www.pudn.com > Bezier.rar > Bezier.c

/*--------------------------------------- 
   BEZIER.C -- Bezier Splines Demo 
               (c) Charles Petzold, 1998 
  ---------------------------------------*/ 
 
#include  
 
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) ; 
}