def test_next_tick_time_on_schedule():
# Best case - 0 delay between current tick and current time
current_tt = time.time()
ntt, delta = engine.calc_next_tick_time(current_tt, current_time=current_tt)
assert ntt == current_tt + utils.frames_to_secs(1)
assert round(delta, 5) == utils.frames_to_secs(1)
# Test what happens if we actually do some work during a frame
ntt, delta = engine.calc_next_tick_time(current_tt, current_time=(current_tt + utils.frames_to_secs(1)/2))
assert ntt == current_tt + utils.frames_to_secs(1)
assert round(delta, 5) == utils.frames_to_secs(1)/2
def calc_next_tick_time(current_tick, current_time=None): # current_time parameter used for unit testing
if current_time is None:
t = time.time()
else:
t = current_time
expected_next_tick = current_tick + utils.frames_to_secs(1)
next_tick = max(expected_next_tick, t)
delta = max(0, next_tick - t) # Time delta to next tick. If we take < 1 frame's time to render a frame, sleep until the next frame tick. If we're taking longer than 1 frame's time to render each frame, don't sleep.
if delta == 0:
logger.warn("Frame ran too long by %f secs", t - expected_next_tick)
return (
next_tick,
delta
)
def test_next_tick_time_behind_schedule():
current_time = time.time()
current_tick = current_time - utils.frames_to_secs(4)
ntt, delta = engine.calc_next_tick_time(current_tick, current_time=current_time)
assert round(ntt, 5) == round(current_time, 5)
assert delta == 0
def test_frames_to_secs():
fts = utils.frames_to_secs(1)
assert 0 < round(fts, 5) < 1