原创 BEZIER.C -- Bezier Splines Demo(VCSDK)

/*-----------------------------------------------------------------------
       
    BEZIER.C -- Bezier Splines Demo
       
                          (c) Charles Petzold, 1998
       
------------------------------------------------------------------------*/
       
#include <windows.h>
       
LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;
       
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
       
                          PSTR szCmdLine, int iCmdShow)
       
{
       
    static TCHAR szAppName[] = TEXT ("Bezier") ;
       
    HWND          hwnd ;
       
    MSG           msg ;
       
    WNDCLASS      wndclass ;
       

    wndclass.style        = CS_HREDRAW | CS_VREDRAW ;
       
    wndclass.lpfnWndProc= WndProc ;
       
    wndclass.cbClsExtra   = 0 ;
       
    wndclass.cbWndExtra   = 0 ;
       
    wndclass.hInstance    = hInstance ;
       
    wndclass.hIcon        = LoadIcon (NULL, IDI_APPLICATION) ;
       
   wndclass.hCursor      = LoadCursor (NULL, IDC_ARROW) ;
       
    wndclass.hbrBackground= (HBRUSH) GetStockObject (WHITE_BRUSH) ;
       
    wndclass.lpszMenuName= NULL ;
       
    wndclass.lpszClassName= szAppName ;
       
  
       
    if (!RegisterClass (&wndclass))
       
    {
       
            MessageBox (NULL, TEXT ("Program requires Windows NT!"),
       
                                    szAppName, MB_ICONERROR) ;
       
                  return 0 ;
       
    }
       
  
       
    hwnd = CreateWindow (szAppName, TEXT ("Bezier Splines"),
       
                                         WS_OVERLAPPEDWINDOW,
       
                           CW_USEDEFAULT, CW_USEDEFAULT,
       
                           CW_USEDEFAULT, CW_USEDEFAULT,
       
                           NULL, NULL, hInstance, NULL) ;
       
  
       
    ShowWindow (hwnd, iCmdShow) ;
       
    UpdateWindow (hwnd) ;
       
  
       
    while (GetMessage (&msg, NULL, 0, 0))
       
    {
       
            TranslateMessage (&msg) ;
       
            DispatchMessage (&msg) ;
       
    }
       
    return msg.wParam ;
       
}
       

void DrawBezier (HDC hdc, POINT apt[])
       
{
       
    PolyBezier (hdc, apt, 4) ;
       
    MoveToEx (hdc, apt[0].x, apt[0].y, NULL) ;
       
    LineTo   (hdc, apt[1].x, apt[1].y) ;
       
  
       
    MoveToEx (hdc, apt[2].x, apt[2].y, NULL) ;
       
    LineTo   (hdc, apt[3].x, apt[3].y) ;
       
}
       
LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
       
{
       
    static POINT apt[4] ;
       
    HDC          hdc ;
       
    int          cxClient, cyClient ;
       
    PAINTSTRUCT  ps ;
       

    switch (message)
       
    {
       
    case WM_SIZE:
       
            cxClient = LOWORD (lParam) ;
       
            cyClient = HIWORD (lParam) ;
       
       
       
                   apt[0].x = cxClient / 4 ;
       
                   apt[0].y = cyClient / 2 ;
       
       
       
                   apt[1].x = cxClient / 2 ;
       
                   apt[1].y = cyClient / 4 ;
       
       
       
                   apt[2].x = cxClient / 2 ;
       
                   apt[2].y = 3 * cyClient / 4 ;
       
       
       
                   apt[3].x = 3 * cxClient / 4 ;
       
                   apt[3].y = cyClient / 2 ;
       
       
       
                   return 0 ;
       

    case WM_LBUTTONDOWN:
       
    case WM_RBUTTONDOWN:
       
    case WM_MOUSEMOVE:
       
            if (wParam & MK_LBUTTON || wParam & MK_RBUTTON)
       
            {
       
                   hdc = GetDC (hwnd) ;
       
                   SelectObject (hdc, GetStockObject (WHITE_PEN)) ;
       
                   DrawBezier (hdc, apt) ;
       
            
       
                   if (wParam & MK_LBUTTON)
       
                   {
       
                           apt[1].x = LOWORD (lParam) ;
       
                           apt[1].y = HIWORD (lParam) ;
       
                   }
       
            
       
              if (wParam & MK_RBUTTON)
       
                  {
       
                                   apt[2].x = LOWORD (lParam) ;
       
                                   apt[2].y = HIWORD (lParam) ;
       
                   }
       
            
       
                   SelectObject (hdc, GetStockObject (BLACK_PEN)) ;
       
                   DrawBezier (hdc, apt) ;
       
                   ReleaseDC (hwnd, hdc) ;
       
            }
       
                   return 0 ;
       
    case   WM_PAINT:
       
            InvalidateRect (hwnd, NULL, TRUE) ;
       
       
       
            hdc = BeginPaint (hwnd, &ps) ;
       
       
       
            DrawBezier (hdc, apt) ;
       
       
       
            EndPaint (hwnd, &ps) ;
       
            return 0 ;
       
       
       
    case WM_DESTROY:
       
            PostQuitMessage (0) ;
       
            return 0 ;
       
    }
       
    return DefWindowProc (hwnd, message, wParam, lParam) ;
       
}