///////////////////////////////////////////////////////////////////////////////
// Snow.cpp
// Date: 2009-2-5 21:16
// A moving ball.
//
///////////////////////////////////////////////////////////////////////////////

#include <assert.h>
#include "Snow.h"

TCHAR strForWin1[] = "時間過得好快啊!";
TCHAR strForWin2[] = "開學已經十周了..." ;
TCHAR strForWin3[] = "你學的怎么樣了?";
TCHAR strForWin4[] = "有問題一定要及時讓我知道";
TCHAR strForWin5[] = "祝大家“小光棍節”快樂";
TCHAR strForWin6[] = "  CJ Wang 2011.11.1";

const int nMaxHeight = 450;

#define ID_TIMER 1

///////////////////////////////////////////////////////////////////////////////

int WINAPI WinMain( HINSTANCE hInst, HINSTANCE hPrevInst, char* cmdParam, int cmdShow )
{
 char className[] = "Snow";
 MovingBall MovingBallClass( WindowsProcedure, className, hInst );
 MovingBallClass.Register();

 WinMaker win( "-- Have a joy here!", className, hInst );
 win.Show( cmdShow );

 MSG msg;
 int status;
 
 while( ( status = ::GetMessage( & msg, NULL, 0, 0 ) ) != 0 )
 {
 if ( status == -1 )
 return -1;
 ::TranslateMessage( & msg );
 ::DispatchMessage( & msg );
 }

 return msg.wParam;
}

///////////////////////////////////////////////////////////////////////////////

MovingBall::MovingBall( WNDPROC wndProc, const char* className, HINSTANCE hInstance )
{
 _class.style = 0;
 _class.lpfnWndProc = wndProc; // Windows procedure: mandatory
 _class.cbClsExtra = 0;
 _class.cbWndExtra = 0;
 _class.hInstance = hInstance;
 _class.hIcon = 0; // Owner of class: mandatory
 _class.hCursor = ::LoadCursor( 0, IDC_ARROW );
 _class.hbrBackground = (HBRUSH) ( COLOR_WINDOW + 1 ); // Optional
 _class.lpszMenuName = 0;
 _class.lpszClassName = className; // Mandatory 
}

WinMaker::WinMaker( const char* szCaption, const char* className, HINSTANCE hInstance )
{
 DWORD dwStyle = WS_OVERLAPPEDWINDOW;
 dwStyle &= ~WS_SIZEBOX;
 dwStyle &= ~WS_MAXIMIZEBOX;
 dwStyle &= ~WS_MINIMIZEBOX;

 _hWnd = ::CreateWindow(
 className, // Name of a registered window class
 szCaption, // Window caption
 dwStyle, // Window style
 CW_USEDEFAULT, // x position
 CW_USEDEFAULT, // y position
 787, // width
 590, // height
 0, // Handle to parent window
 0, // Handle to menu
 hInstance, // Application instance
 0 ); // Window creation data
}

/*:: -- 作用域標識符！如果是在MFC下編程的話，因為MFC封裝了API函數，但是參數有的和API函數不一樣，
比如MFC封裝的函數一般都沒有句柄這個參數，但是API函數都有，
所以在MFC編程中，如果你調用的是全局的API函數的話就要加::符號，
來通知編譯器你調用的是全局的API函數，而不是MFC封裝的API函數！
當然有的函數比如參數是個布爾型的，MFC封裝的函數和全局的API函數的參數相同，
編譯器默認的是調用MFC封裝的函數，所以你加不加::作用域標識符都是一樣的!!

控制臺下編寫的程序用的就是API函數所以沒必要加::作用域標識符的。
*/

///////////////////////////////////////////////////////////////////////////////

LRESULT CALLBACK WindowsProcedure( HWND hWnd, UINT uMessage, WPARAM wParam, LPARAM lParam )
{
 static HBITMAP hbmpBkground = NULL,
 hbmpSnow = NULL,
 hbmpMask = NULL;
 static Snow snowFlakes[ 80 ];
 static int countSnow = 0;
 static int cxClient, cyClient;

 static int nHeightY = nMaxHeight;

