main.lua

require("src.backgroundstar")
require("src.enemyship")
require("src.playership")
require("src.bullet")
require("src.engineanimation")
require("src.animationwrapper")

local anim8 = require("libs.anim8")
local Moan = require("libs.Moan")

local stars = {}
local enemyShips = {}
local enemyBullets = {}
local playerShip
local playerBullets = {}
local animations = {}
local font

local score = 0
local timeSinceLastPlayerBulletFired = 0
local timeSinceLastShipSpawn = 0
local timeSinceLastEnergyGain = 0
local timeSinceLastPlayerShipImpact = 1000
local paused = false
local playerDead = false
local level = 1
local shipSpawningEnabled = true
local infiniteEnergy = false

-- debug
local audioEnabled = true
local drawCollisionHitboxes = false
local showMemoryUsage = false

-- config
local numberOfBackgroundStars = 30
local maxNumberOfEnemyShips = 20
local energyPerShot = 7
local maxEnergy = 200
local maxHealth = 10
local level2Threshold = 3000
local level3Threshold = 7000
local level4Threshold = 14000
local level5Threshold = 22000

function love.load()
    math.randomseed(os.time())
    local major, minor, revision, codename = love.getVersion()
    print("running with LÖVE version: " .. major .. "." .. minor .. "." .. revision .. " " .. codename)

    -- fonts
    Moan.font = love.graphics.newFont("font/Pixel-UniCode.ttf", 32)
    font = love.graphics.newFont("font/Pixel-UniCode.ttf", 32)

    -- load images
    playerShipImg = love.graphics.newImage("image/pixel_ship_red.png")
    enemyYellowShipImg = love.graphics.newImage("image/pixel_ship_yellow.png")
    enemyBlueShipImg = love.graphics.newImage("image/pixel_ship_blue.png")
    enemyGreenShipImg = love.graphics.newImage("image/pixel_ship_green.png")
    enemyRedBossShipImg = love.graphics.newImage("image/pixel_ship_red_small_2.png")
    playerShipImpactImg = love.graphics.newImage("image/impact.png")

    blueStarImg = love.graphics.newImage("image/stars/star_blue_giant01.png")
    redStarImg = love.graphics.newImage("image/stars/star_red_giant01.png")

    goodGuyPortrait = love.graphics.newImage("image/portrait/P01_A_01.png")
    goodGuyName = "Sgt Gaston"
    badGuyPortrait = love.graphics.newImage("image/portrait/P01_B_04.png")
    badGuyName = "Rear Admiral Jax"

    -- enemy ship explosion animation
    explosionSpriteSheet = love.graphics.newImage("image/explosions/explosion31.png")
    explosionGrid = anim8.newGrid(256, 256, explosionSpriteSheet:getWidth(), explosionSpriteSheet:getHeight())
    explosionAnimation = anim8.newAnimation(explosionGrid('1-4', 1, '1-4', 2, '1-4', 3, '1-4', 4), .04)

    -- player ship explosion animation
    playerExplosionSpriteSheet = love.graphics.newImage("image/explosions/explosion23.png")
    playerExplosionGrid = anim8.newGrid(256, 256, playerExplosionSpriteSheet:getWidth(), playerExplosionSpriteSheet:getHeight())
    playerExplosionAnimation = anim8.newAnimation(playerExplosionGrid('1-4', 1, '1-4', 2, '1-4', 3, '1-4', 4), .08)

    -- spawn animation
    spawnSpriteSheet = love.graphics.newImage("image/spawn.png")
    spawnGrid = anim8.newGrid(100, 100, spawnSpriteSheet:getWidth(), spawnSpriteSheet:getHeight())
    spawnAnimation = anim8.newAnimation(spawnGrid('1-6', 1), .025)

    -- player ship
    playerShip = PlayerShip:new(nil, 115, 200, playerShipImg, maxEnergy, maxHealth)

