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# Defines a SnowBlossom object, which uses particle motion to show falling
# cherry blossom petals.
image sakura filmstrip = anim.Filmstrip("sakura.png", (20, 20), (2, 1), .15)
image snowblossom = SnowBlossom("sakura filmstrip")
init python:
class StarField(object):
def __init__(self):
self.sm = SpriteManager(update=self.update)
# A list of (sprite, starting-x, speed).
self.stars = [ ]
# Note: We store the displayable in a variable here.
# That's important - it means that all of the stars at
# a given speed have the same displayable. We render that
# displayable once, and cache the result.
d = Transform("star.png", zoom=.02)
for i in range(0, 50):
self.add(d, 20)
d = Transform("star.png", zoom=.025)
for i in range(0, 25):
self.add(d, 80)
d = Transform("star.png", zoom=.05)
for i in range(0, 25):
self.add(d, 160)
d = Transform("star.png", zoom=.075)
for i in range(0, 25):
self.add(d, 320)
d = Transform("star.png", zoom=.1)
for i in range(0, 25):
self.add(d, 640)
d = Transform("star.png", zoom=.125)
for i in range(0, 25):
self.add(d, 1280)
def add(self, d, speed):
s = self.sm.create(d)
start = renpy.random.randint(0, 840)
s.y = renpy.random.randint(0, 600)
self.stars.append((s, start, speed))
def update(self, st):
for s, start, speed in self.stars:
s.x = (start + speed * st) % 840 - 20
return 0
label tutorial_sprite:
e "Ren'Py supports a sprite system, which allows many similar objects to be shown on the screen at once."
scene black
show expression (StarField().sm) as starfield
show eileen happy
with wipeleft
e "The background behind me consists of one hundred and seventy-five stars, being moved at several different speeds, to give a starflight effect."
e "The OpenGL system should be able to animate this smoothly, but you might see a bit of stuttering if your computer is using software."
e "You'll need to decide which older systems to support."
scene bg washington
show eileen happy
with wipeleft
e "The sprite manager requires you to write a python function to move the sprites around."
show snowblossom
e "In many cases, all you need is something moving around the screen - like cherry blossoms, or snow."
e "That's what the snowblossom function gives you - a simple way to have things falling from the top of the screen."
hide snowblossom
with dissolve
e "And that's it for sprites."
return
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