CodeSnippits pyTweener
From PyWiki
pyTweener
This library provides many equivalent functions of Flash's Caurina Tweener in python, and uses the same set of excellent easing equations by Robert Penner [1].
In a nut-shell, it allows you to move objects with nice smooth acceleration and deceleration using a variety of methods. Plus you dont have to worry about updating them. Any property that supports standard mathematical operations can be tweened, and this is particularly useful with Ogre.Vector3, Ogre.Quaternion etc. etc.
Usage is fairly simple, and an example is provided that doesn't rely on ogre.
At the initialisation phase:
import pyTweener self.tweener = pyTweener.Tweener()
add a tween:
tweener.addTween( myRocket, throttle=50, setThrust=400, tweenTime=5.0, tweenType=tweener.OUT_QUAD onCompleteFunction=myRocket.burn)
get a tween and modify it
mt = tweener.getTweensAffectingObject( myRocket )[0] tweenable = mt.getTweenable( "throttle" ) T.addTween( tweenable, change=1000, tweenTime=0.7 ) T.addTween( mt, duration=-0.2, tweenTime=0.2 )
import pyTweener below :)
# pyTweener # # Tweening functions for python # # Heavily based on caurina Tweener: http://code.google.com/p/tweener/ # # Released under M.I.T License - see above url # Python version by Ben Harling 2009 import math class Tweener: def __init__(self): """Tweener This class manages all active tweens, and provides a factory for creating and spawning tween motions.""" self.currentTweens = [] self.defaultTweenType = self.IN_OUT_QUAD self.defaultDuration = 1.0 def OUT_EXPO(self, t, b, c, d ): return b+c if (t==d) else c * (-2**(-10 * t/d) + 1) + b; def LINEAR (self, t, b, c, d): return c*t/d + b def IN_QUAD (self, t, b, c, d): t/=d return c*(t)*t + b def OUT_QUAD (self, t, b, c, d): t/=d return -c *(t)*(t-2) + b def IN_OUT_QUAD( self, t, b, c, d ): t/=d/2 if ((t) < 1): return c/2*t*t + b t-=1 return -c/2 * ((t)*(t-2) - 1) + b def OUT_IN_QUAD( self, t, b, c, d ): if (t < d/2): return self.OUT_QUAD (t*2, b, c/2, d) return self.IN_QUAD((t*2)-d, b+c/2, c/2) def IN_CUBIC(self, t, b, c, d): t/=d return c*(t)*t*t + b def OUT_CUBIC(self, t, b, c, d): t=t/d-1 return c*((t)*t*t + 1) + b def IN_OUT_CUBIC( self, t, b, c, d): t/=d/2 if ((t) < 1): return c/2*t*t*t + b t-=2 return c/2*((t)*t*t + 2) + b def OUT_IN_CUBIC( self, t, b, c, d ): if (t < d/2): return self.OUT_CUBIC (t*2, b, c/2, d) return self.IN_CUBIC((t*2)-d, b+c/2, c/2, d) def IN_QUART( self, t, b, c, d): t/=d return c*(t)*t*t*t + b def OUT_QUART( self, t, b, c, d): t=t/d-1 return -c * ((t)*t*t*t - 1) + b def IN_OUT_QUART( self, t, b, c, d): t/=d/2 if (t < 1): return c/2*t*t*t*t + b t-=2 return -c/2 * ((t)*t*t*t - 2) + b def OUT_ELASTIC(self, t, b, c, d): # Not working :( if (t==0): return b t/=d if t==1: return b+c p = period = d*.3 a = amplitude = 1.0 if a < abs(c): a = c s = p/4 else: s = p/(2*math.pi) * math.asin (c/a) return (a*math.pow(2,-10*t) * math.sin( (t*d-s)*(2*math.PI)/p ) + c + b) def hasTweens(self): return len(self.currentTweens) > 0 def addTween(self, obj, **kwargs): """ addTween( object, **kwargs) -> tweenObject or False Example: tweener.addTween( myRocket, throttle=50, setThrust=400, tweenTime=5.0, tweenType=tweener.OUT_QUAD ) You must first specify an object, and at least one property or function with a corresponding change value. The tween will throw an error if you specify an attribute the object does not possess. Also the data types of the change and the initial value of the tweened item must match. If you specify a 'set' -type function, the tweener will attempt to get the starting value by call the corresponding 'get' function on the object. If you specify a property, the tweener will read the current state as the starting value. You add both functions and property changes to the same tween. in addition to any properties you specify on the object, these keywords do additional setup of the tween. tweenTime = the duration of the motion tweenType = one of the predefined tweening equations or your own function onCompleteFunction = specify a function to call on completion of the tween onUpdateFunction = specify a function to call every time the tween updates tweenDelay = specify a delay before starting. """ if "tweenTime" in kwargs: t_time = kwargs.pop("tweenTime") else: t_time = self.defaultDuration if "tweenType" in kwargs: t_type = kwargs.pop("tweenType") else: t_type = self.defaultTweenType if "onCompleteFunction" in kwargs: t_completeFunc = kwargs.pop("onCompleteFunction") else: t_completeFunc = None if "onUpdateFunction" in kwargs: t_updateFunc = kwargs.pop("onUpdateFunction") else: t_updateFunc = None if "tweenDelay" in kwargs: t_delay = kwargs.pop("tweenDelay") else: t_delay = 0 tw = Tween( obj, t_time, t_type, t_completeFunc, t_updateFunc, t_delay, **kwargs ) if tw: self.currentTweens.append( tw ) return tw def removeTween( tweenObj ): if self.currentTweens.contains( tweenObj ): tweenObj.complete = True #self.currentTweens.remove( tweenObj ) def getTweensAffectingObject( self, obj ): """Get a list of all tweens acting on the specified object Useful for manipulating tweens on the