f4bfaeca89
Scripts for various Thomson machines, Oric and ZX. All the hard work of Samuel Devulder, with extensive research on color palette reduction algorithms, lots of testing, research and debugging. Thanks a lot!
68 lines
1.4 KiB
Lua
68 lines
1.4 KiB
Lua
-- bayer.lua : bayer matrix suppport.
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--
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-- Version: 02-jan-2017
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--
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-- Copyright 2016-2017 by Samuel Devulder
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--
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-- This program is free software; you can redistribute
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-- it and/or modify it under the terms of the GNU
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-- General Public License as published by the Free
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-- Software Foundation; version 2 of the License.
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-- See <http://www.gnu.org/licenses/>
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if not bayer then
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bayer = {}
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-- doubles a matrix rows and columns
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function bayer.double(matrix)
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local m,n=#matrix,#matrix[1]
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local r = {}
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for j=1,m*2 do
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local t = {}
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for i=1,n*2 do t[i]=0; end
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r[j] = t;
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end
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-- 0 3
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-- 2 1
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for j=1,m do
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for i=1,n do
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local v = 4*matrix[j][i]
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r[m*0+j][n*0+i] = v-3
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r[m*1+j][n*1+i] = v-2
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r[m*1+j][n*0+i] = v-1
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r[m*0+j][n*1+i] = v-0
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end
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end
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return r;
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end
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-- returns a version of the matrix normalized into
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-- the 0-1 range
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function bayer.norm(matrix)
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local m,n=#matrix,#matrix[1]
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local max,ret = 0,{}
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for j=1,m do
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for i=1,n do
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max = math.max(max,matrix[j][i])
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end
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end
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-- max=max+1
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for j=1,m do
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ret[j] = {}
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for i=1,n do
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ret[j][i]=matrix[j][i]/max
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end
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end
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return ret
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end
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-- returns a normalized order-n bayer matrix
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function bayer.make(n)
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local m = {{1}}
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while n>1 do n,m = n/2,bayer.double(m) end
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return bayer.norm(m)
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end
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end -- Bayer |