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ggplot_rs/geom/
point.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, PointShape, PointStyle};
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/// Scatter plot points.
16pub struct GeomPoint {
17    pub size: f64,
18    pub color: (u8, u8, u8),
19    pub alpha: f64,
20}
21
22impl Default for GeomPoint {
23    fn default() -> Self {
24        GeomPoint {
25            size: 3.0,
26            color: (0, 0, 0),
27            alpha: 1.0,
28        }
29    }
30}
31
32impl Geom for GeomPoint {
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 size_col = data.column("size");
49        let alpha_col = data.column("alpha");
50        let shape_col = data.column("shape");
51
52        let plot_area = backend.plot_area();
53        let x_scale = scales.get(&Aesthetic::X);
54        let y_scale = scales.get(&Aesthetic::Y);
55
56        for i in 0..data.nrows() {
57            let nx = x_scale.map(|s| s.map(&x_col[i])).unwrap_or(0.0);
58            let ny = y_scale.map(|s| s.map(&y_col[i])).unwrap_or(0.0);
59            let (px, py) = coord.transform((nx, ny), &plot_area);
60
61            let (r, g, b) = if let Some(cc) = color_col {
62                scales
63                    .map_color(&Aesthetic::Color, &cc[i])
64                    .unwrap_or(self.color)
65            } else {
66                self.color
67            };
68
69            let alpha = alpha_col
70                .and_then(|c| scales.map_alpha(&c[i]))
71                .or_else(|| alpha_col.and_then(|c| c[i].as_f64()))
72                .unwrap_or(self.alpha);
73
74            let size = size_col
75                .and_then(|c| scales.map_size(&c[i]))
76                .or_else(|| size_col.and_then(|c| c[i].as_f64()))
77                .unwrap_or(self.size);
78
79            let shape = shape_col
80                .and_then(|c| scales.map_shape(&c[i]))
81                .unwrap_or(PointShape::Circle);
82
83            backend.draw_shape(
84                (px, py),
85                size,
86                &PointStyle {
87                    color: (r, g, b),
88                    alpha,
89                    filled: true,
90                    shape,
91                },
92            )?;
93        }
94
95        Ok(())
96    }
97
98    fn required_aes(&self) -> Vec<Aesthetic> {
99        vec![Aesthetic::X, Aesthetic::Y]
100    }
101
102    fn default_stat(&self) -> Box<dyn Stat> {
103        Box::new(StatIdentity)
104    }
105
106    fn default_position(&self) -> Box<dyn Position> {
107        Box::new(PositionIdentity)
108    }
109
110    fn default_params(&self) -> GeomParams {
111        GeomParams::default()
112    }
113
114    fn name(&self) -> &str {
115        "point"
116    }
117
118    fn set_series_color(&mut self, color: (u8, u8, u8)) {
119        self.color = color;
120    }
121}