 COLORREF clrBk;
 PAINTSTRUCT ps;
 HDC hdc = NULL,
 hdcMem = NULL;
 HINSTANCE hInst = NULL;

 switch( uMessage )
 {
 case WM_CREATE:
 hInst = ( (LPCREATESTRUCT) lParam )->hInstance;
 assert( hInst );

 hbmpBkground = ::LoadBitmap( hInst, TEXT( "bground" ) );
 assert( hbmpBkground );
 hbmpSnow = ::LoadBitmap( hInst, TEXT( "snow" ) );
 assert( hbmpSnow );
 hbmpMask = ::LoadBitmap( hInst, TEXT( "mask" ) ); 
 assert( hbmpMask );
 ::SetWindowPos( hWnd, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE );

 //設置定時器
 ::SetTimer( hWnd, ID_TIMER, 160, NULL );
 return 0;

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

 case WM_PAINT:
 hdc = ::BeginPaint( hWnd, & ps );
 assert( hdc );
 hdcMem = ::CreateCompatibleDC( hdc );
 assert( hdcMem );

 ::SelectObject( hdcMem, hbmpBkground );
 ::BitBlt(
 hdc,
 0, 0, 
 cxClient, cyClient,
 hdcMem,
 0, 0,
 SRCCOPY );
 
 ::DeleteDC( hdcMem );
 ::EndPaint( hWnd, & ps ); 
 return 0;

 case WM_TIMER:
 ::FlashWindow( hWnd, TRUE );
 if ( countSnow < 80 )
 {
 snowFlakes[ countSnow ].xPos = rand() % cxClient;
 snowFlakes[ countSnow ].yPos = 0;
 snowFlakes[ countSnow ].bIsExist = TRUE;
 countSnow++;
 }

 if ( countSnow == 80 )
 countSnow = 0;

 hdc = ::GetDC( hWnd );
 assert( hdc );
 hdcMem = ::CreateCompatibleDC( hdc );
 assert( hdcMem );

 ::SelectObject( hdcMem, hbmpBkground );
 ::BitBlt(
 hdc,
 0, 0, 
 cxClient, cyClient,
 hdcMem,
 0, 0,
 SRCCOPY );

 clrBk = ::GetBkColor( hdc );
 ::SetTextColor( hdc, RGB( 0, 11, 255 ) );
 ::SetBkColor( hdc, clrBk );
 ::TextOut( hdc, 100, nHeightY, strForWin1, lstrlen( strForWin1 ) );
 ::TextOut( hdc, 100, nHeightY + 18, strForWin2, lstrlen( strForWin2 ) );
 ::TextOut( hdc, 100, nHeightY + 36, strForWin3, lstrlen( strForWin3 ) );
 ::TextOut( hdc, 100, nHeightY + 54, strForWin4, lstrlen( strForWin4 ) );
 ::TextOut( hdc, 100, nHeightY + 70, strForWin5, lstrlen( strForWin5 ) );
 ::TextOut( hdc, 100, nHeightY + 88, strForWin6, lstrlen( strForWin6 ) );
 
 //
 // The redraw area for the text
 //
 nHeightY -= 10;

 if ( nHeightY <= -88 )
 {
 nHeightY = nMaxHeight;
 }
 
 int i;
 for ( i = 0; i < 80; i++ )
 {
 if ( snowFlakes[ i ].bIsExist )
 {
 ::SelectObject( hdcMem, hbmpMask );
 ::BitBlt(
 hdc,
 snowFlakes[ i ].xPos, snowFlakes[ i ].yPos,
 20, 20,
 hdcMem,
 0, 0,
 SRCAND );

 ::SelectObject( hdcMem, hbmpSnow );
 ::BitBlt(
 hdc,
 snowFlakes[ i ].xPos, snowFlakes[ i ].yPos,
 20, 20,
 hdcMem,
 0, 0,
 SRCPAINT );

 if ( rand() % 2 == 0 )
 snowFlakes[ i ].xPos += 3;
 else
 snowFlakes[ i ].xPos -= 3;

 snowFlakes[ i ].yPos += 10;

 if ( snowFlakes[ i ].yPos > cyClient )
 {
 snowFlakes[ i ].xPos = rand() % cxClient;
 snowFlakes[ i ].yPos = 0;
 }
 }
 }
 
 ::ReleaseDC( hWnd, hdc );
 ::DeleteDC( hdcMem );
 return 0;
 
 case WM_DESTROY:
 ::DeleteObject( hbmpBkground );
 ::DeleteObject( hbmpSnow );
 ::DeleteObject( hbmpMask );
 ::KillTimer( hWnd, ID_TIMER );
 ::PostQuitMessage( 0 );
 return 0;
 }

 return ::DefWindowProc( hWnd, uMessage, wParam, lParam );
}