rustmotion_components/
audio_spectrum.rs

1use schemars::JsonSchema;
2use serde::{Deserialize, Serialize};
3use skia_safe::{Canvas, Color, Paint, PaintStyle, Point, Rect};
4
5use rustmotion_core::css::CssStyle;
6use rustmotion_core::engine::animator::AnimatedProperties;
7use rustmotion_core::engine::layout_pass::BoxLayout;
8use rustmotion_core::engine::renderer::audio_analysis::audio_analysis_cache;
9use rustmotion_core::engine::renderer::parse_hex_color;
10use rustmotion_core::schema::TimelineStep;
11use rustmotion_core::traits::{PaintCtx, Painter, TimingConfig};
12
13fn default_bars() -> u32 {
14    16
15}
16fn default_color() -> String {
17    "#38bdf8".to_string()
18}
19fn default_bar_gap() -> f32 {
20    2.0
21}
22fn default_min_height() -> f32 {
23    2.0
24}
25
26#[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize, JsonSchema)]
27#[serde(rename_all = "snake_case")]
28pub enum SpectrumMode {
29    #[default]
30    Bars,
31    Radial,
32}
33
34#[derive(Debug, Serialize, Deserialize, JsonSchema)]
35pub struct AudioSpectrum {
36    /// Source audio track (src path). If None, uses the first track in the cache.
37    #[serde(default)]
38    pub track: Option<String>,
39    /// Number of frequency bars to display (resampled from 16 internal bands).
40    #[serde(default = "default_bars")]
41    pub bars: u32,
42    /// Display mode: bars (vertical) or radial.
43    #[serde(default)]
44    pub mode: SpectrumMode,
45    /// Bar color as hex string.
46    #[serde(default = "default_color")]
47    pub color: String,
48    /// Gap between bars in pixels.
49    #[serde(default = "default_bar_gap")]
50    pub bar_gap: f32,
51    /// Minimum bar height in pixels.
52    #[serde(default = "default_min_height")]
53    pub min_height: f32,
54    #[serde(flatten)]
55    pub timing: TimingConfig,
56    #[serde(default)]
57    pub style: CssStyle,
58    #[serde(default)]
59    pub timeline: Vec<TimelineStep>,
60    #[serde(default)]
61    pub stagger: Option<f32>,
62}
63
64rustmotion_core::impl_traits!(AudioSpectrum {
65    Animatable => animation,
66    Timed => timing,
67    Styled => style,
68});
69
70impl AudioSpectrum {
71    fn get_band_values(&self, time: f64) -> Vec<f32> {
72        let cache = audio_analysis_cache();
73        let analysis = if let Some(ref src) = self.track {
74            cache.get(src).map(|r| r.clone())
75        } else {
76            cache.iter().next().map(|r| r.value().clone())
77        };
78
79        let n = self.bars.max(1) as usize;
80
81        // Empty cache / missing track → all-zero values; the painter clamps
82        // each bar to `min_height`, so this degrades to a flat baseline.
83        let Some(analysis) = analysis else {
84            return vec![0.0; n];
85        };
86
87        // Resample from 16 bands to n bars
88        let num_bands = 16usize;
89        (0..n)
90            .map(|i| {
91                let band_f = i as f32 * (num_bands as f32 - 1.0) / (n as f32 - 1.0).max(1.0);
92                let band_lo = band_f as usize;
93                let band_hi = (band_lo + 1).min(num_bands - 1);
94                let frac = band_f - band_lo as f32;
95                let v_lo = analysis.band_at(time, band_lo as u8);
96                let v_hi = analysis.band_at(time, band_hi as u8);
97                v_lo * (1.0 - frac) + v_hi * frac
98            })
99            .collect()
100    }
101}
102
103impl Painter for AudioSpectrum {
104    fn paint_content(
105        &self,
106        canvas: &Canvas,
107        layout: &BoxLayout,
108        _props: &AnimatedProperties,
109        ctx: &PaintCtx,
110    ) {
111        let w = layout.width;
112        let h = layout.height;
113        let n = self.bars.max(1) as usize;
114        let values = self.get_band_values(ctx.scenario_time);
115        let (r, g, b, a) = parse_hex_color(&self.color);
116        let color = Color::from_argb(a, r, g, b);
117
118        match self.mode {
119            SpectrumMode::Bars => {
120                let total_gap = self.bar_gap * (n as f32 - 1.0);
121                let bar_w = ((w - total_gap) / n as f32).max(1.0);
122                let mut paint = Paint::default();
123                paint.set_color(color);
124                paint.set_style(PaintStyle::Fill);
125                paint.set_anti_alias(true);
126
127                for (i, &v) in values.iter().enumerate() {
128                    let bar_h = (v * h).max(self.min_height);
129                    let x = i as f32 * (bar_w + self.bar_gap);
130                    let y = h - bar_h;
131                    canvas.draw_rect(Rect::from_xywh(x, y, bar_w, bar_h), &paint);
132                }
133            }
134            SpectrumMode::Radial => {
135                let cx = w / 2.0;
136                let cy = h / 2.0;
137                let max_r = cx.min(cy);
138                let inner_r = max_r * 0.3;
139
140                let mut paint = Paint::default();
141                paint.set_color(color);
142                paint.set_style(PaintStyle::Stroke);
143                paint.set_stroke_width(2.0);
144                paint.set_anti_alias(true);
145
146                for (i, &v) in values.iter().enumerate() {
147                    let angle = (i as f32 / n as f32) * 2.0 * std::f32::consts::PI;
148                    let bar_len = (v * (max_r - inner_r)).max(self.min_height);
149                    let x0 = cx + inner_r * angle.cos();
150                    let y0 = cy + inner_r * angle.sin();
151                    let x1 = cx + (inner_r + bar_len) * angle.cos();
152                    let y1 = cy + (inner_r + bar_len) * angle.sin();
153                    canvas.draw_line(Point::new(x0, y0), Point::new(x1, y1), &paint);
154                }
155            }
156        }
157    }
158}
rustmotion_components/audio_spectrum.rs

rustmotion_components/
audio_spectrum.rs
