LÖVE

Code: Select all

do 

local globalAlpha = 255
local _rgba
setAlpha=function(alpha) globalAlpha = alpha end

local translateRGBA={
   [1]=function(i)       return _rgba( i, i, i )                  end,
   [2]=function(i,a)     return _rgba( i, i, i, a )                end,
   [3]=function(r,g,b)   return _rgba( r, g, b )                  end,
   [4]=function(r,g,b,a) return _rgba( r, g, b, a )                end
}

setmetatable(translateRGBA,{__index=function(t,i) error("Color: rgba() accepts 1 to 4 parameters") end})

_rgba = function(...)
   local r, g, b, a = ...
   return function(alpha)
      if alpha then 
         return r, g, b, alpha
      elseif a then 
         return r, g, b, a
      else 
            return r, g, b, globalAlpha
      end
   end
end

function rgba(...)
   return translateRGBA[#{...}](...) -- the use of #{...} is intentional.
end
end