GRRLIB is a C/C++ 2D Graphics library for Wii application developers. It is essentially a wrapper which presents a friendly interface to the Nintendo GX core. With it, coders can quickly and easily start creating graphical applications.

As of v4.1.0, GRRLIB is supplied as a standard C/C++ library (aka. archive) called ‘libgrrlib’. Because GRRLIB processes JPEG and PNG images, it requires the installation of the ‘libjpeg’ and ‘libpngu’ libraries. ‘libpngu’, in turn, requires ‘libpng’ and ‘libpng’ requires ‘libz’. GRRLIB also has FileIO functions to allow real-time loading and saving of graphical data, and thus also requires ‘libfat’.

Changes:

Fully compatible with devkitPro release 18 and 19 (code and examples)
libpng was updated to version 1.2.40
Support for MS-Windows Bitmap format uncompressed (1-bit, 4-bit, 8-bit, 24-bit and 32-bit)
New function called GRRLIB_DrawPart to draw a specific part of a texture
Extra parameters to GRRLIB_Screen2Texture
Video is now initialized even without a SD card
Fixed a problem with scaling images
Documentation improvement

http://wiibrew.org/wiki/GRRLIB