ggplot_rs/geom/
path.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/// Path geometry — connects points in row order (no x-sort).
16pub struct GeomPath {
17    pub color: (u8, u8, u8),
18    pub width: f64,
19    pub alpha: f64,
20}
21
22impl Default for GeomPath {
23    fn default() -> Self {
24        GeomPath {
25            color: (0, 0, 0),
26            width: 1.5,
27            alpha: 1.0,
28        }
29    }
30}
31
32impl Geom for GeomPath {
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 color_col = data.column("color");
48        let linetype_col = data.column("linetype");
49
50        let plot_area = backend.plot_area();
51        let x_scale = scales.get(&Aesthetic::X);
52        let y_scale = scales.get(&Aesthetic::Y);
53
54        if let Some(cc) = color_col {
55            let mut groups: Vec<(String, Vec<usize>)> = Vec::new();
56            for (i, v) in cc.iter().enumerate() {
57                let key = v.to_group_key();
58                if let Some(entry) = groups.iter_mut().find(|(k, _)| k == &key) {
59                    entry.1.push(i);
60                } else {
61                    groups.push((key, vec![i]));
62                }
63            }
64
65            for (_, indices) in &groups {
66                let first_idx = indices[0];
67                let line_color = scales
68                    .map_color(&Aesthetic::Color, &cc[first_idx])
69                    .unwrap_or(self.color);
70
71                let lt = linetype_col
72                    .and_then(|lc| scales.map_linetype(&lc[first_idx]))
73                    .unwrap_or(Linetype::Solid);
74
75                let points: Vec<(f64, f64)> = indices
76                    .iter()
77                    .map(|&i| {
78                        let nx = x_scale.map(|s| s.map(&x_col[i])).unwrap_or(0.0);
79                        let ny = y_scale.map(|s| s.map(&y_col[i])).unwrap_or(0.0);
80                        coord.transform((nx, ny), &plot_area)
81                    })
82                    .collect();
83
84                if points.len() >= 2 {
85                    backend.draw_line(
86                        &points,
87                        &LineStyle {
88                            color: line_color,
89                            alpha: self.alpha,
90                            width: self.width,
91                            linetype: lt,
92                        },
93                    )?;
94                }
95            }
96        } else {
97            let lt = linetype_col
98                .and_then(|lc| {
99                    if lc.is_empty() {
100                        None
101                    } else {
102                        scales.map_linetype(&lc[0])
103                    }
104                })
105                .unwrap_or(Linetype::Solid);
106
107            let points: Vec<(f64, f64)> = (0..data.nrows())
108                .map(|i| {
109                    let nx = x_scale.map(|s| s.map(&x_col[i])).unwrap_or(0.0);
110                    let ny = y_scale.map(|s| s.map(&y_col[i])).unwrap_or(0.0);
111                    coord.transform((nx, ny), &plot_area)
112                })
113                .collect();
114
115            if points.len() >= 2 {
116                backend.draw_line(
117                    &points,
118                    &LineStyle {
119                        color: self.color,
120                        alpha: self.alpha,
121                        width: self.width,
122                        linetype: lt,
123                    },
124                )?;
125            }
126        }
127
128        Ok(())
129    }
130
131    fn required_aes(&self) -> Vec<Aesthetic> {
132        vec![Aesthetic::X, Aesthetic::Y]
133    }
134
135    fn default_stat(&self) -> Box<dyn Stat> {
136        Box::new(StatIdentity)
137    }
138
139    fn default_position(&self) -> Box<dyn Position> {
140        Box::new(PositionIdentity)
141    }
142
143    fn default_params(&self) -> GeomParams {
144        GeomParams::default()
145    }
146
147    fn name(&self) -> &str {
148        "path"
149    }
150
151    fn set_series_color(&mut self, color: (u8, u8, u8)) {
152        self.color = color;
153    }
154}
ggplot_rs/geom/path.rs

ggplot_rs/geom/
path.rs
