Effects

Every effect in the fx package, its fields, and whether it suits a transition, a backdrop, or feedback.

All effects are in github.com/lrstanley/bloom/fx. Each takes a progress t from 0 to 1:

As a transition (bloom.Transition, bloom.Present, Layer.Presence, Layer.Transition), it changes the node's own cells. t runs from 0, starting to enter, to 1, fully shown and unchanged.
As a backdrop or shadow (Layer.Backdrop, Layer.Shadow), it changes the frame beneath a layer. t is the strength, following the layer's transition.
Some take their own progress, such as a shake's or a burst's, and are applied with bloom.Transition while it runs.

Edge fields take bloom.Top, bloom.Bottom, bloom.Left, or bloom.Right (also available as fx.Top and so on). The zero value is Bottom. Seed fields pick a random pattern that stays the same for the same seed.

Entrances

Effect	Fields	Brings a node in by
`Fade`		crossfading from what's beneath it
`Slide`	`From Edge`	moving in from beyond an edge of its viewport
`Wipe`	`From Edge`	revealing it from one edge to the other
`Dissolve`	`Seed`	revealing its cells in a random order
`Typewriter`		revealing its cells in reading order
`Scramble`	`Seed`	random glyphs settling into its own
`Decode`	`Seed`	columns falling into place like digital rain
`Unfold`		opening from its middle row outward, like a CRT turning on
`Iris`	`At image.Point`	a circle growing from `At` (screen coordinates; zero is the node's center)
`Shade`	`Seed`	each cell stepping through ░ ▒ ▓ to its glyph
`Blinds`	`From Edge`, `Size int` (default 3)	opening slats, like window blinds
`Wave`	`From Edge`	a wobbling front sweeping across, with a bright crest
`Glitch`	`Seed`	a breaking-up signal that settles, with jitter and split colors

Backdrops

Effect	Fields	Changes what's beneath a layer by
`Dim`	`Amount float64`	moving colors toward the terminal's background
`Desaturate`	`Amount float64`	moving colors toward gray
`Tint`	`Color color.Color`, `Amount float64`	moving colors toward `Color`
`Recolor`	`Fg, Bg color.Color`	drawing every cell in two colors, keeping the glyphs
`Spotlight`	`Rect image.Rectangle`, `Amount float64` (default 0.7), `Soft int`	dimming everything outside `Rect`, with a soft edge `Soft` cells wide

Amount runs from 0, no change, to 1, all the way. Backdrops also work as transitions; Tint on a node fades it in from a color, for example.

Feedback

These take their own progress rather than an entrance's. See Feedback effects for how to drive them.

Effect	Fields	Does
`Shake`	`Amount int` (default 2), `Times int` (default 4)	moves the node side to side with a decaying wobble; still at 0 and 1
`Shimmer`	`Color color.Color`, `Width int` (default 6)	sweeps a highlight band across the node; `t` is the band's position
`Roll`	`From string`	turns digits over like an odometer, from the number in `From`
`Burst`	`At image.Point`, `Count int` (default 40), `Seed`	throws confetti from `At`; `t` is its age, gone at 1

Combinators

These wrap other effects.

Effect	Fields	Does
`Stagger`	`Effect`, `From Edge`, `Spread float64` (default 0.5)	runs `Effect` on each row (`From` top or bottom) or column (left or right), one after another
`Delay`	`Effect`, `From, To float64` (`To` defaults to 1)	runs `Effect` only between `From` and `To` of the progress
`Reverse`	`Effect`	runs `Effect` with `1-t`
`Ease`	`Effect`, `Easing func(float64) float64`	runs `Effect` with eased progress, such as `anim.OutBack`

Your own

Type	Does
`Func`	turns a `func(*canvas.Surface, float64)` into an effect

Any type with an Apply(*canvas.Surface, float64) method is an effect. See Custom effects.

Things to know

Effects listed together run in order with the same t.
Effects that need the terminal's colors (Dim, Shimmer with no color, Wave) work best when the root has heard them: return m.ui.Init() from Init and pass messages to m.ui.Update.
Effects that replace glyphs (Scramble, Decode, Shade, Glitch) leave wide characters, such as emoji, alone or reveal them in one step, so they never draw half a character.
Ease and Func hold functions, which can't be compared, so frames using them are redrawn every time. Keep them on nodes that are animating.

Effects

EntrancesCopy Anchor Link

BackdropsCopy Anchor Link

FeedbackCopy Anchor Link

CombinatorsCopy Anchor Link

Your ownCopy Anchor Link