错误在于：
game.lua：171：尝试索引全局'playerBul'（零值）
很抱歉，如果我放了太多不必要的代码，我只是不知道是什么导致了这个错误。
以下是此游戏的所有文件：
menu.lua：
local menu = {}
local bannermenu;
local selection;
menu.name = 'Menu'
local function play()
mode = require('game')
mode.load()
end
local options = {
{['text'] = 'Play', ['action'] = play},
{['text'] = 'Exit', ['action'] = love.event.quit}
}
function menu.load()
bannermenu = love.graphics.newImage(BANNER)
selection = 1
pointer = love.graphics.newImage(POINTER)
mode = menu
end
function menu.update()
return mode
end
function menu.draw()
love.graphics.draw(bannermenu, 200,10)
for i = 1,#options do
if i == selection then
love.graphics.draw(pointer, 300, 200 + i *20)
end
love.graphics.printf(options[i].text,0,200 + i * 20, love.graphics.getWidth(), 'center')
end
end
function menu.keypressed(key)
if key == "up" then
selection = (selection - 2)%(#options) + 1
elseif key == "down" then
selection = (selection) % (#options) + 1
elseif key == "return" then
options[selection].action()
elseif key == "escape" then
love.event.quit()
end
end
return menu
main.lua
TITLE = 'Die Aliens Die!'
PLAYER_BULLET = 'Images/playerbullet.png'
ENEMY_BULLET = 'Images/enemybullet.png'
HEALTH_IMG = 'Images/life.png'
ENEMY_UFO = {
ENEMY_1 = 'Images/enemy1.png',
ENEMY_2 = 'Images/enemy2.png',
ENEMY_3 = 'Images/enemy3.png'
}
PLAYER_IMG = 'Images/spaceship.png'
YOU_WIN = 'Images/win.png'
BANNER = 'Images/banner.png'
POINTER = 'Images/pointer.png'
function love.load()
love.window.setTitle(TITLE)
mode = require "menu"
mode.load()
end
function love.draw()
mode.draw()
end
function love.keypressed(key, isrepeat)
mode.keypressed(key)
end
function love.update(dt)
mode.update(dt)
end
game.lua
local game = {}
local playerShip = {}
local alienUFO = {}
local bullets = {}
local alienBullets = {}
local playerBullets = {}
local aliens = {{},{},{},{},{},{},{},{},{},{}}
local health = 3
local score = 0
local level = 1
local alienMovement = true
local healthImage;
local alienQty = 0
local pause
--local function gameOver()
--local function gamwWin()
local function clearTable(t)
for i = #t,1,-1 do
table.remove(t,i)
end
end
local function clearAliens()
for i=#aliens,1,-1 do
for j = #aliens[i],1,-1 do
table.remove(aliens[i],j)
end
end
end
local function insertAliens()
alienQty = 0
for i=1,4 do
for j =1,10 do
local alien = {}
alien.x = (j-1) *alienUFO.width + 10
alien.y = (j-1) *alienUFO.width + 35
if level ==2 then
alien.life = 2
if level == 3 then
alien.life = 3
end
table.insert(aliens[j], alien)
alienQty = alienQty + 1
end
end
end
end
local function initGame()
clearTable(playerBullets)
clearTable(alienBullets)
clearAliens()
insertAliens()
playerShip.x = love.graphics.getWidth() / 2 - playerShip.width /2
end
local function playerShoot()
local bullet = {}
playerShip.x = playerShip.x + 32
playerShip.y = playerShip.y + 10
table.insert(playerBullets, bullet)
end
local function AlienShoot(x,y)
local bullet = {}
bullet.x = alienUFO.width/2
bullet.y = y -5
table.insert(alienBullets, bullet)
end
local function playerShots(dt)
if next(playerBullets) ~= nil then
for i = #playerBullets,1,-1 do
playerBullets[i].y = playerBullets[i].y - dt* playerBullets.bulletSpeed
if playerBullets[i].y < 0 then
table.remove(playerBullets,i)
else
for j = #aliens, 1,-1 do
for k = #aliens[j],1,-1 do
if next(playerBullets) ~= nil and playerBullets[i] ~= nil and
aliens[j][k].x <= playerBullets[i].x and aliens[j] [k].x + 50 >= playerBullets[i].x
and aliens[j][k].y <= playerBullets[i].y and aliens[j] [k].y + 47 >= playerBullets[i].y then
table.remove(playerBullets, i)
if level == 2 and aliens[j][k].life > 0 then
aliens[j][k].life = aliens[j][k].life - 1
if level == 3 and aliens[j][k].life > 0 then
aliens[j][k].life = aliens[j][k].life - 1
else
table.remove(aliens[j], k)
alienQty = alienQty - 1
score = score + 100
end
break
end
end
end
end
end
end
end
local function PlayerShot()
health = health - 1
if health == 0 then
love.event.quit() -- COME BACK HERE FOR LOSE
