Re: MDI app doesn't close - C / C++ / MFC Discussion Boards

Re: MDI app doesn't close

Alex Cutovoi14-Aug-07 7:47

Alex Cutovoi

14-Aug-07 7:47

Right, can you say what messages I need to handle to increase the code?

Re: MDI app doesn't close

Mark Salsbery14-Aug-07 8:13

Mark Salsbery

14-Aug-07 8:13

Except for messages you need to handle, the default window proc is fine.
The point is they'll never get processed if you exit your message loop.

Here's an example of what I'm talking about - problems/changes marked in red.

Note where I put PostQuitMessage() and where DestroyWindow() is called.

/*Loop da janela*/
WPARAM TemplateWindow::MessageLoop()
{
<font color="Red">    while(GetMessage(&msg, m_hwnd, NULL, NULL))
</font>    {
        if(m_uiType == MDI)
        {
            if(!TranslateMDISysAccel(m_hwndFrame, &msg))
            {
                TranslateMessage(&msg);
                DispatchMessage(&msg);
            }
        }
        if(m_uiType == SDI)
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }

<font color="Red">// This is bad design - Using a timer is WAY more efficient
//   than spinning in a loop that mostly does nothing except 
//   consume CPU
//            }
//        }
//        else
//        if(m_uiChildCount > 0)
//        {
//            SendMessage(childsInfo[0].hwnd, WM_PAINT, NULL, NULL);
//        }
//        SwapBuffers(m_hdc);
    }</font>

    return msg.wParam;
}

LRESULT CALLBACK MainWindowCallback(HWND hwnd, UINT uiMessage, WPARAM wParam, LPARAM lParam)
{
    HMENU hMainMenu;
    hMainMenu = CreateMenu(); <font color="Red">//<-- MAJOR resource leak!!!</font>
    static int siRuler = IDM_NEWRULER, siText = IDM_NEWTEXT, siNodule = IDM_NEWNODULE, siPath = IDM_NEWRULERPATH;
    switch(uiMessage)
    {
    case WM_CREATE:
    {
        ...
       <font color="Red"> // should return 0 if successful, -1 to fail the create</font>
        break;
    }
    case WM_CLOSE:
    {
        delete TextMenu;
        delete RulerMenu;
        delete PathMenu;
        delete NoduleMenu;
        delete ProceedingMenu;
        delete ScreenShotMenu;

        <font color="Red">// The default window proc calls DestroyWindow()
        return DefFrameProc(hwnd, g_hwndClient, uiMessage, wParam, lParam);</font>
    }
    <font color="Red">case WM_NCDESTROY:
        PostQuitMessage(0);
        break;</font>
        ...
    <font color="Red">default: 
        break;</font>
    }

    <font color="Red">return DefFrameProc(hwnd, g_hwndClient, uiMessage, wParam, lParam);
}</font>

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: MDI app doesn't close

Alex Cutovoi14-Aug-07 8:33

Alex Cutovoi

14-Aug-07 8:33

Well Mike, I made the changes that you said to me, nut unhapilly it doesn't work. Any other suggestion?
Thanks for the support man.

Re: MDI app doesn't close

Mark Salsbery14-Aug-07 8:43

Mark Salsbery

14-Aug-07 8:43

I'm Mark

How far is it getting? If you set a breakpoint in your WM_CLOSE handler, does it get there?
How about WM_NCDESTROY?

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: MDI app doesn't close

Alex Cutovoi14-Aug-07 9:56

Alex Cutovoi

14-Aug-07 9:56

Either the WM_CLOSE and the WM_NCDESTROY stops on the place that I show to you.
The code below is the code when it's debugged.

<br />
7E41DACF   push        0<br />
7E41DAD1   push        0Ch<br />
7E41DAD3   pop         edx<br />
7E41DAD4   lea         ecx,[ebp-0Ch]<br />
7E41DAD7   mov         dword ptr [ebp-0Ch],edi<br />
7E41DADA   call        7E4194A4               <==that is the place where it stops<br />
<br />

This thing is confusing my brain.

