Improve plot item UX (#1816)

* initial work

* changelog entry

* fix CI

* Update egui/src/widgets/plot/items/values.rs

Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>

* Update egui/src/widgets/plot/items/values.rs

Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>

* derive 'FromIterator'

* remove `bytemuck` dependency again and remove borrowing plot points for now

* update doctest

* update documentation

* remove unnecessary numeric cast

* cargo fmt

* Update egui/src/widgets/plot/items/values.rs

Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>

Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>

CHANGELOG.md

@@ -22,6 +22,7 @@ NOTE: [`epaint`](epaint/CHANGELOG.md), [`eframe`](eframe/CHANGELOG.md), [`egui-w
 * `PaintCallback` shapes now require the whole callback to be put in an `Arc<dyn Any>` with the value being a backend-specific callback type ([#1684](https://github.com/emilk/egui/pull/1684)).
 * Replaced `needs_repaint` in `FullOutput` with `repaint_after`. Used to force repaint after the set duration in reactive mode ([#1694](https://github.com/emilk/egui/pull/1694)).
 * `Layout::left_to_right` and `Layout::right_to_left` now takes the vertical align as an argument. Previous default was `Align::Center`.
+* Improved ergonomics of adding plot items. All plot items that take a series of 2D coordinates can now be created directly from `Vec<[f64; 2]>`. The `Value` and `Values` types were removed in favor of `PlotPoint` and `PlotPoints` respectively.
 
 ### Fixed 🐛
 * Fixed `Response::changed` for `ui.toggle_value` ([#1573](https://github.com/emilk/egui/pull/1573)).

eframe/src/epi.rs

@@ -374,7 +374,7 @@ impl Theme {
 
 // ----------------------------------------------------------------------------
 
-/// `WebGl` Context options
+/// WebGL Context options
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
 pub enum WebGlContextOption {

egui/src/widgets/plot/items/bar.rs

@@ -2,7 +2,7 @@ use crate::emath::NumExt;
 use crate::epaint::{Color32, RectShape, Rounding, Shape, Stroke};
 
 use super::{add_rulers_and_text, highlighted_color, Orientation, PlotConfig, RectElement};
-use crate::plot::{BarChart, ScreenTransform, Value};
+use crate::plot::{BarChart, PlotPoint, ScreenTransform};
 
 /// One bar in a [`BarChart`]. Potentially floating, allowing stacked bar charts.
 /// Width can be changed to allow variable-width histograms.
@@ -157,15 +157,15 @@ impl RectElement for Bar {
         self.name.as_str()
     }
 
-    fn bounds_min(&self) -> Value {
+    fn bounds_min(&self) -> PlotPoint {
         self.point_at(self.argument - self.bar_width / 2.0, self.lower())
     }
 
-    fn bounds_max(&self) -> Value {
+    fn bounds_max(&self) -> PlotPoint {
         self.point_at(self.argument + self.bar_width / 2.0, self.upper())
     }
 
-    fn values_with_ruler(&self) -> Vec<Value> {
+    fn values_with_ruler(&self) -> Vec<PlotPoint> {
         let base = self.base_offset.unwrap_or(0.0);
         let value_center = self.point_at(self.argument, base + self.value);
 

egui/src/widgets/plot/items/box_elem.rs

@@ -2,7 +2,7 @@ use crate::emath::NumExt;
 use crate::epaint::{Color32, RectShape, Rounding, Shape, Stroke};
 
 use super::{add_rulers_and_text, highlighted_color, Orientation, PlotConfig, RectElement};
-use crate::plot::{BoxPlot, ScreenTransform, Value};
+use crate::plot::{BoxPlot, PlotPoint, ScreenTransform};
 
 /// Contains the values of a single box in a box plot.
 #[derive(Clone, Debug, PartialEq)]
@@ -161,8 +161,8 @@ impl BoxElem {
         let line_between = |v1, v2| {
             Shape::line_segment(
                 [
-                    transform.position_from_value(&v1),
-                    transform.position_from_value(&v2),
+                    transform.position_from_point(&v1),
+                    transform.position_from_point(&v2),
                 ],
                 stroke,
             )
@@ -236,19 +236,19 @@ impl RectElement for BoxElem {
         self.name.as_str()
     }
 
-    fn bounds_min(&self) -> Value {
+    fn bounds_min(&self) -> PlotPoint {
         let argument = self.argument - self.box_width.max(self.whisker_width) / 2.0;
         let value = self.spread.lower_whisker;
         self.point_at(argument, value)
     }
 
-    fn bounds_max(&self) -> Value {
+    fn bounds_max(&self) -> PlotPoint {
         let argument = self.argument + self.box_width.max(self.whisker_width) / 2.0;
         let value = self.spread.upper_whisker;
         self.point_at(argument, value)
     }
 
-    fn values_with_ruler(&self) -> Vec<Value> {
+    fn values_with_ruler(&self) -> Vec<PlotPoint> {
         let median = self.point_at(self.argument, self.spread.median);
         let q1 = self.point_at(self.argument, self.spread.quartile1);
         let q3 = self.point_at(self.argument, self.spread.quartile3);
@@ -262,7 +262,7 @@ impl RectElement for BoxElem {
         self.orientation
     }
 
-    fn corner_value(&self) -> Value {
+    fn corner_value(&self) -> PlotPoint {
         self.point_at(self.argument, self.spread.upper_whisker)
     }