ComputerCraft - Ascii Paint

-- ]] Ascii Editor by Redxone [[ --

-- ]] Simple API
local stc = term.setTextColor
local sbc = term.setBackgroundColor
local scp = term.setCursorPos
local cls = term.clear
local w, h = term.getSize()
local function printpos(text,x,y)
    scp(x,y)
    print(text)
    scp(x,y+1)
end
local function writepos(text,x,y)
    local xx, yy = term.getCursorPos()
    scp(x,y)
    write(text)
    scp(xx,yy)
end

-- Program start
local char = "/"
local takinginput = false
local running = true
local inMenu = false
local canvas = {}
local selectedcolorleft = 0
local selectedcolorright = 4
local selectedcharleft = "/"
local selectedcharright = "-"
local selectedoption = 0
local file = "/"
local inputspot = 0
local targ = { ... }

function checkSelected(left,right,equal)
    if tonumber(left) == equal
    and tonumber(right) ~= equal then
        return 1
    elseif tonumber(right) == equal
        and tonumber(left) ~= equal then
        return 2
    elseif tonumber(right) == equal and
        tonumber(left) == equal then
        return 3
    else
        return 0
    end
end

function drawSelected(left,right,equal,x,y,ltext,rtext,btext,ntext)
    if tonumber(left) == equal
    and tonumber(right) ~= equal then
        printpos(ltext, x, y)
    elseif tonumber(right) == equal
        and tonumber(left) ~= equal then
        printpos(rtext, x, y)
    elseif tonumber(right) == equal and
        tonumber(left) == equal then
        printpos(btext, x, y)
    else
        printpos(ntext, x, y)
    end
end

-- ]] GUI Visuals
local function drawGUI()

    sbc(colors.black)
    cls()
    scp(1,1)

    for ch = 0, h-1 do
        for cw = 0, w-1 do
            stc(tonumber(canvas[ch][cw].color))
            writepos(canvas[ch][cw].char,cw,ch)
        end
    end

    -- Draw colors
        for i = 0, 15 do
            stc(colors.black)
            drawSelected(selectedcolorleft,selectedcolorright,math.pow(2,i),w-1, i,"L/","R/","B/","-/")
            sbc( tonumber( math.pow(2,i) ) )
        end

        sbc(colors.black)
        stc(colors.lightGray)
        drawSelected(selectedcolorleft,selectedcolorright,0,w-1, h-3,"|\127","\127|","||","\127\127")
        drawSelected(selectedcolorleft,selectedcolorright,65536,w-1, h-2,"L/","R/","B/","-/")
        sbc(colors.blue)
        stc(colors.white)
        printpos(selectedcharleft,w-1,h-1)
        sbc(colors.lightBlue)
        printpos(selectedcharright,w,h-1)

        paintutils.drawLine(1, h, w, h, colors.black)

        stc(colors.yellow)
        writepos("Press ctrl to open menu. ",1,h)

end

-- ]] Logic functions

local function updateGUI()
        for i = 0, 15 do
            stc(colors.black)
            drawSelected(selectedcolorleft,selectedcolorright,math.pow(2,i),w-1, i,"L/","R/","B/","-/")
            sbc( tonumber( math.pow(2,i) ) )
        end

        sbc(colors.black)
        stc(colors.lightGray)
        drawSelected(selectedcolorleft,selectedcolorright,0,w-1, h-3,"|\127","\127|","||","\127\127")
        drawSelected(selectedcolorleft,selectedcolorright,65536,w-1, h-2,"L/","R/","B/","-/")
        sbc(colors.blue)
        stc(colors.white)
        printpos(selectedcharleft,w-1,h-1)
        sbc(colors.lightBlue)
        printpos(selectedcharright,w,h-1)
end

local function redrawChar(x,y)
    for yy = 0, h-1 do
        for xx = 0, w-1 do
            if(yy == y and xx == x)then
                scp(x,y)
                stc(canvas[yy][xx].color)
                write(canvas[yy][xx].char)
            end
        end
    end
end

