page 309 line 2: subscript on last term is z, 
page 313 line 2: change glPushAttributes to glPushAttrib
page 313 line 2: change glPopAttributes to glPopAttrib
page 316 code: change glPushAttributes to glPushAttrib
page 316 code: change glPopAttributes to glPopAttrib
page 325 caption to Figure 8.31: (b) Subdivided .....
page 336 6th line from bottom: change easily to easy