Question

C++语言编写一个模拟图形时钟

C++语言编写一个模拟图形时钟，有效代码超过500.

Answer 1

/*--------------------------------------
CLOCK.C -- Analog Clock Program
(c) Charles Petzold, 1998
--------------------------------------*/

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

#define ID_TIMER 1
#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 ("Clock") ;
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 = NULL ;
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 0 ;
}

hwnd = CreateWindow (szAppName, TEXT ("Analog Clock"),
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 ;
}

void SetIsotropic (HDC hdc, int cxClient, int cyClient)
{
SetMapMode (hdc, MM_ISOTROPIC) ;
SetWindowExtEx (hdc, 1000, 1000, NULL) ;
SetViewportExtEx (hdc, cxClient / 2, -cyClient / 2, NULL) ;
SetViewportOrgEx (hdc, cxClient / 2, cyClient / 2, NULL) ;
}

void RotatePoint (POINT pt[], int iNum, int iAngle)
{
int i ;
POINT ptTemp ;

for (i = 0 ; i < iNum ; i++)
{
ptTemp.x = (int) (pt[i].x * cos (TWOPI * iAngle / 360) +
pt[i].y * sin (TWOPI * iAngle / 360)) ;

ptTemp.y = (int) (pt[i].y * cos (TWOPI * iAngle / 360) -
pt[i].x * sin (TWOPI * iAngle / 360)) ;

pt[i] = ptTemp ;
}
}

void DrawClock (HDC hdc)
{
int iAngle ;
POINT pt[3] ;

for (iAngle = 0 ; iAngle < 360 ; iAngle += 6)
{
pt[0].x = 0 ;
pt[0].y = 900 ;

RotatePoint (pt, 1, iAngle) ;

pt[2].x = pt[2].y = iAngle % 5 ? 33 : 100 ;

pt[0].x -= pt[2].x / 2 ;
pt[0].y -= pt[2].y / 2 ;

pt[1].x = pt[0].x + pt[2].x ;
pt[1].y = pt[0].y + pt[2].y ;

SelectObject (hdc, GetStockObject (BLACK_BRUSH)) ;

Ellipse (hdc, pt[0].x, pt[0].y, pt[1].x, pt[1].y) ;
}
}

void DrawHands (HDC hdc, SYSTEMTIME * pst, BOOL fChange)
{
static POINT pt[3][5] = { 0, -150, 100, 0, 0, 600, -100, 0, 0, -150,
0, -200, 50, 0, 0, 800, -50, 0, 0, -200,
0, 0, 0, 0, 0, 0, 0, 0, 0, 800 } ;
int i, iAngle[3] ;
POINT ptTemp[3][5] ;

iAngle[0] = (pst->wHour * 30) % 360 + pst->wMinute / 2 ;
iAngle[1] = pst->wMinute * 6 ;
iAngle[2] = pst->wSecond * 6 ;

memcpy (ptTemp, pt, sizeof (pt)) ;

for (i = fChange ? 0 : 2 ; i < 3 ; i++)
{
RotatePoint (ptTemp[i], 5, iAngle[i]) ;

Polyline (hdc, ptTemp[i], 5) ;
}
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
static int cxClient, cyClient ;
static SYSTEMTIME stPrevious ;
BOOL fChange ;
HDC hdc ;
PAINTSTRUCT ps ;
SYSTEMTIME st ;

switch (message)
{
case WM_CREATE :
SetTimer (hwnd, ID_TIMER, 1000, NULL) ;
GetLocalTime (&st) ;
stPrevious = st ;
return 0 ;

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

case WM_TIMER :
GetLocalTime (&st) ;

fChange = st.wHour != stPrevious.wHour ||
st.wMinute != stPrevious.wMinute ;

hdc = GetDC (hwnd) ;

SetIsotropic (hdc, cxClient, cyClient) ;

SelectObject (hdc, GetStockObject (WHITE_PEN)) ;
DrawHands (hdc, &stPrevious, fChange) ;

SelectObject (hdc, GetStockObject (BLACK_PEN)) ;
DrawHands (hdc, &st, TRUE) ;

ReleaseDC (hwnd, hdc) ;

stPrevious = st ;
return 0 ;

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

SetIsotropic (hdc, cxClient, cyClient) ;
DrawClock (hdc) ;
DrawHands (hdc, &stPrevious, TRUE) ;

EndPaint (hwnd, &ps) ;
return 0 ;

case WM_DESTROY :
KillTimer (hwnd, ID_TIMER) ;
PostQuitMessage (0) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam) ;
}