endjoin.c

图形基础 GDI 的例子

/*----------------------------------------
   ENDJOIN.C -- Ends and Joins Demo
                (c) Charles Petzold, 1996
  ----------------------------------------*/

#include <windows.h>

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
     {
     static char szAppName[] = "EndJoin" ;
     HWND        hwnd ;
     MSG         msg ;
     WNDCLASSEX  wndclass ;

     wndclass.cbSize        = sizeof (WNDCLASSEX) ;
     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 ;
     wndclass.hIconSm       = LoadIcon (NULL, IDI_APPLICATION) ;

     RegisterClassEx (&wndclass) ;

     hwnd = CreateWindow (szAppName, "Ends and Joins Demo",
                          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 ;
     }

LRESULT CALLBACK WndProc (HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam)
     {
     static int  iEnd  [] = { PS_ENDCAP_ROUND, PS_ENDCAP_SQUARE,
                              PS_ENDCAP_FLAT } ;
     static int  iJoin [] = { PS_JOIN_ROUND,   PS_JOIN_BEVEL,
                              PS_JOIN_MITER } ;
     static int  cxClient, cyClient ;
     HDC         hdc ;
     int         i ;
     LOGBRUSH    lb ;
     PAINTSTRUCT ps ;

     switch (iMsg)
          {
          case WM_SIZE:
               cxClient = LOWORD (lParam) ;
               cyClient = HIWORD (lParam) ;
               return 0 ;

          case WM_PAINT:
	       hdc = BeginPaint (hwnd, &ps) ;

               SetMapMode (hdc, MM_ANISOTROPIC) ;
               SetWindowExtEx (hdc, 100, 100, NULL) ;
	           SetViewportExtEx (hdc, cxClient, cyClient, NULL) ;

               lb.lbStyle = BS_SOLID ;
               lb.lbColor = RGB (128, 128, 128) ;
               lb.lbHatch = 0 ;


               for (i = 0 ; i < 3 ; i++)
                    {
                    SelectObject (hdc,
                         ExtCreatePen (PS_SOLID | PS_GEOMETRIC |
                                       iEnd [i] | iJoin [i], 10,
                                       &lb, 0, NULL)) ;

                    BeginPath (hdc) ;

                    MoveToEx (hdc, 10 + 30 * i, 25, NULL) ;
                    LineTo   (hdc, 20 + 30 * i, 75) ;
                    LineTo   (hdc, 30 + 30 * i, 25) ;


                    EndPath (hdc) ;

                    StrokePath (hdc) ;

                    DeleteObject (
                         SelectObject (hdc,
                              GetStockObject (BLACK_PEN))) ;

                    MoveToEx (hdc, 10 + 30 * i, 25, NULL) ;
                    LineTo   (hdc, 20 + 30 * i, 75) ;
                    LineTo   (hdc, 30 + 30 * i, 25) ;
                    }


	       EndPaint (hwnd, &ps) ;
               return 0 ;

          case WM_DESTROY:
               PostQuitMessage (0) ;
               return 0 ;
          }

     return DefWindowProc (hwnd, iMsg, wParam, lParam) ;
     }