[ComputerCraft Monitor] Game of Life

--Game of Life programmed by Nick Mead(NickM13)
--A ComputerCraft program
--Monitor-side of the Game of Life found at Pastebin UwLMnfxr

local monitor = nil
local exitGame = false
local playing = false
local dimension = {}
local screen = {}
local cell = {}
local newCell = {}
local livingCells = 0
local mouse = {}
local gps = 2 -- Generations per second
local skipping = false

local function wait(t)
    os.sleep(t)
end

local function resetCells()
    gps = 2
    livingCells = 0
    for i=1, dimension.width, 1 do
        for j=1, dimension.height, 1 do
            cell[i][j] = 0
        end
    end
end

local function centeredText(msg, y)
    local width = monitor.getSize()
    monitor.setCursorPos(math.ceil(width - string.len(msg))/2+1, y)
    monitor.write(msg)
end

local function writeText(msg, x, y)
    monitor.setCursorPos(x, y)
    monitor.write(msg)
end

local function drawRect(color, x0, y0, x1, y1, outline)
    monitor.setBackgroundColor(color)
    for x=0, x1-x0, 1 do
        for y=0, y1-y0, 1 do
            if outline then
                if (x == 0 or x == x1-x0 or y == 0 or y == y1-y0) then
                    monitor.setCursorPos(x+x0, y+y0)
                    monitor.write(" ")
                end
            else
                monitor.setCursorPos(x+x0, y+y0)
                monitor.write(" ")
            end
        end
    end
end

local function keyInput()
    local event, key = os.pullEvent('char')
    if key == 't' then
        exitGame = true
    end
end

local function playerTouch()
    local event, s, x, y = os.pullEvent('monitor_touch')
    mouse.left = true
    mouse.lclick = true
    mouse.x = x
    mouse.y = y
end

local function input()
    parallel.waitForAny(keyInput, playerTouch)
end

local function update()
    if mouse.left then
        if (mouse.x <= dimension.width) then
            if not playing then
                if cell[mouse.x][mouse.y] == 1 then
                    cell[mouse.x][mouse.y] = 0 livingCells = livingCells - 1
                else
                    cell[mouse.x][mouse.y] = 1 livingCells = livingCells + 1
                end
            end
        else
            if mouse.lclick then
                if (mouse.y >= 5 and mouse.y <= 7) then playing = not playing end
                if (mouse.x == screen.width and mouse.y == screen.height) then
                    playing = false
                    resetCells()
                end
                if mouse.x == dimension.width + 1 then if mouse.y == 2 or mouse.y == 3 then gps = gps - 1 end end
                if mouse.x == dimension.width + 10 then if mouse.y == 2 or mouse.y == 3 then gps = gps + 1 end end
                if (mouse.x > dimension.width and mouse.y == 9) then skipping = true end
                if gps < 1 then gps = 1 end
                if gps > 20 then gps = 20 end
            end
        end
        mouse.left = false
        mouse.lclick = false
    end
    if playing or skipping then
        local alive = 0
        livingCells = 0
        for i=1, dimension.width, 1 do
            for j=1, dimension.height, 1 do
                newCell[i][j] = cell[i][j]
            end
        end
        for i=1, dimension.width, 1 do
            for j=1, dimension.height, 1 do
                if (i == 1 and j > 1 and j < dimension.height) then alive = cell[i][j-1] + cell[i+1][j] + cell[i][j+1] + cell[i+1][j-1] + cell[i+1][j+1]
                elseif (i == dimension.width and j > 1 and j < dimension.height) then alive = cell[i-1][j] + cell[i][j-1] + cell[i][j+1] + cell[i-1][j-1] + cell[i-1][j+1]
                elseif (j == 1 and i > 1 and i < dimension.width) then alive = cell[i-1][j] + cell[i+1][j] + cell[i][j+1] + cell[i-1][j+1] + cell[i+1][j+1]
                elseif (j == dimension.height and i > 1 and i < dimension.width) then alive = cell[i-1][j] + cell[i][j-1] + cell[i+1][j] + cell[i-1][j-1] + cell[i+1][j-1]
                elseif (i == 1 and j == 1) then alive = cell[i+1][j] + cell[i][j+1] + cell[i+1][j+1]
                elseif (i == 1 and j == dimension.height) then alive = cell[i][j-1] + cell[i+1][j] + cell[i+1][j-1]
                elseif (i == dimension.width and j == 1) then alive = cell[i-1][j] + cell[i][j+1] + cell[i-1][j+1]
                elseif (i == dimension.width and j == dimension.height) then alive = cell[i-1][j] + cell[i][j-1] + cell[i-1][j-1]
                else alive = cell[i-1][j] + cell[i][j-1] + cell[i+1][j] + cell[i][j+1] + cell[i-1][j-1] + cell[i-1][j+1] + cell[i+1][j-1] + cell[i+1][j+1]
                end
                if cell[i][j] == 1 then
                    if alive < 2 then
                        newCell[i][j] = 0
                    elseif alive > 3 then
                        newCell[i][j] = 0
                    end
                else
                    if alive == 3 then
                        newCell[i][j] = 1
                    end
                end
                livingCells = livingCells + newCell[i][j]
            end
        end
        for i=1, dimension.width, 1 do
            for j=1, dimension.height, 1 do
                cell[i][j] = newCell[i][j]
            end
        end
        skipping = false
    end
end

