About Halcyon

Halcyon is a slim, performant SDL wrapper written in modern C++.
Performance is the main priority here, but work has also been put into making sure there is some level of safety as well.
Namespaces are not cluttered, everything is neatly organized - proper C++ design, plain and simple.

Installation

Halcyon is included into your project via CMake.

1. Clone the repository into your project directory.

Caution

Do a shallow clone, as there was a time when actual MP3 and WAV files were stored here. I'll get around to removing these commits from the history eventually.

2. In your CMakeLists.txt, add_subdirectory(halcyon). This will ensure all necessary packages¹ are installed.
3. Link with Halcyon::Halcyon.

Usage

Halcyon wraps SDL with several concepts:

• Init:: Manages SDL subsystem initialization via RAII.
• Proxy: Provides subsystem functionality.

Tip

These are empty classes. You are encouraged to use them with [[no_unique_address]] (also defined as HAL_NO_SIZE).

Example program

This library is still under heavy developement; some namespaces etc. might not be up-to-date, but the structure should remain the same.

#include <halcyon/video.hpp>

int main(int argc, char* argv[]) {
  static_assert(hal::is_correct_main<main>);

  hal::cleanup_init<hal::system::video> vid;

  hal::window   wnd{vid, "Example", {640, 480}};
  hal::renderer rnd{wnd};

  hal::event::variant evt;

  while (true) {
    while (vid.events.poll(evt)) {
      if (evt.kind() == hal::event::type::quit_requested)
        return EXIT_SUCCESS; // Normal termination.
    }

    rnd.present();
  }

  return EXIT_SUCCESS;
}

Debugging

Halcyon provides several macro functions for easing your debugging experience.
"Vital" variants preserve the condition in case debugging is disabled. Use when your condition has side effects.

• HAL_PRINT - print a variadic amount of arguments (must support std::ostream::operator<<).
• HAL_ASSERT[_VITAL] - Assert that a condition is true, panic if not.
• HAL_WARN_IF[_VITAL] - Print a warning message if a condition is true.
• HAL_PANIC - Print where the panic occurred along with variadic user-supplied information, then exit.

Halcyon's debugging facilities are configured via macros.
If NDEBUG is not defined, debugging is implicitly enabled.

• HAL_DEBUG_ENABLED: Enables all of the aforementioned macros.
• HAL_DEBUG_ADVANCED: Enables time logging, and outputs to an additional file. This adds static variables to your program.

Wishlist

Some things I'd like to eventually implement.
SDL3 should be the big break in this.

• Constexpr variable indicating the platform
• Overload accessing/outputting for lvalues & rvalues

Footnotes

1. Currently SDL2, SDL2_image, and SDL2_ttf. ↩