64 lines
1.3 KiB
Go
64 lines
1.3 KiB
Go
// Package text draws words in the pixel font.
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package text
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import (
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"fmt"
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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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// block is a w×h dot text box that fn draws.
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func block(c *ui.Context, k pixel.Kit, s string, w, h int, fn func(g pixel.Canvas)) *ui.Element {
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return ui.Box(c).Size(k.D(w), k.D(h)).Label(s).Role(ui.RoleText).Draw(func(p *ui.Painter, r ui.Rect) {
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fn(k.Canvas(p, r))
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})
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}
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// orDef is v, or def for zero; negative panics.
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func orDef(name string, v, def int) int {
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if v < 0 {
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panic(fmt.Sprintf("text: %s %d is negative", name, v))
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}
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if v == 0 {
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return def
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}
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return v
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}
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// scale is s, or 1 for zero; outside 1–4 panics.
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func scale(s int) int {
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s = orDef("Scale", s, 1)
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if s > 4 {
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panic(fmt.Sprintf("text: Scale %d outside 1–4", s))
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}
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return s
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}
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// slotOr is s, or def for the zero slot.
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func slotOr(s, def pixel.Slot) pixel.Slot {
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if s == pixel.Ink {
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return def
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}
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return s
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}
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// each walks s rune by rune, with x in dots.
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func each(s string, sc int, fn func(i int, r rune, x int)) {
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i, x := 0, 0
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for _, r := range s {
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fn(i, r, x)
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x += pixel.Measure(string(r)) * sc
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i++
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}
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}
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// noise is a seeded hash for jitter and scrambles.
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func noise(seed, i, step int) uint32 {
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x := uint32(seed*73856093 ^ i*19349663 ^ step*83492791)
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x ^= x >> 13
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x *= 0x5bd1e995
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return x ^ x>>15
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}
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