base16 theme picker

// Debounce a function so it only fires once input settles.
import { readFile } from "node:fs/promises";

const DELAY_MS = 250;

export function debounce(fn, wait = DELAY_MS) {
    let timer = null;
    return (...args) => {
        clearTimeout(timer);
        timer = setTimeout(() => fn.apply(this, args), wait);
    };
}

class Palette extends Map {
    static async load(path) {
        const text = await readFile(path, "utf8");
        const pairs = text.match(/base0[0-9A-F]: "#\w{6}"/g) ?? [];
        return new Palette(pairs.map((p) => p.split(": ")));
    }
}

const log = debounce((msg) => console.log(`[${new Date().toISOString()}] ${msg}\n`));
log(true ? "ready" : null);

using System;
using System.Collections.Generic;
using System.Linq;

namespace Fragment.Engine;

/// <summary>A component that can be attached to an entity.</summary>
[AttributeUsage(AttributeTargets.Class, Inherited = false)]
public sealed class ComponentAttribute(string name) : Attribute
{
    public string Name { get; } = name;
}

[Component("transform")]
public record struct Transform(float X, float Y, float Rotation = 0f);

public static class Registry
{
    private static readonly Dictionary<string, Type> _types = new();

    public static int Scan()
    {
        foreach (var type in typeof(Registry).Assembly.GetTypes())
        {
            if (type.GetCustomAttributes(typeof(ComponentAttribute), false)
                    .FirstOrDefault() is ComponentAttribute attr)
                _types[attr.Name] = type;
        }
        Console.WriteLine($"Found {_types.Count} components\n");
        return _types.Count;
    }
}

use std::collections::HashMap;
use std::fmt;

/// A single 24-bit colour from a Base16 palette.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct Rgb(u8, u8, u8);

impl fmt::Display for Rgb {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "#{:02x}{:02x}{:02x}", self.0, self.1, self.2)
    }
}

pub fn parse(hex: &str) -> Option<Rgb> {
    let hex = hex.strip_prefix('#')?;
    let n = u32::from_str_radix(hex, 16).ok()?;
    Some(Rgb((n >> 16) as u8, (n >> 8) as u8, n as u8))
}

fn main() {
    let mut palette: HashMap<&'static str, Rgb> = HashMap::new();
    for (slot, value) in [("base00", "#1d2021"), ("base08", "#fb4934")] {
        if let Some(rgb) = parse(value) {
            palette.insert(slot, rgb);
        }
    }
    println!("{} colours loaded\n", palette.len());
}

#!/usr/bin/env bash
# Rebuild the system and keep the last few generations.
set -euo pipefail

readonly FLAKE="${HOME}/.nixos"
KEEP=${KEEP:-5}

log() {
    printf '\e[1;34m==>\e[0m %s\n' "$*"
}

if [[ $EUID -eq 0 ]]; then
    echo "Run this as your user, not root." >&2
    exit 1
fi

log "Rebuilding from $FLAKE"
sudo nixos-rebuild switch --flake "$FLAKE#$(hostname)"

for gen in $(nix-env --list-generations -p /nix/var/nix/profiles/system | awk '{print $1}' | head -n -"$KEEP"); do
    log "Removing generation $gen"
    sudo nix-env --delete-generations -p /nix/var/nix/profiles/system "$gen"
done

case "${1:-}" in
    --gc) sudo nix-collect-garbage -d ;;
    *) log "Done. Pass --gc to collect garbage." ;;
esac

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define SLOT_COUNT 16

typedef struct {
    const char *name;
    unsigned int rgb[SLOT_COUNT];
} scheme_t;

/* Parse "#rrggbb" into a packed integer, or return -1. */
static long parse_hex(const char *s) {
    if (s == NULL || *s != '#' || strlen(s) != 7) {
        return -1;
    }
    char *end;
    long value = strtol(s + 1, &end, 16);
    return *end == '\0' ? value : -1;
}

int main(int argc, char **argv) {
    scheme_t scheme = { .name = "example" };
    for (int i = 1; i < argc && i <= SLOT_COUNT; ++i) {
        long v = parse_hex(argv[i]);
        scheme.rgb[i - 1] = v < 0 ? 0x000000 : (unsigned int)v;
    }
    printf("%s: base00 = #%06x\n", scheme.name, scheme.rgb[0]);
    return EXIT_SUCCESS;
}

