Module:Color contrast: Difference between revisions
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v1 should be the brighter of the two |
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Line 147: | Line 147: | ||
local v2 = color2lum(args[2]) |
local v2 = color2lum(args[2]) |
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if (type(v1) == 'number' and type(v2) == 'number') then |
if (type(v1) == 'number' and type(v2) == 'number') then |
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-- v1 should be the brighter of the two. |
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⚫ | |||
if v2 > v1 then |
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v1, v2 = v2, v1 |
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end |
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⚫ | |||
else |
else |
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return args['error'] or '?' |
return args['error'] or '?' |
Revision as of 19:13, 18 July 2015
Documentation for this module may be created at Module:Color contrast/doc
--
-- This module implements
-- {{Color contrast ratio}}
-- {{Greater color contrast ratio}}
-- {{ColorToLum}}
-- {{RGBColorToLum}}
--
local p = {}
local function sRGB ( v )
if (v <= 0.03928) then
v = v / 12.92
else
v = math.pow((v+0.055)/1.055, 2.4)
end
return v
end
local function color2lum( c )
if (c == nil) then
return ''
end
local HTMLcolor = {
white = 1,
silver = 0.52711512570581,
gray = 0.2158605001139,
black = 0,
red = 0.2126,
maroon = 0.045891942324215,
yellow = 0.9278,
olive = 0.20027537200568,
lime = 0.7152,
green = 0.15438342968146,
aqua = 0.7874,
teal = 0.16996855778968,
blue = 0.0722,
navy = 0.015585128108224,
fuchsia = 0.2848,
purple = 0.061477070432439,
orange = 0.4817026703631,
gold = 0.69860877428159,
pink = 0.63271070702466,
lightpink = 0.58566152734898,
hotpink = 0.34658438169715,
deeppink = 0.23866895828276,
palevioletred = 0.28754994117889,
mediumvioletred = 0.14371899849357,
lightsalmon = 0.4780675225206,
salmon = 0.36977241527596,
darksalmon = 0.40541471563381,
lightcoral = 0.35522120733135,
indianred = 0.21406134963884,
crimson = 0.16042199953026,
firebrick = 0.10724525535015,
darkred = 0.054889674531132,
orangered = 0.25516243753416,
tomato = 0.30638612719415,
coral = 0.37017930872924,
darkorange = 0.40016167026524,
lightyellow = 0.98161818392882,
lemonchiffon = 0.94038992245622,
lightgoldenrodyellow = 0.93348351018297,
papayawhip = 0.87797100199835,
moccasin = 0.80083000991567,
peachpuff = 0.74905589878251,
palegoldenrod = 0.78792647887614,
khaki = 0.77012343394121,
darkkhaki = 0.45747326349994,
cornsilk = 0.93562110372965,
blanchedalmond = 0.85084439608156,
bisque = 0.80732327372979,
navajowhite = 0.76519682342785,
wheat = 0.74909702820482,
burlywood = 0.51559844533893,
tan = 0.48237604163921,
rosybrown = 0.32319457649407,
sandybrown = 0.46628543696283,
goldenrod = 0.41919977809569,
darkgoldenrod = 0.27264703559993,
peru = 0.30113074877936,
chocolate = 0.23898526114557,
saddlebrown = 0.097922285020521,
sienna = 0.13697631337098,
brown = 0.098224287876511,
}
-- whitespace
c = c:match( '^%s*(.-)%s*$' )
-- lowercase
c = c:lower()
-- first try to look it up
local L = HTMLcolor[c]
if (L ~= nil) then
return L
end
-- remove leading # (if there is one) and whitespace
c = mw.ustring.match(c, '^[%s#]*([a-f0-9]*)[%s]*$')
-- split into rgb
local cs = mw.text.split(c or '', '')
if( #cs == 6 ) then
local R = sRGB( (16*tonumber('0x' .. cs[1]) + tonumber('0x' .. cs[2]))/255 )
local G = sRGB( (16*tonumber('0x' .. cs[3]) + tonumber('0x' .. cs[4]))/255 )
local B = sRGB( (16*tonumber('0x' .. cs[5]) + tonumber('0x' .. cs[6]))/255 )
L = 0.2126 * R + 0.7152 * G + 0.0722 * B
return L
elseif ( #cs == 3 ) then
local R = sRGB( (16*tonumber('0x' .. cs[1]) + tonumber('0x' .. cs[1]))/255 )
local G = sRGB( (16*tonumber('0x' .. cs[2]) + tonumber('0x' .. cs[2]))/255 )
local B = sRGB( (16*tonumber('0x' .. cs[3]) + tonumber('0x' .. cs[3]))/255 )
L = 0.2126 * R + 0.7152 * G + 0.0722 * B
return L
end
-- failure, return blank
return ''
end
function p._greatercontrast(args)
local bias = tonumber(args['bias'] or '0') or 0
local v1 = color2lum(args[1] or '')
local c2 = args[2] or '#FFFFFF'
local v2 = color2lum(c2)
local c3 = args[3] or '#000000'
local v3 = color2lum(c3)
local ratio1 = 0;
local ratio2 = 0;
if (type(v1) == 'number' and type(v2) == 'number') then
ratio1 = (v2 + 0.05)/(v1 + 0.05)
ratio1 = (ratio1 < 1) and 1/ratio1 or ratio1
end
if (type(v1) == 'number' and type(v3) == 'number') then
ratio2 = (v3 + 0.05)/(v1 + 0.05)
ratio2 = (ratio2 < 1) and 1/ratio2 or ratio2
end
return (ratio1 + bias > ratio2) and c2 or c3
end
function p._ratio(args)
local v1 = color2lum(args[1])
local v2 = color2lum(args[2])
if (type(v1) == 'number' and type(v2) == 'number') then
-- v1 should be the brighter of the two.
if v2 > v1 then
v1, v2 = v2, v1
end
return (v1 + 0.05)/(v2 + 0.05)
else
return args['error'] or '?'
end
end
function p.lum(frame)
return color2lum(frame.args[1] or frame:getParent().args[1])
end
function p.ratio(frame)
local args = frame.args[1] and frame.args or frame:getParent().args
return p._ratio(args)
end
function p.greatercontrast(frame)
local args = frame.args[1] and frame.args or frame:getParent().args
return p._greatercontrast(args)
end
return p