XUtils V1.2

--XUtils API, by Symmetryc.
function init()
    tColors = {}
    for i=1, 51 do tColors[i] = {} for i2=1, 19 do tColors[i][i2] = "00 " end end
    return tColors
end
--[[
Use this to inititialize your screen for modification.

Arguments:
None.

Returns:
tScreen = xutils.init()
tScreen = your initialized screen variable.

Example Usage:
tScreen = xutils.init()
xutils.text(tScreen, "Hi", 1, 1, colors.red)
xutils.render(tScreen)

Note:
Unless you are experienced with handling more than one screen, make
sure to use the variable that you initialized your screen with all
of your xutils functions in that program.
]]
function extract(tColors, ...)
    for i=1, 3 do _[i] = string.sub(tColors[arg[1]][arg[2]], i, i) end
    return _[1], _[2], _[3]
end
--[[
Use this to extract and interpret data from any pixel of your initialized
screen variable.

Arguments:
xutils.extract(tScreen, x, y)
tScreen = your initialized screen variable.
x = x-coordinate of the extraction pixel.
y = y-coordinate of the extraction pixel.

Returns:
background_color, text_color, text = xutils.extract()
background_color = background color of that pixel.
text_color = text color of that pixel.
text = text that is on that pixel.

Example Usage:
tScreen = xutils.init()
_, _, text = xutils.extract(tScreen, 1, 1)
print('The text that is on pixel (1, 1) is "'..text..'"')

Note:
The values of the background and text colors are in Hexadecimal and 2 is
not put to the power of them.
This does not actually alter the values, it just returns them.
If your screen was just initialized, your text and background colors will
be white and the text will be " ".
]]
function insert(tColors, ...)
    tColors[arg[4]][arg[5]] = arg[1]..arg[2]..arg[3]
end
--[[
Use this to insert data into any pixel of your initialized screen variable.

Arguments:
xutils.insert(tScreen, background_color, text_color, text, x, y)
tScreen = your initialized screen variable.
background_color = background color of the pixel.
text_color = text color of your text.
text = text you are putting in.
x = x-coordinate of the pixel.
y = y-coordinate of the pixel.

Returns:
nil.

Example Usage:
tScreen = xutils.init()
xutils.insert(tScreen, "-", e, 6, 1, 1)
xutils.render(tScreen)

Note:
The values of the background and text colors must be in Hexadecimal and
2 should not be put to the power of them.
]]
function unload(tColors, path)
    h = fs.open(path, "w")
    h.writeLine(textutils.serialize(tColors))
end
--[[
Use this to save screen variables in files.

Arguments:
xutils.unload(tScreen, path)
tScreen = your initialized screen variable.
path = file you want to save the screen variable to.

Returns:
nil.

Example Usage:
tScreen = xutils.init()
xutils.unload(tScreen, "MyBlankFile")
]]
function load(path)
    tColors = {}
    h = fs.open(path, "r")
    tColors = textutils.unserialize(h.readLine())
    return tColors
end
--[[
Use this to initialize a screen variable from a file.

Arguments:
xutils.load(path)
path = file your screen is saved on.

Returns:
tScreen = xutils.load()
tScreen = your initialized screen variable.

Example Usage:
tScreen = xutils.load(CatPicture)
xutils.render(tScreen)
]]
function text(tColors, ...)
    arg[1] = tostring(arg[1])
    if arg[2]>51 or arg[2]<1 or arg[3]>19 or arg[3]<1
    then error("coordinate out of bounds") end
    if #arg[1]+arg[2]-1>51 then error("string too long", 0)
    elseif #arg<3 then error("more arguments expected", 0) end
    _ = {}
    if arg[4]==nil then _["text"] = true end
    if arg[5]==nil then _["color"] = true end
    for i=4, 5 do if arg[i] then arg[i] = math.log(arg[i])/math.log(2)
        for i2=11, 16 do
            if arg[i]==i2-1 then arg[i] = string.sub("0123456789abcdef", i2, i2) end
        end
    end end
    for i=1, #arg[1] do
        _[1], _[2] = extract(tColors, arg[2]+i-1, arg[3])
        if _["text"] then arg[4] = _[2] end
        if _["color"] then arg[5] = _[1] end
        insert(tColors, arg[5], arg[4], string.sub(arg[1], i, i), arg[2]+i-1, arg[3])
    end
end
--[[
Equivalent of "write()" in the XUtils API.

