can't get collision detection to work in platform game

[deanhystad]

You collision detection fails because you pass playerx and playery to move() when you should pass player_speed and player_y_momentum.

move() should look like this:

def move(rect, xstep, ystep, tiles):
    collisions = {'top': False, 'bottom': False, 'right': False, 'left': False}
    # Move in x and check for collisions
    rect.x += xstep
    for tile in tiles:
        if rect.colliderect(tile):
            if xstep > 0:
                collisions['right'] = True
            elif xstep < 0:
                collisions['left'] = True
            break

    # Move in y and check for collisions
    rect.x -= xstep
    rect.y += ystep
    for tile in tiles:
        if ystep > 0:
            collisions['bottom'] = True
        elif ystep < 0:
            collisions['top'] = True
        break
    return collisions

You weren't using the returned rect value, so don't return it. After checking for x collisions you want to move rect back (rect.x -= xstep) otherwise an x collision is also reported as a y collision.

You'll also want to change the code that calls move()

    playery += player_y_momentum
    player_y_momentum = min(3, player_y_momentum + 0.2)
    collisions_type = move(playerrect, player_speed, player_y_momentum , tile_rects)