Reanimate.Scene

Scenes are an imperative way of defining animations.

Scenes

data Scene s a

A Scene represents a sequence of animations and variables that change over time.

Instances

Monad (Scene s)

Defined in Reanimate.Scene.Core

Methods

(>>=) :: Scene s a -> (a -> Scene s b) -> Scene s b

(>>) :: Scene s a -> Scene s b -> Scene s b

return :: a -> Scene s a

fail :: String -> Scene s a

Functor (Scene s)

Defined in Reanimate.Scene.Core

Methods

fmap :: (a -> b) -> Scene s a -> Scene s b

(<$) :: a -> Scene s b -> Scene s a

MonadFix (Scene s)

Defined in Reanimate.Scene.Core

Methods

mfix :: (a -> Scene s a) -> Scene s a

Applicative (Scene s)

Defined in Reanimate.Scene.Core

Methods

pure :: a -> Scene s a

(<*>) :: Scene s (a -> b) -> Scene s a -> Scene s b

liftA2 :: (a -> b -> c) -> Scene s a -> Scene s b -> Scene s c

(*>) :: Scene s a -> Scene s b -> Scene s b

(<*) :: Scene s a -> Scene s b -> Scene s a

type ZIndex = Int

The ZIndex property specifies the stack order of sprites and animations. Elements with a higher ZIndex will be drawn on top of elements with a lower index.

scene :: (forall s. Scene s a) -> Animation

Render a Scene to an Animation.

play :: Animation -> Scene s ()

Play an animation once and then remove it. This advances the clock by the duration of the animation.

Example:

do play drawBox
   play drawCircle

fork :: Scene s a -> Scene s a

Execute actions in a scene without advancing the clock. Note that scenes do not end before all forked actions have completed.

Example:

do fork $ play drawBox
   play drawCircle

queryNow :: Scene s Time

Query the current clock timestamp.

Example:

do now <- play drawCircle *> queryNow
   play $ staticFrame 1 $ scale 2 $ withStrokeWidth 0.05 $
     mkText $ "Now=" <> T.pack (show now)

wait :: Duration -> Scene s ()

Advance the clock by a given number of seconds.

Example:

do fork $ play drawBox
   wait 1
   play drawCircle

waitUntil :: Time -> Scene s ()

Wait until the clock is equal to the given timestamp.

waitOn :: Scene s a -> Scene s a

Wait until all forked and sequential animations have finished.

Example:

do waitOn $ fork $ play drawBox
   play drawCircle

adjustZ :: (ZIndex -> ZIndex) -> Scene s a -> Scene s a

Change the ZIndex of a scene.

withSceneDuration :: Scene s () -> Scene s Duration

Query the duration of a scene.

Variables

data Var s a

Time dependent variable.

newVar :: a -> Scene s (Var s a)

Create a new variable with a default value. Variables always have a defined value even if they are read at a timestamp that is earlier than when the variable was created. For example:

do v <- fork (wait 10 >> newVar 0) -- Create a variable at timestamp '10'.
   readVar v                       -- Read the variable at timestamp '0'.
                                   -- The value of the variable will be '0'.

readVar :: Var s a -> Scene s a

Read the value of a variable at the current timestamp.

writeVar :: Var s a -> a -> Scene s ()

Write the value of a variable at the current timestamp.

Example:

do v <- newVar 0
   newSprite $ mkCircle <$> unVar v
   writeVar v 1; wait 1
   writeVar v 2; wait 1
   writeVar v 3; wait 1

modifyVar :: Var s a -> (a -> a) -> Scene s ()

Modify the value of a variable at the current timestamp and all future timestamps.

tweenVar :: Var s a -> Duration -> (a -> Time -> a) -> Scene s ()

Modify a variable between now and now+duration.

simpleVar :: (a -> SVG) -> a -> Scene s (Var s a)

Create and render a variable. The rendering will be born at the current timestamp and will persist until the end of the scene.

Example:

do var <- simpleVar mkCircle 0
   tweenVar var 2 $ \val -> fromToS val (screenHeight/2)

findVar :: (a -> Bool) -> [Var s a] -> Scene s (Var s a)

Helper function for filtering variables.

Sprites

data Sprite s

Sprites are animations with a given time of birth as well as a time of death. They can be controlled using variables, tweening, and effects.

data Frame s a

Sprite frame generator. Generates frames over time in a stateful environment.

