GDI -PIXELS

#include <windows.h>LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);void DrawPixels(HWND hwnd);int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,    PWSTR lpCmdLine, int nCmdShow){  MSG  msg;  WNDCLASSW wc = {0};  wc.style = CS_HREDRAW | CS_VREDRAW;  wc.lpszClassName = L"Pixels";  wc.hInstance     = hInstance;  wc.hbrBackground = GetSysColorBrush(COLOR_3DFACE);  wc.lpfnWndProc   = WndProc;  wc.hCursor       = LoadCursor(0, IDC_ARROW);  RegisterClassW(&wc);  CreateWindowW(wc.lpszClassName, L"Pixels",              WS_OVERLAPPEDWINDOW | WS_VISIBLE,              100, 100, 250, 150, NULL, NULL, hInstance, NULL);  while( GetMessage(&msg, NULL, 0, 0)) {    TranslateMessage(&msg);    DispatchMessage(&msg);  }  return (int) msg.wParam;}LRESULT CALLBACK WndProc(HWND hwnd, UINT msg,    WPARAM wParam, LPARAM lParam){  switch(msg)  {    case WM_PAINT:      DrawPixels(hwnd);      break;    case WM_DESTROY:      PostQuitMessage(0);      return 0;  }  return DefWindowProcW(hwnd, msg, wParam, lParam);}void DrawPixels(HWND hwnd){  PAINTSTRUCT ps;  RECT r;  HDC hdc = BeginPaint(hwnd, &ps);  GetClientRect(hwnd, &r);  for (int i=0; i<1000; i++)   {    int x = (rand() % r.right - r.left);    int y = (rand() % r.bottom - r.top);    SetPixel(hdc, x, y, RGB(255, 0, 0));  }  EndPaint(hwnd, &ps);}