tween.core

Tween library for arcadia-unity

timelines

A version of https://github.com/nasser's timeline concept.

timeline starts a coroutine that iterates a seq? collection. Items are invoked every frame and lazily iterate when falsey.

(timeline [
 #(log "hello")
  (wait 1.0)
 #(log "goodbye")])

timeline-1 uses another fn layer to provide an initialization closure. This closure is needed to repeat wait and tween fns.

(timeline-1 
  (cycle [
    (fn [] (wait (rand)))
    (fn [] #(log 'tick)])))

timeline* macro wraps forms with (fn []), and uses an Array for performance. :loop as first arg cycles the iterator.

(timeline* :loop
  (wait 0.5)
  (tween {:local {
    :position (v3 0 2 0)
    :scale (v3 (rand))}} (object/named "ball") 0.9))

timeline$ macro has similar usage as timeline*, wraps forms with (fn []), and returns a coroutine. Unity supports nesting coroutines making and these performant but not as composable.

(timeline$ 
  (WAIT 1) 
  (timeline$ 
    #(log "foo"))
  #(log "bar"))

wait

(wait 0.5)

returns fn that returns true for the duration after it's first invokation

abort!

Throws a UnityEngine.MissingReferenceException, silently stopping the timeline.

(timeline [
  #(log "foo")
  #(abort!)
  #(log "bar")])

timeline control macros: AND, OR, NOT, ANY

conrol logic fn constructors, returning the boolean result of invoking their forms. Uses let bindings for each form to "evaporate" any closures. Pretty experimental, but does allows temporal control flow. Uses lazy evaluation as in core, since tweens and waits start when first invoked, using (OR a b c) has interesting temporal behaviour.

(timeline* 
  (AND (wait 4.0) 
       (OR (AND (NOT (wait 1.0))
                (tween {:position (v3 0 10 0)} foo 5.0))
           (OR (wait 3) 
              #(log "cancel")))))

tweens

deftag macro

Registers a type for tweening. :pair should be a type with mutable a and b fields. :lerp fn takes two values and a System.Single ratio, which will be between 0 and 1.

(deftag       UnityEngine.Vector3 
  {:pair      Vector3Pair
   :lerp      UnityEngine.Vector3/Lerp           
   :identity  (UnityEngine.Vector3.)})

deftween macro

(deftween [:material :color] [this]
  {:get (.color this)
   :tag UnityEngine.Color
   :base (.material (.GetComponent this UnityEngine.Renderer))
   :base-tag UnityEngine.Material})

register an edn path as a tween. The path is arbitrary and the symbol binding will be to a user provided object.

• arg-1 edn path
• arg-2 vector with symbol used in getter code
• arg-3 map with:
• :tag qualified type of property (should be registered with deftag)
• :get code to get tweenable property
• :base optional getter for derived object
• :base-tag optional type-hint for base object

tween macro

Expands into a fn that returns true for the duration after it's first invokation. The target map is exploded into paths, a path registered with deftween will expand into code.

(tween 
 {:local 
   {:scale (Vector3. 2.0 2.0 2.0)
    :position (Vector3. 0.0 2.0 0.0)}}  
  (GameObject.) 
  2.5 {:in :pow5})

• arg-1 map of target values
• arg-2 object reference
• arg-3 duration
• & more compiles into opt map, naked easing keys compile to both :in and :out opts

easing fns

{:in :pow3}

• keys :in :out
• vals :pow2 :pow3 :pow4 :pow5 nil