(old) GameEngineRev2.lua (for TI-Nspire CX)

local Game = {
    Ticks = 0,
    Window = {0, 0},
    VisibleTiles = {0, 0},
    Redraw = true
}

local UnitDraw = {}

local Board = {}

function NewBoard(width, height)
    local New = {}

    for y = 1, height do
        New[y] = {}
        for x = 1, width do
            New[y][x] = 0
        end
    end

    return New
end

function on.create()
    Board = NewBoard(100, 100)
end

function on.paint(gc)
    gc:setColorRGB(0, 0, 0)
    gc:setFont("serif", "r", 12)
    gc:drawString(DrawBoard(1, 1), 0, 0)

    gc:drawRect(0, 0, Game.Window[1] * 0.9, Game.Window[2] * 0.9)
end

function DrawBoard(fromx, fromy)
    local DrawString = ""
    for y = fromy, #Board do
        if (y - fromy > Game.VisibleTiles[2]) then
            break
        end
        for x = fromx, #Board[y] do
            if (x - fromx > Game.VisibleTiles[1]) then
                break
            end

            if (Board[y][x] == 0) then
                DrawString = DrawString .. math.random(0, 9)
            else
                --TODO: Draw other types
            end
        end
        DrawString = DrawString .. "\n"
    end

    return DrawString
end

function on.timer()
    Game.Ticks = Game.Ticks + 1

    Game.Redraw = true

    if (Game.Redraw) then
        Game.Redraw = false
        platform.window:invalidate()
    end
end

function on.activate()
    timer.start(1 / 30)
    Game.Redraw = true
end

function on.deactivate()
    timer.stop()
end

function on.resize(width, height)
    Game.Window = {width, height}
    CalculatePercents()
end

function CalculatePercents()
    local gc = platform.gc()
    gc:begin()
    Game.VisibleTiles = {math.floor((Game.Window[1] * 0.9) / gc:getStringWidth("0")), math.floor((Game.Window[2] * 0.9) / gc:getStringHeight("0"))}
    gc:finish()

    Game.Redraw = true
end