GLFW

GLFW is a lightweight utility library for use with OpenGL. It provides programmers with the ability to create and manage windows and OpenGL contexts, as well as handle joystick, keyboard and mouse input.

Software architecture

GLFW is a small C library that allows the creation and management of windows with OpenGL contexts, making it also possible to use multiple monitors and video modes. It provides access to input from keyboard, mouse and joysticks. The API provides a thin, multi-platform abstraction layer, primarily for applications whose sole graphics output is through the OpenGL API. While GLFW is very useful when developing multi-platform OpenGL applications, single-platform developers can also benefit from avoiding having to deal with kludgy platform-specific APIs.

A possible reason that libraries like GLFW are needed is that OpenGL by itself does not provide any mechanisms for creating the necessary context, managing windows, user input, timing etc. There are several other libraries available for aiding OpenGL development. The most common ones are freeglut (an Open Source implementation of GLUT) and SDL. However, freeglut is mostly concerned with providing a stable clone of GLUT, while SDL is too large for some people and has never had OpenGL as its main focus. GLFW is predicated on the assumption that there is room for a lightweight, modern library for managing OpenGL contexts, windows and input.

GLFW is by design not^[3]

• a user interface library. It allows the programmer to create top-level windows with OpenGL contexts. No menus, no buttons.
• a Windows-only library. Requests for features that cannot be portably implemented will be denied unless they are unobtrusive, like the Windows port looking for a GLFW_ICON resource at window creation.
• a threading library. There are already good cross-platform threading libraries and threading has been added to both the C11 and C++11 standard libraries.
• an image loading library. There are already good cross-platform image loading libraries.
• capable of rendering text. There are already several libraries that render text with OpenGL and consistent cross-platform text rendering cannot depend on the platform’s text rendering facilities anyway.
• capable of rendering anything at all. Rendering is up to the programmer and/or other libraries.
• integrated with any user interface toolkit on any platform. Good UI toolkits already provide OpenGL-capable widgets and having two libraries both talking to the vast global state of a window system is asking for trouble.
• able to play back sound.
• GLUT or SDL.

Programming language bindings

Although GLFW is written in C, bindings do exist to use the API with other programming languages including Ada, C#, Common Lisp, D, Go, Haskell, Java, Python, Rebol, Red, Ruby and Rust, among others.^[4]

Back-ends

GLFW version 3.2 has experimental support for Mir and Wayland through compile-time flags.^[5]

See also

• GLUT – OpenGL's legacy windowing toolkit
• OpenGL Extension Wrangler Library
• Simple DirectMedia Layer

References

1. ↑ "GLFW version history". Retrieved 30 August 2016. 
2. ↑ "GLFW license". Retrieved 5 July 2013. 
3. ↑ "GLFW – FAQ". Retrieved 11 July 2015. 
4. ↑ "GLFW Programming language bindings". Retrieved 11 July 2015. 
5. ↑ "GLFW: New features in 3.2". 

External links

• Official website
• glfw on GitHub