opengl - GL_SAMPLE_ALPHA_TO_COVERAGE in MSAA -

does make sense use gl_sample_alpha_to_coverage_arb when rendering msaa fbo? or rather alternative multisampling when alpha blending processed?

alpha coverage useful (and used @ all) with multisampling, since transforms fragment's alpha value appropriate coverage value used determining contribution of fragment respective samples. without multisampling doesn't make sense @ all. alpha coverage on own doesn't antialiasing. used improve multisampling behaviour of highly alpha-tested things (like wire fence or alpha-tested tree leaves , grass), otherwise don't profit multisampling (since works on polygon-edges while things consist of single large polygon) leaving quite jaggy boundaries.