basedef

--Assignment one by ikke009. Teacher: nitrogenfingers
--Date of completion: 18-1-2013, Game Name: Basedefense
--Inspiration and knowledge required to make this game was taken from a game called laserblast

w,h = term.getSize()
lives = 5
kills = 0
refreshRate = 0.18

function load() --Runs once, does the intro
    term.clear()
    term.setCursorPos(10,3)
    term.setTextColour(colours.yellow)
    write("Computercraft University, assignment one")
    term.setCursorPos(10,4)
    write("By: ikke009 (inspired by laserblast)")
    term.setCursorPos(10,5)
    write("Instructions: Click baddies!")
    term.setCursorPos(10,7)
    write("Click here to continue")
    while true do
        local ev,but,x,y = os.pullEvent("mouse_click")
        if but == 1 and x >5 and x < 40 and y < 8 and y > 5 then
            term.clear()
            term.setTextColour(colours.white)
            break
        end
    end
end

function drawBase() --Draws the green base at the right side of the screen
    term.setBackgroundColour(colours.green)
    for i=3,h do
        term.setCursorPos(w-2,i)
        write("   ")
    end
end

function drawHeader() --Draws the header with the red healthbar
    term.setTextColour(colours.blue)
    for i=1,w do
        term.setCursorPos(i,2)
        write("-")
    end

    term.setTextColour(colours.white)
    term.setBackgroundColour(colours.red)
    local redbar = math.floor((w/5)*lives)
    for i=1,redbar do
        term.setCursorPos(i,1)
        write(" ")
    end
    term.setBackgroundColour(colours.black)
end

enemylist = {}
enemyxvel = 1.5
explosionlist = {}
function updateGame()
    for i=1,#enemylist do
        local ent = enemylist[i]
        if ent then
            if ent.x < w-3 then
                ent.x = ent.x + enemyxvel
            else table.remove(enemylist,i) --If enemy hits base
                lives = lives - 1
                table.insert(explosionlist,{
                    x=ent.x,
                    y=ent.y,
                    phase=1
                })
            end
        end
    end

    if #enemylist < math.ceil(kills/4) or (#enemylist == 0 and kills == 0) then --for every 4 kills an additional enemy gets spawned, or if there are no enemys and no kills
        table.insert(enemylist,{
            x = 1,
            y = math.random(4,h-1)
        })
    end

    if #explosionlist > 0 then --If there are explosions then
        for i=1,#explosionlist do
            local expl = explosionlist[i]
            if expl then --If explosionlist[i] is not nill
                if expl.phase <= 3 then
                    expl.phase = expl.phase + 1 --there are 3 explosion phases that make it "animated"
                else table.remove(explosionlist,i) --if "animation" is done, remove explosion
                end
            end
        end
    end

    if kills == 10 then --Speeds up the game >:D
        enemyxvel = 1.75
    elseif kills == 20 then
        enemyxvel = 2
    end
end

function drawGame()
    term.clear()
    drawHeader()
    drawBase()
    term.setBackgroundColour(colours.yellow) --Explosion drawing starts here
    for i=1,#explosionlist do
        local expl = explosionlist[i]
        if expl.x then --if explosionlist[i] is not nil
            if expl.phase == 1 then --various drawings for every phase
                term.setCursorPos(expl.x,expl.y)
                write(" ")
            elseif expl.phase == 2 then
                term.setCursorPos(expl.x-1,expl.y-1)
                write(" ")
                term.setCursorPos(expl.x+1,expl.y-1)
                write(" ")
                term.setCursorPos(expl.x-1,expl.y+1)
                write(" ")
                term.setCursorPos(expl.x+1,expl.y+1)
                write(" ")
                term.setCursorPos(expl.x,expl.y)
                write(" ")
            elseif expl.phase == 3 then
                term.setCursorPos(expl.x-1,expl.y-1)
                write(" ")
                term.setCursorPos(expl.x+1,expl.y-1)
                write(" ")
                term.setCursorPos(expl.x-1,expl.y+1)
                write(" ")
                term.setCursorPos(expl.x+1,expl.y+1)
                write(" ")
            end
        end
    end
    term.setBackgroundColour(colours.black)
    term.setTextColour(colours.red) --Enemy drawing starts here
    for i=1,#enemylist do
        local ent = enemylist[i]
        if ent.x then
            term.setCursorPos(ent.x,ent.y)
            write("=>")
        end
    end
end

function maingame()
    load()
    gtID = os.startTimer(refreshRate)
    while lives > 0 do
        ev,id,mx,my = os.pullEvent() --event, mousebutton/timerid, mousex/nil, mousey/nil
        if ev == "mouse_click" then
            for i=1,#enemylist do
                if enemylist[i] then
                    local ent = enemylist[i]
                    if (ent.x == mx+2 or ent.x == mx+3) and ent.y == my then --if the click was on an enemy (mx+2 and mx+3 accounts for lag on the CC uni server)
                        table.remove(enemylist,i)
                        kills = kills + 1
                        table.insert(explosionlist,{
                            x = mx,
                            y = my,
                            phase = 1
                        })
                    end
                end
            end
        elseif ev == "timer" and id == gtID then
            updateGame()
            drawGame()
            gtID = os.startTimer(refreshRate)
        end
    end
    term.setTextColour(colours.yellow) --Game Over screen, game outro
    term.setBackgroundColour(colours.black)
    term.clear()
    term.setCursorPos(10,4)
    textutils.slowPrint("GAME OVER",4)
    term.setCursorPos(10,6)
    write("Kills:   "..kills)
    term.setCursorPos(1,8)
end

maingame()