Class:function inside method

Monkey Forums/Monkey Programming/Class:function inside method

mteo77

(Posted 2013) [#1]

Hello everybody.
It seems i haven't understood functions properly.
I have this chunk of code:
[code]
Import mojo
Class ship
Field posx
Field posy
Field speed
'-------------------------------
Method init()
posx=100
posy=100
speed=5
End
'-------------------------------
Method update()
posx=posx
posy=updown(posy,speed)
End
'-------------------------------
Method render()
DrawCircle (posx,posy,40)
End
'-------------------------------
End

Global player := New ship

Function createplayer()
player.init()
End

Function playerupdate()
player.update()
End

Function playerrender()
player.render()
End

Function updown(y,s)
y=y + s 'start the movement
If y >= 460 'check against bottom border
y=y 'stop movement
s *= -1 'invert the movement by inverting the speed
Endif
If y < = 20 'check against top border
y = y 'stop movement
s *= -1 'invert the speed
Endif
End

Class game Extends App
Method OnCreate()
createplayer()
SetUpdateRate(60)
End
Method OnUpdate()
playerupdate()
End
Method OnRender()
Cls
playerrender()

End
End

Function Main()
New game
End

[\code]

What i want to do is having an external function to calculate movements instead of declaring every movement into a class method, to make the code tidier.
Is it even possible?
Is it the better way to do it?

I am pretty sure i am missing something simple here, but since i am learning the language i just can't get over it.
Thank you.

mteo77

(Posted 2013) [#2]

Import mojo
Class ship
	Field posx
	Field posy
	Field speed
'-------------------------------
	Method init()
		posx=100	
		posy=100
		speed=5
	End
'-------------------------------
	Method update()
		posx=posx
		posy=updown(posy,speed)
	End
'-------------------------------
	Method render()
		DrawCircle (posx,posy,40)
	End
'-------------------------------
End

Global player := New ship

Function createplayer()
	player.init()
End

Function playerupdate()
	player.update()
End

Function playerrender()
	player.render()
End

Function updown(y,s)
	y=y + s				'start the movement
	If y >= 460			'check against bottom border
		y=y				'stop movement
		s *= -1			'invert the movement by inverting the speed
	Endif
	If y < = 20			'check against top border
		y = y			'stop movement
		s *= -1			'invert the speed
	Endif
End


Class game Extends App
	Method OnCreate()
		createplayer()
		SetUpdateRate(60)
	End
	Method OnUpdate()
		playerupdate()  
	End
	Method OnRender()
		Cls 
		playerrender()
		
	End
End

Function Main()
	New game
End

Sorry i used the wrong forum code....

Redbeer

(Posted 2013) [#3]

You can do this if you want to pass your variable player into each of those functions, such as:

Function createplayer(player:Ship)
              player.Init()
End

Then inside Oncreate you'd call:

createplayer(player)

But you don't have to do this and I'm not sure what purpose it serves unless you are making a function that will manage all your method calls for player based on some sort of criteria.

Just call the methods directly in OnCreate(), OnUPdate(), and OnRender(), such as:

Method OnCreate()
            player.Init()
            SetUpdateRate(60)
End

Paul - Taiphoz

(Posted 2013) [#4]

I would first of all recomend that you actually use methods within the class to do this , not only is it far more modular and cleaner but its a lot less hassle.

At the moment your Play is global so there is nothing stopping you from simply setting its x,y position inside an external function.

Player.posx = 10

I think what you should do isntead however is something like this.

[monkeycode]
Import mojo
Class ship
Field posx
Field posy
Field speed
Method movedown()
self.posy+=self.speed
end

Method boundCheck()
'in here you would do that boundery check,
'if posy > 420 then set self.speed = -self.speed
End
'-------------------------------
End

Global player := New ship

Class game Extends App

Method OnUpdate()
playerupdate()

if KeyDown(KEY_A) then Player.movedown()
End
Method OnRender()
Cls
playerrender()

End
End

Function Main()
New game
End
[/monkeycode]

thats not a complete source but should show what I mean.

mteo77

(Posted 2013) [#5]

What i was trying to do is making a function that will execute some code and return a result that is going to be processed inside a method, so i don't have to type the same code to have similar classes doing the same thing (hope it make sense).
Example:
class player
class enemy
class bullet
class dog

All those classes sooner or later will need a boundary check, an up&down, a jump etc etc.
So my idea was to have all those classes with the same methods for updating, rendering etc, and inside those methods have a function that does the calculations for updating etc.
All of this is purely for learning the language and it's possibilities (i was also thinking about inheritance of classes...but it's probably way too early for me!).

Paul - Taiphoz

(Posted 2013) [#6]

What you want to do is use Extend to add that code to those classes.

for example.

sec.. getting daughter from school brb

Redbeer

(Posted 2013) [#7]

Create a generic GameObject class that stores the common information then use Extends to make each different type.

Class GameObject
      Field xPos:Float
      Field yPos:Float
      
      Method New(xPos:Float, yPos:Float)
            Self.xPos = xPos
            Self.yPos = yPos
      End
End

Class Player Extends GameObject
      Field width:Float
      Field height:Float
      Method New(xPos:Float, yPos:Float, width:Float, height:Float)
             Super.New(xPos, yPos)
             Self.width = width
             Self.height = height
      End
End

Then of course any other methods can call the GameObject methods with Super, and have their own parameters, and do their own things, while also storing the base information in the class it extends.

Paul - Taiphoz

(Posted 2013) [#8]

[monkeycode]
Class world
Field leftwall:Int
Field rightwall:Int

Method boundcheck()
'bound checking code is done once.
End Method

End Class

Class dog Extends world
Field x:Int
Field y:Int

Method update()
Self.boundcheck()
End

Method draw()
End

End Class

Function Main:Int()

Return 0
End
[/monkeycode]

Sorry thats kinda rushed, but you get the idea, you would write your boundary checking code in the world class, and then as each new game object extends that world class it would get that boundry checking method.

You would only need to write your method once, and then each new class you add will use it.

You could for example put field x,y inside world, as a world has a position, and then each new class/object or player that extends world would then inherit those fields..

hope this helps last thing I wana do is confuse you.

mteo77

(Posted 2013) [#9]

Thanks, it make sense.
I was wondering if extending the main class was the right way to do it.
It's just that for some strange reason i am still tied to a heavy use of functions...
ok time to study inheritance.
Thank you all.

Paul - Taiphoz

(Posted 2013) [#10]

Glad I am able to help out, its normally me asking for help so its nice to pay it forward.

Gerry Quinn

(Posted 2013) [#11]

In fact, this is a pretty standard example of the sort of thing inheritance is good for.