"""
A system for producing animated sprites.
Only supports frame-by-frame, not gif, apng, or full motion video.
"""
import time
import re
import ppb
FILE_PATTERN = re.compile(r'\{(\d+)\.\.(\d+)\}')
[docs]class Animation:
"""
An "image" that actually rotates through numbered files at the specified rate.
"""
# Override this to change the clock used for frames.
clock = ppb.get_time
[docs] def __init__(self, filename, frames_per_second):
"""
:param str filename: A path containing a ``{2..4}`` indicating the frame number
:param number frames_per_second: The number of frames to show each second
"""
self._filename = filename
self.frames_per_second = frames_per_second
self._paused_frame = None
self._pause_level = 0
self._frames = []
self._offset = -self._clock()
self._compile_filename()
def __repr__(self):
return f"{type(self).__name__}({self._filename!r}, {self.frames_per_second!r})"
# Do we need pickle/copy dunders?
[docs] def copy(self):
"""
Create a new Animation with the same filename and framerate. Pause
status and starting time are reset.
"""
return type(self)(self._filename, self.frames_per_second)
def _clock(self):
return type(self).clock()
@property
def filename(self):
return self._filename
@filename.setter
def filename(self, value):
self._filename = value
self._compile_filename()
def _compile_filename(self):
match = FILE_PATTERN.search(self._filename)
start, end = match.groups()
numdigits = min(len(start), len(end))
start = int(start)
end = int(end)
template = FILE_PATTERN.sub(
'{:0%dd}' % numdigits,
self._filename,
)
self._frames = [
ppb.Image(template.format(n))
for n in range(start, end + 1)
]
[docs] def pause(self):
"""
Pause the animation.
"""
if not self._pause_level:
self._paused_time = self._clock() + self._offset
self._paused_frame = self.current_frame
self._pause_level += 1
[docs] def unpause(self):
"""
Unpause the animation.
"""
self._pause_level -= 1
if not self._pause_level:
self._offset = self._paused_time - self._clock()
def _current_frame(self, time):
if not self._pause_level:
return (
int((time + self._offset) * self.frames_per_second)
% len(self._frames)
)
else:
return self._paused_frame
@property
def current_frame(self):
"""
Compute the number of the current frame (0-indexed)
"""
if not self._pause_level:
return (
int((self._clock() + self._offset) * self.frames_per_second)
% len(self._frames)
)
else:
return self._paused_frame
[docs] def load(self):
"""
Get the current frame path.
"""
return self._frames[self.current_frame].load()
# This is so that if you assign an Animation to a class, instances will get
# their own copy, so their animations run independently.
_prop_name = None
def __get__(self, obj, type=None):
if obj is None:
return self
v = vars(obj)
if self._prop_name not in v:
v[self._prop_name] = self.copy()
return v[self._prop_name]
# Don't need __set__() or __delete__(), additional accesses will be via
# __dict__ directly.
def __set_name__(self, owner, name):
self._prop_name = name