    -- engine animation
    engineFlame_frame1Img = love.graphics.newImage("image/engineflame/flame4-1.png")
    engineFlame_frame2Img = love.graphics.newImage("image/engineflame/flame4-2.png")
    engineFlame_frame3Img = love.graphics.newImage("image/engineflame/flame4-3.png")
    engineFlame_frame4Img = love.graphics.newImage("image/engineflame/flame6-1.png")
    engineFlame_frame5Img = love.graphics.newImage("image/engineflame/flame6-2.png")
    engineFlame_frame6Img = love.graphics.newImage("image/engineflame/flame6-3.png")
    engineFlame_frame7Img = love.graphics.newImage("image/engineflame/flame7-1.png")
    engineFlame_frame8Img = love.graphics.newImage("image/engineflame/flame7-2.png")
    engineFlame_frame9Img = love.graphics.newImage("image/engineflame/flame7-3.png")
    engineFlame_frames = { engineFlame_frame1Img, engineFlame_frame2Img, engineFlame_frame3Img,
                           engineFlame_frame4Img, engineFlame_frame5Img, engineFlame_frame6Img,
                           engineFlame_frame7Img, engineFlame_frame8Img, engineFlame_frame9Img }
    engineAnimation = EngineAnimation:new(nil, engineFlame_frames, true, math.rad(180), .08)

    -- load audio
    explosionSound = love.audio.newSource("audio/effects/explosion.wav", "static")
    explosionSound:setVolume(0.7)

    shotSound = love.audio.newSource("audio/effects/shot.wav", "static")
    shotSound:setVolume(0.4)

    gameOverSound = love.audio.newSource("audio/effects/gameover.wav", "static")
    gameOverSound:setVolume(1)

    shipHitSound = love.audio.newSource("audio/effects/shiphit.wav", "static")
    shipHitSound:setVolume(1)

    song = love.audio.newSource("audio/Religions.mp3", "stream")
    print("audioEnabled: " .. tostring(audioEnabled))
    playMusic()

    -- generate initial background stars
    print("numberOfBackgroundStars: " .. tostring(numberOfBackgroundStars))
    for i = 1, numberOfBackgroundStars do
        size = math.random(1, 3)
        x = math.random(0, 1280)
        y = math.random(0, 720)
        speed = math.random(2, 8)
        stars[i] = BackgroundStar:new(nil, x, y, size, 1, 1, 1, speed)
    end

    Moan.UI.boxColour = { .15, .22, .35, 222 }
    Moan.setSpeed("fast")

    Moan.speak({ goodGuyName, { 1, 1, 1 } },
            {
                "*** INCOMING TRANSMISSION ***",
                "Hey kid! While you were out on that training mission, the Apollo Armada swooped in and attacked!  Most of the fleet has scattered or been destroyed...  it's up to you to try and salvage what's left!",
                "Don't forget your training! SPACEBAR to fire your cannons and the UP and DOWN buttons to dodge.  You have limited ENERGY so don't forget to let your cannons cool down and recharge sometimes.",
                "If things get out of hand you can press ESCAPE to eject...  but once you do that there is no turning back so make sure you really mean it!",
                "I'll check in once I get to safe spot...  here they come! Give them hell!" },
            { image = goodGuyPortrait,
              onstart = function()
                  Moan.UI.messageboxPos = "bottom"
                  paused = true
              end,
              oncomplete = function()
                  paused = false
                  spawnEnemyShips(10)
              end })
end

function love.draw()
    love.graphics.setFont(font)

    -- background big red star
    love.graphics.draw(redStarImg, 400, 0, 0, 0.2, 0.2)

    -- background small stars
    for i, star in ipairs(stars) do
        star:draw()
    end

    -- background big blue stars
    love.graphics.draw(blueStarImg, 600, 400)

    -- health and energy bars
    drawHealthAndEnergyBars()

    -- enemy ships
    for i, ship in ipairs(enemyShips) do
        ship:draw()
    end
    for i, bullet in ipairs(enemyBullets) do
        bullet:draw(.4, 1, 0)
    end