local menu = {
    ['Save'] = {func=function()
        paintutils.drawLine(1, h, w, h, colors.black)
        scp(1,h)
        local f = fs.open(file,"w")
        f.write(textutils.serialize(canvas):gsub("\n%s*",""))
        f.close()
        write("Ascii saved to: " .. file)
        os.pullEvent("key")
        inMenu = false
        drawGUI()
    end},
    ['Load'] = {func=function()
        paintutils.drawLine(1, h, w, h, colors.black)
        scp(1,h)
        write("Load ascii from?: ")
        file_temp = read()
        if(fs.exists(file_temp))then
            local f = fs.open(file_temp,"r")
            local canvas_temp = textutils.unserialize(f.readAll())
            f.close()
            if(type(canvas_temp) == "table")then
                file = file_temp
                canvas = canvas_temp
                drawGUI()
                updateGUI()
                sbc(colors.black)
                stc(colors.white)
                scp(1,h)
                write("Ascii loaded from: " .. file)
                os.pullEvent("key")
                inMenu = false
                drawGUI()
            else
                scp(1,h-1)
                write("Invalid file type!")
                os.pullEvent("key")
                inMenu = false
                drawGUI()
            end
        else
            scp(1,h-1)
            write("No such file: " .. file_temp)
            os.pullEvent("key")
            inMenu = false
            drawGUI()
        end
    end},
    ['Exit'] = {func=function()
        running = false
        sbc(colors.black)
        stc(colors.white)
        cls()
        scp(1,1)
        print("Thank you for using Ascii Editor!, have a nice day.")
    end},
    ['Help'] = {func=function()
        sbc(colors.blue)
        cls()
        stc(colors.white)
        printpos("How to use the Ascii editor.",2,1)
        printpos("1. How to select colors",2,3)
        printpos("Left click a color to assign it to",4,4)
        printpos("the left click on you're mouse.",4,5)
        printpos("Right click a color to assign it to",4,6)
        printpos("the right click on your're mouse.",4,7)
        printpos("2. Changing ascii characters.",2,9)
        printpos("Left click the blue or light blue square,",4,10)
        printpos("hit enter if you dont want to change the char",4,11)
        printpos("or press a key on you're keyboard to change.",4,12)
        printpos("press enter when you have you're desired key.",4,13)
        printpos("Press any key to return to Ascii.",5,15)
        sbc(colors.black)
        stc(colors.white)
        os.pullEvent("key")
        inMenu = false
        drawGUI()
    end},
}

local function drawMenu()
    local i = 0
    for k,v in pairs(menu) do
        if(selectedoption == i)then
            scp(1 + (i * 6),h)
            stc(colors.yellow)
            write("[")
            stc(colors.white)
            write(k)
            stc(colors.yellow)
            write("]")
        else
            scp(1 + (i * 6),h)
            stc(colors.white)
            write(" " .. k .. " ")
        end
        i = i + 1
    end
end

local function updateMenu(event)
    if(event[1] == "key")then
        if(event[2] == keys['left'] and selectedoption > 0)then
            selectedoption = selectedoption - 1
            drawMenu()
        end

        if(event[2] == keys['right'] and selectedoption < 3 )then
            selectedoption = selectedoption + 1
            drawMenu()
        end

        if(event[2] == keys['enter'])then
            local i = 0
                for k,v in pairs(menu) do
                    if(selectedoption == i)then
                        v.func()
                    end
                    i = i + 1
                end
        end
    end
end

local function updateSelector(ev)
    if(not takinginput)then term.setCursorBlink(false) end

    if(ev[1] == "mouse_click")then
        if(takinginput)then takinginput = false end

        for i = 0, 15 do
            if(ev[3] >= w-1 and ev[3] <= w and ev[4] == i)then
                if(ev[2] == 1)then -- left click
                    selectedcolorleft = math.pow(2,i)
                end
                if(ev[2] == 2)then -- right click
                    selectedcolorright = math.pow(2,i)
                end
                updateGUI()
            end
        end

