Precompiled configuration

The precompiled configuration system allows you to embed all configuration directly into the binary at compile time, eliminating runtime TOML parsing and external config files.

Overview

When enabled with -Dprecompiled_config=true, Draconis++ reads configuration from a config.hpp file instead of parsing config.toml at runtime. This provides:

Zero runtime overhead - No TOML parsing or file I/O
Maximum portability - Single binary with no external config files
Compile-time validation - Configuration errors caught at build time
Static plugins - Plugins compiled directly into the binary

When precompiled_config=true, you must provide a config.hpp file at the project root, or the build will fail.

Getting started

Step 1: Copy the example config

# Copy the example to config.hpp
cp config.example.hpp config.hpp

Step 2: Edit your configuration

Open config.hpp and customize the settings:

config.hpp

#pragma once

#if DRAC_PRECOMPILED_CONFIG

#include <Drac++/Config/PrecompiledLayout.hpp>

namespace draconis::config {
  // Your username for the greeting
  constexpr const char* DRAC_USERNAME = "YourName";

  // More config options below...
}

#endif

Step 3: Build with precompiled config

meson setup build -Dprecompiled_config=true
meson compile -C build

Configuration options

Username

Set the display name for the greeting message:

namespace draconis::config {
  constexpr const char* DRAC_USERNAME = "User";
}

Logo configuration

Configure inline image rendering for supported terminal protocols:

No logo (ASCII art)
Kitty protocol
iTerm2 protocol

inline constexpr PrecompiledLogo DRAC_LOGO = {};

inline constexpr PrecompiledLogo DRAC_LOGO = {
  .path     = "/path/to/logo.png",
  .protocol = "kitty",
  .width    = 200,  // pixels
  .height   = 0,    // 0 = auto from aspect ratio
};

inline constexpr PrecompiledLogo DRAC_LOGO = {
  .path     = "/path/to/logo.png",
  .protocol = "iterm2",
  .width    = 200,
  .height   = 200,
};

Supported protocols:

kitty - Kitty graphics protocol
kitty-direct - Kitty direct rendering
iterm2 - iTerm2 inline images

Set path to nullptr to disable inline logo rendering and use ASCII art instead.

Package managers

Only available when packagecount feature is enabled (-Dpackagecount=enabled).

Configure which package managers to display using a bitmask:

#if DRAC_ENABLE_PACKAGECOUNT
#include <Drac++/Services/Packages.hpp>

namespace draconis::config {
  using services::packages::Manager;

  // Enable multiple package managers with bitwise OR
  constexpr Manager DRAC_ENABLED_PACKAGE_MANAGERS = 
    Manager::Cargo | Manager::Pacman | Manager::Nix;
}
#endif

Available package managers by platform:

Linux
macOS
Windows
BSD

Manager::Apk - Alpine Package Keeper
Manager::Cargo - Rust package manager
Manager::Dpkg - Debian packages
Manager::Moss - Serpent OS
Manager::Nix - Nix package manager
Manager::Pacman - Arch Linux
Manager::Rpm - Red Hat packages
Manager::Xbps - Void Linux

Manager::Cargo - Rust package manager
Manager::Homebrew - Homebrew
Manager::Macports - MacPorts
Manager::Nix - Nix package manager

Manager::Cargo - Rust package manager
Manager::Chocolatey - Chocolatey
Manager::Scoop - Scoop
Manager::Winget - Windows Package Manager

Manager::Cargo - Rust package manager
Manager::Nix - Nix package manager
Manager::PkgNg - FreeBSD/DragonFly BSD
Manager::PkgSrc - NetBSD pkgsrc

UI layout

The UI is organized into groups containing rows that display system information.

Layout structure

// 1. Define row arrays as inline constexpr variables
inline constexpr std::array<PrecompiledLayoutRow, 3> DRAC_UI_SYSTEM_ROWS = {
  Row("host"),
  Row("os"),
  Row("kernel"),
};

// 2. Combine groups into the final layout
inline constexpr std::array<PrecompiledLayoutGroup, 1> DRAC_UI_LAYOUT = {
  Group("system", DRAC_UI_SYSTEM_ROWS),
};

Row arrays must be declared as separate inline constexpr variables. Inline temporaries will cause dangling pointers because PrecompiledLayoutGroup uses std::span internally.

Row helper function

Row(key, autoWrap = false, color = LogColor::White, label = nullptr, icon = nullptr)

Parameters:

key - Data key identifying what to display (required)
autoWrap - Enable automatic word wrapping (default: false)
color - Value foreground color (default: White)
label - Custom label override (default: nullptr = use default)
icon - Custom icon override (default: nullptr = use default)

Built-in data keys

Key	Description
`date`	Current date and time
`host`	Hostname and model
`os`	Operating system name
`kernel`	Kernel version
`cpu`	CPU model and info
`gpu`	GPU model and driver
`ram`	Memory usage
`disk`	Disk usage
`uptime`	System uptime
`shell`	Current shell
`packages`	Package counts
`de`	Desktop environment
`wm`	Window manager
`playing`	Now playing (media)

Plugin keys use the format plugin.<name> (e.g., plugin.weather).

