IupGL

IupGL is a component of the IUP (Interface Unit for Portable) toolkit that provides an OpenGL rendering canvas for cross‑platform graphical applications. Introduced as part of IUP’s extensible set of controls, IupGL allows developers to embed OpenGL drawing areas within standard IUP dialogs, enabling interactive 3‑D visualisation, scientific plotting, and custom graphics without leaving the portable GUI framework.

The control is implemented as a native widget on each supported operating system: on Windows it uses a WGL context, on Linux it relies on GLX with X11, and on macOS it employs Cocoa’s NSOpenGLView. IupGL therefore inherits the platform‑specific performance and integration benefits of the underlying OpenGL implementation while presenting a uniform API to the programmer.

Typical usage involves creating an IupGL element, assigning callback functions such as “ACTION” for drawing, “RESIZE_CB” for handling size changes, and “MOUSEBUTTON_CB” for input events. The OpenGL context is automatically created when the element is mapped and is made current before each ACTION call, simplifying resource management. IupGL also supports double buffering, depth testing, and anti‑aliasing through standard OpenGL state settings.

IUP is available for C, Lua, and several other languages via bindings, and IupGL follows the same language interfaces. Its lightweight footprint, permissive license (MIT‑style), and ability to run on Windows, Linux, macOS, and Unix‑like systems make it a practical choice for developers seeking a portable OpenGL widget without dependence on larger GUI libraries.