Linguagem C - LineTo(hdc, cxClient, cyClient / 2);

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

#define NUM   1000
#define TWOPI (2 * 3.14159)

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

int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,PSTR szCmdLine, int iCmdShow) {
    static TCHAR szAppName[] = TEXT("Ondas");
    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("Requer Windows NT!"), szAppName, MB_ICONERROR);
        return 0;
    }
    hwnd = CreateWindow(szAppName, TEXT("Ondas"), 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 int cxClient, cyClient;
    HDC        hdc;
    int        i;
    PAINTSTRUCT ps;
    POINT apt[NUM];
    switch(message) {
        case WM_SIZE:
            cxClient = LOWORD(lParam);
            cyClient = HIWORD(lParam);
            return 0;
        case WM_PAINT:
            hdc = BeginPaint(hwnd, &ps);
            MoveToEx(hdc,0,cyClient/2,NULL);
            LineTo(hdc, cxClient, cyClient/2);
            for(i=0; i<NUM; i++) {
                apt[i].x = i * cxClient / NUM;
                apt[i].y = (int) (cyClient/2 * (1-sin(TWOPI*i/NUM)));
            }
            Polyline(hdc, apt, NUM);
            return 0;
        case WM_DESTROY:
            PostQuitMessage(0);
            return 0;
    }
    return DefWindowProc(hwnd, message, wParam, lParam);
}