anchor: love.graphics.setBlendMode
  Sets the blending mode.
  love.graphics.setBlendMode( mode )
  mode BlendMode The blend mode to use.
  love.graphics.setBlendMode( mode, alphamode )
  mode BlendMode The blend mode to use.
  alphamode ('alphamultiply') BlendAlphaMode What to do with the alpha of drawn objects when blending.