#include <algorithm>
#include <array>
#include <format>
#include <iostream>
#include <string_view>

namespace theme {

template <typename T, std::size_t N>
constexpr T average(const std::array<T, N>& values) {
    T sum{};
    for (const auto& v : values) sum += v;
    return sum / static_cast<T>(N);
}

class Swatch final {
public:
    explicit Swatch(std::string_view name, float lightness)
        : name_{name}, lightness_{lightness} {}

    [[nodiscard]] bool is_dark() const noexcept { return lightness_ < 0.5f; }
    std::string_view name() const { return name_; }

private:
    std::string_view name_;
    float lightness_ = 0.0f;
};

} // namespace theme

int main() {
    constexpr std::array<float, 4> l{0.12f, 0.18f, 0.84f, 0.96f};
    auto swatch = theme::Swatch{"base00", theme::average(l)};
    std::cout << std::format("{} is {}\n", swatch.name(), swatch.is_dark() ? "dark" : "light");
}

;;;; Pick the darkest colour out of a palette.
(defpackage :base16
  (:use :cl)
  (:export #:luminance #:darkest))

(in-package :base16)

(defparameter *palette*
  '((:base00 . #x1d2021) (:base05 . #xd5c4a1) (:base08 . #xfb4934)))

(defun luminance (rgb)
  "Approximate perceived brightness of a packed RGB integer."
  (let ((r (ldb (byte 8 16) rgb))
        (g (ldb (byte 8 8) rgb))
        (b (ldb (byte 8 0) rgb)))
    (+ (* 0.2126 r) (* 0.7152 g) (* 0.0722 b))))

(defmacro with-slot ((name value) entry &body body)
  `(destructuring-bind (,name . ,value) ,entry ,@body))

(defun darkest (&optional (palette *palette*))
  (reduce (lambda (a b)
            (if (< (luminance (cdr a)) (luminance (cdr b))) a b))
          palette))

(with-slot (name value) (darkest)
  (format t "~a is #~6,'0x~%" name value))

// Debounce a function so it only fires once input settles.
import { readFile } from "node:fs/promises";

const DELAY_MS = 250;

export function debounce(fn, wait = DELAY_MS) {
    let timer = null;
    return (...args) => {
        clearTimeout(timer);
        timer = setTimeout(() => fn.apply(this, args), wait);
    };
}

class Palette extends Map {
    static async load(path) {
        const text = await readFile(path, "utf8");
        const pairs = text.match(/base0[0-9A-F]: "#\w{6}"/g) ?? [];
        return new Palette(pairs.map((p) => p.split(": ")));
    }
}

const log = debounce((msg) => console.log(`[${new Date().toISOString()}] ${msg}\n`));
log(true ? "ready" : null);

using System;
using System.Collections.Generic;
using System.Linq;

namespace Fragment.Engine;

/// <summary>A component that can be attached to an entity.</summary>
[AttributeUsage(AttributeTargets.Class, Inherited = false)]
public sealed class ComponentAttribute(string name) : Attribute
{
    public string Name { get; } = name;
}

[Component("transform")]
public record struct Transform(float X, float Y, float Rotation = 0f);

public static class Registry
{
    private static readonly Dictionary<string, Type> _types = new();

    public static int Scan()
    {
        foreach (var type in typeof(Registry).Assembly.GetTypes())
        {
            if (type.GetCustomAttributes(typeof(ComponentAttribute), false)
                    .FirstOrDefault() is ComponentAttribute attr)
                _types[attr.Name] = type;
        }
        Console.WriteLine($"Found {_types.Count} components\n");
        return _types.Count;
    }
}

use std::collections::HashMap;
use std::fmt;

/// A single 24-bit colour from a Base16 palette.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct Rgb(u8, u8, u8);

impl fmt::Display for Rgb {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "#{:02x}{:02x}{:02x}", self.0, self.1, self.2)
    }
}

pub fn parse(hex: &str) -> Option<Rgb> {
    let hex = hex.strip_prefix('#')?;
    let n = u32::from_str_radix(hex, 16).ok()?;
    Some(Rgb((n >> 16) as u8, (n >> 8) as u8, n as u8))
}

fn main() {
    let mut palette: HashMap<&'static str, Rgb> = HashMap::new();
    for (slot, value) in [("base00", "#1d2021"), ("base08", "#fb4934")] {
        if let Some(rgb) = parse(value) {
            palette.insert(slot, rgb);
        }
    }
    println!("{} colours loaded\n", palette.len());
}

