PipelineAlphaFunc
        
        Description:
        public enum PipelineAlphaFunc
        
        
          Alpha testing happens before blending primitives with the framebuffer and gives an opportunity to discard fragments based on a comparison
             with the incoming alpha value and a reference alpha value.
           The PipelineAlphaFunc determines how the comparison is done.
         
        
        
        Content:
        Enum values:
        
          - NEVER - Never let the fragment 
              through.
- LESS - Let the fragment through if the 
              incoming  alpha value is less than the reference alpha value
- EQUAL - Let the fragment through if 
              the incoming  alpha value equals the reference alpha value
- LEQUAL - Let the fragment through if 
              the incoming  alpha value is less than or equal to the reference alpha value
- GREATER - Let the fragment through 
              if the incoming  alpha value is greater than the reference alpha value
- NOTEQUAL - Let the fragment through
               if the incoming  alpha value does not equal the reference alpha value
- GEQUAL - Let the fragment through if 
              the incoming  alpha value is greater than or equal to the reference alpha value.
- ALWAYS - Always let the fragment 
              through.