feat: add support for segmented line and scatter (#33)

Author: 0xb-s

egui_plot/src/items/columnar_series.rs

@@ -1,9 +1,8 @@
 #![allow(rustdoc::missing_crate_level_docs)]
+use crate::transform::PlotBounds;
 use core::fmt;
 use core::ops::{Bound, RangeBounds};
 
-use crate::transform::PlotBounds;
-
 /// A zero-copy Series of `(x, y)`.
 ///
 /// This is the canonical way to pass data into plotting items without packing
@@ -83,6 +82,7 @@ impl<'a> ColumnarSeries<'a> {
     }
 
     /// Return an iterator over `(x, y)` pairs (by value).
+    #[allow(clippy::iter_without_into_iter)]
     #[inline]
     pub fn iter(&self) -> ColumnarSeriesIter<'a> {
         ColumnarSeriesIter {

egui_plot/src/items/geom_helpers.rs

@@ -0,0 +1,47 @@
+use egui::{Color32, Pos2, Shape, Stroke, Vec2};
+use std::f32::consts::PI;
+
+#[inline]
+pub fn regular_ngon(n: usize, r: f32, angle_rad: f32) -> Vec<Pos2> {
+    let n = n.max(3);
+    (0..n)
+        .map(|k| {
+            let a = angle_rad + 2.0 * PI * (k as f32) / (n as f32);
+            Pos2::new(a.cos() * r, a.sin() * r)
+        })
+        .collect()
+}
+
+#[inline]
+pub fn star_ngon(n: usize, r_outer: f32, r_inner: f32, angle_rad: f32) -> Vec<Pos2> {
+    let n = n.max(2);
+    let mut pts = Vec::with_capacity(n * 2);
+    for k in 0..n {
+        let a_outer = angle_rad + 2.0 * PI * (k as f32) / (n as f32);
+        let a_inner = a_outer + PI / (n as f32);
+        pts.push(Pos2::new(a_outer.cos() * r_outer, a_outer.sin() * r_outer));
+        pts.push(Pos2::new(a_inner.cos() * r_inner, a_inner.sin() * r_inner));
+    }
+    pts
+}
+
+pub fn push_polygon_at(
+    out: &mut Vec<Shape>,
+    center: Pos2,
+    local_pts: Vec<Vec2>,
+    color: Color32,
+    stroke: Stroke,
+    filled: bool,
+) {
+    let pts: Vec<Pos2> = local_pts.into_iter().map(|v| center + v).collect();
+    if filled {
+        out.push(Shape::convex_polygon(pts, color, Stroke::NONE));
+    } else {
+        out.push(Shape::closed_line(pts, Stroke::new(stroke.width, color)));
+    }
+}
+// #[inline]
+// //todo
+// pub fn degree_to_radius(d: i16) -> f32 {
+//     (d as f32) * PI / 180.0
+// }