#!/usr/bin/env bash
# Rebuild the system and keep the last few generations.
set -euo pipefail

readonly FLAKE="${HOME}/.nixos"
KEEP=${KEEP:-5}

log() {
    printf '\e[1;34m==>\e[0m %s\n' "$*"
}

if [[ $EUID -eq 0 ]]; then
    echo "Run this as your user, not root." >&2
    exit 1
fi

log "Rebuilding from $FLAKE"
sudo nixos-rebuild switch --flake "$FLAKE#$(hostname)"

for gen in $(nix-env --list-generations -p /nix/var/nix/profiles/system | awk '{print $1}' | head -n -"$KEEP"); do
    log "Removing generation $gen"
    sudo nix-env --delete-generations -p /nix/var/nix/profiles/system "$gen"
done

case "${1:-}" in
    --gc) sudo nix-collect-garbage -d ;;
    *) log "Done. Pass --gc to collect garbage." ;;
esac

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define SLOT_COUNT 16

typedef struct {
    const char *name;
    unsigned int rgb[SLOT_COUNT];
} scheme_t;

/* Parse "#rrggbb" into a packed integer, or return -1. */
static long parse_hex(const char *s) {
    if (s == NULL || *s != '#' || strlen(s) != 7) {
        return -1;
    }
    char *end;
    long value = strtol(s + 1, &end, 16);
    return *end == '\0' ? value : -1;
}

int main(int argc, char **argv) {
    scheme_t scheme = { .name = "example" };
    for (int i = 1; i < argc && i <= SLOT_COUNT; ++i) {
        long v = parse_hex(argv[i]);
        scheme.rgb[i - 1] = v < 0 ? 0x000000 : (unsigned int)v;
    }
    printf("%s: base00 = #%06x\n", scheme.name, scheme.rgb[0]);
    return EXIT_SUCCESS;
}

#include <algorithm>
#include <array>
#include <format>
#include <iostream>
#include <string_view>

namespace theme {

template <typename T, std::size_t N>
constexpr T average(const std::array<T, N>& values) {
    T sum{};
    for (const auto& v : values) sum += v;
    return sum / static_cast<T>(N);
}

class Swatch final {
public:
    explicit Swatch(std::string_view name, float lightness)
        : name_{name}, lightness_{lightness} {}

    [[nodiscard]] bool is_dark() const noexcept { return lightness_ < 0.5f; }
    std::string_view name() const { return name_; }

private:
    std::string_view name_;
    float lightness_ = 0.0f;
};

} // namespace theme

int main() {
    constexpr std::array<float, 4> l{0.12f, 0.18f, 0.84f, 0.96f};
    auto swatch = theme::Swatch{"base00", theme::average(l)};
    std::cout << std::format("{} is {}\n", swatch.name(), swatch.is_dark() ? "dark" : "light");
}

;;;; Pick the darkest colour out of a palette.
(defpackage :base16
  (:use :cl)
  (:export #:luminance #:darkest))

(in-package :base16)

(defparameter *palette*
  '((:base00 . #x1d2021) (:base05 . #xd5c4a1) (:base08 . #xfb4934)))

(defun luminance (rgb)
  "Approximate perceived brightness of a packed RGB integer."
  (let ((r (ldb (byte 8 16) rgb))
        (g (ldb (byte 8 8) rgb))
        (b (ldb (byte 8 0) rgb)))
    (+ (* 0.2126 r) (* 0.7152 g) (* 0.0722 b))))

(defmacro with-slot ((name value) entry &body body)
  `(destructuring-bind (,name . ,value) ,entry ,@body))

(defun darkest (&optional (palette *palette*))
  (reduce (lambda (a b)
            (if (< (luminance (cdr a)) (luminance (cdr b))) a b))
          palette))

(with-slot (name value) (darkest)
  (format t "~a is #~6,'0x~%" name value))