Assignment 01

Here is a version of the WormChase game that are stripped for all gathering of statistics (including score and everything). The worm can't use wrap-around: Obstacles.java, Worm.java, WormChase.java and WormPanel.java.

Now you're going to add a class, Mines, that is a dangerous kind of obstacle.
If the worm hits a mine the game is over as it explodes!

Here's the class-diagram that basicly shows that Mines is known by WormPanel :

Class Mines
It would be nice to extend the Obstacles class as a mine is-a special kind of obstacle (it explodes!).
Unfortunately the Obstacles class is very porly designed for inheritance (variables are private, but as there is no get-methods the sub-classes will inherit variables they can't access). Let that be a lesson!

So - the easiest way is actually to copy the Obstacles.java into Mines.java and then do minor corrections.

But having a mine class is just first step. Below is recommandations for what you should do to make the mines a part of the game.

• To distinquish mines from normal obstacles you should change the color and perhaps size. Change in Draw().
• The WormPanel must declare and create a Mines object
• In WormPanel's testPress() we should add either an obstacle or a mine when the mouse is clicked. To get a lot of mines (makes it easier to test) I suggest the following correction:

  if (!fred.touchedAt(x,y)) // was the worm's body untouched?
    if (Math.random() < 0.2) {
      obs.add(x,y);
    } else {
      min.add(x,y);
    }//if-else

20% of the mouse-clicks gives an obstacle, 80% gives a mine.

• In WormPanel's gameRender() the Mines object should also be drawn.
• To make it possible to see if the worm touches a mine the hits() method in Mines should be changed. It should take the worm as parameter and loop through all mines and test whether each mine is close to the worm's head (using nearHead() in the Worm object). Note that the x and y coordiates for a mine can easily be found as the mine actually is added to the ArrayList as a Rectangle, and x and y are public variables in a Rectangle.
• NOTE that checking whether the mines x and y coordinates are close to the worms head is not very accurate (the nearHead() uses a rough margin). But for our use it is sufficient - we're only practicing, not making a commercial game. If you want you can make the check more precise.
• The actual checking if the worm hits a mine can be done various places. The easiest way is in WormPanel where the gameUpdate() should be changed to:

  private void gameUpdate() {
    if (!isPaused && !gameOver) {
      fred.move();
      gameOver = min.hits(fred);
    }
  } // end of gameUpdate()

This will effectively stop the game if the worms move made the head touch a mine!