Assigning Functions?

BlitzMax Forums/BlitzMax Programming/Assigning Functions?

BLaBZ

(Posted 2010) [#1]

Is there an efficient way to "assign" functions to an object?

I was thinking about function pointers though the issue is each function i would like to assign has a different number of parameters,

H&K	(Posted 2010) [#2]

Make the functions a base class/type/object, and then inherit this by all the objects that need these functions assigned

BLaBZ

(Posted 2010) [#3]

Good idea, guess i had just had a brain fart

Czar Flavius

(Posted 2010) [#4]

Type TPlayer
    Method Update()
        ...
    End Method

    Method Draw(x, y)
        ...
    End Method

    Function Create:TPlayer(x, y, lives)
        ...
    End Function
End Type

Like this?

BLaBZ

(Posted 2010) [#5]

Type TBaseClass

	Function Blah()
		Print "This function is necessarily unnecessary."
	End Function
	
	Function Blah2()
		Print "Do you know how many friends I make with this function?"
	End Function 

End Type


Type TPlayer

	Field BaseClass:TBaseClass

End Type

Local aBaseClass:TBaseClass = New TBaseClass

Local aPlayer:TPlayer = New TPlayer
aPlayer.BaseClass = aBaseClass

aPlayer.BaseClass.Blah()
aPlayer.BaseClass.Blah2()

Czar Flavius

(Posted 2010) [#6]

Type TBaseClass

    Method Blah()
        Print "This function is necessarily unnecessary."
    End Method
    
    Method Blah2()
        Print "Do you know how many friends I make with this function?"
    End Method

End Type


Type TPlayer Extends TBaseClass

    Method UniqueToPlayer()
        Print "I'm a player!"
    End Method

    Method Blah2()
        Print "You can replace functions too"
    End Method

End Type


Local aPlayer:TPlayer = New TPlayer

aPlayer.UniqueToPlayer()
aPlayer.Blah()
aPlayer.Blah2()

BLaBZ

(Posted 2010) [#7]

Print "Cool!"

compile this to reveal a hidden message!

Czar Flavius

(Posted 2010) [#8]

The coolest part is you can have several types, such as players, enemies, even pick ups, extending the same base class which has methods such as Update and Draw. You can put code unique to that type in its own type, but common code to all types can go in the base class.

The even cooler feature is, if you add all these players, enemies etc to the same TList, you can use

For Local base:TBaseClass = Eachin MyList
    base.Update()
Next

for example,
and this will call the Update method of everything in that list which extends TBaseClass! So you can update and draw all your typical game objects from just a single procedure.