local function render()
    for i=1, dimension.width, 1 do
        for j=1, dimension.height, 1 do
            monitor.setCursorPos(i, j)
            if cell[i][j] == 1 then
                monitor.setBackgroundColor(colors.white)
            else
                monitor.setBackgroundColor(colors.black)
            end
            monitor.write(" ")
        end
    end

    drawRect(colors.black, dimension.width + 1, 2, screen.width, 3, false)
    writeText("Gen/s", dimension.width + 4, 2)
    writeText(gps, dimension.width + 5, 3)
    monitor.setBackgroundColor(colors.lightGray)
    writeText("/", dimension.width + 1, 2)
    writeText("\\", dimension.width + 1, 3)
    writeText("\\", dimension.width + 10, 2)
    writeText("/", dimension.width + 10, 3)

    if playing then
        drawRect(colors.green, dimension.width + 1, 5, dimension.width + 10, 7, false)
    else
        drawRect(colors.red, dimension.width + 1, 5, dimension.width + 10, 7, false)
    end

    drawRect(colors.lightGray, dimension.width + 1, 9, dimension.width + 10, 9, false)
    writeText("Skip Frame", dimension.width + 1, 9)

    drawRect(colors.black, dimension.width + 1, dimension.height - 3, dimension.width + 10, dimension.height - 2, false)
    writeText("Cells:"..livingCells, dimension.width + 2, dimension.height - 2)

    monitor.setBackgroundColor(colors.black)
    writeText("C", screen.width, screen.height)

    monitor.setBackgroundColor(colors.black)
    monitor.setCursorPos(1, 19)
end

local function loop()
    update()
    render()
    wait(1 / gps)
end

local function gameLoop()
    while not exitGame do
        parallel.waitForAny(input, loop)
    end
end

local function intro()
    monitor.setBackgroundColor(colors.gray)
    monitor.setTextColor(colors.white)
    monitor.clear()
    for i=1, math.ceil(screen.height / 2), 1 do
        centeredText("Game of Life", math.ceil(screen.height / 2) - 1 - i)
        centeredText("Programmed by NickM13", math.ceil(screen.height / 2) + 1 + i)
        writeText("v 0.0.2", screen.width - 8, screen.height - 1)
        drawRect(colors.orange, 1, 1, screen.width, screen.height, true)
        wait(1.0/i)
        monitor.setBackgroundColor(colors.gray)
        monitor.setTextColor(colors.white)
        monitor.clear()
    end
    monitor.setCursorPos(1, 19)
    wait(1)
end

local function connectMonitor()
    for i,m in pairs(rs.getSides()) do
        if peripheral.getType(m) == "monitor" then
            return m
        end
    end
    return nil
end

local function main()
    print("Connect Monitor")
    while connectMonitor() == nil do end
    print("Monitor Found")
    monitor = peripheral.wrap(connectMonitor())
    screen.width, screen.height = monitor.getSize()
    dimension.height = screen.height
    dimension.width = screen.width - 10
    for i=1, dimension.width, 1 do
        cell[i] = {}
        newCell[i] = {}
    end
    for i=1, dimension.width, 1 do
        for j=1, dimension.height, 1 do
            cell[i][j] = 0
            newCell[i][j] = 0
        end
    end
    cell[6][5] = 1
    cell[7][6] = 1
    cell[7][7] = 1
    cell[6][7] = 1
    cell[5][7] = 1
    livingCells = 5
    intro()
    monitor.setBackgroundColor(colors.gray)
    monitor.clear()
    print("Press 't' to exit")
    gameLoop()
    monitor.clear()
    term.setBackgroundColor(colors.black)
    term.setTextColor(colors.white)
    term.clear()
    term.setCursorPos(1,1)
end

main()