ggplot-rs 0.16.0

use crate::aes::Aesthetic;
use crate::coord::Coord;
use crate::data::DataFrame;
use crate::position::identity::PositionIdentity;
use crate::position::Position;
use crate::render::backend::{DrawBackend, RectStyle};
use crate::render::RenderError;
use crate::scale::ScaleSet;
use crate::stat::identity::StatIdentity;
use crate::stat::Stat;
use crate::theme::Theme;

use super::{Geom, GeomParams};

/// Tessellate a bar — angle span `[t0, t1]`, radius span `[r0, r1]` in
/// normalized coords — into a radial-sector polygon of pixel points under a
/// polar `coord`. Both arcs are sampled so the fill follows the circle.
pub(crate) fn polar_sector(
    coord: &dyn Coord,
    area: &crate::render::Rect,
    t0: f64,
    t1: f64,
    r0: f64,
    r1: f64,
) -> Vec<(f64, f64)> {
    const N: usize = 48;
    let mut pts = Vec::with_capacity(2 * (N + 1));
    if coord.polar_theta_is_x() {
        // angle = x: sweep x along the outer radius (r1), back along the inner (r0)
        for k in 0..=N {
            let t = t0 + (t1 - t0) * k as f64 / N as f64;
            pts.push(coord.transform((t, r1), area));
        }
        for k in 0..=N {
            let t = t1 + (t0 - t1) * k as f64 / N as f64;
            pts.push(coord.transform((t, r0), area));
        }
    } else {
        // angle = y (pie): sweep y along the outer radius (t1), back along t0
        for k in 0..=N {
            let r = r0 + (r1 - r0) * k as f64 / N as f64;
            pts.push(coord.transform((t1, r), area));
        }
        for k in 0..=N {
            let r = r1 + (r0 - r1) * k as f64 / N as f64;
            pts.push(coord.transform((t0, r), area));
        }
    }
    pts
}

/// Column geometry — like GeomBar but with pre-computed heights (uses StatIdentity).
pub struct GeomCol {
    pub fill: (u8, u8, u8),
    pub color: (u8, u8, u8),
    pub alpha: f64,
    pub width: f64,
}

impl Default for GeomCol {
    fn default() -> Self {
        GeomCol {
            fill: (97, 156, 255),
            color: (50, 50, 50),
            alpha: 1.0,
            width: 0.9,
        }
    }
}

impl Geom for GeomCol {
    fn draw(
        &self,
        data: &DataFrame,
        coord: &dyn Coord,
        scales: &ScaleSet,
        _theme: &Theme,
        backend: &mut dyn DrawBackend,
    ) -> Result<(), RenderError> {
        let x_col = data
            .column("x")
            .ok_or(RenderError::MissingAesthetic("x".into()))?;
        let y_col = data
            .column("y")
            .ok_or(RenderError::MissingAesthetic("y".into()))?;
        let fill_col = data.column("fill");

        let plot_area = backend.plot_area();
        let x_scale = scales.get(&Aesthetic::X);
        let y_scale = scales.get(&Aesthetic::Y);
        let x_is_discrete = x_scale.map(|s| s.is_discrete()).unwrap_or(false);

        let ymin_col = data.column("ymin");
        // A `label` mapping (and the value) becomes a hover tooltip on each bar.
        let label_col = data.column("label");

        // Bar width in normalized coords — computed once, not per row (breaks()
        // allocates every level label, which made many-category charts O(n²)).
        let half_width = if x_is_discrete {
            let n_breaks = x_scale.map(|s| s.breaks().len()).unwrap_or(1);
            self.width / (n_breaks.max(1) as f64 * 1.1) / 2.0
        } else {
            super::continuous_bar_half_width(
                x_col.iter().filter_map(|v| x_scale.map(|s| s.map(v))),
                self.width,
                0.02,
            )
        };

        for i in 0..data.nrows() {
            let nx = x_scale.map(|s| s.map(&x_col[i])).unwrap_or(0.0);
            let ny = y_scale.map(|s| s.map(&y_col[i])).unwrap_or(0.0);
            // Honor a stacked/filled base (ymin) so stacked columns draw as
            // distinct segments rather than all from zero.
            let ny_base = ymin_col
                .and_then(|c| c[i].as_f64())
                .and_then(|v| y_scale.map(|s| s.map(&crate::data::Value::Float(v))))
                .unwrap_or_else(|| {
                    y_scale
                        .map(|s| s.map(&crate::data::Value::Float(0.0)))
                        .unwrap_or(0.0)
                });

            let (fr, fg, fb) = if let Some(fc) = fill_col {
                scales
                    .map_color(&Aesthetic::Fill, &fc[i])
                    .unwrap_or(self.fill)
            } else {
                self.fill
            };
            let style = RectStyle {
                fill: Some((fr, fg, fb)),
                stroke: Some(self.color),
                stroke_width: 0.5,
                alpha: self.alpha,
                clip: !coord.is_polar(),
            };

            let label = label_col.and_then(|c| match &c[i] {
                crate::data::Value::Str(s) if !s.is_empty() => Some(s.clone()),
                v => v
                    .as_f64()
                    .map(|f| format!("{}", (f * 1000.0).round() / 1000.0)),
            });
            // The tooltip reports the measured value — for stacked/filled bars
            // the segment's own value, not the cumulative stack top.
            let raw = super::measured_value(data, i);
            let yval = raw
                .as_deref()
                .and_then(|r| r.parse::<f64>().ok())
                .map(|f| format!("{}", (f * 1000.0).round() / 1000.0));
            let tip = match (label, yval) {
                (Some(l), Some(y)) => Some(format!("{l}: {y}")),
                (Some(l), None) => Some(l),
                (None, Some(y)) => Some(y),
                (None, None) => None,
            };
            super::set_mark(
                backend,
                tip,
                Some(super::tip_value(&x_col[i])),
                super::series_key(data, i),
                raw,
            );

            if coord.is_polar() {
                // A bar becomes a radial sector: tessellate the outer arc
                // (radius = value) and the inner arc (radius = base) so the
                // filled polygon follows the circle instead of a warped quad.
                let points = polar_sector(
                    coord,
                    &plot_area,
                    nx - half_width,
                    nx + half_width,
                    ny_base,
                    ny,
                );
                backend.draw_polygon(&points, &style)?;
            } else {
                let (left_px, top_px) = coord.transform((nx - half_width, ny), &plot_area);
                let (right_px, bottom_px) = coord.transform((nx + half_width, ny_base), &plot_area);
                backend.draw_rect(
                    (left_px, top_px.min(bottom_px)),
                    (right_px, top_px.max(bottom_px)),
                    &style,
                )?;
            }
        }
        super::clear_mark(backend);

        Ok(())
    }

    fn required_aes(&self) -> Vec<Aesthetic> {
        vec![Aesthetic::X, Aesthetic::Y]
    }

    fn default_stat(&self) -> Box<dyn Stat> {
        Box::new(StatIdentity)
    }

    fn default_position(&self) -> Box<dyn Position> {
        Box::new(PositionIdentity)
    }

    fn default_params(&self) -> GeomParams {
        GeomParams::default()
    }

    fn name(&self) -> &str {
        "col"
    }

    fn include_zero_baseline(&self) -> bool {
        true
    }

    fn set_series_color(&mut self, color: (u8, u8, u8)) {
        self.fill = color;
    }
}