        -- black and transparent selection
        if(ev[3] >= w-1 and ev[3] <= w and ev[4] == 16)then
            if(ev[2] == 1)then -- left click
                selectedcolorleft = 0
            end
            if(ev[2] == 2)then -- right click
                selectedcolorright = 0
            end
            updateGUI()
        end

        if(ev[3] >= w-1 and ev[3] <= w and ev[4] == 17)then
            if(ev[2] == 1)then -- left click
                selectedcolorleft = 65536
            end
            if(ev[2] == 2)then -- right click
                selectedcolorright = 65536
            end
            updateGUI()
        end

        if(ev[3] >= w-1 and ev[4] == h-1 and takinginput == false )then
            takinginput = true

            sbc(colors.blue)
            stc(colors.white)
            printpos(" ",w-1,h-1)
            sbc(colors.lightBlue)
            printpos(" ",w,h-1)
            scp(w-1,h-1)

            term.setCursorBlink(true)
        end

    end

    if(ev[1] == 'key' and takinginput)then
        if(ev[2] == keys.enter)then
            sbc(colors.blue)
            stc(colors.white)
            if(inputspot == 1)then
                takinginput = false;
                inputspot = 0
                sbc(colors.black)
                sbc(colors.lightBlue)
                printpos(selectedcharright,w,h-1)
                term.setCursorBlink(false)
            elseif(inputspot == 0 )then
                inputspot = 1
                term.setCursorBlink(false)
                printpos(selectedcharleft,w-1,h-1)
                scp(w,h-1)
                term.setCursorBlink(true)
            end
        end
    end

    if(ev[1] == 'char' and takinginput)then
        sbc(colors.blue)
        stc(colors.white)
        if(inputspot == 0)then
            selectedcharleft = ev[2]
            printpos(selectedcharleft,w-1,h-1)
            term.setCursorBlink(false)
        elseif(inputspot == 1)then
            selectedcharright = ev[2]
            sbc(colors.lightBlue)
            printpos(selectedcharright,w,h-1)
            term.setCursorBlink(false)
        end
    end
end

local function asciiDraw(ev)
    if(ev[1] == "mouse_click" or ev[1] == "mouse_drag")then
        if(ev[3] < w-1 and ev[4] < h-1)then
            local xx = ev[3]
            local yy = ev[4]

            -- Draw to screen based on left or right click
            if(ev[2] == 1 and selectedcolorleft ~= 65536)then
                -- left click
                    canvas[yy][xx] = {char=selectedcharleft,color=selectedcolorleft/2}
            elseif(selectedcolorright ~= 0 and selectedcolorright ~= 65536)then
                -- right click
                    canvas[yy][xx] = {char=selectedcharright,color=selectedcolorright/2}
            end

            if(ev[2] == 1 and selectedcolorleft == 0)then
                canvas[yy][xx] = {char="\127",color=tonumber(colors.lightGray)}
            elseif(ev[2] == 1 and selectedcolorleft == 65536)then
                canvas[yy][xx] = {char=selectedcharleft,color=tonumber(colors.black)}
            end

            if(ev[2] == 2 and selectedcolorright == 0)then
                canvas[yy][xx] = {char="\127",color=tonumber(colors.lightGray)}
            elseif(ev[2] == 2 and selectedcolorright == 65536)then
                canvas[yy][xx] = {char=selectedcharright,color=tonumber(colors.black)}
            end

            redrawChar(xx,yy)
        end
    end
end

local function loop()
    while running do
        sbc(colors.black)
        ev = {os.pullEvent()}

        if inMenu then
             updateMenu(ev)
        else
            updateSelector(ev)
            asciiDraw(ev)
        end

        if(ev[1] == "key" and ev[2] == keys['leftCtrl'])then
            if(inMenu)then
                inMenu = false
                paintutils.drawLine(1, h, w, h, colors.black)
                stc(colors.yellow)
                writepos("Press ctrl to access menu. ",1,h)
            else
                inMenu = true
                paintutils.drawLine(1, h, w, h, colors.black)
                drawMenu()
            end
        end
    end
end

local function init()



    if(#targ <= 0)then
        error("Usage: Ascii <file>")
    else
        file = targ[1]
    end

    if(not fs.exists(file))then
    -- Create canvas
        for ch = 0, h-1 do
            canvas[ch] = {}
            for cw = 0, w-1 do
                canvas[ch][cw] = {char="\127", color=colors.lightGray}
            end
        end
    else
        f = fs.open(file,"r")
        local canvas_temp = textutils.unserialize(f.readAll())
        f.close()
        if(type(canvas_temp) == "table")then
            canvas = canvas_temp
        else
            error("Invalid file type!")
        end
    end

    drawGUI();
    loop()
end

init()