Collision detection, projectile hits anything?

After having had a look at the shootem up totorial hich wave made i thought about extending it a little bit.

My extended idea is that some enemys can shoot bigger more powerful bullets/rockets/projectiles. BUT i want the projectiles to desctructible by the player. Furthermore, i'd like to know the owner of a projectile.

Now i cant figure out a way to know the owner of a projectile. I have created a clsBullet which extends the TGameObject.

Its baffling me, and the collision detection.. how can i know who shot a bullet??

check out my code, which extends Wave's code.

'#Region clsBullet
Type clsBullet Extends clsGameObject
	Field MovementSpeedX:Int;
	Field MovementSpeedY:Int;
	Field Layer:Int;
	Field Image:TImage;
	Field DeltaDelay:Int;
	Field IncrementsPosX:Int;	'// beweeg die kogel met nnn-aantal pixels per frame.
	Field IncrementsPosY:Int;
	Field DefaulStartPosX:Int;	'// bij instantieer nieuwe object; dit is startX positie.
	Field DefaulStartPosY:Int;	'// bij instantieer nieuwe object; dit is startY positie.
	Field IsDestructable:Int	'//Sometimes, a enemy shoots a projectile which could be destroyable by the player' projectile, default is invincible enemy projectiles.
	
	Function Create:clsBullet()
		Local objBullet1:clsBullet = New clsBullet;
		
		objBullet1.MovementSpeedX = 3;
		objBullet1.MovementSpeedY = 3;
		objBullet1.ObjectID = MilliSecs();
		objBullet1.Layer 	= 0;   
		objBullet1.DeltaDelay = 40; '// 40 millisecs
		objBullet1.IncrementsPosX = 4;
		objBullet1.IncrementsPosY = 4;
		objBullet1.DefaulStartPosX = 0;
		objBullet1.DefaulStartPosY = 0;
		objBullet1.IsDestructable  = False;
		
		Return objBullet1;
	End Function
	
	Method Update:clsBullet()
	
		If(MilliSecs() > MilliSecs() + Self.DeltaDelay)
			If(Image = Null)
				DrawOval(Self.Xpos1, Self.Ypos1, 3, 9);
			EndIf
		EndIf
		
	End Method
	
	Method MoveBullet:clsBullet()
	
		Try
			Self.Xpos1:+ Self.IncrementsPosX;
			Self.Ypos1:+ Self.IncrementsPosY;
		Catch ex1:String
			Throw ex1;
		EndTry
		
	End Method
	
	Function CollidedWith:clsBullet()
	End Function
End Type
'#EndRegion

All of the above is to be implemented in a 99.999% portable OOP-way.

When you create a bullet you know who created it right? so maybe put a field called Parent.

Field Parent:TObject

Or you can cast the Bullet object to the various kinds of Bullets to find out which one it is.

Just Ideas.

Regards,
Eric

Why?

What difference does it make?

Use the 'parent' method.
@Flameduck, I used it to credit a 'player' with any kills.

Can you just have a separate set of `bullets` associated with each player so that you automatically know they are related?