--PALETTE: Expand Colors v1.0
--by Richard Fhager
--http://hem.fyristorg.com/dawnbringer/
-- Email: dawnbringer@hem.utfors.se
-- MSN: annassar@hotmail.com
--
-- Copyright 2010 Richard Fhager
--
-- This program is free software; you can redistribute it and/or
-- modify it under the terms of the GNU General Public License
-- as published by the Free Software Foundation; version 2
-- of the License. See <http://www.gnu.org/licenses/>
-- Continously fill the greatest void in the area of the color-cube enclosed by (or along ramps of) initial colors
-- This algorithm will create lines of allowed colors (all ranges) in 3d colorspace and the pick
-- new colors from the most void areas (on any line). Almost like a Median-cut in reverse.
--
-- Rather than filling the colorcube symmetrically it adds intermediate colors to the existing ones.
--
-- Running this script on the C64 16-color palette might be educational
--
--
-- Source cols#, Expand to #,
-- Ex: 15-31 means that palette colors 0-15 is expanded to 16 new colors placed at slots 16-31
--
-- Spread mode: OFF - New colors will conform to the contrast & saturation of original colors
-- (new colors will stay on the ramps possible from the original colors)
--
-- ON - New colors will expand their variance by each new addition (mostly notable when adding many new colors)
-- Will add range lines/ramps to all new colors from old ones, but keep within max/min values of the
-- original colors. 15-bit mode will dampen the spread towards extreme colors (if starting with low contrast)
--
-- 15-bit colors: Higher color-resolution, 32768 possible colors rather than the 4096 of 12bit. Slower but perhaps better.
--
SHADES = 16 -- Going 24bit will probably be too slow and steal too much memory, so start with 12bit (4096 colors) for now
ini = 0
exp = 255
OK,ini,exp,linemode,fbit = inputbox("Expand Colors (0-255):",
"Source Cols #: 1-254", 15, 1,254,0,
"Expand to #: 2-255", 31, 2,255,0,
"Spread mode", 0, 0,1,0,
"15-bit colors (slow)", 0, 0,1,0
);
if (fbit == 1) then SHADES = 32; end
function initColorCube(sha)
ary = {}
for z = 0, sha-1, 1 do
ary[z+1] = {}
for y = 0, sha-1, 1 do
ary[z+1][y+1] = {}
for x = 0, sha-1, 1 do
ary[z+1][y+1][x+1] = {false,0}
end
end
end
return ary
end
-- Gravity model (think of colors as stars of equal mass/brightness in a 3d space)
function addColor2Cube(cube,sha,r,g,b)
star = 1000000
fade = 1000
cube[r+1][g+1][b+1] = {false,star}
for z = 0, sha-1, 1 do
for y = 0, sha-1, 1 do
for x = 0, sha-1, 1 do
d = fade / ( (x-b)^2 + (y-g)^2 + (z-r)^2 )
cube[z+1][y+1][x+1][2] = cube[z+1][y+1][x+1][2] + d
end;end;end
end
-- Create new allowed colorlines in colorspace (ramps from which colors can be picked)
function enableRangeColorsInCube(cube,sha,r1,g1,b1,r2,g2,b2)
local div,r,g,b
div = 256 / sha
rs = (r2 - r1) / sha / div
gs = (g2 - g1) / sha / div
bs = (b2 - b1) / sha / div
for n = 0, sha-1, 1 do
r = math.floor(r1/div + rs * n)
g = math.floor(g1/div + gs * n)
b = math.floor(b1/div + bs * n)
cube[r+1][g+1][b+1][1] = true
end
end
function findVoid(cube,sha)
weakest = 999999999999
weak_i = {-1,-1,-1}
for z = 0, sha-1, 1 do
for y = 0, sha-1, 1 do
for x = 0, sha-1, 1 do
c = cube[z+1][y+1][x+1]
if c[1] == true then
w = c[2]
if w <= weakest then weakest = w; weak_i = {z,y,x}; end
end
end;end;end
return weak_i[1],weak_i[2],weak_i[3]
end
--
if OK == true then
cube = initColorCube(SHADES)
-- Define allowed colorspace
for y = 0, ini-1, 1 do
r1,g1,b1 = getcolor(y)
for x = y+1, ini, 1 do
r2,g2,b2 = getcolor(x)
enableRangeColorsInCube(cube,SHADES,r1,g1,b1,r2,g2,b2)
end
end
div = 256 / SHADES
-- Fill cube with initial colors
for n = 0, ini, 1 do
r,g,b = getcolor(n)
addColor2Cube(cube,SHADES,math.floor(r/div),math.floor(g/div),math.floor(b/div))
end
for n = ini+1, exp, 1 do
r,g,b = findVoid(cube,SHADES)
if (r == -1) then messagebox("Report:","No more colors can be found, exit at "..n); break; end
mult = 255 / (SHADES - 1)
setcolor(n, r*mult,g*mult,b*mult)
if linemode == 1 then
-- Add lines from new color to all old
for x = 0, n-1, 1 do
r2,g2,b2 = getcolor(x)
enableRangeColorsInCube(cube,SHADES,r*mult,g*mult,b*mult,r2,g2,b2) -- uses 24bit values rgb
end
end
addColor2Cube(cube,SHADES,r,g,b) -- rgb is in 'shade' format here
end
end