ggplot_rs/coord/
mod.rs

1pub mod cartesian;
2pub mod fixed;
3pub mod flip;
4pub mod polar;
5pub mod radar;
6#[cfg(feature = "sf")]
7pub mod sf;
8pub mod trans;
9
10use crate::render::Rect;
11
12/// A trained axis domain together with the normalized panel positions of its
13/// endpoints. `pmin`/`pmax` are `scale.map(min)`/`scale.map(max)`, so a coord can
14/// invert the (linear, expanded) scale mapping exactly: given a normalized
15/// position `n`, the data value is `min + (n - pmin)/(pmax - pmin) * (max - min)`.
16#[derive(Clone, Copy, Debug)]
17pub struct AxisSpan {
18    pub min: f64,
19    pub max: f64,
20    pub pmin: f64,
21    pub pmax: f64,
22}
23
24/// Trait for coordinate systems.
25pub trait Coord: Send + Sync {
26    /// Transform normalized (0..1, 0..1) coordinates to pixel coordinates.
27    fn transform(&self, point: (f64, f64), plot_area: &Rect) -> (f64, f64);
28
29    /// The panel aspect (height / width) this coord letterboxes to, if any.
30    /// `facet_wrap` sizes its panels to it (so every map panel is filled
31    /// instead of letterboxed in an equal, arbitrary cell). Default `None`.
32    fn fixed_aspect(&self) -> Option<f64> {
33        None
34    }
35
36    /// The rect inside `plot_area` the normalized data window maps onto,
37    /// for a coord that letterboxes (`coord_sf`); `None` when it is the
38    /// whole plot area or not a rectangle. Default `None`.
39    fn data_rect(&self, _plot_area: &Rect) -> Option<Rect> {
40        None
41    }
42
43    /// Whether to draw grid lines.
44    fn gridlines(&self) -> bool {
45        true
46    }
47
48    /// Whether this coordinate system flips X and Y.
49    fn is_flipped(&self) -> bool {
50        false
51    }
52
53    /// Whether this is a non-linear polar system (bars become radial sectors,
54    /// so geoms that draw rectangles must tessellate their edges into an arc).
55    fn is_polar(&self) -> bool {
56        false
57    }
58
59    /// For a polar system, whether the *x* aesthetic maps to angle (`theta="x"`).
60    /// When false (`theta="y"`, pies), the *y* aesthetic is the angle, so sector
61    /// tessellation must sweep the y edge instead of the x edge.
62    fn polar_theta_is_x(&self) -> bool {
63        true
64    }
65
66    /// Zoom limits for x-axis (data coordinates). Clips viewport without filtering data.
67    fn zoom_x(&self) -> Option<(f64, f64)> {
68        None
69    }
70
71    /// Zoom limits for y-axis (data coordinates). Clips viewport without filtering data.
72    fn zoom_y(&self) -> Option<(f64, f64)> {
73        None
74    }
75
76    /// Supply the trained x/y axis spans after scale training. Coordinate systems
77    /// that warp the axis (e.g. `coord_trans`) need this to map a normalized
78    /// position back to a data value. Default is a no-op.
79    fn set_domains(&mut self, _x: Option<AxisSpan>, _y: Option<AxisSpan>) {}
80
81    /// Radar coordinates: straight segments between spokes, closed paths, and
82    /// ring/spoke guides instead of cartesian axes. Default false.
83    fn is_radar(&self) -> bool {
84        false
85    }
86
87    /// Inspect / adjust the trained scales once training is complete (e.g.
88    /// `coord_radar` anchors the radius at 0 and counts its spokes). Default:
89    /// no-op.
90    fn train_scales(&mut self, _scales: &mut crate::scale::ScaleSet) {}
91
92    /// Whether bars on a discrete axis keep the band padding (10 % of the
93    /// panel split across the ends). `coord_polar().expand(false)` turns it
94    /// off so a full-width pie closes at the centre. Default true.
95    fn discrete_expand(&self) -> bool {
96        true
97    }
98
99    /// Whether `Theme::axis_text_x_fit`'s `Reserve` mode may grow the panel
100    /// margin for this coordinate system (B3-1). `transform` isn't a simple
101    /// linear per-axis map for polar/radar (angle) or sf (letterboxed,
102    /// non-degree units), so reserving a left/right margin from a label
103    /// bbox would be meaningless there; those coords still get the
104    /// draw-time `Shift` fallback in `draw_x_axis`. Default true.
105    fn supports_axis_reserve(&self) -> bool {
106        true
107    }
108}
ggplot_rs/coord/mod.rs

ggplot_rs/coord/
mod.rs
