ClientOS/LevelOS/startup/MwMRender

if mwm == nil then _G.mwm = {} end
function tabletext(text)
	local tTable = {}
	for a=1,string.len(text) do
		tTable[a] = string.sub(text,a,a)
	end
	return tTable
end
to_colors, to_blit = {}, {}
for i = 1, 16 do
    to_blit[2^(i-1)] = ("0123456789abcdef"):sub(i, i)
    to_colors[("0123456789abcdef"):sub(i, i)] = 2^(i-1)
end
function mwm.newCvs(tX,tY)
	local cvs = {}
	cvs.rCvs = {}
	cvs.oCvs = {}
	cvs.orCvs = {}
	cvs.color = colors.white
	if tX == nil or tY == nil then
		tX,tY = term.getSize()
	end
	for x=1,tX do
		cvs.rCvs[x] = {}
		for y=1,tY do
			cvs.rCvs[x][y] = {"",term.getBackgroundColor()} -- empty pixel = ""
		end
	end
	cvs.width = tX
	cvs.height = tY
	local function genCvs()
	    cvs.rCvs = {}
	    local tX,tY = cvs.width,cvs.height
	    for x=1,tX do
	        cvs.rCvs[x] = {}
	        for y=1,tY do
	            cvs.rCvs[x][y] = {"",term.getBackgroundColor()} -- empty pixel = ""
	        end
	    end
	end
	function cvs.setColor(color)
		cvs.color = color
	end
	function cvs.rect(x,y,w,h,text,txtcolor)
		if tonumber(x) == nil or tonumber(y) == nil or tonumber(w) == nil or tonumber(h) == nil then
			return
		end
		if text ~= nil then
			if txtcolor == nil then
				txtcolor = colors.white
			end
			if type(text) == "string" then
				text = {text}
			end
			for t=1,#text do
				if string.len(text[t]) > w then
					string.sub(text[t],1,w)
				end
			end
		end
		cvs.oCvs[#cvs.oCvs+1] = {type="rect",x=x,y=y,width=w,height=h,color=cvs.color,txt=text,txtcolor=txtcolor,ref=#cvs.oCvs+1}
		return cvs.oCvs[#cvs.oCvs],true
	end
	function cvs.print(text,x,y)
		if text == nil or tonumber(x) == nil or tonumber(y) == nil then
			return
		end
		cvs.oCvs[#cvs.oCvs+1] = {type="text",txt=text,x=x,y=y,color=cvs.color}
		return cvs.oCvs[#cvs.oCvs],true
	end
	cvs.write = cvs.print
	function cvs.sprite(file,x,y,w,h)
		if fs.exists(file) == false then
			return
		end
		opensprite = fs.open(file,"r")
		local sprite = opensprite.readAll()
		opensprite.close()
		sprite = textutils.unserialize(sprite)
		if sprite == nil then return end
		cvs.oCvs[#cvs.oCvs+1] = {type="sprite",texture=sprite,x=x,y=y,width=w,height=h}
		return cvs.oCvs[#cvs.oCvs]
	end
	-- Support circle rendering. This can be done by calculating with math.cos how many pixels it is from one side of one y coord to the other side of the same y coord and putting that in a string. repeat this for	every y coord then draw
	function cvs.clear()
		cvs.oCvs = {}
	end
	function cvs.render(trans,x1,y1,x2,y2)
		if x1 == nil then x1 = 1 end
		if y1 == nil then y1 = 1 end
		if x2 == nil then x2 = cvs.width end
		if y2 == nil then y2 = cvs.height end
		genCvs()
		bgcolor = term.getBackgroundColor()
		for a=1,#cvs.oCvs do
			local o = cvs.oCvs[a]
			cvs.oCvs[a].ref = a
			o.x = math.floor(o.x+0.5)
			o.y = math.floor(o.y+0.5)
			if o.type == "rect" then
				for b=1,o.height do
					for c=1,o.width do
						local tX,tY = term.getSize()
						if o.x+(c-1) <= tX and o.y+(b-1) <= tY and o.x+(c-1) > 0 and o.y+(b-1) > 0 then
							cvs.rCvs[o.x+(c-1)][o.y+(b-1)] = {" ",o.color}
						end
					end
				end
				if o.txt ~= nil and o.txtcolor ~= nil then
					for b=1,o.height do
						if o.txt[b] ~= nil then
							dObj = tabletext(o.txt[b])
							for c=1,string.len(o.txt[b]) do
								cvs.rCvs[o.x+(c-1)][o.y+(b-1)] = {dObj[c],o.color,o.txtcolor}
							end
						end
					end
				end
			elseif o.type == "sprite" then
				for b=1,o.height do
					for c=1,o.width do
						if o.texture[c] ~= nil then
							local tX,tY = term.getSize()
							if o.x+(c-1) <= tX and o.y+(b-1) <= tY and o.x+(c-1) > 0 and o.y+(b-1) > 0 and o.texture[c][b] ~= nil then
								cvs.rCvs[o.x+(c-1)][o.y+(b-1)] = o.texture[c][b]
							end
						end
					end
				end
			elseif o.type == "text" then
				dObj = tabletext(o.txt)
				for b=1,#dObj do
					local tX,tY = term.getSize()
					if o.x+(b-1) <= tX and o.y <= tY and o.x+(b-1) > 0 and o.y > 0 then
						cvs.rCvs[o.x+(b-1)][o.y][1] = dObj[b]
						cvs.rCvs[o.x+(b-1)][o.y][3] = o.color
					end
				end
			end
		end
		for y=y1,y2 do
			bl1 = ""
			bl2 = ""
			bl3 = ""
			for x=x1,x2 do
				if not (cvs.orCvs[x] ~= nil and cvs.orCvs[x][y] == cvs.rCvs[x][y]) then
					if cvs.rCvs[x][y][1] == "" then
						if term.current().getLine and trans then
							local theline = {term.current().getLine(y)}
							bl1 = bl1..string.sub(theline[1],x,x)
							bl2 = bl2..string.sub(theline[2],x,x)
							bl3 = bl3..string.sub(theline[3],x,x)
						else
							bl1 = bl1.." "
							bl2 = bl2..0
							bl3 = bl3..to_blit[cvs.rCvs[x][y][2]]
						end
					else
						if cvs.rCvs[x][y][3] ~= nil then
							bl2 = bl2..to_blit[cvs.rCvs[x][y][3]]
						else
							bl2 = bl2..0
						end
						bl1 = bl1..tostring(cvs.rCvs[x][y][1])
						bl3 = bl3..to_blit[cvs.rCvs[x][y][2]]
					end
				end
			end
			term.setCursorPos(x1,y)
			term.blit(bl1,bl2,bl3)
		end
		cvs.orCvs = cvs.rCvs
		term.setBackgroundColor(bgcolor)
	end
	return cvs
end