wehub-resource-sync
73 lines
1.6 KiB
Go
73 lines
1.6 KiB
Go
package ui
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import "strings"
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// renderWave draws a Braille-character oscilloscope waveform from raw audio samples.
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// Each Braille character covers a 2×4 dot grid, giving smooth sub-cell resolution.
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func (v *Visualizer) renderWave() string {
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height := v.Rows
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charCols := PanelWidth
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dotRows := height * 4
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dotCols := charCols * 2
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samples := v.waveBuf
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n := len(samples)
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// Downsample audio to one y-position per horizontal dot column.
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if cap(v.waveYBuf) >= dotCols {
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v.waveYBuf = v.waveYBuf[:dotCols]
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} else {
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v.waveYBuf = make([]int, dotCols)
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}
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ypos := v.waveYBuf
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for x := range dotCols {
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var sample float64
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if n > 0 {
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idx := x * n / dotCols
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if idx >= n {
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idx = n - 1
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}
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sample = samples[idx]
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}
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// Map sample [-1, 1] to dot row [0, dotRows-1]; center is dotRows/2.
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y := int((1.0 - sample) * float64(dotRows-1) / 2.0)
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ypos[x] = max(0, min(dotRows-1, y))
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}
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lines := make([]string, height)
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for row := range height {
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var content strings.Builder
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dotRowStart := row * 4
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for ch := range charCols {
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var braille rune = '\u2800'
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dotColStart := ch * 2
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for dc := range 2 {
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x := dotColStart + dc
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y := ypos[x]
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// Connect to previous point so the waveform is continuous.
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prevY := y
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if x > 0 {
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prevY = ypos[x-1]
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}
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yMin := min(y, prevY)
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yMax := max(y, prevY)
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for dr := range 4 {
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dotY := dotRowStart + dr
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if dotY >= yMin && dotY <= yMax {
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braille |= brailleBit[dr][dc]
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}
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}
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}
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content.WriteRune(braille)
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}
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lines[row] = specWrap(float64(height-1-row)/float64(height), content.String())
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}
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return strings.Join(lines, "\n")
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}
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