Lua速成班 第十四课 系统函数第四节 MATH和OS库

local time = 0
local startY = 450
local range = 100

function update()
    time = time + 0.016
    local y = startY + math.sin(time * math.pi * 6) * range
    print("Y位置:", y)
end

local time = 0
local centerX = 500
local centerY = 450
local radius = 150

function update()
    time = time + 0.05
    local x = centerX + math.cos(time) * radius
    local y = centerY + math.sin(time) * radius
    print("位置:", x, y)
end

math.randomseed(os.time() + os.clock())

function lottery()
    local roll = math.random(1, 100)
    if roll <= 30 then
        return "稀有物品"
    else
        return "普通物品"
    end
end

print(lottery())

local total = 1000000
local people = 37

local per1 = math.floor(total / people)
local per2 = math.ceil(total / people)

print("向下取整每人:", per1, "剩余:", total - per1 * people)
print("向上取整每人:", per2, "会长补足:", per2 * people - total)

local targetX = 500
local clickX = 450

local distance = math.abs(clickX - targetX)
local score = math.max(0, 100 - distance)

print("距离:", distance, "得分:", score)

local angle = 30
local radian = angle * math.pi / 180

print("30度的弧度:", radian)
print("sin30度:", math.sin(radian))

local start = os.clock()

for i = 1, 10000 do
    local x = math.sin(i)
end

local cost = os.clock() - start
print("耗时毫秒:", cost * 1000)

local x = 100
local targetX = 700
local speed = 3

function move()
    x = x + speed
    if x < targetX then
        SL:ScheduleOnce(move, 0.016)
    end
end

move()

 前端调用GUIUtil.lua
function Reload()
     SL:Require("test.lua",true)
end

GUI:addKeyboardEvent("KEY_SPACE", Reload)

-- 调度器 
local function onUpdate(dt)
    frameCount = frameCount + 1
    local elapsed = os.clock() - startTime
    
    if elapsed >= 1.0 then
        scheduler:unscheduleScriptEntry(scheduleId)
        SL:print("FPS:", frameCount)
    end
end

scheduleId = scheduler:scheduleScriptFunc(onUpdate, 0, false)  -- COCOS 定时器 ~ C++ 语法规则! 

 
local win = GUI:Win_Create("Win_1", 0, 0, 1136, 640)
local path = "res/custom/feijian/a/jian_6.png"
-- 缓存初始中心坐标
local startX, startY = 450, 250 
local Image_bg = GUI:Image_Create(win, "Image_bg1234", startX, startY, path)

local t = 0
local overTime = 1
local radius = 110 -- 运动半径

-- 假设60 FPS
local delay =  1 / 60  -- 定时器间隔设为一帧的时间 (约 0.016)

function go()
    -- 直接使用外部缓存的 startX/Y 进行计算
    local x = startX + radius * math.sin(t * math.pi * 2)
    local y = startY + radius * math.cos(t * math.pi * 2)
    GUI:setPosition(Image_bg, x, y)
    t = t + delay
    if t < overTime then
        SL:ScheduleOnce(go, delay) 
    end
end

go()

local start = os.clock()
local n = 0
for i = 1, 10000000 do
    n = n + 1
end
local endTime = os.clock() - start
print(string.format("耗时:%.4f秒", endTime))

local t = os.time()
print(t)  -- 输出类似 1773728263

local t = os.time({
    year = 2026,
    month = 5,
    day = 1,
    hour = 0,
    min = 0,
    sec = 0
})
print(t)

-- 标准写法
print("1234")

-- 神仙写法（等效）
print '1234'

-- 标准写法
local t = os.time({year = 2026, month = 3, day = 17})

-- 神仙写法（等效）
local t = os.time{year = 2026, month = 3, day = 17}

function a(b)
    print(b)
    return function(c)
        print(c)
    end
end

-- 标准写法
a("123")("456")

-- 神仙写法（等效）
a"123""456"

print("hello world")
os.date("%Y-%m-%d")

local date = os.date()
print(date)  -- 输出格式如：Tue Mar 17 14:30:00 2026

local t = os.date("*t")
print(t.year, t.month, t.day)
print(t.hour, t.min, t.sec)
print(t.wday)  -- 星期几，1表示周日，2表示周一，以此类推
print(t.yday)  -- 当年的第几天

local day = os.date("%Y-%m-%d %H:%M:%S")
print(day)  -- 输出如：2026-03-17 14:30:00

local now = os.date("*t")
local wday = {"日","一","二","三","四","五","六"}
local nowstr = string.format("%d年%d月%d日 星期%s", now.year, now.month, now.day, wday[now.wday])
print(nowstr)

local t1 = os.time()
local t2 = os.time() + 100
local diff = os.difftime(t1, t2)
print(diff)  -- 输出 -100

-- 列出当前目录文件（Windows）
os.execute("dir")

-- 打开网页
os.execute("start www.qq.com")

-- 关机命令（慎用）
-- os.execute("shutdown -s -t 3")

os.exit(1)  -- 参数为true或非零值时直接退出

print(os.getenv("USERNAME"))  -- 获取当前用户名
print(os.getenv("OS"))        -- 获取操作系统类型
print(os.getenv("TEMP"))      -- 获取临时文件目录

os.remove("test.txt")  -- 删除指定文件

os.rename("old.txt", "new.txt")  -- 将old.txt重命名为new.txt

local file = os.tmpname()
print(file)  -- 输出临时文件路径