fly""" tweens = [] for t in self.currentTweens: if t.target is obj: tweens.append(t) return tweens def removeTweeningFrom( self, obj ): """Stop tweening an object, without completing the motion or firing the completeFunction""" for t in self.currentTweens: if t.target is obj: t.complete = True def update(self, timeSinceLastFrame): for t in self.currentTweens: if not t.complete: t.update( timeSinceLastFrame ) else: self.currentTweens.remove(t) class Tween(object): def __init__(self, obj, tduration, tweenType, completeFunction, updateFunction, delay, **kwargs): """Tween object: Can be created directly, but much more easily using Tweener.addTween( ... ) """ #print obj, tduration, kwargs self.duration = tduration self.delay = delay self.target = obj self.tween = tweenType self.tweenables = kwargs self.delta = 0 self.completeFunction = completeFunction self.updateFunction = updateFunction self.complete = False self.tProps = [] self.tFuncs = [] self.paused = self.delay > 0 self.decodeArguments() def decodeArguments(self): """Internal setup procedure to create tweenables and work out how to deal with each""" if len(self.tweenables) == 0: # nothing to do print "TWEEN ERROR: No Tweenable properties or functions defined" self.complete = True return for k, v in self.tweenables.items(): # check that its compatible if not hasattr( self.target, k): print "TWEEN ERROR: " + str(self.target) + " has no function " + k self.complete = True break prop = func = False startVal = 0 change = v try: startVal = self.target.__dict__[k] prop = k propName = k except: func = getattr( self.target, k) funcName = k if func: try: getFunc = getattr(self.target, funcName.replace("set", "get") ) startVal = getFunc() except: # no start value, assume its 0 # but make sure the start and change # dataTypes match :) startVal = change * 0 tweenable = Tweenable( startVal, change) newFunc = [ k, func, tweenable] #setattr(self, funcName, newFunc[2]) self.tFuncs.append( newFunc ) if prop: tweenable = Tweenable( startVal, change) newProp = [ k, prop, tweenable] self.tProps.append( newProp ) #print dir(self) def pause( self, numSeconds=-1 ): """Pause this tween do tween.pause( 2 ) to pause for a specific time or tween.pause() which pauses indefinitely.""" self.paused = True self.delay = numSeconds def resume( self ): """Resume from pause""" if self.paused: self.paused=False def update(self, ptime): """Update this tween with the time since the last frame if there is an update function, it is always called whether the tween is running or paused""" if self.paused: if self.delay > 0: self.delay = max( 0, self.delay - ptime ) if self.delay == 0: self.paused = False self.delay = -1 if self.updateFunction: self.updateFunction() return self.delta = min(self.delta + ptime, self.duration) if not self.complete: for propName, prop, tweenable in self.tProps: self.target.__dict__[prop] = self.tween( self.delta, tweenable.startValue, tweenable.change, self.duration ) for funcName, func, tweenable in self.tFuncs: func( self.tween( self.delta, tweenable.startValue, tweenable.change, self.duration ) ) if self.delta == self.duration: self.complete = True if self.completeFunction: self.completeFunction() if self.updateFunction: self.updateFunction() def getTweenable(self, name): """Return the tweenable values corresponding to the name of the original tweening function or property. Allows the parameters of tweens to be changed at runtime. The parameters can even be tweened themselves! eg: # the rocket needs to escape!! - we're already moving, but must go faster! twn = tweener.getTweensAffectingObject( myRocket )[0] tweenable = twn.getTweenable( "thrusterPower" ) tweener.addTween( tweenable, change=1000.0, tweenTime=0.4, tweenType=tweener.IN_QUAD ) """ ret = None for n, f, t in self.tFuncs: if n == name: ret = t return ret for n, p, t in self.tProps: if n == name: ret = t return ret return ret def Remove(self): """Disables and removes this tween without calling the complete function""" self.complete = True class Tweenable: def __init__(self, start, change): """Tweenable: Holds values for anything that can be tweened these are normally only created by Tweens""" self.startValue = start self.change = change class TweenTestObject: def __init__(self): self.pos = 20 self.rot = 50 def update(self): print self.pos, self.rot def setRotation(self, rot): self.rot = rot def getRotation(self): return self.rot def complete(self): print "I'm done tweening now mommy!" if __name__=="__main__": import time T = Tweener() tst = TweenTestObject() mt = T.addTween( tst, setRotation=500.0, tweenTime=2.5, tweenType=T.OUT_EXPO, pos=-200, tweenDelay=0.4, onCompleteFunction=tst.complete, onUpdateFunction=tst.update ) s = time.clock() changed = False while T.hasTweens(): tm = time.clock() d = tm - s s = tm T.update( d ) if mt.delta > 1.0 and not changed: tweenable = mt.getTweenable( "setRotation" ) T.addTween( tweenable, change=-1000, tweenTime=0.7 ) T.addTween( mt, duration=-0.2, tweenTime=0.2 ) changed = True #print mt.duration, print tst.getRotation(), tst.pos time.sleep(0.06) print tst.getRotation(), tst.pos
