monitor_mUnit

local args = { ... }

os.loadAPI("vislib")

local m = peripheral.find("monitor")
m.setTextScale(0.5)
local monX, monY = m.getSize()

local sx = math.floor(0.047 * monX + 0.8)
local sy = math.floor(0.07 * monY + 0.8)

local scrW = 16 * sx - 4
local scrH = 16 * sy - 4

local scrResX = (scrH / monY) / (scrW / monX)
local f = monY / scrH
local scrResX = scrResX * f
local scrResY = f

function round(num)
    return math.floor(num + 0.4)
end

function drawLine(x1, y1, x2, y2, color)
    m.setBackgroundColor(color)
    x1 = round(x1 * scrResX)
    x2 = round(x2 * scrResX)
    y1 = round(y1 * scrResY)
    y2 = round(y2 * scrResY)

    if math.abs(x2 - x1) > math.abs(y2 - y1) then
        for x = math.min(x1, x2), math.max(x1, x2) do
            if x > 0 and x <= monX then
                local y = round(y1 + 1.0 * (x - x1) * (y2 - y1) / (x2 - x1))
                if y > 0 and y <= monY then
                    m.setCursorPos(x, y)
                    m.write(" ")
                end
            end
        end
    else
        for y = math.min(y1, y2), math.max(y1, y2) do
            local x = x1 + 1.0 * (y - y1) * (x2 - x1) / (y2 - y1)
            m.setCursorPos(x, y)
            m.write(" ")
        end
    end
end

function drawRect(x, y, w, h, c)
    m.setBackgroundColor(c)
    local x1 = round((x + w) * scrResX)
    x = round(x * scrResX)
    local y1 = round((y + h) * scrResY)
    y = round(y * scrResY)

    if 0 < x1 and x <= monX and 0 < y1 and y <= monY then
        if x < 0 then x = 0 end
        if y < 0 then y = 0 end
        if x1 > monX then x1 = monX end
        if y1 > monY then y1 = monY end
        local txt = ""
        for x2 = x, x1 do
            txt = txt .. " "
        end
        for y2 = y, y1 do
            m.setCursorPos(x, y2)
            m.write(txt)
        end
    end
end

function getSize()
    local x, y = m.getSize()
    return x / scrResX, y / scrResY
end

function clear()
    m.setBackgroundColor(colors.black)
    m.clear()
end

if #args < 3 then error("3 arguments expected") end

local screenName = args[1]
local screenX = 0 --tonumber(args[2])
local screenY = 0 --tonumber(args[3])
local screenCX = tonumber(args[2])
local screenCY = tonumber(args[3])

local screenW, screenH = getSize()

print("screen[" .. screenName .. "]: ", screenX, ", ", screenY, ", ", screenW, ", ", screenH)

rednet.open("top")

function main()
    local id, msg = vislib.receiveRednet()
    local tag, pts = vislib.getMsgData(msg)
    if tag == "@mon" and pts[1] == screenName then
        if pts[2] == "clear" then
            clear()
        elseif pts[2] == "line" then
            drawLine(tonumber(pts[3]) - screenX, tonumber(pts[4]) - screenY,
                tonumber(pts[5]) - screenX, tonumber(pts[6]) - screenY,
                tonumber(pts[7]))
        elseif pts[2] == "rect" then
            drawRect(tonumber(pts[3]) - screenX, tonumber(pts[4]) - screenY,
                tonumber(pts[5]), tonumber(pts[6]),
                tonumber(pts[7]))
        elseif pts[2] == "reboot" then
            os.reboot()
        elseif pts[2] == "sendData" then
            vislib.sendRednet(id, "@monman:" .. screenName .. ",monData," .. os.getComputerLabel() .. "," .. screenCX .. "," .. screenCY .. "," .. screenW .. "," .. screenH)
        elseif pts[2] == "setPos" then
            print("setPos:"..screenX..","..screenY)
            screenX = tonumber(pts[3])
            screenY = tonumber(pts[4])
        else print("unknown message: ", msg)
        end
    end
end

while true do
    local status, msg = pcall(main)
    if not status then
        if msg=="Terminated" then return end
        print("err: " .. msg)
    end
end

--pastebin run 0YB9PsQV startup={files={vislib=<pb:GYvMFCY5>,mon=<pb:aTJkv2dh>},cmds={{'mon',<input:'monitorName'>,<input:'x'>,<input:'y'>}}} label=<input:'Label'> reboot=true
--cp disk/pastebin pastebin