Re: MDI app doesn't close

Mark Salsbery14-Aug-07 10:05

Mark Salsbery

14-Aug-07 10:05

Heh. I have NO idea where that assembly code is Smile | :)

Can you post the code for your current message loop and your
window procedures for the frame and the child windows?

I'd be happy to look at it, but witout it I can only guess.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: MDI app doesn't close

Alex Cutovoi14-Aug-07 10:54

Alex Cutovoi

14-Aug-07 10:54

Sure, I post now.
The first code is for the message loop:

<br />
WPARAM TemplateWindow::MessageLoop()<br />
{<br />
   while(!m_bQuit)<br />
   {<br />
      if(PeekMessage(&msg, m_hwnd, NULL, NULL, PM_REMOVE))<br />
      {<br />
         if(msg.message == WM_QUIT)<br />
         {<br />
			if(m_uiType == MDI)DestroyWindow(m_hwndFrame);<br />
            m_bQuit = true;<br />
			//UnregisterClass(wnd.lpszClassName, m_hInstance);<br />
            break;<br />
         }<br />
	     else<br />
	     {<br />
            if(m_uiType == MDI)<br />
            {<br />
               if(!TranslateMDISysAccel(m_hwndFrame, &msg))<br />
	           {<br />
	              TranslateMessage(&msg);<br />
		          DispatchMessage(&msg);<br />
	           }<br />
            }<br />
            if(m_uiType == SDI)<br />
            {<br />
               TranslateMessage(&msg);<br />
	           DispatchMessage(&msg);<br />
            }<br />
         }<br />
      }<br />
	  else<br />
	  if(m_uiChildCount > 0)<br />
	  {<br />
		 SendMessage(childsInfo[0].hwnd, WM_PAINT, NULL, NULL);<br />
	  }<br />
	  SwapBuffers(m_hdc);<br />
   }<br />
   return msg.wParam;<br />
}<br />

And the following codes is the callback for my windows. Look at the codes. Again, thanks for your help.

