第五章 绘图基础（SINEWAVE）

 //SINEWAVE.C -- Sine Wave Using Polyline (c) Charles Petzold, 1998

 #include <Windows.h>

 #include <math.h>

 #define NUM        1000

 #define TWOPI    (2 * 3.14159)

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

 int WINAPI WinMain( __in HINSTANCE hInstance

                     , __in_opt HINSTANCE hPrevInstance

                     , __in LPSTR lpCmdLine

                     , __in int nShowCmd )

 {

     static TCHAR szAppName[] = TEXT("SineWave");

     HWND hwnd;

     MSG msg;

     WNDCLASS wndclass;

     wndclass.style = CS_HREDRAW | CS_VREDRAW;

     wndclass.lpfnWndProc = WndPorc;

     wndclass.cbClsExtra = ;

     wndclass.cbWndExtra = ;

     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 ;

     }

     hwnd = CreateWindow(szAppName, TEXT("Sine Wave Using Polyline")

         , WS_OVERLAPPEDWINDOW

         , CW_USEDEFAULT, CW_USEDEFAULT

         , CW_USEDEFAULT, CW_USEDEFAULT

         , NULL, NULL, hInstance, NULL);

     ShowWindow(hwnd, nShowCmd);

     UpdateWindow(hwnd);

     while (GetMessage(&msg, NULL, , ))

     {

         TranslateMessage(&msg);

         DispatchMessage(&msg);

     }

     return msg.wParam;

 }

 LRESULT CALLBACK WndPorc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)

 {

     static int cxClient, cyClient;

     HDC hdc;

     int i;

     PAINTSTRUCT ps;

     POINT apt[NUM];

     switch (message)

     {

     case WM_SIZE:

         cxClient = LOWORD(lParam);

         cyClient = HIWORD(lParam);

         return ;

     case WM_PAINT:

         hdc = BeginPaint(hwnd, &ps);

         MoveToEx(hdc, , cyClient / , NULL);

         LineTo(hdc, cxClient, cyClient / );

         for (i = ; i != NUM; ++i)

         {

             apt[i].x = i * cxClient / NUM;

             apt[i].y = (int)(cyClient /  * ( - sin(TWOPI * i / NUM)));

         }

         Polyline(hdc, apt, NUM);

         EndPaint(hwnd, &ps);

         return ;

     case WM_DESTROY:

         PostQuitMessage();

         return ;

     }

     return DefWindowProc(hwnd, message, wParam, lParam);

 }

SINEWAVE.C

SINEWAVE显示结果