What's an easy way to check type of an object

BlitzMax Forums/BlitzMax Beginners Area/What's an easy way to check type of an object

qim	(Posted 2009) [#1]

I'm using a list of gameobjects which are different types (tplayer, tenemy, tbullet, etc.)

If I want to check collision between a bullet and an enemy, I'm doing the following:

For Local o:TGameObject = EachIn GameObjects
    Select o.name
        Case "Enemy"
            If ImagesCollide(Self.Image, X, Y, 0, o.Image, o.X, o.Y, 0) Then
                ListRemove(GameObjects, o)
                ListRemove(GameObjects, Self)
            EndIf
        End Select
    Next

"name" is a field var in my type object.

Is there an easier way to find out, what's the current type of object is instead of using select?

Jesse

(Posted 2009) [#2]

you can do it like this:

For Local o:TEnemy = EachIn GameObjects
            If ImagesCollide(Self.Image, X, Y, 0, o.Image, o.X, o.Y, 0) Then
                ListRemove(GameObjects, o)
                ListRemove(GameObjects, Self)
            EndIf
    Next

Czar Flavius

(Posted 2009) [#3]

For Local o:TGameObject = EachIn GameObjects
	Select True
		Case TEnemy(o) <> Null
			Print "I am an enemy"
			ListRemove(GameObjects, o)
			
		Case TPlayer(o) <> Null
			Print "I am a player"
			
			'if you want to call a specific method or field of TPlayer from o
			Local player:TPlayer = TPlayer(o)
			player.lives :- 1
	End Select
Next

If speed is a concern, you are better off doing it the way you have done, BUT replacing a string called name that is "Enemy" etc, with an integer TID (type id) field, and declaring a set of constants like Const TPlayerID = 0, TEnemyID = 1 etc as this is faster than checking strings.