1 files changed, 108 insertions, 13 deletions
diff --git a/img/better_disp.lua b/img/better_disp.lua
index d7b59c1..1d36f7a 100644
--- a/img/better_disp.lua
+++ b/img/better_disp.lua
@@ -1,3 +1,5 @@
+local disp_common = require("disp_common")
+
 -- a vlorb consists of six gromlings[A
 -- 1  2
 -- 4  8
@@ -22,10 +24,102 @@ local function vlorb(onc,offc, g1,g2,g3,g4,g5,g6)
 	return textc,bgc,string.char(vlorbchar)
 end
 
-local function should_be_on(col)
-	return col[1]+col[2]+col[3] > 1.5
+local function all_palette_distances(R)
+	local out = {}
+	for a=0,15 do
+		for b = 0,15 do
+			local ia=2^a
+			local ib=2^b
+			local ca = R.getPaletteColor(ia)
+			local cb = R.getPaletteColor(ib)
+			local dist = disp_common.color_dist(ca,cb)
+			out[ia][ib] = dist
+		end
+	end
+	return out
+end
+
+local function list_contains(list,val)
+	for _,v in ipairs(list) do
+		if v == val then return true end
+	end
+	return false
 end
 
+-- R, lPx_gromlings, l_pdists  -> lCx_gromlings
+local function adjust_to_2_colors(R,gromlings,pdists)
+	-- gromlings goes 1 2 3 4 5 6
+	-- compress the 6 pixels to just 2 colors
+	-- return the list of cidxs
+	local gromling_colors = {}
+	for i,c in ipairs(gromlings) do
+		gromling_colors[i] = disp_common.closest_palette_color(R,c)
+	end
+
+	local all_current_colors = {}
+	local ncolors = 0
+	for _,cidx in ipairs(gromling_colors) do
+		all_current_colors[cidx] = true
+		ncolors = ncolors+1
+	end
+	
+	while ncolors > 2 do
+		-- merge closest two colors until there are only 2 distinct ones left
+		local best_dist = 9999
+		local best_a = nil
+		local best_b = nil
+		for a in pairs(all_current_colors) do
+			for b in pairs(all_current_colors) do
+				if a ~= b then
+					local dist = pdists[a][b]
+					if dist < best_dist then
+						best_dist = dist
+						best_a = a
+						best_b = b
+					end
+				end
+			end
+		end
+
+		-- todo: be cleverer when deciding whether to merge a into b, or b into a
+		-- currently just merge b into a
+		assert(best_a and best_b and best_a ~= best_b)
+		all_current_colors[best_b] = false
+		ncolors=ncolors-1
+		for gidx,col in ipairs(gromling_colors) do
+			if col == best_b then gromling_colors[gidx] = best_a end
+		end
+	end
+
+	return gromling_colors
+end
+
+local function gromling_list_to_vlorb(gromling_colors)
+	-- takes list of cidxs 
+	local ca = nil
+	local cb = nil
+	local gs = {}
+	for i,col in ipairs(gromling_colors) do
+		if col == ca then
+			gs[i] = true
+		elseif col == cb then
+			gs[i] = false
+		else
+			if not ca then
+				ca = col
+				gs[i] = true
+			elseif not cb then
+				cb = col
+				gs[i] = false
+			else
+				error("third gromling color in vlorb")
+			end
+		end
+	end
+	return ca,cb,table.unpack(gs)
+end
+	
+
 -- todo: refactor common stuff into a common file
 local function disp(R,img,scrx,scry,w,h,imgx,imgy)
 	-- w and h are image coords
@@ -36,6 +130,9 @@ local function disp(R,img,scrx,scry,w,h,imgx,imgy)
 	imgx = imgx or 1
 	imgy = imgy or 1
 
+	disp_common.improve_palette(R,img,w,h,imgx,imgy)
+	local pdists=all_palette_distances(R)
+
 	local sw = math.ceil(w/2)
 	local sh = math.ceil(h/3)
 
@@ -44,23 +141,21 @@ local function disp(R,img,scrx,scry,w,h,imgx,imgy)
 			local ioffx=soffx*2
 			local ioffy=soffy*3
 			R.setCursorPos(scrx+soffx,scry+soffy)
-			local gs = {}
+			local lPx_gromlings = {}
 			for goffy=0,2 do
 				for goffx=0,1 do
-					local ic = img[imgy+ioffy+goffy][imgx+ioffx+goffx] or {0,0,0}
-					table.insert(gs,should_be_on(ic))
+					local px = img[imgy+ioffy+goffy][imgx+ioffx+goffx] or {0,0,0}
+					table.insert(lPx_gromlings,px)
 				end
 			end
-			local tc,bc,ch = vlorb(colors.white,colors.black,table.unpack(gs))
-			R.setTextColor(tc)
-			R.setBackgroundColor(bc)
-			R.write(ch)
+
+			local lCx_gromlings = adjust_to_2_colors(lPx_gromlings)
+			local textc,bgc,vlorbchar = vlorb(gromling_list_to_vlorb(lCx_gromlings))
+			R.setTextColor(textc)
+			R.setBackgroundColor(bgc)
+			R.write(vlorbchar)
 		end
 	end
 end
 
-
-	
-	
-
 return {vlorb=vlorb,disp=disp}