<br />
#ifndef CALLBACKS_H<br />
#define CALLBACKS_H<br />
#include <windows.h><br />
#include <stdio.h><br />
#include <RichEdit.h><br />
#include <time.h><br />
<br />
WindowInfo windowInfos; //this is a struct that have the hwnd, hdc and the hglrc of child  <br />
                        //windows<br />
GLUquadricObj * Cilinder;<br />
unsigned int uiList = 0;<br />
int iValueSelected = -1;<br />
<br />
HINSTANCE hRichEdit; //HINSTANCE used to load theRichEdit's dll control<br />
<br />
HWND g_hwndClient, FrameHwnd, RenderHwnd, InstructHwnd, DialogHwnd;<br />
<br />
LRESULT CALLBACK MainWindowCallback(HWND, UINT, WPARAM, LPARAM);<br />
LRESULT CALLBACK InstructorWindowCallback(HWND, UINT, WPARAM, LPARAM);<br />
LRESULT CALLBACK RenderWindowCallback(HWND, UINT, WPARAM, LPARAM);<br />
LRESULT CALLBACK DialogWindowCallback(HWND, UINT, WPARAM, LPARAM);<br />
<br />
static bool bShow = false, bTrue = false;<br />
<br />
/*Instructor callback. Just a single callback defined to a richedit*/<br />
LRESULT CALLBACK InstructorWindowCallback(HWND hwnd, UINT uiMessage, WPARAM wParam, LPARAM lParam)<br />
{<br />
   HWND  textBox = NULL, editBox = NULL;<br />
   HFONT textFont = 0;<br />
   switch(uiMessage)<br />
   {<br />
      case WM_CREATE:<br />
	  {<br />
		 RECT richEditSize;<br />
		 hRichEdit = LoadLibrary("RichEd20.dll");<br />
		 InstructHwnd = hwnd;<br />
		 GetClientRect(hwnd, &richEditSize);<br />
		 HINSTANCE hInst = ((LPCREATESTRUCT)lParam)->hInstance;<br />
		 if(hRichEdit != NULL)<br />
		 { <br />
		    editBox = CreateWindowEx(WS_EX_CLIENTEDGE, TEXT("RICHEDIT20A"), "", WS_CHILD|WS_VISIBLE|WS_VSCROLL|WS_HSCROLL|ES_AUTOHSCROLL|ES_AUTOVSCROLL|ES_MULTILINE, 0, 0, richEditSize.right, richEditSize.bottom, hwnd, HMENU(IDC_EDITBOX), hInst, NULL);<br />
		    if(editBox != NULL)<br />
			{<br />
		       HDC editHdc = GetDC(editBox);<br />
               int iSize = -MulDiv(10, GetDeviceCaps(GetDC(hwnd), LOGPIXELSY), 72);<br />
		       textFont = CreateFont(iSize, 0, 0, 0, FW_NORMAL, FALSE, FALSE, FALSE, ANSI_CHARSET, OUT_TT_PRECIS, CLIP_DEFAULT_PRECIS, ANTIALIASED_QUALITY, FF_DONTCARE|DEFAULT_PITCH, "Courier");<br />
		       if(textFont == 0)<br />
			   {<br />
			      MessageBox(NULL, "Fonte não criada", "Erro", MB_OK|MB_ICONERROR);<br />
			      break;<br />
			   }<br />
		       SetBkMode(editHdc, TRANSPARENT);<br />
		       SelectObject(editHdc, textFont);<br />
		       ShowWindow(editBox, SW_SHOW);<br />
			   ReleaseDC(editBox, editHdc);<br />
			   SendMessage(editBox, WM_SETFONT,(WPARAM)textFont, (LPARAM)TRUE);<br />
			}<br />
		 }<br />
		 HMENU hSysMenu = GetSystemMenu(hwnd, false);<br />
		 EnableMenuItem(hSysMenu, SC_CLOSE, MF_GRAYED|MF_BYCOMMAND);<br />
		 if(DialogHwnd != NULL)ShowWindow(DialogHwnd, SW_HIDE);<br />
		 break;<br />
	  }<br />
	  case WM_GETMINMAXINFO:<br />
	  {<br />
		 RECT instructSize;<br />
		 GetClientRect(GetParent(hwnd), &instructSize);<br />
		 MINMAXINFO * minMax = (MINMAXINFO*)lParam;<br />
		 minMax->ptMinTrackSize.x = instructSize.right;<br />
		 minMax->ptMinTrackSize.y = (instructSize.bottom/5);<br />
	     break;<br />
	  }<br />
	  case WM_INSTRUCTOR:<br />
	  {<br />
	     /* <br />
		    Struct CHARFORMAT: formata a fonte informando os atributos de: nome, máscara da fonte, <br />
		    qual o conjunto de caracteres.<br />
		 */<br />
		 CHARFORMAT2 textFormat;<br />
		 textFormat.cbSize = sizeof(CHARFORMAT2);<br />
		 textFormat.dwMask = CFM_COLOR|CFM_FACE|CFM_CHARSET;<br />
