README
¶
Tween 
Tween is a small library to perform tweening in Go. It has a minimal interface, and it comes with several easing functions.
Examples
see examples folder
Easing functions
Easing functions are functions that express how slow/fast the interpolation happens in tween.
The easing functions can be found in the ease package.
They can be divided into several families:
linearis the simplest easing function, straight from one value to the other.quad,cubic,quart,quint,expo,sineandcircleare all "smooth" curves that will make transitions look natural.- The
backfamily starts by moving the interpolation slightly "backwards" before moving it forward. - The
bouncefamily simulates the motion of an object bouncing. - The
elasticfamily simulates inertia in the easing, like an elastic gum.
Each family (except linear) has 4 variants:
Instarts slow, and accelerates at the endOutstarts fast, and decelerates at the endInOutstarts and ends slow, but it's fast in the middleOutInstarts and ends fast, but it's slow in the middle
| family | in | out | inOut | outIn |
|---|---|---|---|---|
| Linear | Linear | Linear | Linear | Linear |
| Quad | InQuad | OutQuad | InOutQuad | OutInQuad |
| Cubic | InCubic | OutCubic | InOutCubic | OutInCubic |
| Quart | InQuart | OutQuart | InOutQuart | OutInQuart |
| Quint | InQuint | OutQuint | InOutQuint | OutInQuint |
| Expo | InExpo | OutExpo | InOutExpo | OutInExpo |
| Sine | InSine | OutSine | InOutSine | OutInSine |
| Circ | InCirc | OutCirc | InOutCirc | OutInCirc |
| Back | InBack | OutBack | InOutBack | OutInBack |
| Bounce | InBounce | OutBounce | InOutBounce | OutInBounce |
| Elastic | InElastic | OutElastic | InOutElastic | OutInElastic |
Custom easing functions
You are not limited to gween's easing functions; if you pass a function parameter in the easing, it will be used.
The passed function will need to suite the TweenFunc interface: func(t, b, c, d float32) float32
t(time): starts in 0 and usually moves towards durationb(begin): initial value of the of the property being eased.c(change): ending value of the property - starting value of the propertyd(duration): total duration of the tween
And must return the new value after the interpolation occurs.
Here's an example using a custom easing.
labelTween := tween.new(0, 300, 4, func(t, b, c, d) float32 {
return c*t/d + b // linear ease
})
Credits
tween is an independent fork of the gween package. The API is different.
Documentation
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Overview ¶
Package tween provides the Tween struct that allows an easing function to be animated over time. This can be used in tandem with the ease package to provide the easing functions.
Index ¶
- type Sequence
- func (seq *Sequence) Add(tweens ...*Tween)
- func (seq *Sequence) HasTweens() bool
- func (seq *Sequence) Index() int
- func (seq *Sequence) IsActiveTweenFinished() bool
- func (seq *Sequence) IsFinished() bool
- func (seq *Sequence) IsReversed() bool
- func (seq *Sequence) Remove(index int)
- func (seq *Sequence) Reset()
- func (seq *Sequence) SetIndex(index int)
- func (seq *Sequence) SetLoop(amount int)
- func (seq *Sequence) SetReverse(r bool)
- func (s *Sequence) Update(dt float32)
- func (seq *Sequence) Value() float32
- type Tween
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Sequence ¶
type Sequence struct {
Tweens []*Tween
// YoyoEnabled makes the sequence "Yoyo" back to the beginning after it reaches the end
YoyoEnabled bool
// contains filtered or unexported fields
}
Sequence represents a sequence of Tweens, executed one after the other.
func NewSequence ¶
NewSequence returns a new Sequence object.
func (*Sequence) HasTweens ¶
HasTweens returns whether the Sequence is populated with Tweens or not.
func (*Sequence) Index ¶
Index returns the current index of the Sequence. Note that this can exceed the number of Tweens in the Sequence.
func (*Sequence) IsActiveTweenFinished ¶
IsActiveTweenFinished returns whether the currently active Tween is finished.
func (*Sequence) IsFinished ¶
IsFinished returns whether the entire Sequence is finished. This is true when all Tweens in the Sequence are finished and the Sequence has no remaining loops. If the Sequence is set to loop infinitely, this will always return false.
func (*Sequence) IsReversed ¶
IsReversed returns whether the Sequence currently running in reverse.
func (*Sequence) Reset ¶
func (seq *Sequence) Reset()
Reset resets the Sequence, resetting all Tweens and setting the Sequence's index back to 0.
func (*Sequence) SetIndex ¶
SetIndex sets the current index of the Sequence, influencing which Tween is active at any given time.
func (*Sequence) SetLoop ¶
SetLoop sets the default loop and the current remaining loops
-1 means infinite loops
0 means no loops
1 means one loop
func (*Sequence) SetReverse ¶
SetReverse sets whether the Sequence will start running in reverse.
type Tween ¶
type Tween struct {
Reverse bool
// contains filtered or unexported fields
}
Tween encapsulates the easing function along with timing data. This allows a ease.TweenFunc to be used to be easily animated.
func NewTween ¶
NewTween will return a new Tween when passed a beginning and end value, the duration of the tween and the easing function to animate between the two values. The easing function can be one of the provided easing functions from the ease package or you can provide one of your own.
func (*Tween) IsFinished ¶
IsFinished will return true if the tween is finished.
func (*Tween) Reset ¶
func (t *Tween) Reset()
Reset will set the Tween to the beginning of the two values.
func (*Tween) Set ¶
Set will set the current time along the duration of the tween. It will then return the current value as well as a boolean to determine if the tween is finished.
Source Files
Directories