opencode/packages/tui/internal/util/shimmer.go
2025-08-18 05:55:01 -05:00

143 lines
2.9 KiB
Go

package util
import (
"math"
"os"
"strings"
"time"
"github.com/charmbracelet/lipgloss/v2"
"github.com/charmbracelet/lipgloss/v2/compat"
"github.com/sst/opencode/internal/styles"
)
var shimmerStart = time.Now()
// Shimmer renders text with a moving foreground highlight.
// bg is the background color, dim is the base text color, bright is the highlight color.
func Shimmer(s string, bg compat.AdaptiveColor, _ compat.AdaptiveColor, _ compat.AdaptiveColor) string {
if s == "" {
return ""
}
runes := []rune(s)
n := len(runes)
if n == 0 {
return s
}
pad := 10
period := float64(n + pad*2)
sweep := 2.5
elapsed := time.Since(shimmerStart).Seconds()
pos := (math.Mod(elapsed, sweep) / sweep) * period
half := 4.0
type seg struct {
useHex bool
hex string
bold bool
faint bool
text string
}
var segs []seg
useHex := hasTrueColor()
for i, r := range runes {
ip := float64(i + pad)
dist := math.Abs(ip - pos)
t := 0.0
if dist <= half {
x := math.Pi * (dist / half)
t = 0.5 * (1.0 + math.Cos(x))
}
// Cosine brightness: base + amp*t (quantized for grouping)
base := 0.55
amp := 0.45
brightness := base
if t > 0 {
brightness = base + amp*t
}
lvl := int(math.Round(brightness * 255.0))
if !useHex {
step := 24 // ~11 steps across range for non-truecolor
lvl = int(math.Round(float64(lvl)/float64(step))) * step
}
bold := lvl >= 208
faint := lvl <= 128
// truecolor if possible; else fallback to modifiers only
hex := ""
if useHex {
if lvl < 0 {
lvl = 0
}
if lvl > 255 {
lvl = 255
}
hex = rgbHex(lvl, lvl, lvl)
}
if len(segs) == 0 {
segs = append(segs, seg{useHex: useHex, hex: hex, bold: bold, faint: faint, text: string(r)})
} else {
last := &segs[len(segs)-1]
if last.useHex == useHex && last.hex == hex && last.bold == bold && last.faint == faint {
last.text += string(r)
} else {
segs = append(segs, seg{useHex: useHex, hex: hex, bold: bold, faint: faint, text: string(r)})
}
}
}
var b strings.Builder
for _, g := range segs {
st := styles.NewStyle().Background(bg)
if g.useHex && g.hex != "" {
c := compat.AdaptiveColor{Dark: lipgloss.Color(g.hex), Light: lipgloss.Color(g.hex)}
st = st.Foreground(c)
}
if g.bold {
st = st.Bold(true)
}
if g.faint {
st = st.Faint(true)
}
b.WriteString(st.Render(g.text))
}
return b.String()
}
func hasTrueColor() bool {
c := strings.ToLower(os.Getenv("COLORTERM"))
return strings.Contains(c, "truecolor") || strings.Contains(c, "24bit")
}
func rgbHex(r, g, b int) string {
if r < 0 {
r = 0
}
if r > 255 {
r = 255
}
if g < 0 {
g = 0
}
if g > 255 {
g = 255
}
if b < 0 {
b = 0
}
if b > 255 {
b = 255
}
return "#" + hex2(r) + hex2(g) + hex2(b)
}
func hex2(v int) string {
const digits = "0123456789abcdef"
return string([]byte{digits[(v>>4)&0xF], digits[v&0xF]})
}