		 textFormat.dwEffects = 0;<br />
		 textFormat.bCharSet = ANSI_CHARSET;<br />
		 strcpy(textFormat.szFaceName, "Courier");<br />
		 HWND editHw = GetDlgItem(hwnd, IDC_EDITBOX);<br />
		 int iLength = GetWindowTextLength(editHw);<br />
		 //Define o local de seleção do texto(o final do texto inserido na richedit)<br />
		 SendMessage(editHw, EM_SETSEL, (WPARAM)iLength, (LPARAM)iLength);<br />
		 //Seta os attribs do texto<br />
		 SendMessage(editHw, EM_SETCHARFORMAT, (WPARAM)SCF_SELECTION, (LPARAM)&textFormat);<br />
		 /* <br />
		    A partir da seleção do texto repõe por um novo, como WPARAM está FALSE mantém o texto anterior e coloca<br />
		    o novo texto formatado<br />
		 */<br />
		 SendMessage(editHw, EM_REPLACESEL, (WPARAM)FALSE, lParam);<br />
		 int iLineCount = (int)SendMessage(editHw, EM_GETLINECOUNT, NULL, NULL);<br />
	     SendMessage(editHw, EM_LINESCROLL, NULL, (LPARAM)(iLineCount-(iLineCount-1)));<br />
		 int iLines = 0;<br />
		 while(iLines < iLineCount - 1)<br />
		 {<br />
		    char cString[256];<br />
			SendMessage(editHw, EM_GETLINE, (WPARAM)iLines, (LPARAM)cString);<br />
			iLines++;<br />
		 }<br />
	     break;<br />
	  }<br />
      case WM_MOVE:<br />
	  {<br />
		 RECT instructSize;<br />
	     GetClientRect(GetParent(hwnd), &instructSize);<br />
	     SetWindowPos(hwnd, HWND_TOPMOST, 0, instructSize.bottom-(instructSize.bottom/5), 0, 0, SWP_NOZORDER);<br />
		 break;<br />
	  }<br />
	  case WM_NCACTIVATE:<br />
	  {<br />
	     return DefMDIChildProc(hwnd, uiMessage, true, lParam);<br />
	  }<br />
      default: return DefMDIChildProc(hwnd, uiMessage, wParam, lParam);<br />
   }<br />
}<br />
<br />
/*Callback de renderização da janela do OpenGL.*/<br />
LRESULT CALLBACK RenderWindowCallback(HWND hwnd, UINT uiMessage, WPARAM wParam, LPARAM lParam)<br />
{<br />
   static POINT currentPosition, oldPosition, mousePos;<br />
   static unsigned int uiTex[20];<br />
   static float fTest = -0.3;<br />
   static bool bMousing = false;<br />
   static unsigned int uiCount = 0;<br />
   RECT windowRect;<br />
   switch(uiMessage)<br />
   {<br />
	  case WM_CREATE:<br />
	  {<br />
		 RenderHwnd = hwnd;<br />
		 windowInfos.hwnd = hwnd;<br />
		 GetClientRect(hwnd, &windowRect);<br />
		 windowInfos.hdc = GetDC(windowInfos.hwnd);<br />
	     OpenGLInitialization::EnableGL(windowInfos.hwnd, &windowInfos.hdc, &windowInfos.hrc);<br />
	     OpenGLInitialization::InitializeGL();<br />
         OpenGLInitialization::SetFieldOfView(windowRect);<br />
		 currentPosition.x = oldPosition.x = NULL;<br />
		 currentPosition.y = oldPosition.y = NULL;<br />
		 fXNeedle = fYNeedle = fZNeedle = 0.0f;		 HMENU hSysMenu = GetSystemMenu(hwnd, false);<br />
		 EnableMenuItem(hSysMenu, SC_CLOSE, MF_GRAYED|MF_BYCOMMAND);<br />
	     break;<br />
	  }<br />
	  case WM_PAINT:<br />
	  {<br />
	     PAINTSTRUCT ps;<br />
		    HDC hdc = BeginPaint(hwnd, &ps);<br />
		    GetClientRect(hwnd, &windowRect);<br />
			OpenGLInitialization::SetFieldOfView(windowRect);<br />
			glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);<br />
			   glMatrixMode(GL_PROJECTION);<br />
			   glPushMatrix();<br />
			      glLoadIdentity();<br />
			      gluOrtho2D(0, windowRect.right, windowRect.bottom, 0);<br />
			   glPopMatrix();	  <br />
			   glMatrixMode(GL_MODELVIEW);<br />
			   glPushMatrix();<br />
			      glLoadIdentity();<br />
			   glPopMatrix();<br />
		 EndPaint(hwnd, &ps);<br />