Instances

Functor (Frame s)

Defined in Reanimate.Scene.Sprite

Methods

fmap :: (a -> b) -> Frame s a -> Frame s b

(<$) :: a -> Frame s b -> Frame s a

Applicative (Frame s)

Defined in Reanimate.Scene.Sprite

Methods

pure :: a -> Frame s a

(<*>) :: Frame s (a -> b) -> Frame s a -> Frame s b

liftA2 :: (a -> b -> c) -> Frame s a -> Frame s b -> Frame s c

(*>) :: Frame s a -> Frame s b -> Frame s b

(<*) :: Frame s a -> Frame s b -> Frame s a

unVar :: Var s a -> Frame s a

Dereference a variable as a Sprite frame.

Example:

do v <- newVar 0
   newSprite $ mkCircle <$> unVar v
   tweenVar v 1 $ \val -> fromToS val 3
   tweenVar v 1 $ \val -> fromToS val 0

spriteT :: Frame s Time

Dereference seconds since sprite birth.

spriteDuration :: Frame s Duration

Dereference duration of the current sprite.

newSprite :: Frame s SVG -> Scene s (Sprite s)

Create new sprite defined by a frame generator. Unless otherwise specified using destroySprite, the sprite will die at the end of the scene.

Example:

do newSprite $ mkCircle <$> spriteT -- Circle sprite where radius=time.
   wait 2

newSprite_ :: Frame s SVG -> Scene s ()

Create new sprite defined by a frame generator. The sprite will die at the end of the scene.

newSpriteA :: Animation -> Scene s (Sprite s)

Create a new sprite from an animation. This advances the clock by the duration of the animation. Unless otherwise specified using destroySprite, the sprite will die at the end of the scene.

Note: If the scene doesn't end immediately after the duration of the animation, the animation will be stretched to match the lifetime of the sprite. See newSpriteA' and play.

Example:

do fork $ newSpriteA drawCircle
   play drawBox
   play $ reverseA drawBox

newSpriteA' :: Sync -> Animation -> Scene s (Sprite s)

Create a new sprite from an animation and specify the synchronization policy. This advances the clock by the duration of the animation.

Example:

do fork $ newSpriteA' SyncFreeze drawCircle
   play drawBox
   play $ reverseA drawBox

newSpriteSVG :: SVG -> Scene s (Sprite s)

Create a sprite from a static SVG image.

Example:

do newSpriteSVG $ mkBackground "lightblue"
   play drawCircle

newSpriteSVG_ :: SVG -> Scene s ()

Create a permanent sprite from a static SVG image. Same as newSpriteSVG but the sprite isn't returned and thus cannot be destroyed.

destroySprite :: Sprite s -> Scene s ()

Destroy a sprite, preventing it from being rendered in the future of the scene. If destroySprite is invoked multiple times, the earliest time-of-death is used.

Example:

do s <- newSpriteSVG $ withFillOpacity 1 $ mkCircle 1
   fork $ wait 1 >> destroySprite s
   play drawBox

applyVar :: Var s a -> Sprite s -> (a -> SVG -> SVG) -> Scene s ()

Change the rendering of a sprite using data from a variable. If data from several variables is needed, use a frame generator instead.

Example:

do s <- fork $ newSpriteA drawBox
   v <- newVar 0
   applyVar v s rotate
   tweenVar v 2 $ \val -> fromToS val 90

spriteModify :: Sprite s -> Frame s ((SVG, ZIndex) -> (SVG, ZIndex)) -> Scene s ()

Low-level frame modifier.

spriteMap :: Sprite s -> (SVG -> SVG) -> Scene s ()

Map the SVG output of a sprite.

Example:

do s <- fork $ newSpriteA drawCircle
   wait 1
   spriteMap s flipYAxis

spriteTween :: Sprite s -> Duration -> (Double -> SVG -> SVG) -> Scene s ()

Modify the output of a sprite between now and now+duration.

Example:

do s <- fork $ newSpriteA drawCircle
   spriteTween s 1 $ \val -> translate (screenWidth*0.3*val) 0

spriteVar :: Sprite s -> a -> (a -> SVG -> SVG) -> Scene s (Var s a)

Create a new variable and apply it to a sprite.

Example:

do s <- fork $ newSpriteA drawBox
   v <- spriteVar s 0 rotate
   tweenVar v 2 $ \val -> fromToS val 90

spriteE :: Sprite s -> Effect -> Scene s ()

Apply an effect to a sprite.

