Module:Sandbox/AlexNB/nmColor: Difference between revisions

Revision as of 19:07, 24 October 2013

Latest revision as of 23:15, 27 September 2014

(81 intermediate revisions by the same user not shown)

Line 28:

greenvalue = (645 - wavelength) / 65

bluevalue = 0

elseif (wavelength >= 645) and (wavelength <= 780) then

redvalue = 1

greenvalue = 0

Line 55:

local result='#' .. string.format("%.2X%.2X%.2X", 255*redvalue, 255*greenvalue, 255*bluevalue)

return result

end

local function absorption_to_visible(wavelength_abs)

-- code based on a color wheel drawn at: http://www2.chemistry.msu.edu/faculty/reusch/virttxtjml/spectrpy/uv-vis/spectrum.htm

local wavelength_vis

local minVioletIndigo = 380 -- originally, it was 400

local maxVioletIndigo = 430

local widthVioletIndigo = maxVioletIndigo - minVioletIndigo

local redsumminBlue = 0430

local bluesummaxBlue = 0490

local widthBlue = maxBlue - minBlue

local greensumminGreen = 0490

local numofitemsmaxGreen = 400560

local widthGreen = maxGreen - minGreen

local minYellow = 560

local maxYellow = 580

local widthYellow = maxYellow - minYellow

local minOrange = 580

local maxOrange = 650 -- originally, it was 620

local widthOrange = maxOrange - minOrange

local minRed = 650 -- originally, it was 620

local maxRed = 780 -- originally, it was 800

local widthRed = maxRed - minRed

if (wavelength_abs>=minVioletIndigo) and (wavelength_abs<=maxVioletIndigo) then

wavelength_vis = (wavelength_abs - minVioletIndigo)*widthYellow/widthVioletIndigo + minYellow

elseif (wavelength_abs>minBlue) and (wavelength_abs<=maxBlue) then

wavelength_vis = (wavelength_abs - minBlue)*widthOrange/widthBlue + minOrange

elseif (wavelength_abs>minGreen) and (wavelength_abs<=maxGreen) then

wavelength_vis = (wavelength_abs - minGreen)*widthRed/widthGreen + minRed

elseif (wavelength_abs>minYellow) and (wavelength_abs<=maxYellow) then

wavelength_vis = (wavelength_abs - minYellow)*widthVioletIndigo/widthYellow + minVioletIndigo

elseif (wavelength_abs>minOrange) and (wavelength_abs<=maxOrange) then

wavelength_vis = (wavelength_abs - minOrange)*widthBlue/widthOrange + minBlue

elseif (wavelength_abs>minRed) and (wavelength_abs<=maxRed) then

wavelength_vis = (wavelength_abs - minRed)*widthGreen/(widthRed + 20) + minGreen

-- one of the "corrected" versions: wavelength_vis = (wavelength_abs - minRed - 30)*widthGreen/widthRed + minGreen

end

return wavelength_vis

end

local minAntiMagenta = 550

local maxAntiMagenta = 570

local function process_magenta(wavelength_abs)

local redvalue_RED

local bluevalue_RED

local greenvalue_RED

local redvalue_BLUE

local bluevalue_BLUE

local greenvalue_BLUE

local widthAntiMagenta = maxAntiMagenta - minAntiMagenta

local bias_BLUE = (wavelength_abs - minAntiMagenta)/widthAntiMagenta

local bias_RED = (maxAntiMagenta - wavelength_abs)/widthAntiMagenta

nm2RGB(wlcycle700, false)

redvalue_RED = redvalue*bias_RED

bluevalue_RED = bluevalue*bias_RED

greenvalue_RED = greenvalue*bias_RED

-- nm2RGB(wavelength400, false)

redvalue_BLUE = redvalue*bias_BLUE

bluevalue_BLUE = bluevalue*bias_BLUE

greenvalue_BLUE = greenvalue*bias_BLUE

redvalue = 0.6+ 0.4*(redvalue_RED + redvalue_BLUE)

bluevalue = 0.7 + 0.3*(bluevalue_RED + bluevalue_BLUE)

greenvalue = greenvalue_RED + greenvalue_BLUE

end

function p.absorption(frame)

-- this function returns the string "#RRGGBB" with approximate RGB value for a complementary color (reflection) to a color, defined as a wavelength passed as a first argument

-- The following formula is used for the complimentary color: {0xFF - RR, 0xFF - (RR + BB)/2, 0xFF - BB}

-- local wavelength = tonumber(frame.args[1])

-- nm2RGB(wavelength)

-- local result='#' .. string.format("%.2X%.2X%.2X", 255*(1-redvalue), 255*(1-greenvalue), 255*(1-bluevalue))

local wavelength = tonumber(frame.args[1])

-- adding magentas to smoothen red->blue transition. Trying 540..570 nm

local redsum = 0

if (wavelength>=minAntiMagenta) and (wavelength<=maxAntiMagenta) then

local greensum = 0

if wlcycle < process_magenta(wavelength then)

local bluesum = 0

else nm2RGB(absorption_to_visible(wavelength), false)

local intensityfactor = 0

local numofitems = 400

for wlcycle = 380,780,1 do

nm2RGB(wlcycle, false)

if wlcycle < wavelength then

intensityfactor = (wlcycle - 380) / (wavelength - 380)

else

intensityfactor = (wlcycle - wavelength) / (380 - wavelength) + 1

end

if intensityfactor < 0 then

intensityfactor = 0

numofitems = numofitems - 1

end

redsum = redsum + redvalue*(intensityfactor*0.3)

greensum = greensum + greenvalue*(intensityfactor*0.59)

bluesum = bluesum + bluevalue*(intensityfactor*0.11)

end

local result='#' .. string.format("%.2X%.2X%.2X", 255*(1-redsum/numofitems)redvalue, 255*(1-greensum/numofitems)greenvalue, 255*(1-bluesum/numofitems)bluevalue)

return result

end

return p