Как написать свой таймер?

#include <iostream>
#include <ctime> 
using namespace std;
void how2timer(int ms) {
    int CLOCKS_PER_MSEC = CLOCKS_PER_SEC / 1000; 
    clock_t end_time = clock() + ms * CLOCKS_PER_MSEC ;
    while (clock() < end_time) {}
    cout << "Время вышло!!!\n";
}
int main (){
    how2timer(5000);  // 5 секунд
    return 0;
}

#include "windows.h"
#include <deque>
#include <algorithm>
#include <iostream>
#include <time.h>
 
const int cellCountX = 60;
const int cellCountY = 40;
const int cellSize   = 10;
 
const int windowWidth  = cellSize * cellCountX+7;
const int windowHeight = cellSize * cellCountY+29;
const int clientWidth  = cellSize * cellCountX;
const int clientHeight = cellSize * cellCountY;
 
int snakeSize  = 6;
int snakeLives = 4;
struct snake{
  int x;
  int y;
};
 
std::deque<snake> snakePos;
std::deque<snake> lifePos;
std::deque<snake> foodPos;
 
LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);
 
int WINAPI WinMain(HINSTANCE h,HINSTANCE hprevinstance,LPSTR lpcmdline,int ncmdshow){
  WNDCLASSEX wc;
  HWND hwnd;
  MSG msg;
 
  ZeroMemory(&msg,sizeof(MSG));
  wc.cbSize=sizeof(wc);
  wc.style=CS_OWNDC|CS_HREDRAW|CS_VREDRAW;
  wc.lpfnWndProc=WndProc;
  wc.cbClsExtra=0;
  wc.cbWndExtra=0;
  wc.hInstance=h;
  wc.hIcon=LoadIcon(NULL,IDI_APPLICATION);
  wc.hCursor=LoadCursor(h,IDC_ARROW);
  wc.hbrBackground=(HBRUSH)GetStockObject(GRAY_BRUSH);
  wc.lpszMenuName=NULL;
  wc.lpszClassName="main";
  wc.hIconSm=LoadIcon(NULL,IDI_APPLICATION);
  if(!RegisterClassEx(&wc)) return 0;
 
  if(!(hwnd=CreateWindowEx(NULL,"main","Snake",WS_OVERLAPPEDWINDOW^WS_MAXIMIZEBOX^WS_THICKFRAME|WS_VISIBLE,(GetSystemMetrics(SM_CXSCREEN) - windowWidth) / 2, (GetSystemMetrics(SM_CYSCREEN) - windowHeight-300) / 2,windowWidth,windowHeight,NULL,NULL,h,NULL))) return 0;
  ShowWindow(hwnd,SW_SHOWDEFAULT);
  UpdateWindow(hwnd);
 
  while(msg.message != WM_QUIT){
    if(PeekMessage(&msg,NULL,0,0,PM_REMOVE)){
      TranslateMessage(&msg);
      DispatchMessage(&msg);
    }
  }
  return msg.wParam;
}
 
snake GenFoodPos() {
  int foodPosX;
  int foodPosY;
  snake foodPosTemp;
  srand(clock());
  foodPosX = rand() % cellCountX;
  foodPosY = rand() % cellCountY;
  foodPosTemp.x = foodPosX*cellSize;
  foodPosTemp.y = foodPosY*cellSize;
  return foodPosTemp;
}
 
bool CheckFoodPos(snake foodPos){
  for(std::deque<snake>::iterator it = snakePos.begin(); it!=snakePos.end();++it){
    if(foodPos.x == it->x && foodPos.y == it->y){
      return FALSE;
    }
  }
  return TRUE;
}
 
void SetFoodPos(){
  snake newFoodTemp;
  bool badFoodPos;
  do
  {
    newFoodTemp = GenFoodPos();
    badFoodPos = CheckFoodPos(newFoodTemp);
  } while(!badFoodPos);
  foodPos.push_front(newFoodTemp);
  if(foodPos.size() > 1) foodPos.pop_back();
}
 
bool CheckGettingFood(){
  if(snakePos.front().x == foodPos.front().x && snakePos.front().y == foodPos.front().y){
    SetFoodPos();
    return TRUE;
  }
  return FALSE;
}
 
void OriginSnakePos() {
  for(int i=0; i < snakeSize; i++){
    snake snakePosTemp ={cellSize * ((cellCountX/2)+i),  cellSize * (cellCountY/2)};
    snakePos.push_back(snakePosTemp);
  }
}
 
snake GenLifePos() {
  int lifePosX;
  int lifePosY;
  snake lifePosTemp;
  srand(clock());
  lifePosX = rand() % cellCountX;
  lifePosY = rand() % cellCountY;
  lifePosTemp.x = lifePosX*cellSize;
  lifePosTemp.y = lifePosY*cellSize;
  return lifePosTemp;
}
 
bool CheckLifePos(snake lifePos){
  for(std::deque<snake>::iterator it = snakePos.begin(); it!=snakePos.end();++it){
    if(lifePos.x == it->x && lifePos.y == it->y){
      return FALSE;
    }
  }
  if(lifePos.x == foodPos.front().x && lifePos.y == foodPos.front().y){
    return FALSE;
  }
  return TRUE;
}
 
