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ggplot_rs/geom/
spoke.rs

1use crate::aes::Aesthetic;
2use crate::coord::Coord;
3use crate::data::DataFrame;
4use crate::position::identity::PositionIdentity;
5use crate::position::Position;
6use crate::render::backend::{DrawBackend, LineStyle, Linetype};
7use crate::render::RenderError;
8use crate::scale::ScaleSet;
9use crate::stat::identity::StatIdentity;
10use crate::stat::Stat;
11use crate::theme::Theme;
12
13use super::{Geom, GeomParams};
14
15/// Spoke geometry — line segments from (x, y) with angle and radius.
16pub struct GeomSpoke {
17    pub color: (u8, u8, u8),
18    pub width: f64,
19    pub alpha: f64,
20}
21
22impl Default for GeomSpoke {
23    fn default() -> Self {
24        GeomSpoke {
25            color: (0, 0, 0),
26            width: 1.0,
27            alpha: 1.0,
28        }
29    }
30}
31
32impl Geom for GeomSpoke {
33    fn draw(
34        &self,
35        data: &DataFrame,
36        coord: &dyn Coord,
37        scales: &ScaleSet,
38        _theme: &Theme,
39        backend: &mut dyn DrawBackend,
40    ) -> Result<(), RenderError> {
41        let x_col = data
42            .column("x")
43            .ok_or(RenderError::MissingAesthetic("x".into()))?;
44        let y_col = data
45            .column("y")
46            .ok_or(RenderError::MissingAesthetic("y".into()))?;
47        let angle_col = data
48            .column("angle")
49            .ok_or(RenderError::MissingAesthetic("angle".into()))?;
50        let radius_col = data
51            .column("radius")
52            .ok_or(RenderError::MissingAesthetic("radius".into()))?;
53        let color_col = data.column("color");
54
55        let plot_area = backend.plot_area();
56        let x_scale = scales.get(&Aesthetic::X);
57        let y_scale = scales.get(&Aesthetic::Y);
58
59        for i in 0..data.nrows() {
60            let x = x_col[i].as_f64().unwrap_or(0.0);
61            let y = y_col[i].as_f64().unwrap_or(0.0);
62            let angle = angle_col[i].as_f64().unwrap_or(0.0);
63            let radius = radius_col[i].as_f64().unwrap_or(1.0);
64
65            let xend = x + radius * angle.cos();
66            let yend = y + radius * angle.sin();
67
68            let nx1 = x_scale
69                .map(|s| s.map(&crate::data::Value::Float(x)))
70                .unwrap_or(0.0);
71            let ny1 = y_scale
72                .map(|s| s.map(&crate::data::Value::Float(y)))
73                .unwrap_or(0.0);
74            let nx2 = x_scale
75                .map(|s| s.map(&crate::data::Value::Float(xend)))
76                .unwrap_or(0.0);
77            let ny2 = y_scale
78                .map(|s| s.map(&crate::data::Value::Float(yend)))
79                .unwrap_or(0.0);
80
81            let (px1, py1) = coord.transform((nx1, ny1), &plot_area);
82            let (px2, py2) = coord.transform((nx2, ny2), &plot_area);
83
84            let line_color = color_col
85                .and_then(|cc| scales.map_color(&Aesthetic::Color, &cc[i]))
86                .unwrap_or(self.color);
87
88            backend.draw_line(
89                &[(px1, py1), (px2, py2)],
90                &LineStyle {
91                    color: line_color,
92                    alpha: self.alpha,
93                    width: self.width,
94                    linetype: Linetype::Solid,
95                },
96            )?;
97        }
98
99        Ok(())
100    }
101
102    fn required_aes(&self) -> Vec<Aesthetic> {
103        vec![
104            Aesthetic::X,
105            Aesthetic::Y,
106            Aesthetic::Angle,
107            Aesthetic::Radius,
108        ]
109    }
110
111    fn default_stat(&self) -> Box<dyn Stat> {
112        Box::new(StatIdentity)
113    }
114
115    fn default_position(&self) -> Box<dyn Position> {
116        Box::new(PositionIdentity)
117    }
118
119    fn default_params(&self) -> GeomParams {
120        GeomParams::default()
121    }
122
123    fn name(&self) -> &str {
124        "spoke"
125    }
126
127    fn set_series_color(&mut self, color: (u8, u8, u8)) {
128        self.color = color;
129    }
130}