Terminal redirect API

function newTerm(x, y, width, height, baseTerm)
    local textColor = colors.white
    local backgroundColor = colors.black
    local characters -- Characters as table of rows, i.e. a given is at characters[y][x]
    local textColors -- Text colors, same as above
    local backgroundColors -- Background colors, same as above
    local cursorPosX, cursorPosY = 1, 1
    local cursorBlink = false;
    local terminal -- Terminal redirect object
    local baseTerm = baseTerm or term.native;

    local function newRow() -- Creates an empty row (table of spaces)
        local row = {}
        for i=1,width do
            row[i] = ' '
        end
        return row
    end

    local function outputLine(rowNum, keepCursor)
        for j=1,width do
            baseTerm.setCursorPos(x+j-1, y+rowNum-1);
            baseTerm.setTextColor(textColors[rowNum][j]);
            baseTerm.setBackgroundColor(backgroundColors[rowNum][j]);
            baseTerm.write(characters[rowNum][j]);
        end
    end

    local function output()
        baseTerm.setCursorBlink(false)
        local cursorX, cursorY = baseTerm.getCursorPos()
        for i=1,height do
            outputLine(height);
        end
        baseTerm.setCursorPos(cursorX, cursorY)
        baseTerm.setCursorBlink(cursorBlink)
    end

    local function newCharTable() -- Creates an empty character table (table of empty rows)
        local charTable = {};
        for i=1,height do
            charTable[i] = newRow();
        end
        return charTable;
    end

    local function newColorRow(color) -- Creates a row of whatever the color is
        local row = {}
        for i=1,width do
            row[i] = color
        end
        return row
    end

    local function newColorTable(color) -- Creates a table of whatever the color is
        local colorTable = {}
        for i=1,height do
            colorTable[i]=newColorRow(color)
        end
        return colorTable
    end

    local function setup() -- Sets cursor position and color before writing to terminal
        baseTerm.setCursorPos(x+cursorPosX-1,y+cursorPosY-1)
        baseTerm.setTextColor(textColor)
        baseTerm.setBackgroundColor(backgroundColor)
        baseTerm.setCursorBlink(cursorBlink)
    end

    terminal = {
        scroll = function(times)
            for i = 1,times do
                table.remove(characters, 1) -- Remove first row
                characters[#characters+1] = newRow() -- Add empty row at the end
                table.remove(textColors, 1)
                textColors[#textColors+1] = newColorRow(textColor)
                table.remove(backgroundColors, 1)
                backgroundColors[#backgroundColors+1] = newColorRow(backgroundColor)
            end
            times = -times -- Reverse for scrolling up
            for i = 1,times do
                characters[#characters] = nil -- Remove last row
                table.insert(characters, 1, newRow()) -- Add empty row at the beginning
                textColors[#textColors] = nil
                table.insert(textColors, 1, newColorRow(textColor))
                backgroundColors[#backgroundColors] = nil
                table.insert(backgroundColors, 1, newColorRow(backgroundColor))
            end
            cursorPosY = cursorPosY + times;
            if cursorPosY < 1 then
                cursorPosY = 1
            end
            if cursorPosY > height then
                cursorPosY = height
            end
        end,
        setCursorPos = function(newX, newY)
            --if newX <= width and newX >= 1 then
                cursorPosX = newX
            --end
            --if newY <= height and newY >= 1 then
                cursorPosY = newY
            --end
            baseTerm.setCursorPos(x+cursorPosX-1,y+cursorPosY-1)
        end,
        write = function(text)
            setup()
            local totalLength = text:len();
            if cursorPosY>=1 and cursorPosY <= height then
                local textLength = math.min(math.max(0,width-cursorPosX+1), totalLength)
                local textStart = 1
                if cursorPosX < 1 then textStart = 1 - cursorPosX end
                text = text:sub(textStart, textLength)
                baseTerm.write(text)
                for i=1,textLength do
                    if cursorPosX+i-1 >=1 and cursorPosX+i-1 <= width then
                        characters[cursorPosY][cursorPosX+i-1] = text:sub(i,i)
                        textColors[cursorPosY][cursorPosX+i-1] = textColor
                        backgroundColors[cursorPosY][cursorPosX+i-1] = backgroundColor
                    end
                end
            end
            cursorPosX = cursorPosX + totalLength;
            --[[if cursorPosX > width then
                cursorPosX = width
            end]]
            terminal.setCursorPos(cursorPosX, cursorPosY);
        end,
        clear = function()
            characters=newCharTable()
            textColors = newColorTable(textColor)
            backgroundColors = newColorTable(backgroundColor)
            output()
        end,
        setTextColor=function(color)
            textColor = color
            --baseTerm.setTextColor(color);
        end,
        setBackgroundColor = function(color)
            backgroundColor = color
            --baseTerm.setBackgroundColor(color)
        end,
        getTextColor=function()
            return textColor
        end,
        getBackgroundColor = function()
            return backgroundColor
        end,
        getCursorPos = function()
            return cursorPosX, cursorPosY
        end,
        setCursorBlink = function(blink)
            cursorBlink = blink
            baseTerm.setCursorBlink(blink)
        end,
        clearLine = function()
            if cursorPosY<1 or cursorPosY>height then return end
            characters[cursorPosY] = newRow() -- Set current row to empty row
            textColors[cursorPosY] = newColorRow(textColor)
            backgroundColors[cursorPosY] = newColorRow(backgroundColor)
            baseTerm.setCursorBlink(false)
            local cursorX, cursorY = baseTerm.getCursorPos()
            outputLine(cursorPosY, true)
            baseTerm.setCursorBlink(cursorBlink)
            baseTerm.setCursorPos(cursorX,cursorY)
        end,
        isColor = function()
            return baseTerm.isColor()
        end,
        getSize = function()
            return width, height
        end,
        getCursorBlink = function()
            return cursorBlink
        end
    }
    terminal.isColour = terminal.isColor
    terminal.setBackgroundColour=terminal.setBackgroundColor
    terminal.setTextColour=terminal.setTextColor
    terminal.getBackgroundColour=terminal.getBackgroundColor
    terminal.getTextColour=terminal.getTextColor

    terminal.clear()
    terminal.setCursorPos(1,1)

    return terminal
end