Example:

do s <- fork $ newSpriteA drawCircle
   spriteE s $ overBeginning 1 fadeInE
   spriteE s $ overEnding 0.5 fadeOutE

spriteZ :: Sprite s -> ZIndex -> Scene s ()

Set new ZIndex of a sprite.

Example:

do s1 <- newSpriteSVG $ withFillOpacity 1 $ withFillColor "blue" $ mkCircle 3
   newSpriteSVG $ withFillOpacity 1 $ withFillColor "red" $ mkRect 8 3
   wait 1
   spriteZ s1 1
   wait 1

spriteScope :: Scene s a -> Scene s a

Destroy all local sprites at the end of a scene.

Example:

do -- the rect lives through the entire 3s animation
   newSpriteSVG_ $ translate (-3) 0 $ mkRect 4 4
   wait 1
   spriteScope $ do
     -- the circle only lives for 1 second.
     local <- newSpriteSVG $ translate 3 0 $ mkCircle 2
     spriteE local $ overBeginning 0.3 fadeInE
     spriteE local $ overEnding 0.3 fadeOutE
     wait 1
   wait 1

Object API

data Object s a

Objects are SVG nodes (represented as Haskell values) with identity, location, and several other properties that can change over time.

data ObjectData a

Container for object properties.

oNew :: Renderable a => a -> Scene s (Object s a)

Create new object.

newObject :: Renderable a => a -> Scene s (Object s a)

Create new object.

oModify :: Object s a -> (ObjectData a -> ObjectData a) -> Scene s ()

Modify object properties.

oModifyS :: Object s a -> State (ObjectData a) b -> Scene s ()

Modify object properties using a stateful API.

oRead :: Object s a -> Getting b (ObjectData a) b -> Scene s b

Query object property.

oTween :: Object s a -> Duration -> (Double -> ObjectData a -> ObjectData a) -> Scene s ()

Modify object properties over a set duration.

oTweenS :: Object s a -> Duration -> (Double -> State (ObjectData a) b) -> Scene s ()

Modify object properties over a set duration using a stateful API.

oTweenV :: Renderable a => Object s a -> Duration -> (Double -> a -> a) -> Scene s ()

Modify object value over a set duration. This is a convenience function for modifying oValue.

oTweenVS :: Renderable a => Object s a -> Duration -> (Double -> State a b) -> Scene s ()

Modify object value over a set duration using a stateful API. This is a convenience function for modifying oValue.

class Renderable a where

Objects can be any Haskell structure as long as it can be rendered to SVG.

Methods

toSVG :: a -> SVG

Instances

Renderable Tree

Defined in Reanimate.Scene.Object

Methods

toSVG :: Tree -> SVG

Renderable Camera

Defined in Reanimate.Scene.Object

Methods

toSVG :: Camera -> SVG

Renderable Morph

Defined in Reanimate.Scene.Object

Methods

toSVG :: Morph -> SVG

Renderable Rectangle

Defined in Reanimate.Scene.Object

Methods

toSVG :: Rectangle -> SVG

Renderable Circle

Defined in Reanimate.Scene.Object

Methods

toSVG :: Circle -> SVG

Object Properties

oTranslate :: Lens' (ObjectData a) (V2 Double)

Object position. Default: <0,0>

oTranslateX :: Lens' (ObjectData a) Double

Object X position. Default: 0

oTranslateY :: Lens' (ObjectData a) Double

Object Y position. Default: 0

oSVG :: Getter (ObjectData a) SVG

Rendered SVG node of an object. Does not include context or object properties. Read-only.

oContext :: Lens' (ObjectData a) (SVG -> SVG)

Custom render context. Is applied to the object for every frame that it is shown.

oMargin :: Lens' (ObjectData a) (Double, Double, Double, Double)

Object margins (top, right, bottom, left) in local units.

oMarginTop :: Lens' (ObjectData a) Double

Object's top margin.

oMarginRight :: Lens' (ObjectData a) Double

Object's right margin.

oMarginBottom :: Lens' (ObjectData a) Double

Object's bottom margin.

oMarginLeft :: Lens' (ObjectData a) Double

Object's left margin.

oBB :: Getter (ObjectData a) (Double, Double, Double, Double)

