Accessing class 1 fields from class 2 fields

Monkey Forums/Monkey Programming/Accessing class 1 fields from class 2 fields

mteo77

(Posted 2013) [#1]

Hello.
I am in the process of rewriting my code, which at the moment uses loads of external functions, into using just classes as fields on the game main class.
It seems that i don't understand how to access fields.
What i want is to create a class with 2 variables that are based of what is contained into another class.

#rem
31/3/2013
#end





Import mojo



Function Main()
	New MyApp
End Function
	
Class MyApp Extends App
	Field ship:= New player							'declaration for the player class which is a class
	Field bull:=New bullet							'declaration for the bullet class which is a class
	Method OnCreate()
		ship.init()
		SetUpdateRate(60)
	End 
	Method OnRender()
		Cls 
		ship.render()
		bull.render()
	End 
	Method OnUpdate()
			ship.update()
			bull.update()
			If KeyHit(KEY_1) Then bull.init()
	End 
	
'---------- extra functions
	
	
	
'---------- end extra functions
	
	
	
End Class


Class actor
	Field posx:Int
	Field posy:Int
	Field speed:Int
	Field life:Int
	Field Lbound:Int
	Field Rbound:Int
	Field Ubound:Int
	Field Dbound:Int
	Field size:Int
	Field power:Int
End




Class player Extends actor
'----------
	Method init()
		posx=300
		posy=300
		speed=5
		size=60
	End
'----------
	Method update()
		
	End
'----------
	Method render()
		DrawCircle(posx,posy,size)	'draw ship
	End
End


Class bullet Extends actor
'-------------------------------
	Method init()
		power=1
		size=5
		posx=222			'what i want here is to be able to access x and y of the player class
		posy=222			'to be able to create the new class x and y based on the player one
		speed=5
	End
'--------------------------------
	Method update()
		posy=posy-speed	'start the movement upward
	End
'-----------------------------
	Method render()
		DrawCircle(posx,posy,size)	'draw bullet
	End
End

As you can see i made a comment where i want the class to grab the other class fields.
Everything works if i use external functions and variables declared globals.
Hope it make any sense...

MikeHart

(Posted 2013) [#2]

The only ways are to connect via MyApp containing field inside the bullet class or you store ship inside the bullet app too. Or store ship as a global.

MikeHart

(Posted 2013) [#3]

I would do it like this:

[monkeycode]
#rem
31/3/2013
#end

Import mojo

Global ma:MyApp

Function Main()
ma = New MyApp
End Function

Class MyApp Extends App
Field ship:= New player 'declaration for the player class which is a class
Field bull:=New bullet 'declaration for the bullet class which is a class
Method OnCreate()
ship.init()
SetUpdateRate(60)
End
Method OnRender()
Cls
ship.render()
bull.render()
End
Method OnUpdate()
ship.update()
bull.update()
If KeyHit(KEY_1) Then bull.init()
End

'---------- extra functions

'---------- end extra functions

End Class

Class actor
Field posx:Int
Field posy:Int
Field speed:Int
Field life:Int
Field Lbound:Int
Field Rbound:Int
Field Ubound:Int
Field Dbound:Int
Field size:Int
Field power:Int
End

Class player Extends actor
'----------
Method init()
posx=300
posy=300
speed=5
size=60
End
'----------
Method update()

End
'----------
Method render()
DrawCircle(posx,posy,size) 'draw ship
End
End

Class bullet Extends actor
'-------------------------------
Method init()
power=1
size=5
posx=222 'what i want here is to be able to access x and y of the player class

'Access the ship like this
ma.ship.posx = 100

posy=222 'to be able to create the new class x and y based on the player one
speed=5
End
'--------------------------------
Method update()
posy=posy-speed 'start the movement upward
End
'-----------------------------
Method render()
DrawCircle(posx,posy,size) 'draw bullet
End
End

[/monkeycode]

Jesse

(Posted 2013) [#4]

this would do what you want and make it a bit flexible.


#rem
31/3/2013
#end





Import mojo



Function Main()
	New MyApp
End Function
	
Class MyApp Extends App
	Field ship:= New player						'declaration for the player class which is a class
	Field bull:=New bullet(ship)					'declaration for the bullet class which is a class
	Method OnCreate()
		ship.init()
		SetUpdateRate(60)
	End 
	Method OnRender()
		Cls 
		ship.render()
		bull.render()
	End 
	Method OnUpdate()
			ship.update()
			bull.update()
			If KeyHit(KEY_1) Then bull.init()
	End 
	
'---------- extra functions
	
	
	
'---------- end extra functions
	
	
	
End Class


Class actor
	Field posx:Int
	Field posy:Int
	Field speed:Int
	Field life:Int
	Field Lbound:Int
	Field Rbound:Int
	Field Ubound:Int
	Field Dbound:Int
	Field size:Int
	Field power:Int
End




Class player Extends actor
'----------
	Method init()
		posx=300
		posy=300
		speed=5
		size=60
	End
'----------
	Method update()
		
	End
'----------
	Method render()
		DrawCircle(posx,posy,size)	'draw ship
	End
End


Class bullet Extends actor

'-------------------------------
	Method New(a:actor)
		power=1
		size=5
		posx=a.posx			'what i want here is to be able to access x and y of the player class
		posy=a.posy			'to be able to create the new class x and y based on the player one
		speed=5
	End
'--------------------------------
	Method update()
		posy=posy-speed	'start the movement upward
	End
'-----------------------------
	Method render()
		DrawCircle(posx,posy,size)	'draw bullet
	End
End

mteo77

(Posted 2013) [#5]

So basically in the initialisation method's brackets i have to put the name of the class i want to get the values from?
Interesting.
Thank you!

Gerry Quinn

(Posted 2013) [#6]

It's just one way to do it. The important thing is that anything that wants to know about an instance of anything else must have a way of finding it.