This example demonstrates texture filtering.  The transform keys allow the
textured quad to be rotated and scaled.  The default (Euro) texture shows the
artifacts of magnifying a small texture (blurring or blockiness), while the
checkerboard texture shows the artifacts of minifying a large, high-frequency
texture (moire patterns).  The filter mode may be changed between nearest and
bilinear 

The key commands are:

u, o - rotate quad around its normal axis
;, p - scale quad larger and smaller
Space - reset transforms
f - switch filtering between nearest and bilinear
t - switch between low-resolution texture and high-resolution texture