Object bounding-box (minimal X-coordinate, minimal Y-coordinate, width, height). Uses boundingBox and has the same limitations.

oBBMinX :: Getter (ObjectData a) Double

Object's minimal X-coordinate..

oBBMinY :: Getter (ObjectData a) Double

Object's minimal Y-coordinate..

oBBWidth :: Getter (ObjectData a) Double

Object's width without margin.

oBBHeight :: Getter (ObjectData a) Double

Object's height without margin.

oOpacity :: Lens' (ObjectData a) Double

Object opacity. Default: 1

oShown :: Lens' (ObjectData a) Bool

Toggle for whether or not the object should be rendered. Default: False

oZIndex :: Lens' (ObjectData a) Int

Object's z-index.

oEasing :: Lens' (ObjectData a) Signal

Easing function used when modifying object properties. Default: curveS 2

oScale :: Lens' (ObjectData a) Double

Object's scale. Default: 1

oScaleOrigin :: Lens' (ObjectData a) (V2 Double)

Origin point for scaling. Default: <0,0>

oTopY :: Lens' (ObjectData a) Double

Derived location of the top-most point of an object + margin.

oBottomY :: Lens' (ObjectData a) Double

Derived location of the bottom-most point of an object + margin.

oLeftX :: Lens' (ObjectData a) Double

Derived location of the left-most point of an object + margin.

oRightX :: Lens' (ObjectData a) Double

Derived location of the right-most point of an object + margin.

oCenterXY :: Lens' (ObjectData a) (V2 Double)

Derived location of an object's center point.

oCenterX :: Lens' (ObjectData a) Double

Derived location of an object's center X value.

oCenterY :: Lens' (ObjectData a) Double

Derived location of an object's center Y value.

oValue :: Renderable a => Lens' (ObjectData a) a

Lens for the source value contained in an object.

Graphics object methods

oShow :: Object s a -> Scene s ()

Instantly show object.

oHide :: Object s a -> Scene s ()

Instantly hide object.

oShowWith :: Object s a -> (SVG -> Animation) -> Scene s ()

Show object with an animator function. The animator is responsible for transitioning the object from invisible to having its final shape. If this doesn't hold true for the animator function then the final animation will be discontinuous.

oHideWith :: Object s a -> (SVG -> Animation) -> Scene s ()

Hide object with an animator function. The animator is responsible for transitioning the object from visible to invisible. If this doesn't hold true for the animator function then the final animation will be discontinuous.

oFadeIn :: SVG -> Animation

Fade in object over a set duration.

oFadeOut :: SVG -> Animation

Fade out object over a set duration.

oGrow :: SVG -> Animation

Scale in object over a set duration.

Example:

do txt <- oNew $ withStrokeWidth 0 $ withFillOpacity 1 $
     center $ scale 3 $ latex "oGrow"
   oShowWith txt oGrow
   wait 1; oHideWith txt oFadeOut

oShrink :: SVG -> Animation

Scale out object over a set duration.

oTransform :: Object s a -> Object s b -> Duration -> Scene s ()

Morph source object into target object over a set duration.

type Origin = (Double, Double)

Relative coordinates for an SVG node.

oScaleIn :: SVG -> Animation

Scale in children from left to right, with an origin at the top of each child.

Example:

do txt <- oNew $ withStrokeWidth 0 $ withFillOpacity 1 $
     center $ scale 3 $ latex "oScaleIn"
   oShowWith txt $ adjustDuration (*2) . oScaleIn
   wait 1; oHideWith txt oFadeOut

oScaleIn' :: Signal -> Origin -> SVG -> Animation

Like oScaleIn but takes an easing function and an origin.

oScaleOut :: SVG -> Animation

Scale out children from left to right, with an origin at the bottom of each child.

Example:

do txt <- oNew $ withStrokeWidth 0 $ withFillOpacity 1 $
     center $ scale 3 $ latex "oScaleOut"
   oShowWith txt oFadeIn
   oHideWith txt $ adjustDuration (*2) . oScaleOut

oScaleOut' :: Signal -> Origin -> SVG -> Animation

Like oScaleOut but takes an easing function and an origin.

oDraw :: SVG -> Animation

Render SVG by first drawing outlines and then filling shapes.