		 SwapBuffers(hdc);<br />
		 break;<br />
	  }<br />
	  case WM_MOVE:<br />
	  {<br />
		 RECT renderRect;<br />
		 GetClientRect(GetParent(hwnd), &renderRect);<br />
	     SetWindowPos(hwnd, HWND_TOPMOST, renderRect.left, renderRect.top, 0, 0, SWP_NOZORDER);<br />
		 break;<br />
	  }<br />
	  case WM_GETMINMAXINFO:<br />
	  {<br />
		 RECT renderRect;<br />
		 GetClientRect(GetParent(hwnd), &renderRect);<br />
		 MINMAXINFO * minMax = (MINMAXINFO*)lParam;<br />
		 minMax->ptMinTrackSize.x = renderRect.right;<br />
		 minMax->ptMinTrackSize.y = renderRect.bottom-(renderRect.bottom/5);<br />
	     break;<br />
	  }<br />
      case WM_LBUTTONDOWN:<br />
	  {<br />
		 if(!bMousing)<br />
		 {<br />
		    currentPosition.x = oldPosition.x = LOWORD(lParam);<br />
		    currentPosition.y = oldPosition.y = HIWORD(lParam);<br />
			bMousing = true;<br />
		 }<br />
		 else<br />
		 {<br />
		    currentPosition.x = LOWORD(lParam);<br />
			currentPosition.y = HIWORD(lParam);<br />
			bMousing = false;<br />
		 }<br />
	     break;<br />
	  }<br />
      case WM_NCACTIVATE:<br />
	  {<br />
	     return DefMDIChildProc(hwnd, uiMessage, true, lParam);<br />
	  }<br />
      default: return DefMDIChildProc(hwnd, uiMessage, wParam, lParam);<br />
   }<br />
}<br />
<br />
/*Callback de processamento de mensagens enviadas à janela.*/<br />
LRESULT CALLBACK MainWindowCallback(HWND hwnd, UINT uiMessage, WPARAM wParam, LPARAM lParam)<br />
{<br />
   HMENU hMainMenu;<br />
   hMainMenu  = CreateMenu();<br />
   static int siRuler = IDM_NEWRULER, siText = IDM_NEWTEXT, siNodule = IDM_NEWNODULE, siPath = IDM_NEWRULERPATH;<br />
   switch(uiMessage)<br />
   {<br />
	  case WM_CREATE:<br />
	  {<br />
		 fXNeedle = fYNeedle = 0.0f;<br />
		 fZNeedle = -0.3f;<br />
		 FrameHwnd = hwnd;<br />
		 RulerMenu        = new DynamicMenu();<br />
		 TextMenu         = new DynamicMenu();<br />
		 PathMenu         = new DynamicMenu();<br />
		 NoduleMenu       = new DynamicMenu();<br />
		 ProceedingMenu   = new DynamicMenu();<br />
		 ScreenShotMenu   = new DynamicMenu();<br />
		 ImageListMenu    = new DynamicMenu();<br />
		 AppendMenu(hMainMenu, MF_STRING|MF_POPUP, 0, NULL);<br />
		 SetMenu(hwnd, hMainMenu);<br />
		 break;<br />
	  }<br />
	  case WM_CLOSE:<br />
	  {<br />
		 delete TextMenu;<br />
		 delete RulerMenu;<br />
		 delete PathMenu;<br />
		 delete NoduleMenu;<br />
		 delete ProceedingMenu;<br />
		 delete ScreenShotMenu;<br />
		 //FreeLibrary(hRichEdit);<br />
		 //hRichEdit = NULL;*/<br />
		 //DestroyWindow(RenderHwnd);<br />
		 //DestroyWindow(InstructHwnd);<br />
		 return DefFrameProc(hwnd, g_hwndClient, uiMessage, wParam, lParam);<br />
	  }<br />
	  case WM_NCDESTROY:<br />
	  {<br />
		 PostQuitMessage(0);<br />
		 break;<br />
	  }<br />
	  case WM_GETMINMAXINFO:<br />
	  {<br />
		 MINMAXINFO * mainWindowSizes = (MINMAXINFO*)lParam;<br />
		 mainWindowSizes->ptMinTrackSize.x = WIDTH;<br />
		 mainWindowSizes->ptMinTrackSize.y = HEIGHT;<br />
	     break;<br />
	  }<br />
	  case WM_KEYDOWN:<br />
	  {<br />
	     switch(wParam)<br />
		 {<br />
		    case VK_ESCAPE:<br />
			{<br />
			   FreeLibrary(hRichEdit);<br />
			   PostQuitMessage(0);<br />
			   break;<br />
			}<br />
		 }<br />
		 break;<br />
	  }<br />
	  case WM_COMMAND:<br />
	  {<br />
		 break;<br />
	  }<br />
	  default: break;<br />
   }<br />
   return DefFrameProc(hwnd, g_hwndClient, uiMessage, wParam, lParam);<br />
}<br />
<br />
#endif CALLBACKS_H<br />

