Monkey Game Development：Beginner's Guide

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Time for action — implementing explosions

To implement explosions follow the ensuing steps:

Create a new script and save it under the name explosionClass.monkey.
Again, switch into Strict mode, import gameClasses, and create a global list called explosions, to store each explosion created in it.
```
Strict
Import gameClasses
Global explosions := New List<explosion>
```
Just like with the other objects before, we need some wrapper functions, which we can implement into the RocketCommander class. Only the names of the functions are different, so you already now how they work.

Implement functions to create, update, render, and remove explosions.

Function UpdateExplosions:Int()
For Local explosion := Eachin explosions
explosion.Update()
Next
Return True
End
Function RenderExplosions:Int()
For Local explosion := Eachin explosions
explosion.Render()
Next
Return True
End
Function RemoveExplosions:Int()
explosions.Clear()
Return True
End
Function CreateExplosion:Int(x:Float, y:Float)
Local e:explosion = New explosion
e.Init(x, y)
explosions.AddLast(e)
Return True
End

Now, we will add the actual explosion class.

Add a new class called explosion.
```
Class explosion
```

To store the position of an explosion, we need the usual fields.

Field x:Float = 0.0 'x pos of an explosion
Field y:Float = 0.0 'y pos of an explosion

As an explosion is a circle, we need fields to store the radius.

Field cr:Float = 2.0 'current radius
Field tr:Float = 40.0 'target radius

The last field will be a score modifier, which will be used when a bomb collides with the explosion and we get points for it.
```
Field score:Int = 100 'Points for destroying a bomb
```
Now, let's add some methods so that the class is functional.

Add methods to initialize, render, and update an explosion.

Method Init:Int(xp:Float,yp:Float)
x = xp
y = yp
Return True
End
Method Update:Int()
cr += 0.25 'Raise the radius
'Check if target radius is reached
If cr > tr Then
explosions.Remove(Self)
Endif
Return True
End
Method Render:Int()
Local cd:Int = Rnd(0,100)
SetColor(255-cd, 155+cd, 0)
DrawCircle(x, y, cr)
Return True
End
End

What just happened?

We have created a class that deals with explosions. The explanation to implement it was very short as we did similar things with cities, launchers, and rockets, before. There is no need to repeat everything again.

Implementing the explosion class into the game

Let us implement the explosion class into the game.