mcPaint.lua

local function fileGen()
    if not fs.exists('mcPaintFolder/info.txt') then
        term.clear()
        term.write('Enter monitor side: ')
        side = io.read()
        if peripheral.getType(side) ~= 'monitor' then
            term.write('No monitor on this side!')
            fileGen()
        else
        term.write('Data saved!')
        info = fs.open('mcPaintFolder/info.txt', 'w')
        info.write(side)
        info.close()
        os.sleep(2)
        end
    end
end

fileGen()
info = fs.open('mcPaintFolder/info.txt', 'r')
side = info.readAll()

local mon = peripheral.wrap(side)
mon.setTextScale(0.5)
mon.setBackgroundColor(2^15)
mon.clear()
local x, y = 1, 1
local length, width = mon.getSize()
local colorTable = {}
local currentColor = 2^15
local imageTable = {}
local fileName = ''
local boxMode = false

local function createImageFile(color) -- creates a table of the form imageTable[x][y] = black as default
    for x = 1, length-1 do
        imageTable[x] = {}
        for y = 1, width do
            imageTable[x][y] = color
        end
    end
end

local function drawPalette() -- Draws up the GUI
    local color = 0
    for i = 1, 16 do
        color = 2^(i-1)
        colorTable[i] = color
        mon.setBackgroundColor(color)
        mon.setCursorPos(length, i)
        mon.write(' ')
    end
    mon.setCursorPos(length, 17)
    mon.write('E')
    mon.setCursorPos(length, 18)
    mon.write('B')
    mon.setCursorPos(length, 19)
    mon.write('S')
    mon.setCursorPos(length, 20)
    mon.write('X')
end

local function draw() -- function called to draw and record individual pixels
    if not boxModeToggled then
        if not eraseMode then
            imageTable[x][y] = currentColor
            mon.setCursorPos(x,y)
            mon.write(' ')
        else
            imageTable[x][y] = currentColor
            mon.setCursorPos(x,y)
            mon.write(' ')
        end
    else
        local _, _, x2, y2 = os.pullEvent('monitor_touch')
        local xinc, yinc = 1, 1
        if x < x2 then
            xinc = 1
        else
            xinc = -1
        end
        if y < y2 then
            yinc = 1
        else
            yinc = -1
        end
        for i = x, x2, xinc do
            for k = y, y2, yinc do
                imageTable[i][k] = currentColor
                mon.setCursorPos(i,k)
                mon.write(' ')
            end
        end
    end
end

local function saveImage() -- exports the image to a file
    if not fs.exists('/images/') then
        fs.makeDir('/images')
    end
    term.clear()
    term.setCursorPos(1,1)
    term.write('Enter your file\'s name: \n')
    fileName = io.read()
    if not fs.exists('mcPaintFolder/images/'..fileName) then
    image = fs.open('mcPaintFolder/images/'..fileName, 'w')
    imageString = textutils.serialise(imageTable)
    image.write(imageString)
    image.close()
    else term.write('file already exists! Change file name: \n')
    fileName = io.read()
    saveImage()
    end
end

local function boxMode() -- toggles box creation
    if boxModeToggled == true then
        boxModeToggled = false
        mon.setBackgroundColor(2^15)
        mon.setCursorPos(length,18)
        mon.write('B')
    else
        boxModeToggled = true
        mon.setBackgroundColor(2^14)
        mon.setCursorPos(length,18)
        mon.write('B')
    end
    mon.setBackgroundColor(currentColor)
end

local function selectColor() -- sets the selected color
    mon.setBackgroundColor(colorTable[y])
    currentColor = colorTable[y]
end

drawPalette()
createImageFile(2^15)
while true do
    _, _, x, y = os.pullEvent('monitor_touch')
    if x == length then
        eraseMode = false
        if y <= 16 then
            selectColor()
        elseif y == 17 then
            eraseMode = true
            mon.setBackgroundColor(2^15)
            currentColor = 2^15
        elseif y == 18 then
            boxMode()
        elseif y == 19 then
            saveImage()
        elseif y == 20 then
            mon.setBackgroundColor(2^15)
            mon.clear()
            return
        end
    elseif x < length then
        draw()
    end
end