The following generates a 64x64 checker texture,
in which we alternate between black and white
at 8 pixel intervals.

<pre>

# define texWidth 64
# define texHeight 64

GLubyte checkerTex[texWidth][texHeight][3];

void makeCheckerTex( void )
{
  int i, j, r, c;
  
  for (i=0; i< checkWidth; i++){
    for (j=0; i< texHeight; j++){
      c = (((i&0x8)==0)^((j&0x8))==0)*255;
      checkerTex[i][j][0] = (GLubyte) c;
      checkerTex[i][j][1] = (GLubyte) c;
      checkerTex[i][j][2] = (GLubyte) c;
    }
  }
}

</pre>