Feat: UI / UX improvements once more (mouse)

crates/ratatui/src/lissajous.rs

@@ -9,6 +9,13 @@ use std::cell::RefCell;
 
 thread_local! {
     static PATTERNS: RefCell<Vec<u8>> = const { RefCell::new(Vec::new()) };
+    static TRAIL: RefCell<TrailState> = const { RefCell::new(TrailState { fine_w: 0, fine_h: 0, heat: Vec::new() }) };
+}
+
+struct TrailState {
+    fine_w: usize,
+    fine_h: usize,
+    heat: Vec<f32>,
 }
 
 /// XY oscilloscope plotting left vs right channels as a Lissajous curve.
@@ -17,6 +24,7 @@ pub struct Lissajous<'a> {
     right: &'a [f32],
     color: Option<Color>,
     gain: f32,
+    trails: bool,
 }
 
 impl<'a> Lissajous<'a> {
@@ -26,9 +34,15 @@ impl<'a> Lissajous<'a> {
             right,
             color: None,
             gain: 1.0,
+            trails: false,
         }
     }
 
+    pub fn trails(mut self, enabled: bool) -> Self {
+        self.trails = enabled;
+        self
+    }
+
     pub fn color(mut self, c: Color) -> Self {
         self.color = Some(c);
         self
@@ -46,6 +60,16 @@ impl Widget for Lissajous<'_> {
             return;
         }
 
+        if self.trails {
+            self.render_trails(area, buf);
+        } else {
+            self.render_normal(area, buf);
+        }
+    }
+}
+
+impl Lissajous<'_> {
+    fn render_normal(self, area: Rect, buf: &mut Buffer) {
         let color = self.color.unwrap_or_else(|| theme::get().meter.low);
         let width = area.width as usize;
         let height = area.height as usize;
@@ -63,7 +87,6 @@ impl Widget for Lissajous<'_> {
                 let l = (self.left[i] * self.gain).clamp(-1.0, 1.0);
                 let r = (self.right[i] * self.gain).clamp(-1.0, 1.0);
 
-                // X = right channel, Y = left channel (inverted so up = positive)
                 let fine_x = ((r + 1.0) * 0.5 * (fine_width - 1) as f32).round() as usize;
                 let fine_y = ((1.0 - l) * 0.5 * (fine_height - 1) as f32).round() as usize;
                 let fine_x = fine_x.min(fine_width - 1);
@@ -74,19 +97,7 @@ impl Widget for Lissajous<'_> {
                 let dot_x = fine_x % 2;
                 let dot_y = fine_y % 4;
 
-                let bit = match (dot_x, dot_y) {
-                    (0, 0) => 0x01,
-                    (0, 1) => 0x02,
-                    (0, 2) => 0x04,
-                    (0, 3) => 0x40,
-                    (1, 0) => 0x08,
-                    (1, 1) => 0x10,
-                    (1, 2) => 0x20,
-                    (1, 3) => 0x80,
-                    _ => unreachable!(),
-                };
-
-                patterns[char_y * width + char_x] |= bit;
+                patterns[char_y * width + char_x] |= braille_bit(dot_x, dot_y);
             }
 
             for cy in 0..height {
@@ -102,4 +113,122 @@ impl Widget for Lissajous<'_> {
             }
         });
     }
+
+    fn render_trails(self, area: Rect, buf: &mut Buffer) {
+        let theme = theme::get();
+        let width = area.width as usize;
+        let height = area.height as usize;
+        let fine_w = width * 2;
+        let fine_h = height * 4;
+        let len = self.left.len().min(self.right.len());
+
+        TRAIL.with(|t| {
+            let mut trail = t.borrow_mut();
+
+            // Reset if dimensions changed
+            if trail.fine_w != fine_w || trail.fine_h != fine_h {
+                trail.fine_w = fine_w;
+                trail.fine_h = fine_h;
+                trail.heat.clear();
+                trail.heat.resize(fine_w * fine_h, 0.0);
+            }
+
+            // Decay existing heat
+            for h in trail.heat.iter_mut() {
+                *h *= 0.85;
+            }
+
+            // Plot new sample points
+            for i in 0..len {
+                let l = (self.left[i] * self.gain).clamp(-1.0, 1.0);
+                let r = (self.right[i] * self.gain).clamp(-1.0, 1.0);
+
+                let fx = ((r + 1.0) * 0.5 * (fine_w - 1) as f32).round() as usize;
+                let fy = ((1.0 - l) * 0.5 * (fine_h - 1) as f32).round() as usize;
+                let fx = fx.min(fine_w - 1);
+                let fy = fy.min(fine_h - 1);
+
+                trail.heat[fy * fine_w + fx] = 1.0;
+            }
+
+            // Convert heat map to braille
+            PATTERNS.with(|p| {
+                let mut patterns = p.borrow_mut();
+                patterns.clear();
+                patterns.resize(width * height, 0);
+
+                // Track brightest color per cell
+                let mut colors: Vec<Option<Color>> = vec![None; width * height];
+
+                for fy in 0..fine_h {
+                    for fx in 0..fine_w {
+                        let h = trail.heat[fy * fine_w + fx];
+                        if h < 0.05 {
+                            continue;
+                        }
+
+                        let cx = fx / 2;
+                        let cy = fy / 4;
+                        let dx = fx % 2;
+                        let dy = fy % 4;
+
+                        let idx = cy * width + cx;
+                        patterns[idx] |= braille_bit(dx, dy);
+
+                        let dot_color = if h > 0.7 {
+                            theme.meter.high
+                        } else if h > 0.25 {
+                            theme.meter.mid
+                        } else {
+                            theme.meter.low
+                        };
+
+                        let replace = match colors[idx] {
+                            None => true,
+                            Some(cur) => {
+                                rank_color(dot_color, &theme) > rank_color(cur, &theme)
+                            }
+                        };
+                        if replace {
+                            colors[idx] = Some(dot_color);
+                        }
+                    }
+                }
+
+                for cy in 0..height {
+                    for cx in 0..width {
+                        let idx = cy * width + cx;
+                        let pattern = patterns[idx];
+                        if pattern != 0 {
+                            let ch = char::from_u32(0x2800 + pattern as u32).unwrap_or(' ');
+                            let color = colors[idx].unwrap_or(theme.meter.low);
+                            buf[(area.x + cx as u16, area.y + cy as u16)]
+                                .set_char(ch)
+                                .set_fg(color);
+                        }
+                    }
+                }
+            });
+        });
+    }
+}
+
+fn braille_bit(dot_x: usize, dot_y: usize) -> u8 {
+    match (dot_x, dot_y) {
+        (0, 0) => 0x01,
+        (0, 1) => 0x02,
+        (0, 2) => 0x04,
+        (0, 3) => 0x40,
+        (1, 0) => 0x08,
+        (1, 1) => 0x10,
+        (1, 2) => 0x20,
+        (1, 3) => 0x80,
+        _ => unreachable!(),
+    }
+}
+
+fn rank_color(c: Color, theme: &crate::theme::ThemeColors) -> u8 {
+    if c == theme.meter.high { 2 }
+    else if c == theme.meter.mid { 1 }
+    else { 0 }
 }