《windows程序设计》（四）-------GDI编程之动态正弦曲线

/*--------------------------------------------------- sinwave.h --- sinwave,(c) jiyun.xia 2011 ---------------------------------------------------*/#ifndef SINWAVE_H_#define SINWAVE_H_#include <windows.h>LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);#endif

 

 

/*----------------------------------------------- sinwave.cpp --- draw sine. ------------------------------------------------*/#include "sinwave.h"#include <math.h>#include <time.h>#define ID_TIME11int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR szCmdLine, int iCmdShow){static TCHARszAppName[] = TEXT("sinwave");HWNDhWnd;MSGmsg;WNDCLASSwndClass;wndClass.cbClsExtra = 0;wndClass.cbWndExtra = 0;wndClass.hbrBackground = (HBRUSH)::GetStockObject(BLACK_BRUSH);wndClass.hCursor = ::LoadCursor(NULL, IDC_ARROW);wndClass.hIcon = ::LoadIcon(NULL, IDI_APPLICATION);wndClass.hInstance = hInstance;wndClass.lpfnWndProc = WndProc;wndClass.lpszClassName = szAppName;wndClass.lpszMenuName = NULL;wndClass.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;if (!::RegisterClass(&wndClass)){::MessageBox(NULL, TEXT("This program requires Windows NT!"), szAppName, MB_ICONERROR);return 0;}hWnd = ::CreateWindow(szAppName, TEXT("sinwave No.1"), 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 message, WPARAM wParam, LPARAM lParam){static lineNum;static intcyClient, yHight;static intcxClient;HDChdc;PAINTSTRUCT ps;HPEN hPen, hBlackPen;static int sign = -2;static unsigned char rColor, gColor, bColor;int i;static POINT *pPt;switch (message){case WM_CREATE:::SetTimer(hWnd, ID_TIME1, 10, NULL);return 0;case WM_SIZE:cyClient = HIWORD(lParam);cxClient = LOWORD(lParam);yHight = cyClient;sign = -2;if (!pPt)delete [] pPt;pPt = new POINT[cxClient + 1];return 0;case WM_TIMER:if (wParam == ID_TIME1){hdc = ::GetDC(hWnd);::Polyline(hdc, pPt, cxClient);yHight +=sign;if (yHight <= -cyClient || yHight >= cyClient) sign *= -1;for (i = 0; i <= cxClient; ++i){pPt[i].x = i;pPt[i].y =int(cyClient / 2.0 - yHight / 2.0 * sin(2 * 2 * 3.1415926 / cxClient * i));}srand( (unsigned)time(NULL));rColor = rand() % 255;gColor = rand() % 255;bColor = rand() % 255;hPen = ::CreatePen(PS_SOLID, 1, RGB(rColor, gColor, bColor));hBlackPen= (HPEN)::SelectObject(hdc, (HPEN)hPen);::Polyline(hdc, pPt, cxClient);SelectObject(hdc, (HPEN)hBlackPen);::DeleteObject((HPEN)hPen);::ReleaseDC(hWnd, hdc);}return 0;case WM_PAINT:hdc = ::BeginPaint(hWnd, &ps);for (i = 0; i <= cxClient; ++i){pPt[i].x = i;pPt[i].y =int(cyClient / 2.0 * (1 - sin(2 * 3.1415926 / cxClient * i)));}::Polyline(hdc, pPt, cxClient);::EndPaint(hWnd, &ps);return 0;case WM_DESTROY:::PostQuitMessage(0);return 0;}return ::DefWindowProc(hWnd, message, wParam, lParam);}