> I do not agree with the hiding the step() interface for Physics. You
> *need* to be able to provide the step duration there. Why? It is simple
> - your app has rarely constant framerate. If you couple the framerate to
> the physics sim in a fixed manner (e.g. one frame = one step), you are
> going to get problems with the physics, as each frame takes a slightly
> different amount of time.
This is true, however I have achieved a solution to both the above
problems using the below class. Using the default arguments, it will
count from 0 to 360 at a rate of 1 unit per second. Try it and see :-)
You could use this class to transparently supply the correct duration
value to the ste() function.
Sw.
class GovernedRange(object):
"""
Returns values in range, with each successive value incremented at
a set speed rather than value.
"""
def __init__(self, speed=1, low=0, high=359):
self.speed = float(speed)
self.low = float(low)
self.high = float(high)
self._i = self.low
self._t = time.time()
def __iter__(self):
while True:
yield self.next()
def next(self):
i = self._i
speed = float(self.speed)
inc = speed * (time.time() - self._t)
i += inc
i = i % self.high
self._t = time.time()
self._i = i
return i
if __name__ == "__main__":
for v in GovernedRange():
print v