void SetLifePos(){
  snake newLifeTemp;
  bool badLifePos;
  do
  {
    newLifeTemp = GenLifePos();
    badLifePos = CheckLifePos(newLifeTemp);
  } while(!badLifePos);
  lifePos.push_front(newLifeTemp);
  if(lifePos.size() > 1) lifePos.pop_back();
}
 
bool CheckGettingLife(){
  if(snakePos.front().x == lifePos.front().x && snakePos.front().y == lifePos.front().y){
    SetLifePos();
    ++snakeLives;
    return TRUE;
  }
  return FALSE;
}
 
bool CheckWrongMove(){
  for(std::deque<snake>::iterator it = snakePos.begin()+4; it!=snakePos.end();++it){
    //Проверка на касение головы с хвостом
    if(snakePos.front().x == it->x && snakePos.front().y == it->y){
      return TRUE;
    }
  }
  //Проверка на касание головы со стенами
  if(snakePos.front().x <= -1 || snakePos.front().x >= clientWidth
    || snakePos.front().y >= clientHeight || snakePos.front().y <= -1) {
      return TRUE;
  }
  return FALSE;
}
 
void SnakeMove(int keyPressed, HWND hwnd){
  if(!snakeLives) snakeLives = 4;
  snakePos.push_front(snakePos.front());
  switch(keyPressed){
  case VK_LEFT:
    snakePos.front().x -= cellSize;
    break;
  case VK_UP:
    snakePos.front().y -= cellSize;
    break;
  case VK_RIGHT:
    snakePos.front().x += cellSize;
    break;
  case VK_DOWN:
    snakePos.front().y += cellSize;
    break;
  }
  if(!CheckGettingFood()) snakePos.pop_back();
  if(CheckWrongMove()){
    snakePos.erase(snakePos.begin(),snakePos.end());
    OriginSnakePos();
    --snakeLives;
  }
  InvalidateRect(hwnd, NULL, TRUE);
}
 
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam){
  HDC hdc;
  PAINTSTRUCT ps;
  HPEN redPen;
  HPEN greenPen;
  HBRUSH hBrush;
  static HWND hwndB;
  static int keyPressed;
  static int keyPrvPres;
  switch (message){
 
  case WM_CREATE:
    keyPressed = VK_LEFT;
    keyPrvPres = VK_LEFT;
    OriginSnakePos();
    SetFoodPos();
    SetTimer(hwnd, 1, 300, NULL);
 
    return 0;
 
  case WM_KEYDOWN:
    switch(wParam){
    case VK_UP:
      if(keyPrvPres != VK_DOWN) keyPressed = VK_UP;
      break;
    case VK_DOWN:
      if(keyPrvPres != VK_UP) keyPressed = VK_DOWN;
      break;
    case VK_LEFT:
      if(keyPrvPres != VK_RIGHT) keyPressed = VK_LEFT;
      break;
    case VK_RIGHT:
      if(keyPrvPres != VK_LEFT) keyPressed = VK_RIGHT;
      break;
    }
    return 0;
 
  case WM_TIMER:
    SnakeMove(keyPressed, hwnd);
    keyPrvPres = keyPressed;
    return 0;
 
  case WM_PAINT:
    hdc = BeginPaint(hwnd, &ps);
    greenPen = CreatePen(PS_SOLID,1,RGB(0,255,0));
    hBrush = CreateSolidBrush(RGB(0,255,0));
    redPen = CreatePen(PS_SOLID,1,RGB(255,0,0));
    SelectObject(hdc, greenPen);
    if(snakeLives){ 
      //Отрисовка змеи
      for(std::deque<snake>::iterator it = snakePos.begin(); it!=snakePos.end(); ++it){
        Rectangle(hdc, it->x+cellSize, it->y+cellSize, it->x, it->y);
      }
 
      //Отрисовка еды
      SelectObject(hdc, redPen);
      Rectangle(hdc, foodPos.back().x+cellSize, foodPos.back().y+cellSize, foodPos.back().x, foodPos.back().y);
      SelectObject(hdc, greenPen);
      //Отрисовка поля
      for(int i=0;i<=clientWidth;i+=cellSize){
        MoveToEx(hdc,i,0,NULL);
        LineTo(hdc,i,clientHeight);
      }
      for(int j=0;j<=clientHeight;j+=cellSize){
        MoveToEx(hdc,0,j,NULL);
        LineTo(hdc,clientWidth,j);
      }
    }
    else {
      KillTimer(hwnd, 1);
      if(MessageBox(hwnd, "\nPress 'OK' to play again", "Game Over", MB_OK|MB_APPLMODAL) == IDOK)
        SetTimer(hwnd, 1, 300, NULL);
    }
    EndPaint(hwnd, &ps);
    return 0;
 
  case WM_DESTROY:
    KillTimer(hwnd, 1);
    PostQuitMessage(0);
    return 0;
  }
  return DefWindowProc(hwnd, message, wParam, lParam);
}