    -- animations
    for i, animation in ipairs(animations) do
        animation:draw()
    end

    -- draw collison hitboxes
    if drawCollisionHitboxes then
        for i, ship in ipairs(enemyShips) do
            local x, y, w, h = ship:getHitbox()
            love.graphics.rectangle("line", x, y, w, h)
        end
    end

    -- text displays
    love.graphics.print("EXP: " .. score, 1050, 25)
    love.graphics.print("Level: " .. level, 925, 25)
    if showMemoryUsage then
        love.graphics.print('Memory used (kB): ' .. collectgarbage('count'), 950, 75)
    end

    -- player ship
    if playerDead == false then
        playerShip:draw()
        engineAnimation:drawAtPosition(50, playerShip.y)
        if timeSinceLastPlayerShipImpact < .2 then
            love.graphics.draw(playerShipImpactImg,
                    playerShip:getTopLeftX() + 85,
                    playerShip:getTopLeftY() + 55,
                    math.rad(180),
                    1,
                    1)
        end
    else
        love.graphics.print("GAME OVER", 375, 275, 0, 5, 5)
    end

    for i, bullet in ipairs(playerBullets) do
        bullet:draw(1, 0, 0)
    end

    -- if the boss ship has been defeated
    if level == 7 then
        love.graphics.print("YOU WIN!!", 400, 275, 0, 5, 5)
    end

    -- text boxes
    Moan.draw()
end

function love.update(dt)
    Moan.update(dt)

    if paused == true then
        return
    end

    handleMessageBoxes()
    handleUnpausedInput(dt)

    -- engine animation
    engineAnimation:update(dt)

    -- background stars
    for i, star in ipairs(stars) do
        star.x = star.x - star.speed
        if star.x < 0 then
            star.x = 1280
            star.y = math.random(0, 720)
            star.speed = math.random(2, 8)
        end
    end

    -- player ship and bullets
    if playerDead == false then
        playerShip:update(dt)
    end

    for i, bullet in ipairs(playerBullets) do
        bullet:update(dt, 10)
        if bullet.x > 1280 then
            table.remove(playerBullets, i)
        end
    end

    -- enemy ships and bullets
    for i, ship in ipairs(enemyShips) do
        ship:update(dt, enemyBullets)
    end

    for i, bullet in ipairs(enemyBullets) do
        bullet:update(dt, -5)
        if bullet.x > 1280 or bullet.x < 0 then
            table.remove(enemyBullets, i)
        end
    end

    -- other animations
    for i, animation in ipairs(animations) do
        animation:update(dt)
        if animation.elapsedDuration >= animation.expiresAfter then
            table.remove(animations, i)
        end
    end

    -- check collisions
    for i, ship in ipairs(enemyShips) do
        for l, bullet in ipairs(playerBullets) do
            local collisionDectected = checkCollisionOfShipAndBullet(ship, bullet)
            if collisionDectected then
                enemyShips[i].health = enemyShips[i].health - 1;
                table.remove(playerBullets, l)

                if enemyShips[i].health <= 0 then
                    destroyEnemyShip(enemyShips[i], i)
                end
            end
        end
    end

    timeSinceLastPlayerShipImpact = timeSinceLastPlayerShipImpact + dt
    for i, bullet in ipairs(enemyBullets) do
        local collisionDectected = checkCollisionOfShipAndBullet(playerShip, bullet)
        if collisionDectected then
            print("player ship collision detected")
            playerShip.health = playerShip.health - 1
            table.remove(enemyBullets, i)
            playSound("shiphit")
            timeSinceLastPlayerShipImpact = 0
        end
    end

    -- spawn new ships
    timeSinceLastShipSpawn = timeSinceLastShipSpawn + dt
    if timeSinceLastShipSpawn > 3 then
        if level >= 4 then
            spawnEnemyShips(8)
        else
            spawnEnemyShips(5)
        end
        timeSinceLastShipSpawn = 0
    end

