Interaction with 2 types

Hello, i have a problem:
I have a type called "bomb", and wanna use imagescollide command for determine collision with 2 "bomb"´s, but i don´t know how to do,it´s posible make imagescollide with the same type "bomb"?

mi code it´s this, but don´t work..

For a1.bomb=Each bomb
For b1.bomb=Each bomb
If ImagesCollide (a1\graf,a1\x,a1\y,0,b1\graf,b1\x,b1\y,0)
Delete a1: Return
EndIf
Next
Next

well, i have it now, thanks equally :)

Ok, but just as a little hint, you shouldn't go through the objects with two FOR loops. You end up doing too much work. Do this instead:

a1.bomb = First bomb
While a1 <> null
  b1.bomb = After a1
  While b1 <> null
    ; collision checking here
    b1 = After b1
  Wend
  a1 = After a1
Wend

First of all, with FOR loops, you check collisions of object with itself. Secondly, most collisions get checked more than once.
You could of course do this

For a1.bomb = Each bomb
  For b1.bomb = Each bomb
    If Handle(b1) > Handle(a1) Then
      ; collision checking here
    EndIf
  Next
Next

But you would be wasting processing power.

thanks for the code Jasu, i think it´s better solution than the one i found ;)
Now i have another question, i don´t know this "Handle(x)" command, because i have v.1.88 version of docs, and in this version, don´t appear "handle" like a keyword. Ehere i can find the last version? thanks in advantage

I think v1.88 is the latest docs version. Handle() and Object() functions are a bit underdocumented. I tried them out a couple of years ago, but had some problems and gave up on them. You can live without them, really.

In the above code Handle() is just used because it returns an integer for an object. It doesn't matter what the integer is, as long as they're different for all objects of the type.

just a question, but what exactly is happening in the example where you are using while loops and <> null expressions?

I think it check if there are almost 2 or many types, for check the collision

It's not that complex, is it? It goes through the Type list, allowing comparison between each object.

Have you ever heard of 'table testing' code?

Variable matrix for loop iteration with four bombs.
Read: L1I1 = Loop 1, iteration 1

     L1I1 | L2I1 | L2I2 | L2I3 | L1I2 | L2I1 | L2I2 | L1I3 | L2I1 | L1I4 |
a1 |   1  |   1  |   1  |   1  |   2  |   2  |   2  |   3  |   3  |   4  |
b1 |   -  |   2  |   3  |   4  |   -  |   3  |   4  |   -  |   4  |   -  |

Something like this. As you can see, only six collision checks are made with four bombs. And that's all that is needed.

Thanks Jasu, i understand the process now