84 lines
2.3 KiB
Rust
84 lines
2.3 KiB
Rust
use crate::theme;
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use ratatui::buffer::Buffer;
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use ratatui::layout::Rect;
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use ratatui::style::Color;
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use ratatui::widgets::Widget;
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const DB_MIN: f32 = -48.0;
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const DB_MAX: f32 = 3.0;
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const DB_RANGE: f32 = DB_MAX - DB_MIN;
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pub struct VuMeter {
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left: f32,
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right: f32,
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}
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impl VuMeter {
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pub fn new(left: f32, right: f32) -> Self {
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Self { left, right }
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}
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fn amplitude_to_db(amp: f32) -> f32 {
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if amp <= 0.0 {
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DB_MIN
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} else {
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(20.0 * amp.log10()).clamp(DB_MIN, DB_MAX)
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}
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}
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fn db_to_normalized(db: f32) -> f32 {
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(db - DB_MIN) / DB_RANGE
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}
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fn row_to_color(row_position: f32, colors: &theme::ThemeColors) -> Color {
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if row_position > 0.9 {
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colors.meter.high
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} else if row_position > 0.75 {
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colors.meter.mid
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} else {
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colors.meter.low
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}
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}
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}
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impl Widget for VuMeter {
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fn render(self, area: Rect, buf: &mut Buffer) {
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if area.width < 3 || area.height == 0 {
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return;
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}
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let colors = theme::get();
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let height = area.height as usize;
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let half_width = area.width / 2;
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let gap = 1u16;
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let left_db = Self::amplitude_to_db(self.left);
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let right_db = Self::amplitude_to_db(self.right);
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let left_norm = Self::db_to_normalized(left_db);
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let right_norm = Self::db_to_normalized(right_db);
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let left_rows = (left_norm * height as f32).round() as usize;
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let right_rows = (right_norm * height as f32).round() as usize;
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for row in 0..height {
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let y = area.y + area.height - 1 - row as u16;
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let row_position = (row as f32 + 0.5) / height as f32;
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let color = Self::row_to_color(row_position, &colors);
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for col in 0..half_width.saturating_sub(gap) {
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let x = area.x + col;
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if row < left_rows {
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buf[(x, y)].set_char(' ').set_bg(color);
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}
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}
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for col in 0..half_width.saturating_sub(gap) {
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let x = area.x + half_width + gap + col;
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if x < area.x + area.width && row < right_rows {
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buf[(x, y)].set_char(' ').set_bg(color);
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}
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}
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}
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}
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}
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