    -- update energy
    timeSinceLastEnergyGain = timeSinceLastEnergyGain + dt
    if playerShip.energy < maxEnergy and timeSinceLastEnergyGain > .03 then
        playerShip.energy = playerShip.energy + 1
        timeSinceLastEnergyGain = 0
    end

    -- check if player is dead
    if playerShip.health <= 0 and playerDead == false then
        playerDead = true
        love.audio.stop()
        playSound("gameover")
        table.insert(animations,
                AnimationWrapper:new(o,
                        playerExplosionSpriteSheet,
                        playerExplosionAnimation,
                        playerShip.x,
                        playerShip.y,
                        1.28,
                        playerShip.scale * 2.5))
    end
end

function love.keypressed(key)
    if key == "space" then
        Moan.advanceMsg()
    end

    if key == "escape" then
        love.event.quit()
    end
end

function handleUnpausedInput(dt)
    if love.keyboard.isDown("up") then
        playerShip.y = playerShip.y - 8
        if playerShip.y < 45 then
            playerShip.y = 45
        end
    end

    if love.keyboard.isDown("down") then
        playerShip.y = playerShip.y + 8
        if playerShip.y > 670 then
            playerShip.y = 670
        end
    end

    if love.keyboard.isDown("space") and playerDead == false then
        if playerShip.energy >= energyPerShot then
            timeSinceLastPlayerBulletFired = timeSinceLastPlayerBulletFired + dt
            if timeSinceLastPlayerBulletFired > .10 then
                local newBullet = Bullet:new(nil, playerShip.x + 25, playerShip.y, 4, false)
                table.insert(playerBullets, newBullet)
                timeSinceLastPlayerBulletFired = 0
                playSound("shot")
                if not infiniteEnergy then
                    playerShip.energy = playerShip.energy - energyPerShot
                end
            end
        end
    end
end

function destroyEnemyShip(ship, i)
    score = score + ship:getScoreValue()
    local expiresAfter = .64

    -- if boss ship, make the explosion go off five times instead of just once
    if ship.type == 4 then
        expiresAfter = expiresAfter * 5
    end

    table.insert(animations,
            AnimationWrapper:new(o,
                    explosionSpriteSheet,
                    explosionAnimation,
                    ship.x,
                    ship.y,
                    expiresAfter,
                    ship.scale))
    table.remove(enemyShips, i)
    playSound("explosion")
end

function destroyAllShips()
    for i, ship in ipairs(enemyShips) do
        destroyEnemyShip(ship, i)
    end
end

function drawHealthAndEnergyBars()
    -- armor
    local healthPercentage = playerShip.health / maxHealth
    local healthBarLength = healthPercentage * 200

    love.graphics.setColor(1, 1, 1)
    love.graphics.polygon("fill", 424, 38, 856, 38, 842, 52, 438, 52)
    if playerShip.health > 0 then
        love.graphics.setColor(1, 0, 0)
        love.graphics.polygon("fill", 640, 40, 630 - healthBarLength, 40, 640 - healthBarLength, 50, 640, 50)
        love.graphics.polygon("fill", 640, 40, 650 + healthBarLength, 40, 640 + healthBarLength, 50, 640, 50)
    end

    -- energy
    local energyPercentage = playerShip.energy / maxEnergy
    local energyBarLength = energyPercentage * 200

    love.graphics.setColor(1, 1, 1)
    love.graphics.polygon("fill", 424, 53, 856, 53, 842, 67, 438, 67)
    if playerShip.energy > 0 then
        love.graphics.setColor(1, .5, 0)
        love.graphics.polygon("fill", 640, 55, 630 - energyBarLength, 55, 640 - energyBarLength, 65, 640, 65)
        love.graphics.polygon("fill", 640, 55, 650 + energyBarLength, 55, 640 + energyBarLength, 65, 640, 65)
    end

