EmbeddedPkg: Extend NvVarStoreFormattedLib LIBRARY_CLASS

[mirror_edk2.git] / AppPkg / Applications / Python / Python-2.7.2 / Lib / colorsys.py

"""Conversion functions between RGB and other color systems.\r
\r
This modules provides two functions for each color system ABC:\r
\r
  rgb_to_abc(r, g, b) --> a, b, c\r
  abc_to_rgb(a, b, c) --> r, g, b\r
\r
All inputs and outputs are triples of floats in the range [0.0...1.0]\r
(with the exception of I and Q, which covers a slightly larger range).\r
Inputs outside the valid range may cause exceptions or invalid outputs.\r
\r
Supported color systems:\r
RGB: Red, Green, Blue components\r
YIQ: Luminance, Chrominance (used by composite video signals)\r
HLS: Hue, Luminance, Saturation\r
HSV: Hue, Saturation, Value\r
"""\r
\r
# References:\r
# http://en.wikipedia.org/wiki/YIQ\r
# http://en.wikipedia.org/wiki/HLS_color_space\r
# http://en.wikipedia.org/wiki/HSV_color_space\r
\r
__all__ = ["rgb_to_yiq","yiq_to_rgb","rgb_to_hls","hls_to_rgb",\r
           "rgb_to_hsv","hsv_to_rgb"]\r
\r
# Some floating point constants\r
\r
ONE_THIRD = 1.0/3.0\r
ONE_SIXTH = 1.0/6.0\r
TWO_THIRD = 2.0/3.0\r
\r
# YIQ: used by composite video signals (linear combinations of RGB)\r
# Y: perceived grey level (0.0 == black, 1.0 == white)\r
# I, Q: color components\r
\r
def rgb_to_yiq(r, g, b):\r
    y = 0.30*r + 0.59*g + 0.11*b\r
    i = 0.60*r - 0.28*g - 0.32*b\r
    q = 0.21*r - 0.52*g + 0.31*b\r
    return (y, i, q)\r
\r
def yiq_to_rgb(y, i, q):\r
    r = y + 0.948262*i + 0.624013*q\r
    g = y - 0.276066*i - 0.639810*q\r
    b = y - 1.105450*i + 1.729860*q\r
    if r < 0.0:\r
        r = 0.0\r
    if g < 0.0:\r
        g = 0.0\r
    if b < 0.0:\r
        b = 0.0\r
    if r > 1.0:\r
        r = 1.0\r
    if g > 1.0:\r
        g = 1.0\r
    if b > 1.0:\r
        b = 1.0\r
    return (r, g, b)\r
\r
\r
# HLS: Hue, Luminance, Saturation\r
# H: position in the spectrum\r
# L: color lightness\r
# S: color saturation\r
\r
def rgb_to_hls(r, g, b):\r
    maxc = max(r, g, b)\r
    minc = min(r, g, b)\r
    # XXX Can optimize (maxc+minc) and (maxc-minc)\r
    l = (minc+maxc)/2.0\r
    if minc == maxc:\r
        return 0.0, l, 0.0\r
    if l <= 0.5:\r
        s = (maxc-minc) / (maxc+minc)\r
    else:\r
        s = (maxc-minc) / (2.0-maxc-minc)\r
    rc = (maxc-r) / (maxc-minc)\r
    gc = (maxc-g) / (maxc-minc)\r
    bc = (maxc-b) / (maxc-minc)\r
    if r == maxc:\r
        h = bc-gc\r
    elif g == maxc:\r
        h = 2.0+rc-bc\r
    else:\r
        h = 4.0+gc-rc\r
    h = (h/6.0) % 1.0\r
    return h, l, s\r
\r
def hls_to_rgb(h, l, s):\r
    if s == 0.0:\r
        return l, l, l\r
    if l <= 0.5:\r
        m2 = l * (1.0+s)\r
    else:\r
        m2 = l+s-(l*s)\r
    m1 = 2.0*l - m2\r
    return (_v(m1, m2, h+ONE_THIRD), _v(m1, m2, h), _v(m1, m2, h-ONE_THIRD))\r
\r
def _v(m1, m2, hue):\r
    hue = hue % 1.0\r
    if hue < ONE_SIXTH:\r
        return m1 + (m2-m1)*hue*6.0\r
    if hue < 0.5:\r
        return m2\r
    if hue < TWO_THIRD:\r
        return m1 + (m2-m1)*(TWO_THIRD-hue)*6.0\r
    return m1\r
\r
\r
# HSV: Hue, Saturation, Value\r
# H: position in the spectrum\r
# S: color saturation ("purity")\r
# V: color brightness\r
\r
def rgb_to_hsv(r, g, b):\r
    maxc = max(r, g, b)\r
    minc = min(r, g, b)\r
    v = maxc\r
    if minc == maxc:\r
        return 0.0, 0.0, v\r
    s = (maxc-minc) / maxc\r
    rc = (maxc-r) / (maxc-minc)\r
    gc = (maxc-g) / (maxc-minc)\r
    bc = (maxc-b) / (maxc-minc)\r
    if r == maxc:\r
        h = bc-gc\r
    elif g == maxc:\r
        h = 2.0+rc-bc\r
    else:\r
        h = 4.0+gc-rc\r
    h = (h/6.0) % 1.0\r
    return h, s, v\r
\r
def hsv_to_rgb(h, s, v):\r
    if s == 0.0:\r
        return v, v, v\r
    i = int(h*6.0) # XXX assume int() truncates!\r
    f = (h*6.0) - i\r
    p = v*(1.0 - s)\r
    q = v*(1.0 - s*f)\r
    t = v*(1.0 - s*(1.0-f))\r
    i = i%6\r
    if i == 0:\r
        return v, t, p\r
    if i == 1:\r
        return q, v, p\r
    if i == 2:\r
        return p, v, t\r
    if i == 3:\r
        return p, q, v\r
    if i == 4:\r
        return t, p, v\r
    if i == 5:\r
        return v, p, q\r
    # Cannot get here\r