Reanimate.Scene

Scenes are an imperative way of defining animations.

Scenes

data Scene s a

Instances

Monad (Scene s)

Defined in Reanimate.Scene

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

Methods

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

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

MonadFix (Scene s)

Defined in Reanimate.Scene

Methods

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

Applicative (Scene s)

Defined in Reanimate.Scene

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.

sceneAnimation :: (forall s. Scene s a) -> 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. Note: The modification function is invoked for past timestamps (with a time value of 0) and for timestamps after now+duration (with a time value of 1). See tweenVarUnclamped.

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

Modify a variable between now and now+duration. Note: The modification function is invoked for past timestamps (with a negative time value) and for timestamps after now+duration (with a time value greater than 1).

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

Methods

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

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

Applicative (Frame s)

Defined in Reanimate.Scene

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

ST internals

liftST :: ST s a -> Scene s a