    love.graphics.setColor(1, 1, 1)
end

function handleMessageBoxes()
    if score > level2Threshold and level <= 1 then
        Moan.speak({ goodGuyName, { 1, 1, 1 } },
                {
                    "*** INCOMING TRANSMISSION ***",
                    "Hey kid! I'm still being chased but I had to pop in and warn you...  the Apollo Armada has called out their elite pilots!  Keep an eye out for blue sharpshooter ships!",
                    "They are extremely agile and fire faster than the standard yellow armada fodder.  Don't let them hit you too many times or your armor will fail!",
                    "**EXPLOSION**  **WARNING ALARM**  Damn!  I took a hit!  I've got to go kid, keep up the good work!" },
                { image = goodGuyPortrait,
                  onstart = function()
                      Moan.UI.messageboxPos = "bottom"
                      paused = true
                  end,
                  oncomplete = function()
                      level = 2
                      paused = false
                  end })
    end

    if score > level3Threshold and level <= 2 then
        Moan.speak({ goodGuyName, { 1, 1, 1 } },
                {
                    "*** INCOMING TRANSMISSION ***",
                    "Looks like you're making out pretty well...  I've got half the armada chasing me down at this point.  Don't know how much longer I'll make it...",
                    "The Apollo's have pulled out all the stops and are now deploying their green bombers...  they fire fast and have super strong armor.  Don't be surprised if you have to hit them a few times before they go down.",
                    "Best of luck out there...  I hope we get to chat again." },
                { image = goodGuyPortrait,
                  onstart = function()
                      Moan.UI.messageboxPos = "bottom"
                      paused = true
                  end,
                  oncomplete = function()
                      level = 3
                      paused = false
                  end })
    end

    if score > level4Threshold and level <= 3 then
        Moan.speak({ goodGuyName, { 1, 1, 1 } },
                {
                    "*** INCOMING TRANSMISSION ***",
                    "Ok...  this is it!  You've given the armada such a beating that they've called out all their spare ships and pilots!",
                    "Your reflexes and dodging skills are about to be tested to the max.  Get through this wave and we might be in the clear!!!" },
                { image = goodGuyPortrait,
                  onstart = function()
                      Moan.UI.messageboxPos = "bottom"
                      paused = true
                  end,
                  oncomplete = function()
                      level = 4
                      paused = false
                  end })
    end

    if score > level5Threshold and level <= 4 then
        Moan.speak({ goodGuyName, { 1, 1, 1 } },
                {
                    "*** INCOMING TRANSMISSION ***",
                    "You did it! You've depleted their forces to the point that Rear Admiral Jax has boarded their flagship and is on his way!",
                    "Now is the time to overload your ships reactor, it will give you more energy. For this fight you won't have to worry about your cannons overloading.",
                    "Don't let up now, if you can defeat the admiral then we will have saved our people from certain invasion..." },
                { image = goodGuyPortrait,
                  onstart = function()
                      Moan.UI.messageboxPos = "bottom"
                      infiniteEnergy = true
                      paused = true
                  end })
        Moan.speak({ badGuyName, { 1, 1, 1 } },
                {
                    "*** INCOMING TRANSMISSION ***",
                    "So you're the one who has caused us so much trouble.  I thought your ship would be cool.  Do you even have nitrous on that thing?  Where are the missiles?",
                    "No matter.  Sit still while I pulverize you and then invade your stupid planet..." },
                { image = badGuyPortrait,
                  onstart = function()
                      Moan.UI.messageboxPos = "top"
                      paused = true
                  end,
                  oncomplete = function()
                      level = 5
                      paused = false
                      shipSpawningEnabled = false
                      destroyAllShips() -- todo fix this
                      destroyAllShips()
                      destroyAllShips()
                      destroyAllShips()
                      destroyAllShips()
                      destroyAllShips()
                      spawnBossShip()
                  end })
    end

