62 lines
1.2 KiB
Lua
62 lines
1.2 KiB
Lua
--PICTURE: Rainbow - Dark to Bright
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--by Richard Fhager
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--http://hem.fyristorg.com/dawnbringer/
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-- Email: dawnbringer@hem.utfors.se
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-- MSN: annassar@hotmail.com
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--
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-- This script was adopted from Evalion, a Javascript codecrafting/imageprocessing project
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-- http://goto.glocalnet.net/richard_fhager/evalion/evalion.html
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--
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--
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function shiftHUE(r,g,b,deg) -- V1.3 R.Fhager 2007, adopted from Evalion
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local c,h,mi,mx,d,s,p,i,f,q,t
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c = {g,b,r}
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mi = math.min(r,g,b)
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mx = math.max(r,g,b); v = mx;
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d = mx - mi;
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s = 0; if mx ~= 0 then s = d/mx; end
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p = 1; if g ~= mx then p = 2; if b ~= mx then p = 0; end; end
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if s~=0 then
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h=(deg/60+(6+p*2+(c[1+p]-c[1+(p+1)%3])/d))%6;
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i=math.floor(h);
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f=h-i;
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p=v*(1-s);
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q=v*(1-s*f);
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t=v*(1-s*(1-f));
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c={v,q,p,p,t,v}
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r = c[1+i]
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g = c[1+(i+4)%6]
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b = c[1+(i+2)%6]
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end
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return r,g,b
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end
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--
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w, h = getpicturesize()
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for y = 0, h - 1, 1 do
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for x = 0, w - 1, 1 do
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-- Fractionalize image dimensions
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ox = x / w;
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oy = y / h;
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r = 255 * math.sin(oy * 2)
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g = (oy-0.5)*512 * oy
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b = (oy-0.5)*512 * oy
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r, g, b = shiftHUE(r,g,b,ox * 360);
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c = matchcolor(math.max(0,math.min(255,r)),math.max(0,math.min(255,g)),math.max(0,math.min(255,b)))
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putpicturepixel(x, y, c);
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end
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end
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