-----------------------------
-- HSV > RGB color conversion
-----------------------------
-- adapted from:
-- http://mjijackson.com/2008/02/rgb-to-hsl-and-rgb-to-hsv-color-model-conversion-algorithms-in-javascript
-----------------------------

function HSVtoRGB(h, s, v)

  local r, g, b

  local i = math.floor(h * 6)
  local f = h * 6 - i
  local p = v * (1 - s)
  local q = v * (1 - f * s)
  local t = v * (1 - (1 - f) * s)

  local switch = i % 6
  if switch == 0 then
    r = v g = t b = p
  elseif switch == 1 then
    r = q g = v b = p
  elseif switch == 2 then
    r = p g = v b = t
  elseif switch == 3 then
    r = p g = q b = v
  elseif switch == 4 then
    r = t g = p b = v
  elseif switch == 5 then
    r = v g = p b = q
  end

  return math.floor(r*255), math.floor(g*255), math.floor(b*255)

end