plotters/element/
points.rs

1use super::*;
2use super::{Drawable, PointCollection};
3use crate::style::{Color, ShapeStyle, SizeDesc};
4use plotters_backend::{BackendCoord, DrawingBackend, DrawingErrorKind};
5
6/**
7A common trait for elements that can be interpreted as points: A cross, a circle, a triangle marker...
8
9This is used internally by Plotters and should probably not be included in user code.
10See [`EmptyElement`] for more information and examples.
11*/
12pub trait PointElement<Coord, Size: SizeDesc> {
13    /**
14    Point creator.
15
16    This is used internally by Plotters and should probably not be included in user code.
17    See [`EmptyElement`] for more information and examples.
18    */
19    fn make_point(pos: Coord, size: Size, style: ShapeStyle) -> Self;
20}
21
22/**
23A cross marker for visualizing data series.
24
25See [`EmptyElement`] for more information and examples.
26*/
27pub struct Cross<Coord, Size: SizeDesc> {
28    center: Coord,
29    size: Size,
30    style: ShapeStyle,
31}
32
33impl<Coord, Size: SizeDesc> Cross<Coord, Size> {
34    /**
35    Creates a cross marker.
36
37    See [`EmptyElement`] for more information and examples.
38    */
39    pub fn new<T: Into<ShapeStyle>>(coord: Coord, size: Size, style: T) -> Self {
40        Self {
41            center: coord,
42            size,
43            style: style.into(),
44        }
45    }
46}
47
48impl<'a, Coord: 'a, Size: SizeDesc> PointCollection<'a, Coord> for &'a Cross<Coord, Size> {
49    type Point = &'a Coord;
50    type IntoIter = std::iter::Once<&'a Coord>;
51    fn point_iter(self) -> std::iter::Once<&'a Coord> {
52        std::iter::once(&self.center)
53    }
54}
55
56impl<Coord, DB: DrawingBackend, Size: SizeDesc> Drawable<DB> for Cross<Coord, Size> {
57    fn draw<I: Iterator<Item = BackendCoord>>(
58        &self,
59        mut points: I,
60        backend: &mut DB,
61        ps: (u32, u32),
62    ) -> Result<(), DrawingErrorKind<DB::ErrorType>> {
63        if let Some((x, y)) = points.next() {
64            let size = self.size.in_pixels(&ps);
65            let (x0, y0) = (x - size, y - size);
66            let (x1, y1) = (x + size, y + size);
67            backend.draw_line((x0, y0), (x1, y1), &self.style)?;
68            backend.draw_line((x0, y1), (x1, y0), &self.style)?;
69        }
70        Ok(())
71    }
72}
73
74/**
75A triangle marker for visualizing data series.
76
77See [`EmptyElement`] for more information and examples.
78*/
79pub struct TriangleMarker<Coord, Size: SizeDesc> {
80    center: Coord,
81    size: Size,
82    style: ShapeStyle,
83}
84
85impl<Coord, Size: SizeDesc> TriangleMarker<Coord, Size> {
86    /**
87    Creates a triangle marker.
88
89    See [`EmptyElement`] for more information and examples.
90    */
91    pub fn new<T: Into<ShapeStyle>>(coord: Coord, size: Size, style: T) -> Self {
92        Self {
93            center: coord,
94            size,
95            style: style.into(),
96        }
97    }
98}
99
100impl<'a, Coord: 'a, Size: SizeDesc> PointCollection<'a, Coord> for &'a TriangleMarker<Coord, Size> {
101    type Point = &'a Coord;
102    type IntoIter = std::iter::Once<&'a Coord>;
103    fn point_iter(self) -> std::iter::Once<&'a Coord> {
104        std::iter::once(&self.center)
105    }
106}
107
108impl<Coord, DB: DrawingBackend, Size: SizeDesc> Drawable<DB> for TriangleMarker<Coord, Size> {
109    fn draw<I: Iterator<Item = BackendCoord>>(
110        &self,
111        mut points: I,
112        backend: &mut DB,
113        ps: (u32, u32),
114    ) -> Result<(), DrawingErrorKind<DB::ErrorType>> {
115        if let Some((x, y)) = points.next() {
116            let size = self.size.in_pixels(&ps);
117            let points = [-90, -210, -330]
118                .iter()
119                .map(|deg| f64::from(*deg) * std::f64::consts::PI / 180.0)
120                .map(|rad| {
121                    (
122                        (rad.cos() * f64::from(size) + f64::from(x)).ceil() as i32,
123                        (rad.sin() * f64::from(size) + f64::from(y)).ceil() as i32,
124                    )
125                });
126            backend.fill_polygon(points, &self.style.color.to_backend_color())?;
127        }
128        Ok(())
129    }
130}
131
132impl<Coord, Size: SizeDesc> PointElement<Coord, Size> for Cross<Coord, Size> {
133    fn make_point(pos: Coord, size: Size, style: ShapeStyle) -> Self {
134        Self::new(pos, size, style)
135    }
136}
137
138impl<Coord, Size: SizeDesc> PointElement<Coord, Size> for TriangleMarker<Coord, Size> {
139    fn make_point(pos: Coord, size: Size, style: ShapeStyle) -> Self {
140        Self::new(pos, size, style)
141    }
142}
143
144impl<Coord, Size: SizeDesc> PointElement<Coord, Size> for Circle<Coord, Size> {
145    fn make_point(pos: Coord, size: Size, style: ShapeStyle) -> Self {
146        Self::new(pos, size, style)
147    }
148}
149
150impl<Coord, Size: SizeDesc> PointElement<Coord, Size> for Pixel<Coord> {
151    fn make_point(pos: Coord, _: Size, style: ShapeStyle) -> Self {
152        Self::new(pos, style)
153    }
154}
plotters/element/points.rs

plotters/element/
points.rs
