Inherit Me

[kevin]

   This example shows how you can create a parent Type, And Then spawn other; child types from it.   So now our child object types (i.e Aliens/Bullets in this example) contain both the common properties of the parent As well As extending these with their own properties.  You Not limited there, the children can spawn children etc etc.    Creating entire family tree of;  Data types.  Now since the child types inherit their the properties from the parent and we can pass typed arrays to functions given a suitable typed function, this now means that we can  not only pass the parent into a function, but any children of that parent as well.. So common sets of functions can now; be shared between the various data types.. providing they were derived (spawned) from the same parent..

All in all, it mean we can create more compact code, through more; re-usable functions.

PlayBASIC Code: [Select]

; Create the Parent Type from which we'll derive the child types
 Type MyObject
     status,X#,Y#,Class,Spr,score,speed#,direction#
 EndType
 
; Create the alien 
Type tAliens As MyObject
    Name$
    AI
  hits
  TimeToFire
EndType

  ; Create the Bullet type
 Type tBullets As myObject
  ExtraStuff  
 EndType

; create the two arrays to hold the entities
 Dim Aliens(0) As tAliens
 Dim Bullets(0) As tBullets

; Create a New Type
Function Create(me().MyObject,X#,y#)
  index=GetFree(me().myobject)
   me(index).status=true
   Me(index).x =x#
   Me(index).x =x#
   Spr=GetFreeSprite()
   me(index).spr=spr
   CreateSprite Spr
   PositionSpriteXyz spr,x#,y#,10
EndFunction index   

; Delete a type instance
Function Delete(me().MyObject,index)
   If me(index).status=true
  DeleteSprite me(index).spr
  ClearArrayCells me().myobject,index,1,1,0
   EndIf
EndFunction   


; Positon 
Function Position(me().MyObject,Index,X#,y#)
   Me(index).x =x#
   Me(index).x =x#
   PositionSprite me(index).spr,x#,y#
EndFunction   
; 

Function PointAt(me().MyObject,Index,HereX#,Herey#)
   x#=GetSpriteX(me(index).spr)
   y#=GetSpriteY(me(index).spr)
   Angle#=GetAngle2D(x#,y#,herex#,herey#) 
   Me(index).direction =angle#
EndFunction   
     
   
Function GetFree(me().myobject)
   Repeat
  Size=GetArrayElements(me().myobject,1)
  index=FindArrayCell(me().myobject,0,1,Size,0)
  If Index=-1
     ReDim Me(size+25) As MyObject
  EndIf
   Until index<>-1
EndFunction Index
   

; ================================
; Load Media
; ================================

   Global img_Ship=1  :LoadImage "..\..\..\gfx\ship.bmp",img_Ship
   Global img_Ball=2  :LoadImage "..\..\..\gfx\bubble_64x64.bmp",img_Ball
   Global img_Bullet=3  :CircleC 10,10,10,1,$ff0000 :   GetImage img_bullet,0,0,20,20
   

; ================================
; Main Loop
; ================================

  Do   
     Cls 0
    Print "Making Life Easier With Inherited Types"
    DrawImage 1,MouseX(),MouseY(),1
    UpdateBullets()
    UpdateAliens()
    DrawOrderedSprites
     Sync
  Loop

    



; ================================
; Control the aliens
; ================================

Function UpdateAliens()
   Static TimeToMakeAlien

   ScreenWidth=GetScreenWidth()
   ScreenHeight=GetScreenHeight()
   
   If TimeToMakeAlien=<0
  Index=Create(Aliens().tAliens,Rnd(ScreenWidth),Rnd(ScreenHeight))
  SpriteImage ALiens(index).spr,img_Ball
  Aliens(index).speed=Rnd(100)/50.0
  Aliens(index).Direction=Rnd(360)
  Aliens(index).TimeToFire=Rnd(100)

  TimeToMakeAlien=Rnd(100)
   Else
  DEC TimeToMakeAlien   
   EndIf
    
   For ThisAlien=0 To GetArrayElements(Aliens().taliens,1)
     If Aliens(ThisAlien).status
    Spr=ALiens(ThisAlien).spr
    speed#=aliens(thisALien).speed
    Direction#=aliens(thisALien).direction
    MoveSprite spr,CosRadius(Direction#,Speed#),SinRadius(Direction#,speed#)    

    ShootDelay=Aliens(index).TimeToFire-1
    If ShootDelay<0
       ShootDelay=Rnd(100)
       CreateBullet(GetSpriteX(spr),GetSpriteY(spr))
    EndIf              

    If SpriteInRegion(spr,0,0,ScreenWidth,ScreenHeight)=false        
       Delete(Aliens().tAliens,ThisAlien)
       Continue
    EndIf        
   
    Aliens(index).TimeToFire=ShootDelay
     EndIf    
   Next   
EndFunction


; ================================
; Control the aliens
; ================================

Function CreateBUllet(x#,y#)
  BulletIndex=Create(Bullets().tBullets,x#,y#)

Login required to view complete source code

[kevin]

repost - Same code as above, easier to read though.

