Phlips Hue - RGB Color Feedback - Zigbee

[admin]

Try this updated conversion function:

Code:

function xytorgb(x, y, level)
  local function revgamma(v)
    if v <= 0.0031308 then
      return v * 12.92
    else
      return (1 + 0.055) * math.pow(v, (1 / 2.4)) - 0.055
    end
  end

  local function round(v)
    if v <= 0 then
      return 0
    else
      return math.round(v * level)
    end
  end

  x = x / 0xFFFE
  y = y / 0xFFFE

  local z = 1.0 - x - y

  local Y = level
  local X = (Y / y) * x
  local Z = (Y / y) * z

  local r = X * 1.656492 - Y * 0.354851 - Z * 0.255038
  local g = -X * 0.707196 + Y * 1.655397 + Z * 0.036152
  local b = X * 0.051713 - Y * 0.121364 + Z * 1.01153

  if r > b and r > g and r > 1 then
    g = g / r
    b = b / r
    r = 1
  elseif g > b and g > r and g > 1 then
    r = r / g
    b = b / g
    g = 1
  elseif b > r and b > g and b > 1 then
    r = r / b
    g = g / b
    b = 1
  end

  r = round(revgamma(r))
  g = round(revgamma(g))
  b = round(revgamma(b))

  return r * 0x10000 + g * 0x100 + b
end