file=io.open(arg[1],"rb")
oname=arg[1]:gsub("%.[^%.]+","_output.txt")

byte=nil

--54 is size of header
file:read(18)

--Read in the pixel width of the image
_width=file:read(4)
swidth=""
for _w in _width:gmatch(".") do
	swidth=string.format("%02X",string.byte(_w))..swidth
end
rowsize=tonumber(swidth,16)

--Read the pixel height of the image, including its orientation
_height=file:read(4)
sheight=""
for _h in _height:gmatch(".") do
	sheight=string.format("%02X",string.byte(_h))..sheight
end
imgheight=tonumber(sheight,16)

--Handle two's complement. Good god this is hacky
if imgheight>tonumber("7FFFFFFF",16) then
	imgheight=imgheight-tonumber("FFFFFFFF",16)-1
end

file:read(2)

--Read in whether the bitmap is 24 or 32 bit (fuck handling anything less)
bitsize=string.byte(file:read(1))

wordsize=bitsize/8

file:read(25)

--Pixel size
px=tonumber(arg[2]) or 1

--Multiple lines or single line?
multi=arg[3] or "true"

--Tolerance in rgb-space for standard deviation of average pixel color
tolerance=tonumber(arg[4]) or 40

--Alpha channel?
alpha=false
afile=nil
if arg[5]~=nil then
	alpha=true
	afile=io.open(arg[5],"rb")
	afile:read(54)
end

--Distance in rgb space
local function cdist(r1,g1,b1,r2,g2,b2)
	return math.sqrt((r1-r2)^2+(g1-g2)^2+(b1-b2)^2)
end

counter=0

bytesread=0

--Stores previous color used, standard deviation, last color
_r,_g,_b=-1*tolerance-1,-1*tolerance-1,-1*tolerance-1
sr,sg,sb=_r,_g,_b
lr,lg,lb=_r,_g,_b

--Stores current and previous alphas
aval="00"
praval="00"
ppraval="00"

--Width of next shape to draw
width=1

--String to store each line
line=""

--Table to store processed image
imgtable={}

print("\nProcessing "..arg[1].." with "..px.."x"..px.." pixels at tolerance "..tolerance..".")
if multi=="true" then print("Each row will be output on a new line.")
else print("The entire image will be output as one line.")
end

--For progress reporting
print("\n"..("_"):rep(20).."/100%")
progstep=math.floor(math.abs(imgheight)/20)

--Force alpha tag if alpha channel is on
if alpha then ppraval="GG" end

while true do
	byte=file:read(wordsize)
	bytesread=bytesread+wordsize
	
	if byte==nil then break end
	
	b,g,r=byte:match("^(.)(.)(.)")
	
	if b==nil or g==nil or r==nil then break end
	
	r=string.byte(r)
	g=string.byte(g)
	b=string.byte(b)
	
	--Temporary old values of the average
	_tr,_tg,_tb=_r,_g,_b
	
	if _r>=0 then
		
		--Keep a running average of the rgb values
		_r=_r+(r-_r)/(width+1)
		_g=_g+(g-_g)/(width+1)
		_b=_b+(b-_b)/(width+1)
		
		--Keep a running standard deviation or the rbg values
		sr=sr+(r-_tr)*(r-_r)
		sg=sg+(g-_tg)*(g-_g)
		sb=sb+(b-_tb)*(b-_b)
	end
	
	--Read and average alpha channel
	if alpha then
		abyte=afile:read(wordsize)
		ab,ag,ar=abyte:match("^(.)(.)(.)")
		aval=string.format("%02X",
			math.floor((string.byte(ab)+string.byte(ag)+string.byte(ar))/3))
	end
	
	if ((cdist(lr,lg,lb,r,g,b)<tolerance
		and cdist(sr,sg,sb,0,0,0)<tolerance and aval==praval))
		or (aval=="FF" and aval==praval) then
	
		--Increase width
		width=width+1
		
	else
		
		--Only add the colors if this is not the first pixel in a row
		if _r>=0 then
			shape=string.format("m 0 0 l 0 %d %d %d %d 0",px,width*px,px,width*px)
			
			--Add color code
			code=string.format("%02X%02X%02X",_tb,_tg,_tr)
			
			if praval~=ppraval then
				line=line.."{\\c&H"..code.."&\\alpha&H"..praval.."&}"
			else
				line=line.."{\\c&H"..code.."&}"
			end
			line=line..shape
		end
		
		--Reset width and colors
		width=1
		_r,_g,_b=r,g,b
		sr,sg,sb=0,0,0
	
		--Set last alpha value
		if alpha then
			ppraval=praval
			praval=aval
		end
	end
	
	--Set last r,g,b values
	lr,lg,lb=r,g,b
	
	counter=counter+1
	if counter%rowsize==0 then
	
		--Read filler bytes
		file:read(math.abs((4-bytesread)%4))
		if alpha then afile:read(math.abs((4-bytesread)%4)) end
		bytesread=0
		
		--Dump current shape on end of line
		code=string.format("%02X%02X%02X",_b,_g,_r)
		shape=string.format("m 0 0 l 0 %d %d %d %d 0",px,width*px,px,width*px)
		if alpha then
			line=line.."{\\c&H"..code.."&\\alpha&H"..aval.."&}"
		else
			line=line.."{\\c&H"..code.."&}"
		end
		line=line..shape
		
		--Add line to table
		table.insert(imgtable,line)
		
		--Progress report
		rprog=math.floor(counter/rowsize)
		if rprog%progstep==0 or rprog==math.abs(imgheight) then
			io.write("|")
		end
		
		--Reset the line
		line=""
		
		--Reset previous colors
		_r=-1*tolerance-1
		_g=-1*tolerance-1
		_b=-1*tolerance-1
		sr,sg,sb=_r,_g,_b
		lr,lg,lb=_r,_g,_b
		
		--Reset alpha if alpha channel is on
		if alpha then praval="GG" end
		
		--Reset width
		width=1
	end
end

--Close files
file:close()
if alpha then afile:close() end

--Open output file
output=io.open(oname,"wb")

--Set proper prefixes and eol
prefix=function() return "{\\p1}" end
eol="{\\p0}\\N"
if multi=="true" then
	prefix=function(h) return string.format("{\\p1\\an7\\pos(0,%d)}",h) end
	eol="\r\n"
end

--Write the rows in the correct order
rstart,rend,step=#imgtable,1,-1
if imgheight<0 then rstart,rend,step=1,#imgtable,1 end

count=0
for i=rstart,rend,step do
	output:write(prefix(count*px)..imgtable[i])
	if i~=rend then output:write(eol) end
	count=count+1
end

output:close()
io.write("\n")--just for prettiness