--------------------
 Local fill pattern
--------------------

See here for source:
https://www.lexaloffle.com/bbs/?tid=30518



_fillp_original=fillp

function fillp(pattern,x,y)
		local add_bits=band(pattern,0x0000.ffff)
		pattern=band(pattern,0xffff)
		y=flr(y)%4
		if(y~=0)then
				local r={0xfff0,0xff00,0xf000}
				local l={0x000f,0x00ff,0x0fff}
				pattern=bxor(lshr(band(pattern,r[y]),y*4),shl(band(pattern,l[y]),(4-y)*4))
		end

		x=flr(x)%4
		if(x~=0)then
				local r={0xeeee,0xcccc,0x8888}
				local l={0x1111,0x3333,0x7777}
				pattern=bxor(lshr(band(pattern,r[x]),x),shl(band(pattern,l[x]),4-x))
		end

		return _fillp_original(bxor(pattern,add_bits))
end