Variables starting with `z' in 321/ref_gl

• z 321/ref_gl/qgl.h:265
• zfail 321/ref_gl/qgl.h:301
• zFar 321/ref_gl/qgl.h:107
• zNear 321/ref_gl/qgl.h:107
• zpass 321/ref_gl/qgl.h:301