samples_2.4 => samples

share/grafx2/scripts/samples/picture/thomson/none_to9.lua

@@ -0,0 +1,55 @@
+-- ostro_mo5.lua : converts a color image into a
+-- TO9 image (320x200x16 with color clashes)
+-- using Ostromoukhov's error diffusion algorithm.
+--
+-- Version: 02-jan-2017
+--
+-- Copyright 2016-2017 by Samuel Devulder
+--
+-- 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/>
+
+run('lib/thomson.lua')
+thomson.optiMAP = false
+
+run('lib/ostromoukhov.lua')
+run('lib/color_reduction.lua')
+
+local dith=OstroDither:new()
+local tmp=dith.setLevelsFromPalette
+dith.setLevelsFromPalette = function(self)
+	tmp(self)
+	self.attenuation=0
+end
+dith:dither40cols(function(w,h,getLinearPixel)
+	local c16 = true
+	for y=0,h-1 do
+		for x=0,w-1 do
+			if getbackuppixel(x,y)>15 then c16 = false end
+		end
+	end
+
+	local pal
+	if c16 then
+		pal = {}
+		for i=0,15 do
+			local r,g,b=getbackupcolor(i)
+			r = thomson.levels.pc2to[r]
+			g = thomson.levels.pc2to[g]
+			b = thomson.levels.pc2to[b]
+			pal[i+1] = r+g*16+b*256-273
+		end
+	else
+		pal=ColorReducer:new():analyzeWithDither(w,h,
+			getLinearPixel,
+			function(y)
+				thomson.info("Building palette...",math.floor(y*100/h),"%")
+			end):buildPalette(16)
+	end
+	thomson.palette(0, pal)
+
+	return pal
+end)