Point on a line - C / C++ / MFC Discussion Boards

Trollslayer27-May-05 21:51

27-May-05 21:51

MFC is, generally speaking, easier. Also, make full use of the articles in here and MSDN[^].
There are a lot of very useful examples in both.

Elaine Rose | [Rose]

The tigress is here Big Grin | :-D

Re: converting C++ to VC++

Member 200054928-May-05 6:56

Member 2000549

28-May-05 6:56

Thank u both for ur help Roll eyes | :rolleyes:

i appretiate it Big Grin | :-D

Image resizing algorithm (bilinear)

Budric B.27-May-05 18:01

Budric B.

27-May-05 18:01

Hi,
Can someone point me to some sites with a good explanation of the bilinear interpolation algorithm to resample images? My searches give me "features" web pages of graphics packages and libraries that implement it, but nothing that explains it well with some pictures and formulas =). I'm hoping someone with experience can point me to a good website on this matter.

What I"m trying to understand is the following quote:
"using bilinear interpolation with a pixel spacing of 1.5 in each direction."

Thanks.

Re: Image resizing algorithm (bilinear)

Andrew Kirillov27-May-05 22:03

Andrew Kirillov

27-May-05 22:03

Hello

Here is an article (the title is "Bicubic", but it's Bilinear):
http://astronomy.swin.edu.au/~pbourke/colour/bicubic/[^]
The approach is implemented in all libraries I've seen.

You can try tool look at Christian's article:
http://www.codeproject.com/cs/media/imageprocessing4.asp[^]

With best regards,
Andrew

Re: Image resizing algorithm (bilinear)

Christian Graus28-May-05 11:57

Christian Graus

28-May-05 11:57

Budric B. wrote:
using bilinear interpolation with a pixel spacing of 1.5 in each direction

Bilinear interpolation means when you do an operation that theoretically requires a pixel position that is not a whole number, you use the fractional part to work out what percentage of surrounding, actual, pixels to use to determine a colour for the pixel that doesn't really exist. As someone else said, I have an article that explains this further and has C# code showing how it is done.

Christian Graus - Microsoft MVP - C++

Re: Image resizing algorithm (bilinear)

C^hris L^osinger29-May-05 5:31

C^hris L^osinger

29-May-05 5:31

Christian Graus wrote:
you use the fractional part to work out what percentage of surrounding, actual, pixels to use to determine a colour for the pixel that doesn't really exist

that actually applies to nearly all interpolation methods. Smile | :)

bi-lin just means using linear interpolation in two dimensions.

(i know you know this - just filling-in)

Cleek | Image Toolkits | Thumbnail maker

Thanks for your replies (nt)

Anonymous29-May-05 4:40

Anonymous

29-May-05 4:40

Point on a line

rocky_pulley27-May-05 16:40

rocky_pulley

27-May-05 16:40

I'm trying to find out if my mouse position is on a specific line. I've tried using the slopes of the line and of the mouse position from the starting point but this doesn't work because when you get close to the starting point and the line is almost horizontal the slopes vary greatly.

Has anyone done this sort of thing before?

Thanks

-- Rocky Dean Pulley

Re: Point on a line

Jack Puppy27-May-05 17:33

Jack Puppy

27-May-05 17:33

I used this article to hit test a line:
Win32: Hit Testing Lines and Curves

Pssst. You see that little light on your monitor? That's actually a government installed spy camera. Smile and wave to big brother!

Re: Point on a line

rocky_pulley28-May-05 4:17

rocky_pulley

28-May-05 4:17

thanks a lot

-- Rocky Dean Pulley

Re: Point on a line

Ted Ferenc28-May-05 4:38

Ted Ferenc

28-May-05 4:38

I did this c. 30 years ago using Fortran, but I can't remember how we did it! and I still have the source code!

The last time I did it I cheated and use PtInRect, I assume the mouse could be X pixels away from the line? If so then just create a bounding rectange and check if the mouse position is within the rectangle or if it must be on the line just make a 1 pixel rectangle.

You will need to 'cheat' slightly the docs state "A point on the right or bottom side is considered outside the rectangle." so make the rectangle 1 pixel too big on these axis.

"An education isn't how much you have committed to memory, or even how much you know. It's being able to differentiate between what you do know and what you don't." - Anatole France

Re: Point on a line

Christian Graus28-May-05 11:59

Christian Graus

28-May-05 11:59

If the line is curved, you need to know the rate of curve. otherwise, it's basic trigonometry.

Christian Graus - Microsoft MVP - C++

LoadFrame Fails on target machine

drallen127-May-05 12:28

drallen1

27-May-05 12:28

I have an MFC Winapp that runs fine on dev machine, but when I deploy to target machine (XP Pro and WinNT) the pMainFrame->LoadFrame(IDR_MAINFRAME) fails. I have a menu, icon and string associated with the resource ID IDR_MAINFRAME.

I have had a heck of a time trying to determine the difference between the dev machine besides the obvious (ie development studio).

Using IDE 2003, unmanaged project.

Any advice or help is much appreciated.

