def on_paint(self, event):
'''EVT_PAINT handler.'''
# todo: optimization: if motion blur is (rounded to) zero, don't draw
event.Skip()
if self.recalculation_flag:
self._recalculate(possibly_refresh=False)
# We make sure `_recalculate` won't refresh, because that would make
# an infinite loop
bw, bh = self.GetWindowBorderSize()
ox, oy = ((4 - bw) / 2 , (4 - bh) / 2)
self.current_bitmap = images.get_blurred_gear_image_by_ratio(
self.current_frame_number,
self.current_blur_alpha
)
#print(self.current_frame_number,
#self.current_blur_alpha)
dc = wx.PaintDC(self)
dc.DrawBitmap(self.current_bitmap, ox, oy)
def __update_motion_blur_bitmap(self, possibly_refresh):
'''
Check the speed and update the motion blur bitmap if necessary.
If `possibly_refresh` is True, and this function sees that the image on
the scratch wheel should change, then it will trigger a `Refresh`.
'''
current = (time.time(), self.get_current_angle())
last = self.last_tracked_time_and_angle
d_time = current[0] - last[0]
d_angle = current[1] - last[1]
if d_time < self.velocity_time_sampling_minimum:
self.motion_blur_update_timer.Start(30)
return
# This protects us from two things: Having a grossly inaccurate
# velocity reading because of tiny sample, and having a division by
# zero.
self.current_velocity_estimate = velocity = d_angle / d_time
r_velocity = velocity / self.velocity_for_maximal_motion_blur
alpha = min(abs(r_velocity), 1)
alpha = min(alpha, 0.8)
# I'm limiting the alpha, still want to see some animation
self.current_blur_alpha = alpha
new_bitmap = images.get_blurred_gear_image_by_ratio(
self.current_frame_number,
alpha
)
if self.current_bitmap is not new_bitmap:
# No need to do this:
# self.current_bitmap = new_bitmap
# The `on_paint` handler will do it anyway
if possibly_refresh:
self.Refresh()
if new_bitmap.blur_raw is not images.get_blur_image_raw(0):
# We have a non-zero visible motion blur
self.motion_blur_update_timer.Start(30)
else:
self.motion_blur_update_timer.Stop()
self.last_tracked_time_and_angle = current