    if level == 5 and enemyShips[1].health <= 250 then
        Moan.speak({ badGuyName, { 1, 1, 1 } },
                {
                    "*** INCOMING TRANSMISSION ***",
                    "You have become a nuisance. No matter... from this point forward you will feel the power of this flagship unrestrained!" },
                { image = badGuyPortrait,
                  onstart = function()
                      Moan.UI.messageboxPos = "top"
                      paused = true
                  end,
                  oncomplete = function()
                      level = 6
                      paused = false
                      enemyShips[1].firingRate = 1.25
                  end })
    end

    if level == 6 and enemyShips[1].health <= 1 then
        Moan.speak({ badGuyName, { 1, 1, 1 } },
                {
                    "*** INCOMING TRANSMISSION ***",
                    "NOOO! WHAT HAVE YOU DONE!!!" },
                { image = badGuyPortrait,
                  onstart = function()
                      Moan.UI.messageboxPos = "top"
                      paused = true
                  end })
        Moan.speak({ goodGuyName, { 1, 1, 1 } },
                {
                    "*** INCOMING TRANSMISSION ***",
                    "We did it kid!!! Nice shootin!!!!!!!!!!!!!",
                    "Fly on back to fleet, you'll surely get a medal for this!" },
                { image = goodGuyPortrait,
                  onstart = function()
                      Moan.UI.messageboxPos = "bottom"
                      paused = true
                  end,
                  oncomplete = function()
                      level = 7
                      playerShip.health = maxHealth
                      paused = false
                  end })
    end
end

function spawnEnemyShips(numOfShips)
    if shipSpawningEnabled == false then
        print("ship spawning disabled")
        return
    end

    for i = 0, numOfShips, 1 do
        if table.getn(enemyShips) >= maxNumberOfEnemyShips then
            print("Can't spawn more ships, already at max " .. table.getn(enemyShips))
            return
        end

        local startingX = math.random(575, 1200)
        local startingY = math.random(75, 650)
        local scale

        local shipToSpawn = math.random(1, 8)
        if shipToSpawn == 1 and level >= 2 then
            scale = 0.55
            local newShip = EnemyShip:new(nil, startingX, startingY, enemyBlueShipImg, scale, 1)
            table.insert(enemyShips, newShip)
        elseif shipToSpawn == 2 and level >= 3 then
            scale = 1.25
            local newShip = EnemyShip:new(nil, startingX, startingY, enemyGreenShipImg, scale, 2)
            table.insert(enemyShips, newShip)
        else
            scale = 0.7
            local newShip = EnemyShip:new(nil, startingX, startingY, enemyYellowShipImg, scale, 3)
            table.insert(enemyShips, newShip)
        end

        table.insert(animations,
                AnimationWrapper:new(o,
                        spawnSpriteSheet,
                        spawnAnimation,
                        startingX,
                        startingY,
                        .1,
                        scale))
    end
end

function spawnBossShip()
    local newShip = EnemyShip:new(nil, 1000, 360, enemyRedBossShipImg, 14, 4)
    table.insert(enemyShips, newShip)
end

function checkCollisionOfShipAndBullet(ship, bullet)
    local x1, y1, w1, h1 = ship:getHitbox()
    return checkCollision(
            x1, y1,
            w1, h1,
            bullet.x, bullet.y,
            5, 5) --todo make this variable based on the bullet size, not hard coded to a width of 5
end

function checkCollision(x1, y1, w1, h1, x2, y2, w2, h2)
    return x1 < x2 + w2 and
            x2 < x1 + w1 and
            y1 < y2 + h2 and
            y2 < y1 + h1
end

function playSound(sound)
    if audioEnabled == false then
        return
    end

    if sound == "explosion" then
        explosionSound:clone():play()
    elseif sound == "shot" then
        shotSound:clone():play()
    elseif sound == "gameover" then
        gameOverSound:clone():play()
    elseif sound == "shiphit" then
        shipHitSound:clone():play()
    else
        print("unknown sound: " .. tostring(sound))
    end
end

function playMusic()
    if audioEnabled then
        song:setLooping(true)
        song:setVolume(0.7)
        song:play()
    end
end