Mix colours

svldplotter/src/plot.rs

@@ -1,5 +1,6 @@
 use eframe::egui;
-use egui::Vec2b;
+use egui::ecolor::Hsva;
+use egui::{Color32, Vec2b};
 use egui_plot::{AxisHints, Legend, Line, Plot, PlotPoints, VPlacement};
 
 use crate::signal::{decimate, nearest_y, PlottedSignal};
@@ -40,6 +41,12 @@ fn full_x_range(signals: &[PlottedSignal]) -> (f64, f64) {
     (min, max)
 }
 
+fn color_for(id: u64) -> Color32 {
+    let mixed = (id.wrapping_mul(2654435761)) as u32;
+    let hue = mixed as f32 / u32::MAX as f32;
+    Hsva::new(hue, 0.85, 0.9, 1.0).into()
+}
+
 fn line_label(sig: &PlottedSignal, cursor_x: Option<f64>) -> String {
     let unit_suffix = if sig.unit.is_empty() {
         String::new()
@@ -117,7 +124,7 @@ pub fn show_plot_panel(
                     decimate(&sig.points, x_min, x_max, pixel_width.max(1), &mut buf);
                     let plot_points = PlotPoints::Owned(std::mem::take(&mut buf));
                     let name = line_label(sig, prev_cursor_x);
-                    plot_ui.line(Line::new(name, plot_points));
+                    plot_ui.line(Line::new(name, plot_points).color(color_for(sig.id)));
                 }
                 plot_ui.pointer_coordinate().map(|c| c.x)
             });