Add fx components 291-320 and the home scene; Kit.Shot, Kit.Toward

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.

fx/sprites.go

@@ -0,0 +1,179 @@
+package fx
+
+import "git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+
+var smallCloud = pixel.MustSprite(`
+.....lll......
+..llllllll.l..
+.llllllllllll.
+llllllllllllll
+fllllllllllllf
+.ffffffffffff.
+`)
+
+var bigCloud = pixel.MustSprite(`
+.........llll...........
+....llll.llllll.........
+..lllllllllllllll.llll..
+.lllllllllllllllllllllll
+llllllllllllllllllllllll
+lllllllllllllllllllllllf
+fllllllllllllllllllllllf
+.fffllllllllllllllllfff.
+...ffffffffffffffffff...
+`)
+
+// trees stand in the scene, one per season.
+var trees = [4]*pixel.Sprite{
+	pixel.MustSprite(`
+.....AAAAA.....
+...AAAaAAAAA...
+..AAAAAAAAaAA..
+.AAaAAAAAAAAAA.
+.AAAAAAaAAAAAA.
+AAAAAAAAAAAaAAA
+AAaAAAAAAAAAAAA
+AAAAAAaAAAAAAAA
+.AAAAAAAAAaAAA.
+..AAAaAAAAAAA..
+...AAAAnAAAA...
+.....AnnnA.....
+......nnn......
+......nnn......
+......nnn......
+......nnn......
+.....nnnnn.....
+`),
+	pixel.MustSprite(`
+.....ggggg.....
+...ggglgggggg..
+..ggllggggggg..
+.gggllgggggggg.
+.ggggggggggggg.
+ggggggggggggggg
+ggggggggggggggg
+.ggggggggggggg.
+.ggggggggggggg.
+..ggggggggggg..
+...gggnggggg...
+.....ggnngg....
+......nnn......
+......nnn......
+......nnn......
+......nnn......
+.....nnnnn.....
+`),
+	pixel.MustSprite(`
+.....yyyyy.....
+...yyryyyyay...
+..yyyyyyryyyy..
+.yyayyyyyyyyry.
+.yyyyyryyyyyyy.
+yyyryyyyyyayyyy
+yyyyyyyyryyyyyy
+.yyyayyyyyyyry.
+.yyyyyyyyyyyyy.
+..yyyryyyyyyy..
+...yyyynyyyy...
+.....yynnyy....
+......nnn......
+......nnn......
+......nnn......
+......nnn......
+.....nnnnn.....
+`),
+	pixel.MustSprite(`
+.......l.......
+......lgl......
+.....lgggl.....
+......ggg......
+....llgggll....
+...lgggggggl...
+....ggggggg....
+...llgggggll...
+..lgggggggggl..
+...ggggggggg...
+..llgggggggll..
+.lgggggggggggl.
+lgggggggggggggl
+......nnn......
+......nnn......
+......nnn......
+.....nnnnn.....
+`),
+}
+
+// petal turns: face, tilt, edge, tilt back.
+var petal = pixel.MustSprite(`
+.A.
+AAA
+.a.
+
+..A
+.Aa
+a..
+
+...
+AAa
+...
+
+A..
+aA.
+..a
+`)
+
+// leaf turns about its stem; # takes the leaf's slot.
+var leaf = pixel.MustSprite(`
+.###.
+#####
+#####
+.###.
+..#..
+
+..##.
+.###.
+####.
+.##..
+..#..
+
+..#..
+..#..
+..#..
+..#..
+..#..
+
+.##..
+.###.
+.####
+..##.
+..#..
+`)
+
+// twinkle grows from a dot to a star.
+var twinkle = pixel.MustSprite(`
+.....
+.....
+..#..
+.....
+.....
+
+.....
+..#..
+.###.
+..#..
+.....
+
+..#..
+..#..
+#####
+..#..
+..#..
+`)
+
+// nightLit draws Lit art in Ink, bright at night.
+func nightLit(g pixel.Canvas, k pixel.Kit) pixel.Canvas {
+	if k.Palette().Night {
+		return g.Cycled([]pixel.Slot{pixel.Lit, pixel.Ink}, 1)
+	}
+	return g
+}