ratatui/examples/demo2/colors.rs
EdJoPaTo c12bcfefa2
refactor(non-src): apply pedantic lints (#976)
Fixes many not yet enabled lints (mostly pedantic) on everything that is
not the lib (examples, benchs, tests). Therefore, this is not containing
anything that can be a breaking change.

Lints are not enabled as that should be the job of #974. I created this
as a separate PR as its mostly independent and would only clutter up the
diff of #974 even more.

Also see
https://github.com/ratatui-org/ratatui/pull/974#discussion_r1506458743

---------

Co-authored-by: Josh McKinney <joshka@users.noreply.github.com>
2024-03-02 01:06:53 -08:00

35 lines
1.6 KiB
Rust

use palette::{IntoColor, Okhsv, Srgb};
use ratatui::prelude::*;
/// A widget that renders a color swatch of RGB colors.
///
/// The widget is rendered as a rectangle with the hue changing along the x-axis from 0.0 to 360.0
/// and the value changing along the y-axis (from 1.0 to 0.0). Each pixel is rendered as a block
/// character with the top half slightly lighter than the bottom half.
pub struct RgbSwatch;
impl Widget for RgbSwatch {
#[allow(clippy::cast_precision_loss, clippy::similar_names)]
fn render(self, area: Rect, buf: &mut Buffer) {
for (yi, y) in (area.top()..area.bottom()).enumerate() {
let value = f32::from(area.height) - yi as f32;
let value_fg = value / f32::from(area.height);
let value_bg = (value - 0.5) / f32::from(area.height);
for (xi, x) in (area.left()..area.right()).enumerate() {
let hue = xi as f32 * 360.0 / f32::from(area.width);
let fg = color_from_oklab(hue, Okhsv::max_saturation(), value_fg);
let bg = color_from_oklab(hue, Okhsv::max_saturation(), value_bg);
buf.get_mut(x, y).set_char('▀').set_fg(fg).set_bg(bg);
}
}
}
}
/// Convert a hue and value into an RGB color via the Oklab color space.
///
/// See <https://bottosson.github.io/posts/oklab/> for more details.
pub fn color_from_oklab(hue: f32, saturation: f32, value: f32) -> Color {
let color: Srgb = Okhsv::new(hue, saturation, value).into_color();
let color = color.into_format();
Color::Rgb(color.red, color.green, color.blue)
}