Re: [pygame] Directional collision detection.

[René Dudfield <renesd@xxxxxxxxx>]

ps.  I like your Struct class there!  very clever, haven't seen that before.

cu,

On Mon, Feb 23, 2009 at 8:53 AM, B W <stabbingfinger@xxxxxxxxx> wrote:
> I did the following, which adequately fit my needs. Unfortunately
> there is some ambiguity to overcome. For example, if one rect is
> moving at speed 5,5 and the other at -5,-5 their corners will collide.
> In this case two sides are in contact and you must quantify it in
> program code to decide which way they should rebound.
>
> class Struct(object):
>    def __init__(self, **entries):
>        self.__dict__.update(entries)
>
> def collide_edges(r, other):
>    """Detect the edges of rectangle r that collide with rectangle
>    other. Returns an ad hoc object with boolean attributes left,
>    right, top, and bottom whose values indicate whether that side
>    collided."""
>    Rect = pygame.Rect
>    side = Struct(left=False, right=False, top=False, bottom=False)
>    left=Rect(r.left, r.top+1, 1, r.height-2)
>    right=Rect(r.right, r.top+1, 1, r.height-2)
>    top=Rect(r.left+1, r.top, r.width-2, 1)
>    bottom=Rect(r.left+1, r.bottom, r.width-2, 1)
>    if left.colliderect(other):
>        side.left = True
>    if right.colliderect(other):
>        side.right = True
>    if bottom.colliderect(other):
>        side.bottom = True
>    if top.colliderect(other):
>        side.top = True
>    return side
>
> if __name__ == '__main__':
>    pygame.init()
>    r1 = pygame.Rect(1,1,10,10)
>    r2 = pygame.Rect(9,9,10,10)
>    edges = collide_edges(r1, r2)
>    print '%s: %s' % ('left',edges.left)
>    print '%s: %s' % ('right',edges.right)
>    print '%s: %s' % ('top',edges.top)
>    print '%s: %s' % ('bottom',edges.bottom)
>
> fin
>
> On Sun, Feb 22, 2009 at 1:21 PM, Daniel Mateos <daniel@xxxxxxxxx> wrote:
>> Hey,
>>
>> Can anyone suggest a good way to do collision detection between two
>> rects in a way that i can also get the side of the rect that the
>> collision was detected on.
>>
>> --
>> Daniel Mateos
>> http://daniel.mateos.cc
>>
>>
>