ZacharyZhang-NY
8be66c09f2
Palette cycling, sky, sun and moon, clouds, starfield, rain, snow, petals, leaves, fireflies, waterfall, ocean, campfire, lava, aurora, lightning, mountains and a season scene; scanlines, vignette, screen shake, flash, dither fades, iris wipes, dissolves, mosaics, glitches, sparkles, explosions and confetti. Home opens on a live scene in the palette's season and a strip of all eight palettes. pixel adds Canvas.Cycled, Sprite.At, SpriteOf, Kit.Toward and Kit.Shot, which spends a cue under Reduce Motion so it never replays; display exports Reduce. Gallery grids and the sidebar are one Tab stop each.
66 lines
1.6 KiB
Go
66 lines
1.6 KiB
Go
package fx
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import (
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"github.com/egoist/mygo/ui"
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"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
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)
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type LightningOptions struct {
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// Cue strikes each time it changes.
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Cue int
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// Width and Height are dots; zeros mean 96 by 96.
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Width, Height int
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Label string
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}
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// strikeSteps run flash, half flash, bolt, bolt, dim bolt.
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const strikeSteps = 5
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// Lightning flashes, then forks a bolt to the ground.
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func Lightning(c *ui.Context, o LightningOptions) *ui.Element {
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k := pixel.K(c)
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w, h := size("Lightning", o.Width, o.Height, 96, 96)
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e := box(c, k, o.Label, w, h)
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step := k.Shot(c, e, o.Cue, 15, strikeSteps)
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return e.Draw(func(p *ui.Painter, r ui.Rect) {
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if step == strikeSteps {
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return
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}
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g := k.Canvas(p, r)
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g.Clip(0, 0, g.W, g.H, func() { strike(g, k, step, o.Cue) })
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})
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}
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// strike draws step of a strike; seed shapes the bolt.
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func strike(g pixel.Canvas, k pixel.Kit, step, seed int) {
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switch step {
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case 0:
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g.Rect(0, 0, g.W, g.H, light(k))
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return
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case 1:
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g.Veil(0, 0, g.W, g.H, light(k), 6)
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}
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core, glow := pick(k, pixel.Warn, pixel.Ink), pixel.Info
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if step == 4 {
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core = pixel.AccentLit
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}
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x, y := g.W/3+rnd(seed, 140)%max(1, g.W/3), 0
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fork := 1 + rnd(seed, 141)%3
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for i := 0; y < g.H; i++ {
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nx, ny := x+rnd(seed+i, 142)%7-3, y+4+rnd(seed+i, 143)%6
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g.Line(x+1, y, nx+1, ny, glow)
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g.Line(x, y, nx, ny, core)
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// One branch forks off and dies out.
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if i == fork {
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bx, by, dir := nx, ny, 1-2*(rnd(seed, 144)%2)
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for j := range 3 {
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ex, ey := bx+dir*(3+rnd(seed+j, 145)%3), by+3+rnd(seed+j, 146)%4
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g.Line(bx, by, ex, ey, core)
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bx, by = ex, ey
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}
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}
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x, y = nx, ny
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}
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}
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