3d cube

WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {//обработчик сообщений
 PAINTSTRUCT ps;
 static HBRUSH hBrush;
 class TFPoint{
 public:
 float X;
 float Y;
 float Z;
 };
 TFPoint CubePoints[]={
 {-50, -50, -50},
 {50, -50, -50},
 {50, 50, -50},
 {-50, 50, -50},
 {-50, 50, 50},
 {-50, -50, 50},
 {50, -50, 50},
 {50, 50, 50}
 };
 int Gran[6][4]={
 {0, 3, 4, 5},
 {0, 5, 6, 1},
 {2, 7, 4, 3},
 {7, 6, 5, 4},
 {0, 1, 2, 3},
 {2, 1, 6, 7}
 };
 POINT point1[4];
 HDC hdc;
 int sx, sy, xPos, yPos, zDelta;
 switch (message)
 {
 case WM_MOUSEMOVE:
 sx = LOWORD(lParam);
 sy = HIWORD(lParam);
 thetta+=((sx%180)-90)/10;
 phi+=((sy%180)-90)/10;
 InvalidateRect(hWnd, NULL, TRUE);
 break;
 case WM_MOUSEWHEEL:
 zDelta=(int) wParam;
 ScreenDist-=zDelta/1000000.;
 InvalidateRect(hWnd, NULL, TRUE);
 break;
 case WM_SIZE:
 sx = LOWORD(lParam);//Ширина
 sy = HIWORD(lParam);//Высота
 break;
 case WM_PAINT:
 hBrush = CreateSolidBrush(RGB(255, 0, 0)); // Создание кисти
 hdc = BeginPaint(hWnd, &ps);//Установка режима
 th=thetta*factor;
 ph=phi*factor;
 costh=cos(th);
 sinth=sin(th);
 cosph=cos(ph);
 sinph=sin(ph);
 A=rho*sinph*costh; B=rho*sinph*sinth; C=rho*cosph;
 Al=A/(sqrt(A*A+B*B+C*C));
 Bl=B/(sqrt(A*A+B*B+C*C));
 Cl=C/(sqrt(A*A+B*B+C*C));
 for(int i = 0; i<6; i++){
 for(int j=0; j<3; j++){
 xt[j]=CubePoints[Gran[i][j]].X;
 yt[j]=CubePoints[Gran[i][j]].Y;
 zt[j]=CubePoints[Gran[i][j]].Z;
 }
 A = yt[0]*(zt[1]-zt[2])-yt[1]*(zt[0]-zt[2])+yt[2]*(zt[0]-zt[1]);
 B =-(xt[0]*(zt[1]-zt[2])-xt[1]*(zt[0]-zt[2])+xt[2]*(zt[0]-zt[1]));
 C = xt[0]*(yt[1]-yt[2])-xt[1]*(yt[0]-yt[2])+xt[2]*(yt[0]-yt[1]);
 An = A/(sqrt(A*A+B*B+C*C));
 Bn = B/(sqrt(A*A+B*B+C*C));
 Cn = C/(sqrt(A*A+B*B+C*C));
 alpha=(An*Al+Bn*Bl+Cn*Cl);
 for(int j=0; j<4; j++){
 point1[j]=Perspective(CubePoints[Gran[i][j]].X,
 CubePoints[Gran[i][j]].Y,
 CubePoints[Gran[i][j]].Z);
 }
 D = point1[0].x*(point1[1].y-point1[2].y)-
 point1[1].x*(point1[0].y-point1[2].y)+
 point1[2].x*(point1[0].y-point1[1].y);
 if (D<0){
 hBrush = CreateSolidBrush(RGB((1-alpha)*255,
 (1-alpha)*255,(1-alpha)*255));
 SelectObject(hdc,hBrush);
 Polygon(hdc,point1,4);
 }
 }
 EndPaint(hWnd, &ps);
 break;
 case WM_DESTROY:PostQuitMessage(0);
 break;
 default:return DefWindowProc(hWnd, message, wParam, lParam);
 }
 return 0;
}

// Обработчик сообщений для окна "О программе".
INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
 UNREFERENCED_PARAMETER(lParam);
 switch (message)
 {
 case WM_INITDIALOG:
  return (INT_PTR)TRUE;

 case WM_COMMAND:
  if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL)
  {
   EndDialog(hDlg, LOWORD(wParam));
   return (INT_PTR)TRUE;
  }
  break;
 }
 return (INT_PTR)FALSE;
}