collision between two images

Question

I have two images image1 and image2 and I want to "do something"when they collide, but I don't know the code for the collision and if we need a timer for the collision method. How can I do this please?

Answer 1

if you schedule a timer to serve as a runloop

[NSTimer scheduledTimerWithTimeInterval:0.01 target:self selector:@selector(myRunloop) userInfo:nil repeats:YES];

and then in that runloop you check for collisions

- (void)myRunloop
{
    // check collision
    if( CGRectIntersectsRect(image1.frame, image2.frame) )
    {
        // ..do your stuff.. //
    }
}

you're done:-)