Files
Cagire/crates/ratatui/src/spectrum.rs

76 lines
2.5 KiB
Rust

//! 32-band frequency spectrum bar display.
use crate::theme;
use ratatui::buffer::Buffer;
use ratatui::layout::Rect;
use ratatui::style::Color;
use ratatui::widgets::Widget;
const BLOCKS: [char; 8] = ['\u{2581}', '\u{2582}', '\u{2583}', '\u{2584}', '\u{2585}', '\u{2586}', '\u{2587}', '\u{2588}'];
/// 32-band spectrum analyzer using block characters.
pub struct Spectrum<'a> {
data: &'a [f32; 32],
gain: f32,
}
impl<'a> Spectrum<'a> {
pub fn new(data: &'a [f32; 32]) -> Self {
Self { data, gain: 1.0 }
}
pub fn gain(mut self, g: f32) -> Self {
self.gain = g;
self
}
}
impl Widget for Spectrum<'_> {
fn render(self, area: Rect, buf: &mut Buffer) {
if area.width == 0 || area.height == 0 {
return;
}
let colors = theme::get();
let height = area.height as f32;
let base = area.width as usize / 32;
let remainder = area.width as usize % 32;
if base == 0 && remainder == 0 {
return;
}
let mut x_start = area.x;
for (band, &mag) in self.data.iter().enumerate() {
let w = base + if band < remainder { 1 } else { 0 };
if w == 0 {
continue;
}
let bar_height = (mag * self.gain).min(1.0) * height;
let full_cells = bar_height as usize;
let frac = bar_height - full_cells as f32;
let frac_idx = (frac * 8.0) as usize;
for row in 0..area.height as usize {
let y = area.y + area.height - 1 - row as u16;
let ratio = row as f32 / area.height as f32;
let color = if ratio < 0.33 {
Color::Rgb(colors.meter.low_rgb.0, colors.meter.low_rgb.1, colors.meter.low_rgb.2)
} else if ratio < 0.66 {
Color::Rgb(colors.meter.mid_rgb.0, colors.meter.mid_rgb.1, colors.meter.mid_rgb.2)
} else {
Color::Rgb(colors.meter.high_rgb.0, colors.meter.high_rgb.1, colors.meter.high_rgb.2)
};
for dx in 0..w as u16 {
let x = x_start + dx;
if row < full_cells {
buf[(x, y)].set_char(BLOCKS[7]).set_fg(color);
} else if row == full_cells && frac_idx > 0 {
buf[(x, y)].set_char(BLOCKS[frac_idx - 1]).set_fg(color);
}
}
}
x_start += w as u16;
}
}
}