CollideImage Function?

denzilquixode

i.e. Lets say I have a one list of player bullets which I need to test against another list of enemy sprites, resulting the identity of the specific bullet/alien which collided.

Here's my attempt, bare in mind I'm not 100% sure of it all yet. Assuming bullet-to-alien collisions are the only ones you're interested in (not bullet-to-bullet etc):

Type TAlien
  Global AlienImage:TImage
  Global AlienList:TList
  Field X:Int
  Field Y:Int
  ...
End Type

Type TBullet
  Global BulletImage:TImage
  Global BulletList:TList
  Field X:Int
  Field Y:Int
  ...
End Type

'...

Const ALIEN_LAYER = 1 ' Collision layer used for aliens

Function DoCollisions()

  ResetCollisions ALIEN_LAYER

  For A:TAlien = EachIn TAlien.AlienList
    CollideImage(TAlien.AlienImage, A.X, A.Y, 0, 0, ALIEN_LAYER, A)
  Next

  Local AliensCollided:Object[]

  For B:TBullet = EachIn TBullet.BulletList
    AliensCollided = CollideImage(TBullet.BulletImage, B.X, B.Y, 0, ALIEN_LAYER, 0, Null)
    For i = 0 To Len(AliensCollided)-1
      A:TAlien = TAlien(AliensCollided[i])
      ' Alien = A
      ' Bullet = B
    Next
  Next
 
End Function