sinewave.cpp

wince下的一个简单的正弦曲线的画法

#include <windows.h>
#include <math.h>


#define SEGMENTS 500  // 取的点数（在一个周期内取500个点）
#define PI 3.1415926  // 圆周率

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


int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    LPWSTR lpCmdLine, int nCmdShow) 
{
	WNDCLASS wc;
	MSG msg;
	HWND hWnd;

	// Register application main window class
	wc.style = CS_HREDRAW | CS_VREDRAW; // Window style
    wc.lpfnWndProc = MainWndProc;             // Callback function
    wc.cbClsExtra = 0;                        // Extra class data
    wc.cbWndExtra = 0;                        // Extra window data
    wc.hInstance = hInstance;                 // Owner handle
    wc.hIcon = NULL,                          // Application icon
    wc.hCursor = LoadCursor (NULL, IDC_ARROW);// Default cursor
    wc.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH);
    wc.lpszMenuName =  NULL;                  // Menu name
    wc.lpszClassName = TEXT("SineWave");         // Window class name
   
    if (RegisterClass (&wc) == 0) return -1;

	// Create main window.
    hWnd = CreateWindowEx(
		                  WS_EX_CLIENTEDGE,   // Ex style flags
                          TEXT("SineWave"),   // Window class
                          TEXT("SineWave"),   // Window title
                          // Style flags
						  WS_VISIBLE | WS_CAPTION | WS_SYSMENU,
                          CW_USEDEFAULT,      // x position
                          CW_USEDEFAULT,      // y position
                          CW_USEDEFAULT,      // Initial width
                          CW_USEDEFAULT,      // Initial height
                          NULL,               // Parent
                          NULL,               // Menu, must be null
                          hInstance,          // Application instance
                          NULL);              // Pointer to create
                                              // parameters
    if (!IsWindow (hWnd)) return -2;  // Fail code if not created.
   
    // Standard show and update calls
    ShowWindow (hWnd, nCmdShow);
    UpdateWindow (hWnd);
   
    // Application message loop
    while (GetMessage (&msg, NULL, 0, 0)) {
        TranslateMessage (&msg);
        DispatchMessage (&msg);
    }
    // Instance cleanup
    return 1;
}

// MainWndProc - Callback function for application window
//
LRESULT CALLBACK MainWndProc (HWND hWnd, UINT wMsg, WPARAM wParam,LPARAM lParam) 
{
	PAINTSTRUCT ps;
    RECT rt;
    HDC hdc;
	int cxClient, cyClient;
	POINT pt[SEGMENTS];
	int i;
	switch(wMsg)
	{
	case WM_PAINT:
		hdc = BeginPaint(hWnd, &ps);
		GetClientRect(hWnd, &rt);
		cxClient = rt.right - rt.left;
		cyClient = rt.bottom - rt.top;

		// 画横坐标轴
		MoveToEx(hdc, 0, cyClient/2, NULL);
		LineTo(hdc, cxClient, cyClient/2);
		// 找出500个点的坐标
		for(i=0; i<SEGMENTS; i++)
		{
			pt[i].x = cxClient*i/SEGMENTS;
			pt[i].y = (int)((cyClient/2)*(1 - sin(2*PI*i/SEGMENTS)));
		}
		// 将各点连在一起
		Polyline(hdc, pt, SEGMENTS);

		EndPaint(hWnd, &ps);
		break;
	case WM_DESTROY:
		PostQuitMessage(0);
		break;
	}
	return DefWindowProc(hWnd, wMsg, wParam, lParam);
}