Наклонить эллипс

#include <Windows.h> 
#include <tchar.h> 
#include <math.h> 
 
 
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM); 
TCHAR WinName[] = _T("MainFrame"); 
 
int APIENTRY WinMain(HINSTANCE This, HINSTANCE Prev, LPSTR cmd, int mode) { 
HWND hWnd; // Дескриптор главного окна программы 
MSG msg; // Структура для хранения сообщений 
WNDCLASS wc; // Класс окна 
 
wc.hInstance = This; 
wc.lpszClassName = WinName; 
wc.lpfnWndProc = WndProc; 
wc.style = CS_HREDRAW | CS_VREDRAW; 
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION); 
wc.hCursor = LoadCursor(NULL, IDC_ARROW); 
wc.lpszMenuName = NULL; 
wc.cbClsExtra = 0; 
wc.cbWndExtra = 0; 
wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 5); 
if (!RegisterClass(&wc)) 
return 0; 
hWnd = CreateWindow(WinName, _T("Каркас Windows-приложения"), WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, HWND_DESKTOP, NULL, This, NULL); 
ShowWindow(hWnd, mode); 
while (GetMessage(&msg, NULL, 0, 0)) { 
TranslateMessage(&msg); 
DispatchMessage(&msg); 
} 
return 0; 
} 
 
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) 
{//обработчик сообщений 
PAINTSTRUCT ps; 
HDC hdc; 
POINT pt[5] = { { -300,-300 },{ -450, 300 },{ 450, 300 },{ 300, -300 },{ -300, -300 } };
POINT el[2] = { { 300, 300 },{ 75, 75 } }; 
const int WIDTH = 500; 
const int HEIGHT = 300; 
int n = 2; 
const float M_PI = 3.14; 
static int sx, sy, i, k; 
static HBRUSH hBrush; 
static HBRUSH hBrush1; 
float alpha = M_PI / 7; 
HRGN ellipse; 
switch (message) 
{ 
case WM_CREATE: 
break; 
case WM_SIZE: 
sx = LOWORD(lParam);//Ширина 
sy = HIWORD(lParam);//Высота 
break; 
case WM_PAINT: 
hBrush = CreateSolidBrush(RGB(255, 0, 0)); 
hBrush1 = CreateSolidBrush(RGB(0, 0, 255)); 
hdc = BeginPaint(hWnd, &ps); 
//Установка режима SetMapMode(hdc,MM_ANISOTROPIC); 
//Установка логических размеров вывода , ось Y направлена вверх SetWindowExtEx(hdc,WIDTH,-HEIGHT,NULL); 
//Усновка физических размеров 
SetViewportExtEx(hdc, sx, sy, NULL); 
//Установка начала координат 
SetViewportOrgEx(hdc, sx / 2, sy / 2, NULL); 
SelectObject(hdc, hBrush); 
for(int i = 0; i < 2; i++) { 
el[i].x = (el[i].x*cos(alpha) - el[i].y*sin(alpha)); 
el[i].y = (el[i].x*sin(alpha) + el[i].y*cos(alpha)); 
} 
 
SelectObject(hdc, hBrush); 
ellipse = CreateEllipticRgn(el[0].x, el[0].y, el[1].x, el[1].y); 
FillRgn(hdc, ellipse, hBrush1); 
EndPaint(hWnd, &ps); 
DeleteObject(ellipse); 
break; 
case WM_DESTROY:PostQuitMessage(0); 
break; 
default:return DefWindowProc(hWnd, message, wParam, lParam); 
} 
return 0; 
}