Introduction

This document describes VGUI, a library that provides 2D and 3D drawing in a way that is both simple and powerful. The basic design goals are:

• Provide drawing of images and geometric primitives using OpenGL, in a platform independent manner.
• Define the handling of user events such as keypresses and mouse movements.
• Do *not* deal with widgets (buttons, sliders, menus etc), but instead provide a single simple interface to whatever widget toolkit the user chooses. Current interfaces include ones to GTK, FLTK, glut, and glX.
• OpenGL should be usable ``raw'', without any special wrapping by the library, so that existing documentation is used to best advantage.

The basic concept in the new GUI is that the user has access to a rectangular area (or areas) of the screen, on which OpenGL may be used to draw and from which events are received. Such an area is called a tableau. Once-off adaptor code is provided that plugs a tableau into any supported GUI toolkit.