Lua Cheat Engine

local ffi = require("ffi")
ffi.cdef[[
    typedef unsigned long DWORD;
    typedef struct { float x, y, z; } vec3;
    DWORD GetModuleHandleA(const char* lpModuleName);
    DWORD GetAsyncKeyState(int vKey);
    void Sleep(DWORD dwMilliseconds);
    bool FreeLibraryAndExitThread(void* hModule, DWORD dwExitCode);
]]

local pi = 3.1415926535897932
local client = ffi.C.GetModuleHandleA("client.dll")
local engine = ffi.C.GetModuleHandleA("engine.dll")

local function ValidPlayer(ent, lp)
    if ent ~= lp and ffi.cast("DWORD*", ent + 0x100)[0] > 0 then
        return true
    else
        return false
    end
end

local function GetDistance(p1, p2)
    return math.sqrt((p1.x - p2.x)^2 + (p1.y - p2.y)^2 + (p1.z - p2.z)^2)
end

local function GetBonePos(entaddress, bone)
    local boneptr = ffi.cast("DWORD*", entaddress + 0x26A8)[0]
    local bonepos = ffi.new("vec3")
    bonepos.x = ffi.cast("float*", boneptr + 0x30 * bone + 0x0C)[0]
    bonepos.y = ffi.cast("float*", boneptr + 0x30 * bone + 0x1C)[0]
    bonepos.z = ffi.cast("float*", boneptr + 0x30 * bone + 0x2C)[0]
    return bonepos
end

local function GetClosestEnemy(lp, entitylist)
    local maxDist = 99999
    local entNum
    for i = 0, 31 do
        local entityptr = ffi.cast("DWORD*", entitylist + i * 0x10)[0]
        if entityptr ~= nil then
            local entityaddr = ffi.cast("DWORD*", entityptr)[0]
            if ValidPlayer(entityaddr, lp) then
                local entdistance = GetDistance(ffi.cast("vec3*", entityaddr + 0x138)[0], ffi.cast("vec3*", lp + 0x138)[0])
                if entdistance < maxDist then
                    maxDist = entdistance
                    entNum = i
                end
            end
        end
    end
    return ffi.cast("DWORD*", entitylist + entNum * 0x10)[0]
end

local function Thread(hModule)
    local clientstate = ffi.cast("DWORD*", engine + 0x58ADD4)[0]
    local entitylist = client + 0x4D5450C
    local pLocalplayer = client + 0xD3FC5C
    local localcamerapos = ffi.new("vec3")
    local entityaddr
    local localplayer
    local entheadpos = ffi.new("vec3")
    local cameraoffset = ffi.new("vec3")
    local localplayerpos = ffi.new("vec3")
    while true do
        ffi.C.Sleep(2)
        if ffi.C.GetAsyncKeyState(0x12) ~= 0 then
            if ffi.cast("DWORD*", pLocalplayer)[0] ~= nil then
                localplayer = ffi.cast("DWORD*", pLocalplayer)[0]
                entityaddr = GetClosestEnemy(localplayer, entitylist)
                entheadpos = GetBonePos(entityaddr, 8)
                localplayerpos = ffi.cast("vec3*", localplayer + 0x138)[0]
                cameraoffset = ffi.cast("vec3*", localplayer + 0x108)[0]
                localcamerapos.x = localplayerpos.x + cameraoffset.x
                localcamerapos.y = localplayerpos.y + cameraoffset.y
                localcamerapos.z = localplayerpos.z + cameraoffset.z
                local hyp = math.sqrt((entheadpos.x - localcamerapos.x)^2 + (entheadpos.y - localcamerapos.y)^2 + (entheadpos.z - localcamerapos.z)^2)
                local opp = entheadpos.z - localcamerapos.z
                local delta = -math.asin(opp / hyp) * (180 / pi)
                ffi.cast("float*", clientstate + 0x4D88)[0] = delta
                local adj = entheadpos.y - localcamerapos.y
                local opp2 = entheadpos.x - localcamerapos.x
                local delta2 = math.atan2(adj, opp2) * (180 / pi)
                ffi.cast("float*", clientstate + 0x4D8C)[0] = delta2
            end
        elseif ffi.C.GetAsyncKeyState(0x23) ~= 0 then
            break
        end
    end
    ffi.C.FreeLibraryAndExitThread(hModule, 0)
    return 0
end

local function DllMain(hModule, ul_reason_for_call, lpReserved)
    if ul_reason_for_call == 1 then
        ffi.C.CreateThread(nil, 0, ffi.cast("LPTHREAD_START_ROUTINE", Thread), hModule, 0, nil)
    end
    return true
end