I$\text{'}$m completing a java game of flying machine shooting meteorites, please help me complete some part of the java code as required below, thank you very much

Task $1.$ Adding a Bullet Actor Class

Adding a Moving Bullet

To shoot a bullet you need to add a bullet image as an$$Actor$$class in the scenario. The bullet image is already given in the starting scenario, inside the$$images$$folder$.$ The image looks like this:

In your starting scenario you need add a new$$Actor$$subclass using the above image. Let's call this class$$Bullet$.$

After adding the bullet class you will need to make it move. Even though your bullet is supposed to move along the direction of the spaceship, you only need to make it move to the right at this stage. This is similar to what we have done for the$$Rock$$class in the lesson. When you move the bullet you need to make it travel faster than the spaceship and the rock, say, using a distance value of $6$ when you move the bullet.

Removing the Bullet

Once your bullet moves out of the game area, you need to remove the bullet from the world. You have to add the code in the$$act$$method of the class. First you use an if statement to check whether the location of the bullet is not within the game area. If the bullet is out of the world you will then need to use the$$removeObject$$method to remove it$.$

Task $2.$ Shooting the Bullet from the Spaceship

Shooting a Bullet When the Spacebar Key Is Pressed

You can shoot a bullet by pressing the spacebar key. In the$$act$$method of the spaceship, you see the code to turn the spaceship left $($the left arrow key$),$ turn right $($the right arrow key$)$ and move forward $($the up arrow key$).$ You will add an additional key for controlling the shooting of the bullet. The key you need to use is the spacebar key. For example, the following code checks if the spacebar key, using the text$"$space$",$ has been pressed:

if $($Greenfoot$.$isKeyDown$("$space$"))\{$

$...$shoot the bullet...

$\}$

If the spacebar key has been pressed you can shoot the bullet by creating a new instance of the$$Bullet$$class and adding it to the world using the$$addObject$$method$.$ To do that, you can use the following code:

Bullet bullet $=$ new Bullet$()$;

getWorld$().$addObject$($bullet$,$ getX$(),$ getY$())$;

Checking for the Existing Bullet in the World

To solve the first problem you don't shoot the bullet every time the player presses the spacebar. You only shoot the bullet when there is no bullet currently on the screen.You can use the$$getObjects$$method of the world object to do that. For example, the following if statement checks whether there is any bullet in the world:

if $($getWorld$().$getObjects$($Bullet$.$class$).$isEmpty$())\{$

$...$

$\}$

Turning the Bullet to the Direction of the Spaceship

$$You need to turn the bullet so that it travels in the direction of the spaceship.

There are two helpful methods in this task. The first method is the$$getRotation$$method$,$ which allows you to get the current direction of an actor. Another method is the$$setRotation$$method$,$ which lets you change the direction of an actor to a specific angle.You need to do this when you add the bullet to the world.

Task $3.$ Destroying the Rocks

When a bullet hits a rock, both the bullet and the rock are destroyed from the world. Recall that we have done a similar task in our game. When the spaceship is very close to the rock, we show the explosion image, remove the spaceship and the game is over. Therefore, you can use similar code to do this task.

You will write the code in the$$act$$method of the$$Bullet$$class$.$ First, you check whether the bullet is very close to a rock, using this if statement:

if $(!$getObjectsInRange$(20,$ Rock.class$).$isEmpty$())\{$

$...$

$\}$

To destroy the bullet you simply use$$getWorld$().$removeObject$($this$)$to do it$.$ However, it is a bit of trouble to remove the rock. The reason is that you don't know which rock is very close to the bullet in the code.

So you need to get the corresponding rock first. To do that you use the$$getObjectsInRange$$method again, together with the$$get$$method on the returned list, like this:

Rock rock $=($Rock$)$ getObjectsInRange$(20,$ Rock.class$).$get$(0)$;

The above code means getting the first item from the list returned by$$getObjectsInRange$$and putting the item in the$$rock$$variable$.$ The variable now contains the rock that is very close to the bullet. You can use the$$removeObject$$method to remove it from the world.

Since both the bullet and the rock have been removed you can use the return statement at the end of the if statement like this:

if $(!$getObjectsInRange$(20,$ Rock.class$).$isEmpty$())\{$

$...$remove the rock and the bullet from the world...

return;

$\}$

The return statement ensures that you don't do anything more when both the rock and the bullet have been destroyed.