how do i find the canvas location of an object?

[deanhystad]

You're right, that is an ugly function. My logic was testing if a and b did not collide and returned the appropriate boolean value. It is sloppy coding using True and False instead returning the result of the comparison. To fix that I need to invert the logic. I could use not.

def collide(self, object):
    a = self.bounds()
    b = object.bounds()
    return not(b[0] > a[2] or b[2] < a[0] or b[1] > a[3] or b[3] < a[1])

That looks a little awkward, but it is better than before.

The bounding box is (left, top, right, bottom). The function does not make it clear that a[0] is a left. In Python it is easy to extract values from a collection. How does this function look if I replace indexing with more readable variable names.

def collide(self, object):
    aleft, atop, aright, abot = self.bounds()
    bleft, btop, bright, bbot = object.bounds()
    return not(bleft > aright or bright < aleft or btop > abot or bbot < atop)

That looks better, but there is still that ungainly not(). Lets get rid of that by inverting the logic.

bleft <= aright and bright >= aleft and btop <= abot and bbot >= atop

If I allow the ships to just touch without calling that a collision, I can shorten the expression a bit (drop the "="). I think I'll also change the order in the comparison to make it read better.

def collide(self, object):
    aleft, atop, aright, abot = self.bounds()
    bleft, btop, bright, bbot = object.bounds()
    return aleft < bright and atop < bbot and bleft < aright and btop < abot

I like that much better.