/* @author Job Zwiers  
 * $Date: 2005/15/12 21:52:17 $    
 * Shows a possible bug in the Jogl implemention of gluBuild2DMipmaps 
 * The Jogl version being used is some "nightly build" from december 2005.
 * Usage: 
 * 1) Use the G key to switch between a mipmap created by means of gluBuild2DMipmaps and
 *    an auto-generated mipmap obtained by setting GL_GENERATE_MIPMAP to true.
 * 2) use up/down arrows and PgUp/PgDown to navigate. 
 * 3) use Escape to exit
 * With the GLU based mipmap, the "chromic" texture produces a red "glow" at some areas on the ground, 
 * which is absent when OpenGL generated mipmaps are used. 
 * Other textures have similar problems.
 * For instance, the (512 X 512) "Grass.png" texture shows black areas when using gluBuild2DMipmaps.
 * Using System.setProperty("jogl.glu.nojava", "true"); the red glow on the chromic is gone, 
 * but the visual appearance of the mipmaps is still not identical. 
 * (Especially visible with the chromic texture).
 * This program is based on a small fragment of a C based program called "Sphereworld" 
 * from the OpenGL SuperBible by Richard Wright/Benjamin Lipschak . 
 * This "Sphereworld" is also using gluBuild2DMipmaps, but does not seem to suffer 
 * from the same problem.
 */