Example:

do txt <- oNew $ withStrokeWidth 0 $ withFillOpacity 1 $
     center $ scale 4 $ latex "oDraw"
   oModify txt $ oEasing .~ id
   oShowWith txt oDraw; wait 1
   oHideWith txt oFadeOut

oSim :: (SVG -> Animation) -> SVG -> Animation

Animate each child node in parallel.

oStagger :: (SVG -> Animation) -> SVG -> Animation

Animate each child node in parallel, staggered by 0.2 seconds.

oStaggerRev :: (SVG -> Animation) -> SVG -> Animation

Animate each child node in parallel, staggered by 0.2 seconds and in reverse order.

oStagger' :: Duration -> (SVG -> Animation) -> SVG -> Animation

Animate each child node in parallel, staggered by a given duration.

oStaggerRev' :: Duration -> (SVG -> Animation) -> SVG -> Animation

Animate each child node in parallel, staggered by given duration and in reverse order.

Pre-defined objects

newtype Circle

Basic object mapping to <circle/> in SVG.

Constructors

Circle

Fields

• _circleRadius :: Double

Instances

Renderable Circle

Defined in Reanimate.Scene.Object

Methods

toSVG :: Circle -> SVG

circleRadius :: Lens' Circle Double

Circle radius in local units.

data Rectangle

Basic object mapping to <rect/> in SVG.

Constructors

Rectangle

Fields

• _rectWidth :: Double
• _rectHeight :: Double

Instances

Renderable Rectangle

Defined in Reanimate.Scene.Object

Methods

toSVG :: Rectangle -> SVG

rectWidth :: Lens' Rectangle Double

Rectangle width in local units.

rectHeight :: Lens' Rectangle Double

Rectangle height in local units.

data Morph

Object representing an interpolation between SVG nodes.

Constructors

Morph

Fields

• _morphDelta :: Double
• _morphSrc :: SVG
• _morphDst :: SVG

Instances

Renderable Morph

Defined in Reanimate.Scene.Object

Methods

toSVG :: Morph -> SVG

morphDelta :: Lens' Morph Double

Control variable for the interpolation. A value of 0 gives the source SVG and 1 gives the target svg.

morphSrc :: Lens' Morph SVG

Source shape.

morphDst :: Lens' Morph SVG

Target shape.

data Camera

Cameras can take control of objects and manipulate them with convenient pan and zoom operations.

Constructors

Camera

Instances

Renderable Camera

Defined in Reanimate.Scene.Object

Methods

toSVG :: Camera -> SVG

cameraAttach :: Object s Camera -> Object s a -> Scene s ()

Connect an object to a camera such that camera settings (position, zoom, and rotation) is applied to the object.

Example

do cam <- newObject Camera
   circ <- newObject $ Circle 2
   oModifyS circ $
     oContext .= withFillOpacity 1 . withFillColor "blue"
   oShow circ
   cameraAttach cam circ
   cameraZoom cam 1 2
   cameraZoom cam 1 1

cameraFocus :: Object s Camera -> V2 Double -> Scene s ()

Example

do cam <- newObject Camera
   circ <- newObject $ Circle 2; oShow circ
   oModify circ $ oTranslate .~ (-3,0)
   box <- newObject $ Rectangle 4 4; oShow box
   oModify box $ oTranslate .~ (3,0)
   cameraAttach cam circ
   cameraAttach cam box
   cameraFocus cam (-3,0)
   cameraZoom cam 2 2      -- Zoom in
   cameraZoom cam 2 1      -- Zoom out
   cameraFocus cam (3,0)
   cameraZoom cam 2 2      -- Zoom in
   cameraZoom cam 2 1      -- Zoom out

cameraSetZoom :: Object s Camera -> Double -> Scene s ()

Instantaneously set camera zoom level.

cameraZoom :: Object s Camera -> Duration -> Double -> Scene s ()

Change camera zoom level over a set duration.

cameraSetPan :: Object s Camera -> V2 Double -> Scene s ()

Instantaneously set camera location.

cameraPan :: Object s Camera -> Duration -> V2 Double -> Scene s ()

Change camera location over a set duration.

ST internals

liftST :: ST s a -> Scene s a

Lift ST action into the Scene monad.

transitionO :: Transition -> Double -> (forall s'. Scene s' a) -> (forall s'. Scene s' b) -> Scene s ()

Apply a transformation with a given overlap. This makes sure to keep timestamps intact such that events can still be timed by transcripts.

evalScene :: (forall s. Scene s a) -> a

Evaluate the value of a scene.