Re: MDI app doesn't close

Mark Salsbery14-Aug-07 11:12

Mark Salsbery

14-Aug-07 11:12

Honestly, there's so many problems here it could take hours to reply.

Many of the window messages are not handled correctly, proper return values aren't considered.

You don't seem to want to fix your message loop - again, the way you have it now is BAD.
It's going to perform terribly, and slow the rest of the system down.

This has nothing to do with opengl. It has everything to do with fundamental Windows messaging.

I would recommend getting a basic MDI app up and running. Just a frame window, an MDI client,
and child windows. You should be able to create windows, destroy windows, and cleanly terminate
the application. The few messages related to these tasks should be handled properly, with the
unhandled messages being handled by the default window procedure.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: MDI app doesn't close

Alex Cutovoi15-Aug-07 3:36

Alex Cutovoi

15-Aug-07 3:36

man, I would be very happy if you point me out some errors about the messages that are not handled correctly. I'm a little bit new in MDI with Win32.
The strange is in my machine, this code works fine. But in other 2 machines not.

Re: MDI app doesn't close

Mark Salsbery15-Aug-07 5:12

Mark Salsbery

15-Aug-07 5:12

I posted a project (zipped) here[^]

The project is for VS 205 - if you're using a lower version and you want to run the code
in the debugger, , you can just extract the 3 header files, 2 cpp fles, 1 rc file, and 2 ico files
and put them in an empty project created with your VS.

It's a simple Win32 MDI app with the frame/MDI client and one child window class.
The project started as a Win32 wizard-generated project and I changed the appropriate
window stuff to MDI.
All the code's in one CPP file. I added comments in the window procedures (callbacks).

Some of the key things are:

Make sure you return the proper value after handling messages - many are the same, some are different.

Make sure you call the default window procedure for certain messages that require it in MDI -
They are documented here[^]

Proper DestroyWindow()/PostQuitMessage sequence

Also shown is a proper message loop. Once you get your windows working properly I should
be able to help you get your painting and redrawing up and running. You definitely don't need to spin in
a loop, nor do you want to - you'll get really bad graphics and system performance Smile | :)

I think you'll be much happier using all those CPU cycles for drawing instead of spinning in a loop doing nothing.

Feel free to email me as well as posting here - just click the email link at the bottom of my posts.

Cheers,
Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: MDI app doesn't close

Alex Cutovoi15-Aug-07 6:47

Alex Cutovoi

15-Aug-07 6:47

Thanks for your post man. I'll look the code.

_finite (CRT) [modified]

Maxwell Chen14-Aug-07 5:15

Maxwell Chen

14-Aug-07 5:15

The Microsoft version CRT Library routine, _finite(double)[^], seems not working.

int _finite( 
   double x 
);

Return Value:
_finite returns a nonzero value if its argument x is not infinite; 
that is, if – INF < x < + INF. 
It returns 0 if the argument is infinite or a NAN.

