Module:Color contrast: Difference between revisions

    From Nonbinary Wiki
    m>Frietjes
    (typo)
    m>Frietjes
    Line 2: Line 2:
    -- This module implements  
    -- This module implements  
    --  {{Color contrast ratio}}
    --  {{Color contrast ratio}}
    --  {{Greater contrast ratio}}
    --  {{ColorToLum}}
    --  {{ColorToLum}}
    --  {{RGBColorToLum}}
    --  {{RGBColorToLum}}
    Line 120: Line 121:
    -- failure, return blank
    -- failure, return blank
    return ''
    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
    ratio1 = (v3 + 0.05)/(v1 + 0.05)
    ratio1 = (ratio1 < 1) and 1/ratio1 or ratio1
    end
    return (ratio1 + bias > ratio2) and c2 or c3
    end
    end


    Line 140: Line 161:
    return p._ratio(args)
    return p._ratio(args)
    end
    end
     
    function p.greatercontrast(frame)
    local args = frame.args[1] and frame.args or frame:getParent().args
    return p._greatercontrast(args)
    end
     
    return p
    return p

    Revision as of 20:42, 3 April 2015

    Documentation for this module may be created at Module:Color contrast/doc

    --
    -- This module implements 
    --  {{Color contrast ratio}}
    --  {{Greater 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
    		ratio1 = (v3 + 0.05)/(v1 + 0.05)
    		ratio1 = (ratio1 < 1) and 1/ratio1 or ratio1
    	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
    		return (v2 + 0.05)/(v1 + 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