关于love2d：Lua错误“尝试调用方法”(nil值)

Lua Error "Attempt to call method '' (a nil Value)

我想制作一个2D平台(带有Love2D-Framework)，并有一个main.lua文件从状态文件夹中选择随机映射。
首先，我只是说main-main.lua应该在/ states / map1 /中打开main.lua文件。但是每次我尝试运行它时，我都会收到以下错误消息：

错误

States / map1 / main.lua：169：尝试调用方法" update"(nil值)

追溯

States / map1 / main.lua：169：在"更新"函数中
[C]：在函数" xpcall"中

main-main.lua代码：

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function clearLoveCallbacks()
love.draw = nil
love.joystickpressed = nil
love.joystickreleased = nil
love.keypressed = nil
love.keyreleased = nil
--love.load = nil
love.mousepressed = nil
love.mousereleased = nil
love.update = nil
end

state = {}
function loadState(name)
state = {}
clearLoveCallbacks()
local path ="states/" .. name
require(path .."/main")
load()
local player
end

function load()
end

function love.load()
loadState("map1")
end

/ states / map1 /-文件中的main.lua：

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player = table
local AdvTiledLoader = require("AdvTiledLoader.Loader")
require("camera")

function love.load()
love.graphics.setBackgroundColor( 198, 220, 255 )
song1 = love.audio.newSource("sound/Brightly_Fancy.mp3", true)
song1:setVolume(0.1)
song1:play()

imgPlayer = love.graphics.newImage("textures/player.png")
AdvTiledLoader.path ="maps/"
map = AdvTiledLoader.load("map1.tmx")
map:setDrawRange(0, 0, map.width * map.tileWidth, map.height * map.tileHeight)

camera:setBounds(0, 0, map.width * map.tileWidth - love.graphics.getWidth(), map.height * map.tileHeight - love.graphics.getHeight() )

world = {
gravity = 1536, --1536
ground = 512,
}

player = {
x = 256,
y = 256,
x_vel = 0,
y_vel = 0,
jump_vel = -1024,
speed = 512, --512
flySpeed = 700,
state ="",
h = 32,
w = 32,
standing = false,
}
function player:jump()
if self.standing then
self.y_vel = self.jump_vel
self.standing = false
end
end

function player:right()
self.x_vel = self.speed
end

function player:left()
self.x_vel = -1 * (self.speed)
end

function player:stop()
self.x_vel = 0
end

function player:collide(event)
if event =="floor" then
self.y_vel = 0
self.standing = true
end
if event =="cieling" then
self.y_vel = 0
end
end

function player:update(dt)
local halfX = self.w / 2
local halfY = self.h / 2

self.y_vel = self.y_vel + (world.gravity * dt)

self.x_vel = math.clamp(self.x_vel, -self.speed, self.speed)
self.y_vel = math.clamp(self.y_vel, -self.flySpeed, self.flySpeed)

local nextY = self.y + (self.y_vel*dt)
if self.y_vel < 0 then
if not (self:isColliding(map, self.x - halfX, nextY - halfY))
and not (self:isColliding(map, self.x + halfX - 1, nextY - halfY)) then
self.y = nextY
self.standing = false
else
self.y = nextY + map.tileHeight - ((nextY - halfY) % map.tileHeight)
self:collide("cieling")
end
end
if self.y_vel > 0 then
if not (self:isColliding(map, self.x-halfX, nextY + halfY))
and not(self:isColliding(map, self.x + halfX - 1, nextY + halfY)) then
self.y = nextY
self.standing = false
else
self.y = nextY - ((nextY + halfY) % map.tileHeight)
self:collide("floor")
end
end

local nextX = self.x + (self.x_vel * dt)
if self.x_vel > 0 then
if not(self:isColliding(map, nextX + halfX, self.y - halfY))
and not(self:isColliding(map, nextX + halfX, self.y + halfY - 1)) then
self.x = nextX
else
self.x = nextX - ((nextX + halfX) % map.tileWidth)
end
elseif self.x_vel < 0 then
if not(self:isColliding(map, nextX - halfX, self.y - halfY))
and not(self:isColliding(map, nextX - halfX, self.y + halfY - 1)) then
self.x = nextX
else
self.x = nextX + map.tileWidth - ((nextX - halfX) % map.tileWidth)
end
end

self.state = self:getState()
end

function player:isColliding(map, x, y)
local layer = map.tl["Solid"]
local tileX, tileY = math.floor(x / map.tileWidth), math.floor(y / map.tileHeight)
local tile = layer.tileData(tileX, tileY)
return not(tile == nil)
end

function player:getState()
local tempState =""
if self.standing then
if self.x_vel > 0 then
tempState ="right"
elseif self.x_vel < 0 then
tempState ="left"
else
tampState ="stand"
end
end
if self.y_vel > 0 then
tempState ="fall"
elseif self.y_vel < 0 then
tempState ="jump"
end
return tempState
end
end

function love.draw()
camera:set()

love.graphics.setColor( 255, 255, 255, 255 )
love.graphics.draw( imgPlayer, player.x - player.w/2, player.y - player.h/2, 0, 1, 1, 0, 0)
love.graphics.setColor( 255, 255, 255 )
map:draw()

camera:unset()
end

function love.update(dt)
if dt > 0.05 then
dt = 0.05
end
if love.keyboard.isDown("d") then
player:right()
end
if love.keyboard.isDown("a") then
player:left()
end
if love.keyboard.isDown("w") then --and not (hasJumped) then
player:jump()
end

player:update(dt)

camera:setPosition( player.x - (love.graphics.getWidth()/2), player.y - (love.graphics.getHeight()/2))
end

function love.keyreleased(key)
if (key =="a") or (key =="d") then
player.x_vel = 0
end
end

我真的不知道问题出在哪里：/