

diff --git a/src/break_out/model/Ball.java b/src/break_out/model/Ball.java
index a60e79c..c44f4b8 100644
--- a/src/break_out/model/Ball.java
+++ b/src/break_out/model/Ball.java
@@ -140,29 +140,43 @@ public class Ball implements IBall {
 	/**
 	 * Ball got hit by Paddle paddle
 	 * @param paddle hitbox mechanism of paddle
-	 * @todo implementation
 	 */
-	public void reflectOnPaddle(Paddle p) {
-		// get the Position of the middle of the paddle
-		Position newOffset = new Position(
-			p.getPosition().getX() + p.getWidth() / 2.0,//the middle of the x coordinates
-			p.getPosition().getY() + p.getHeight() / 2.0);//the middle of the y coordinates
+	public void reflectOnPaddle(Paddle paddle) {
+		// reflection point / offset point
+		Position reflectionPoint = new Position(
+			paddle.getPosition().getX() + (paddle.getWidth() / 2.0),
+			paddle.getPosition().getY() + (paddle.getHeight() / 2.0)
+		);
+		// new direction vector; assignment not here
+		Vector2D reflectionVector;
+
+		// no general solution, estimation required
+		// only two paddles defined in the game design, therefore greater or smaller than middle of screen
+
 		//deciding if the paddle is at the top or bottom to adjust if its +or- y direction
-		if (p.getPosition().getY() == 0) { 		    
-			newOffset.setY(newOffset.getY() - Constants.REFLECTION_OFFSET);// paddle at the top with negative direction
-		} else {		   
-			newOffset.setY(newOffset.getY() + Constants.REFLECTION_OFFSET); // the paddle at the bottom with positive direction
+		if (paddle.getPosition().getY() <= Constants.SCREEN_HEIGHT) {
+			// top paddle
+			reflectionPoint.setY(reflectionPoint.getY() - Constants.REFLECTION_OFFSET);
+		} else {
+			// bottom paddle
+			reflectionPoint.setY(reflectionPoint.getY() + Constants.REFLECTION_OFFSET);
 		}
 		
-		// calculating the center of the ball by dividing by zero
+		// calculating the center of the ball; needed for correct vector calculation
 		Position ballCenter = new Position(
-			position.getX() + Constants.BALL_DIAMETER/2.0, //the middle of the x coordinates
-			position.getY() + Constants.BALL_DIAMETER/2.0); //the middle of the y coordinates
+			position.getX() + (Constants.BALL_DIAMETER/2.0),
+			position.getY() + (Constants.BALL_DIAMETER/2.0)
+		);
 		
-		// The direction is set to the middle of the offset point and the ball
-		direction = new Vector2D(newOffset, ballCenter);
-		// rescaling to adjust the balls speed
-		direction.rescale();
+		// The direction is set to the vector between offset point and the ball's center
+		reflectionVector = new Vector2D(reflectionPoint, ballCenter);
+
+		// normalize vector
+		reflectionVector.rescale();
+
+		// replace direction vector
+		this.direction.setDx(reflectionVector.getDx());
+		this.direction.setDy(reflectionVector.getDy());
 	    }
 
 }