lethal-guitar / RigelLib

Useful stuff for SDL/OpenGL based C++ projects

RigelLib

This library offers a collection of reusable code and utilities for C++ applications based on SDL and OpenGL. Most of this is based on code originally written for RigelEngine.

How to use this

The easiest way to integrate RigelLib into a project is to add the code as a git submodule, or copy it into your source tree.

Set up the submodule:

git submodule add https://github.com/lethal-guitar/RigelLib.git RigelLib
git submodule update --init --recursive

Then add a CMakeLists.txt like this:

# 3.13 is the minimum required by RigelLib. You can of course require a higher
# version here
cmake_minimum_required(VERSION 3.13 FATAL_ERROR)

project(MyAwesomeGame)

# This will build the library as part of your project and make its CMake targets
# available (including SDL2::Core and SDL2::Main).
# It also does the necessary find_package() call to locate SDL2.
include(RigelLib/setup.cmake)

# Now define your own build targets, and depend on RigelLib
add_executable(MyAwesomeGame
    main.cpp
)
target_link_libraries(MyAwesomeGame PRIVATE
    SDL2::Main
    RigelLib::RigelLib
)

And that's it! You now have the foundation of a SDL2+OpenGL application.

Also see the examples.

What's in here?

The library is organized into a few different modules:

bootstrap.hpp (top-level)

Mini-framework for setting up an SDL+OpenGL application. Provides a helper function which initializes SDL and OpenGL and creates an application window, then repeatedly calls a user-provided "new frame" function. There's also command line parsing functionality (based on the Lyra library). The code handles some Windows-specific intricacies like enabling high DPI support and allowing terminal output when running as a GUI application (subsystem "Windows").

See the bootstrap.cpp example.

base

This is essentially an "extended standard library" containing various utilities. It includes types for working with 2D bitmaps (Image, Color), functions for loading of common image formats like .png and .jpeg, some 2D vector math, helpers for binary file format I/O, and useful C++ utilities like match (more convenient std::variant visitation) and ArrayView (similar to std::span).

opengl

OpenGL header and a shader class.

sdl_utils

Mostly tools to make working with SDL easier in C++, specifically memory management and error handling.

ui

Dear ImGui integration and an FPS counter.