end
end
local function AlienShots(dt)
if next(alienBullets) ~= nil then
for i = #alienBullets,1,-1 do
alienBullets[i].y = alienBullets[i].y + dt * alienUFO.bulletSpeed
if alienBullets[i].y > love.graphics.getHeight() then
table.remove(alienBullets, i)
elseif playerShip.x <= alienBullets[i].x and playerShip.x + playerShip.width >= alienBullets[i].x
and playerShip.y <= alienBullets[i].y and playerShip.y + playerShip.height >- alienBullets[i].y then
table.remove(alienBullets, i)
PlayerShot()
end
end
end
end
local function nextLVL()
level = level + 1
if level == 2 then
alienUFO.image = love.graphics.newImage(alienUFO.ENEMY1)
alienUFO.speed = 100
alienUFO.shotProb = 20
alienUFO.bullet = alienBul.image
initGame()
elseif level == 3 then
alienUFO.image = love.graphics.newImage(alienUFO.ENEMY2)
initGame()
elseif level > 3 then
love.event.quit() -- COME BACK HERE FOR WIN
end
end
function game.load()
pause = false
level = 1
health = 3
score = 0
playerShip.speed = 300
playerShip.bulletSpeed = 300
playerShip.width = 75
playerShip.height = 71
alienUFO.speed = 70
alienUFO.width = 50
alienUFO.height = 47
alienUFO.ENEMY1 = ENEMY_UFO.ENEMY_1
alienUFO.ENEMY2 = ENEMY_UFO.ENEMY_2
alienUFO.ENEMY3 = ENEMY_UFO.ENEMY_3
alienUFO.bulletSpeed = 300
alienUFO.image = love.graphics.newImage(alienUFO.ENEMY3)
playerShip.IMAGE = PLAYER_IMG
playerShip.image = love.graphics.newImage(playerShip.IMAGE)
healthImage = love.graphics.newImage(HEALTH_IMG)
playerShip.x = love.graphics.getWidth() / 2 - playerShip.width/2
playerShip.y = love.graphics.getHeight() - 100
playerBul.image = love.graphics.newImage(PLAYER_BULLET)
alienBul.image = love.graphics.newImage(ENEMY_BULLET)
initGame()
end
function game.draw()
if pause then
love.graphics.print('GAME PAUSED',love.graphics.getWidth()/2 - 20,20)
end
if next(playerBullets) ~= nil then
for i = 1, #playerBullets do
love.graphics.draw(playerBul.image, playerBullets[i].x, playerBullets[i].y)
end
end
if next(alienBullets) ~= nil then
for i = 1, #alienBullets do
love.graphics.draw(alienBul.image, alienBullets[i].x, alienBullets[i].y)
end
end
if next(aliens) ~= nil then
for i = 1, #aliens do
for j = 1, #aliens[i] do
love.graphics.draw(alienUFO.image, aliens[i][j].x, aliens[i][j].y)
end
end
end
love.graphics.print('Score: '..score, love.graphics.getWidth() - 100,20)
love.graphics.draw(playership.image, playership.x, playerShip.y)
for i = 1, lives do
love.graphics.draw(healthImage, 10+ 1 * 15,20)
end
end
function game.update(dt)
if not pause then
if alienQty == 0 then
nextLVL()
end
if love.keyboard.isDown("right") then
playerShip.x = playerShip.x + dt * playerShip.speed
elseif love.keyboard.isDown("left") then
playerShip.x = playerShip.x - dt * playerShip.speed
end
if love.keyboard.isDown(" ") then
playerShoot()
end
playerShots(dt)
AlienShots(dt)
if love.math.random(1,100) < alienUFO.shotProb then
local r = love.math.random(1,#aliens)
if next(aliens[r]) ~= nil then
alienShoot(aliens[r][#aliens[r]].x, aliens[r][#aliens[r]].y)
end
end
if alienMovement then
for i = 1, #aliens do
for j = 1, #aliens[i] do
aliens[i][j].x = aliens[i][j].x + dt * alienUFO.speed
if aliens[i][j].x + alienUFO.width + 2 >= love.graphics.getWidth() then
alienMovement = false
end
end
end
else
for i =1, #aliens do
for j = 1, #aliens[i] do
aliens[i][j].x = aliens[i][j].x - dt * alienUFO.speed
if aliens[i][j].x - 2 <= 0 then
alienMovement = true
end
end
end
end
if playerShip.x < 0 then
playerShip.x = 0
elseif playerShip.x > love.graphics.getWidth() - 75 then
playerShip.x = love.graphics.getWidth() -75
end
end
end
end
function game.keypressed(key)
if key =='p' then
pause = not pause
end
end
return game
答案 0 :(得分：3)
您尚未在load返回的游戏桌上定义game.lua功能。看起来您已经编写了加载逻辑，但将其编写为名为loadGame的本地函数。修复你的问题更新game.lua以导出加载函数，并让它调用你已经创建的加载函数，如下所示：
function game.load()
loadGame()
end
在您返回game.lua中的游戏桌之前的某个地方，请在您定义game.keypressed之后说明
或者您也可以将local function loadGame()更改为function game.load()以删除本地功能并将其重新定义为导出功能