So I tried this function by:

double n = 1.0 / 3.0;
int v = _finite(n);

While debugging it, the value of n is 0.3333333333333340.
And _finite(n) returns 1.

-- move at 11:34 Tuesday 14th August, 2007

Maxwell Chen

Re: _finite (CRT)

Vasudevan Deepak Kumar14-Aug-07 5:18

Vasudevan Deepak Kumar

14-Aug-07 5:18

I think this forum is oriented towards "General discussions, site bug reports and suggestions about the site."

Your query should go into C++ forums right?

Vasudevan Deepak Kumar
Personal Homepage
Tech Gossips

Re: _finite (CRT)

Maxwell Chen14-Aug-07 5:22

Maxwell Chen

14-Aug-07 5:22

Oops!

Maxwell Chen

Re: _finite (CRT)

Mark Salsbery14-Aug-07 6:12

Mark Salsbery

14-Aug-07 6:12

Maxwell Chen wrote:
0.3333333333333340

That looks finite to me.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: _finite (CRT)

Maxwell Chen14-Aug-07 6:14

Maxwell Chen

14-Aug-07 6:14

1.0 / 3.0 should be 0.3333333333333333333333333333.......

Anyone knows where to switch something for that?

Maxwell Chen

Re: _finite (CRT)

Mark Salsbery14-Aug-07 6:20

Mark Salsbery

14-Aug-07 6:20

It should be, yes, but a floating point variable has a limit on precision.

What are you trying to do?

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: _finite (CRT)

led mike14-Aug-07 6:48

led mike

14-Aug-07 6:48

Mark Salsbery wrote:
has a limit

We don't need no stinkin limits!

Mark Salsbery wrote:
What are you trying to do?

He's fishing. Send him here.[^]

Re: _finite (CRT)

Mark Salsbery14-Aug-07 6:52

Mark Salsbery

14-Aug-07 6:52

"...has been sold by McDonald's since 1963"

The year I was born. Coincidence? I think not! LMAO

Beer | [beer]

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: _finite (CRT)

Maxwell Chen14-Aug-07 6:53

Maxwell Chen

14-Aug-07 6:53

Mark Salsbery wrote:
What are you trying to do?

This:
how to know a double is infinite directly?[^]

I saw your reply in that thread, but my _finite always returns 1 with any input!

Maxwell Chen

Re: _finite (CRT)

Mark Salsbery14-Aug-07 7:03

Mark Salsbery

14-Aug-07 7:03

Maxwell Chen wrote:
I saw your reply in that thread, but my _finite always returns 1 with any input!

Stealing from the other thread on this topic...

    double dbInf = 1.0 / sin((double)0);
    int a = _finite(dbInf);

   // a should be 0

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: _finite (CRT)

Maxwell Chen14-Aug-07 7:05

Maxwell Chen

14-Aug-07 7:05

Let me try again tomorrow with the PC with VC++2005.
I'll be back! Big Grin | :-D

Maxwell Chen

Re: _finite (CRT)

led mike14-Aug-07 8:09

led mike

14-Aug-07 8:09

Maxwell Chen wrote:
I'll be back!

Threats will get you nowhere. Poke tongue | ;-P

Re: _finite (CRT)

Maxwell Chen14-Aug-07 8:19

Maxwell Chen

14-Aug-07 8:19

Maxwell Chen

Re: _finite (CRT)

El Corazon14-Aug-07 7:17

El Corazon

14-Aug-07 7:17

Maxwell Chen wrote:
but my _finite always returns 1 with any input!

you are not testing if an given fraction is infinite in precision, you are testing for an error condition for "infinity." Any valid floating point number, whether infinite precision or not, is a finite number. 1.0/3.0 is a finite number, thus it returns a value of 1 (true) for _finite(value).

Return Value<br />
<br />
_finite returns a nonzero value if its argument x is not infinite; that is, if –INF < x < +INF. It returns 0 if the argument is infinite or a NAN.<br />

-INF < (1.0/3.0) < +INF is true.

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