Customizing rows

// Uses default label and icon
Row("cpu")

Complete example

config.hpp

#pragma once

#if DRAC_PRECOMPILED_CONFIG

#include <array>
#include <Drac++/Config/PrecompiledLayout.hpp>

#if DRAC_ENABLE_PACKAGECOUNT
#include <Drac++/Services/Packages.hpp>
#endif

namespace draconis::config {
  using utils::logging::LogColor;

  constexpr const char* DRAC_USERNAME = "MyUser";

  inline constexpr PrecompiledLogo DRAC_LOGO = {
    .path     = "/home/user/.config/draconis++/logo.png",
    .protocol = "kitty",
    .width    = 200,
  };

  #if DRAC_ENABLE_PACKAGECOUNT
  constexpr services::packages::Manager DRAC_ENABLED_PACKAGE_MANAGERS = 
    services::packages::Manager::Pacman | 
    services::packages::Manager::Cargo;
  #endif

  // Intro section
  inline constexpr std::array<PrecompiledLayoutRow, 2> DRAC_UI_INTRO_ROWS = {
    Row("date"),
    Row("plugin.weather", true, LogColor::Cyan),
  };

  // System info
  inline constexpr std::array<PrecompiledLayoutRow, 3> DRAC_UI_SYSTEM_ROWS = {
    Row("host"),
    Row("os"),
    Row("kernel"),
  };

  // Hardware info
  inline constexpr std::array<PrecompiledLayoutRow, 5> DRAC_UI_HARDWARE_ROWS = {
    Row("cpu"),
    Row("gpu"),
    Row("ram", false, LogColor::Yellow),
    Row("disk", false, LogColor::Yellow),
    Row("uptime"),
  };

  // Final layout
  inline constexpr std::array<PrecompiledLayoutGroup, 3> DRAC_UI_LAYOUT = {
    Group("intro", DRAC_UI_INTRO_ROWS),
    Group("system", DRAC_UI_SYSTEM_ROWS),
    Group("hardware", DRAC_UI_HARDWARE_ROWS),
  };
}

#endif // DRAC_PRECOMPILED_CONFIG

Static plugins

When combining precompiled_config with static plugins, plugin configuration goes in config.hpp:

config.hpp

// Only include plugin headers you're actually using!
#include "plugins/weather/WeatherConfig.hpp"

namespace draconis::config {
  // Weather plugin config (only needed with -Dstatic_plugins=weather)
  inline constexpr auto WEATHER_CONFIG = weather::config::MakeConfig(
    weather::config::Provider::OpenMeteo,
    weather::config::Units::Metric,
    weather::config::Coordinates { 40.7128, -74.0060 } // New York
  );
}

Build with static plugins:

meson setup build \
  -Dprecompiled_config=true \
  -Dstatic_plugins=['weather']

When precompiled_config=true, plugins are only enabled if static_plugins is non-empty. The plugins option is ignored in this mode.

Color options

Available LogColor values for row customization:

Basic colors
Bright colors

LogColor::White
LogColor::Black
LogColor::Red
LogColor::Green
LogColor::Yellow
LogColor::Blue
LogColor::Magenta
LogColor::Cyan

LogColor::BrightRed
LogColor::BrightGreen
LogColor::BrightYellow
LogColor::BrightBlue
LogColor::BrightMagenta
LogColor::BrightCyan
LogColor::BrightWhite

Advantages vs runtime config

Feature	Precompiled	Runtime TOML
Configuration file	`config.hpp`	`config.toml`
Parsing overhead	None	TOML parser at startup
Validation	Compile-time	Runtime
File I/O	None	Reads config file
Plugin loading	Static linking	Dynamic loading
Portability	Single binary	Requires config file
Flexibility	Rebuild to change	Edit config anytime
Binary size	Larger (plugins embedded)	Smaller

Use precompiled config for deployment and distribution. Use runtime config for development and customization.

Getting Started

Core Concepts

Configuration

Platform Support

Precompiled configuration

Overview

Getting started

Step 1: Copy the example config

Step 2: Edit your configuration

Step 3: Build with precompiled config

Configuration options

Username

Logo configuration

Package managers

UI layout

Layout structure

Row helper function

Built-in data keys

Customizing rows

Complete example

Static plugins

Color options

Advantages vs runtime config

Build docs developers (and LLMs) love

Getting Started

Core Concepts

Configuration

Platform Support

​Overview

​Getting started

​Step 1: Copy the example config

​Step 2: Edit your configuration

​Step 3: Build with precompiled config

​Configuration options

​Username

​Logo configuration

​Package managers

​UI layout

​Layout structure

​Row helper function

​Built-in data keys

​Customizing rows

​Complete example

​Static plugins

​Color options

​Advantages vs runtime config

Build docs developers (and LLMs) love

Overview

Getting started

Step 1: Copy the example config

Step 2: Edit your configuration

Step 3: Build with precompiled config

Configuration options

Username

Logo configuration

Package managers

UI layout

Layout structure

Row helper function

Built-in data keys

Customizing rows

Complete example

Static plugins

Color options

Advantages vs runtime config