Arguments:
xutils.text(tScreen, text, x, y, [text_color, background_color])
tScreen = your initialized screen variable.
text = what you are writing.
x = x-coordinate of the start of the text.
y = y-coordinate of text.
text_color = text color of the text, nil if the text will adopt the
text color that is already in the pixel(s).
background_color = background color of the text, nil if the text
will adopt the background color that is already in the pixel(s).

Returns:
nil.

Example Usage:
tScreen = xutils.init()
xutils.text(tScreen, "Hello World", 1, 1, colors.red)
xutils.render(tScreen)

Note:
Will error if the string is too long to be portrayed within a 51 by 19
pixel space, given the x and y arguments of the function.
]]
function color(tColors, ...)
    for i=4, 5 do if arg[i]==nil then arg[i] = arg[i-2] end end
    if #arg<3 then error("more arguments expected") end
    for i=2, 5 do if arg[i]<1 then error("coordinate out of bounds") end end
    for i=2, 4, 2 do if arg[i]>51 then error("coordinate out of bounds") end end
    for i=3, 5, 2 do if arg[i]>19 then error("coordinator out of bounds") end end
    arg[1] = math.log(arg[1])/math.log(2)
    for i=2, 3 do
        _ = math.min(arg[i], arg[i+2])
        arg[i+2] = math.max(arg[i], arg[i+2])
        arg[i] = _
    end
    _ = {}
    for i=11, 16 do
        if arg[1]==i-1 then arg[1] = string.sub("0123456789abcdef", i, i) end
    end
    for i=arg[2], arg[4] do for i2=arg[3], arg[5] do
        _[1], _[2], _[3] = extract(tColors, i, i2)
        insert(tColors, arg[1], _[2], _[3], i, i2)
    end end
end
--[[
Pixel/Rectangle drawer, the main method of background color manipulation
in the XUtils API.

Arguments:
xutils.color(tScreen, background_color, x1, y1, [x2, y2])
tScreen = your initialized screen variable.
background_color = color of what you're drawing.
x1 = x-coordinate of the pixel/corner of the rectangle.
y1 = y-coordinate of the pixel/corner of the rectangle.
x2 = x-coordinate of the opposite corner of the rectangle.
y2 = y-coordinate of the opposite corner of the rectangle.

Returns:
nil.

Example Usage:
tScreen = xutils.init()
xutils.color(tScreen, colors.red, 1, 1, 5, 5)
xutils.render(tScreen)

Note:
Will error if any of the x-coordinates are not within 1 to 51 and if
any of the y-coordinates are not within 1 to 19.
]]
function render(tColors)
    if tColors==nil then error("more arguments expected") end
    _ = {}
    for i=1, 51 do for i2=1, 19 do
        _[1], _[2], _[3] = extract(tColors, i, i2)
        for i3=1, 2 do for i4=11, 16 do
            if _[i3]==string.sub("0123456789abcdef", i4, i4) then _[i3] = i4-1 end
        end end
        term.setCursorPos(i, i2)
        term.setBackgroundColor(2^_[1])
        term.setTextColor(2^_[2])
        write(_[3])
    end end
end
--[[
Renders the initialized screen variable onto the screen.

Arguments:
xutils.render(tScreen)
tScreen = your initialized screen variable.

Returns:
nil.

Example Usage:
tScreen = xutils.init()
xutils.text(tScreen, "Rendered stuffs", 1, 1)
xutils.render(tScreen)
]]