PlayBASIC Code: [Select]

; ==============================================================================
; PlayBasic Inherited Types Example
; By Kevin Picone
; www.PlayBasic.com
; ==============================================================================

;  This example shows how you can create a parent Type, then spawn other
; child types from it.   So now our child object types (i.e Aliens/Bullets
; in this example) contain both the common properties of the parent, as well
; as extending these with their own properties.  You Not limited there, the
; children can in turn spawn children etc etc.  Creating an entire family
; tree of Data types. 
; 
;  Now since the child types inherit their the properties from the parent,
; and we can pass typed arrays into functions given a suitable typed function,
; this now means that we can  not only pass the parent into a function, but
; any children of that parent as well.. So common sets of functions can now
; be shared between the various Data types.. providing they were derived
; (spawned) from the same parent..

;  All in all, this will help us create more compact code, through functions
; that are re-use friendly..

; ==============================================================================

 Cls 0

; Create the Parent Type from which we'll dereive the child types
 Type MyObject
     status,X#,Y#,Class,Spr,score,speed#,direction#
 EndType
 
; Create the alien 
Type tAliens As MyObject
    Name$
    AI
  hits
  TimeToFire
EndType
  
; Create the Bullet Type
 Type tBullets As myObject
  ExtraStuff  
 EndType


; create the two arrays To hold the entities
 Dim Aliens(0) As tAliens
 Dim Bullets(0) As tBullets

; Create a New Type
Function Create(me().MyObject,X#,y#)
  index=GetFree(me().myobject)
   me(index).status=True
   Me(index).x =x#
   Me(index).x =x#
   Spr=GetFreeSprite()
   me(index).spr=spr
   CreateSprite Spr
   PositionSpriteXYZ spr,x#,y#,10
EndFunction index   

; Delete a Type instance
Function Delete(me().MyObject,index)
   If me(index).status=True
  DeleteSprite me(index).spr
  ClearArrayCells me().myobject,index,1,1,0
   EndIf
EndFunction   

; Positon 
Function Position(me().MyObject,Index,X#,y#)
   Me(index).x =x#
   Me(index).x =x#
   PositionSprite me(index).spr,x#,y#
EndFunction   

; 
Function PointAt(me().MyObject,Index,HereX#,Herey#)
   x#=GetSpriteX(me(index).spr)
   y#=GetSpriteY(me(index).spr)
   Angle#=GetAngle2D(x#,y#,herex#,herey#) 
   Me(index).direction =angle#
EndFunction   
     
   
Function GetFree(me().myobject)
   Repeat
  Size=GetArrayElements(me().myobject,1)
  index=FindArrayCell(me().myobject,0,1,Size,0)
  If Index=-1
     ReDim Me(size+25) As MyObject
  EndIf
   Until index<>-1
EndFunction Index
   
; ================================
; Load Media
; ================================

   Global img_Ship=1  :LoadImage "..\..\..\gfx\ship.bmp",img_Ship
   Global img_Ball=2  :LoadImage "..\..\..\gfx\bubble_64x64.bmp",img_Ball
   Global img_Bullet=3  :CircleC 10,10,10,1,$ff0000 :   GetImage img_bullet,0,0,21,21
   

; ================================
; Main Loop
; ================================


  Do   
     Cls 0
    Print "Making Life Easier With Inherited Types"

     ; Update the Bullet objects    
       UpdateBullets()

     ; Update the Aliens
       UpdateAliens()

     ; DRaw the Z ordered Sprites
       DrawOrderedSprites

     ; Draw the PLayer
       DrawImage 1,MouseX()-(GetImageWidth(img_ship)/2),MouseY()-(GetImageHeight(img_ship)/2),1

     Sync
  Loop

    



; ================================
; Control the aliens
; ================================

Function UpdateAliens()
   Static TimeToMakeAlien

   ScreenWidth=GetScreenWidth()
   ScreenHeight=GetScreenHeight()
   
   If TimeToMakeAlien=<0
  Index=Create(Aliens().tAliens,Rnd(ScreenWidth),Rnd(ScreenHeight))
  SpriteImage ALiens(index).spr,img_Ball
  Aliens(index).speed=Rnd(100)/50.0
  Aliens(index).Direction=Rnd(360)
  Aliens(index).TimeToFire=Rnd(100)

Login required to view complete source code

[ale870]

Hello,

I found this interesting example, but I noticed the following code:

Code Select Expand

Type MyObject
     status,X#,Y#,Class,Spr,score,speed#,direction#
EndType

There is a name "Class" which is highlighted from the editor, but I cannot get any info in the help. Furthermore I eliminated it, and the example works as well.

So I wish to know if "Class" word is a PB reserved instruction or... what?

Thank you!

[kevin]

Today 'Class/EndClass' are reserved words.  They are to be implemented in VM2, when we can break free of VM1 - Never though it'd take this long :(

[ale870]

Wow! I smell about OOP!  :P

I'm very excited waiting for next version (I know several OOP languages!  ;) and I like OO concept.

Thank you !