DRA

Throwing Exceptions during Message handling

Uwe Keim27-May-05 12:18

Uwe Keim

27-May-05 12:18

Strange things happen in my C++-MFC-application:

At this position on the call stack I throw a user-defined exception:

>	ProducerUD.exe!Gui::Dialogs::BuildDialog::OnCancel()  Zeile 604	C++
 	mfc71ud.dll!_AfxDispatchCmdMsg(CCmdTarget * pTarget=0x0013ee04, unsigned int nID=0x00000002, int nCode=0x00000000, void (void)* pfn=0x7c295980, ....)  Zeile 89	C++
 	mfc71ud.dll!CCmdTarget::OnCmdMsg(unsigned int nID=0x00000002, int nCode=0x00000000, void * pExtra=0x00000000, AFX_CMDHANDLERINFO * pHandlerInfo=0x00000000)  Zeile 396 + 0x27	C++
 	mfc71ud.dll!CDialog::OnCmdMsg(unsigned int nID=0x00000002, int nCode=0x00000000, void * pExtra=0x00000000, AFX_CMDHANDLERINFO * pHandlerInfo=0x00000000)  Zeile 88 + 0x18	C++
 	mfc71ud.dll!CWnd::OnCommand(unsigned int wParam=0x00000002, long lParam=0x00460622)  Zeile 2550	C++
 	mfc71ud.dll!CWnd::OnWndMsg(unsigned int message=0x00000111, unsigned int wParam=0x00000002, long lParam=0x00460622, long * pResult=0x0013d9e8)  Zeile 1759 + 0x1c	C++
 	mfc71ud.dll!CWnd::WindowProc(unsigned int message=0x00000111, unsigned int wParam=0x00000002, long lParam=0x00460622)  Zeile 1745 + 0x1e	C++
 	zlzwfud.dll!Zeta::Windows::Forms::Specialized::DialogBase::WindowProc(unsigned int message=0x00000111, unsigned int wParam=0x00000002, long lParam=0x00460622)  Zeile 221	C++
 	mfc71ud.dll!AfxCallWndProc(CWnd * pWnd=0x0013ee04, HWND__ * hWnd=0x0116057a, unsigned int nMsg=0x00000111, unsigned int wParam=0x00000002, long lParam=0x00460622)  Zeile 241 + 0x1a	C++
 	mfc71ud.dll!AfxWndProc(HWND__ * hWnd=0x0116057a, unsigned int nMsg=0x00000111, unsigned int wParam=0x00000002, long lParam=0x00460622)  Zeile 389	C++
 	mfc71ud.dll!AfxWndProcBase(HWND__ * hWnd=0x0116057a, unsigned int nMsg=0x00000111, unsigned int wParam=0x00000002, long lParam=0x00460622)  Zeile 209 + 0x15	C++
 	user32.dll!_InternalCallWinProc@20()  + 0x28	
 	user32.dll!_UserCallWinProcCheckWow@32()  + 0xb7	
 	user32.dll!_DispatchClientMessage@20()  + 0x4d	
 	user32.dll!___fnDWORD@4()  + 0x24	
 	ntdll.dll!_KiUserCallbackDispatcher@12()  + 0x13	
 	user32.dll!_NtUserMessageCall@28()  + 0xc	
 	user32.dll!_SendMessageW@16()  + 0x49	
 	comctl32.dll!_Button_NotifyParent@8()  + 0x3d	
 	comctl32.dll!_Button_ReleaseCapture@8()  + 0xd7	
 	comctl32.dll!_Button_WndProc@16()  + 0x842	
 	user32.dll!_InternalCallWinProc@20()  + 0x28	
 	user32.dll!_UserCallWinProcCheckWow@32()  + 0xb7	
 	user32.dll!_DispatchMessageWorker@8()  + 0xdc	
 	user32.dll!_DispatchMessageW@4()  + 0xf	
 	user32.dll!_IsDialogMessageW@8()  + 0xdb	
 	mfc71ud.dll!CWnd::IsDialogMessageW(tagMSG * lpMsg=0x001640e8)  Zeile 200	C++
 	mfc71ud.dll!CWnd::PreTranslateInput(tagMSG * lpMsg=0x001640e8)  Zeile 4512	C++
 	mfc71ud.dll!CDialog::PreTranslateMessage(tagMSG * pMsg=0x001640e8)  Zeile 83	C++
 	zlzwfud.dll!Zeta::Windows::Forms::EnhancedDialog::PreTranslateMessage(tagMSG * pMsg=0x001640e8)  Zeile 194	C++
 	mfc71ud.dll!CWnd::WalkPreTranslateTree(HWND__ * hWndStop=0x004b09e4, tagMSG * pMsg=0x001640e8)  Zeile 3129 + 0x12	C++
 	mfc71ud.dll!AfxInternalPreTranslateMessage(tagMSG * pMsg=0x001640e8)  Zeile 238 + 0x12	C++
 	mfc71ud.dll!CWinThread::PreTranslateMessage(tagMSG * pMsg=0x001640e8)  Zeile 795 + 0x9	C++
 	mfc71ud.dll!AfxPreTranslateMessage(tagMSG * pMsg=0x001640e8)  Zeile 257 + 0xf	C++
 	mfc71ud.dll!AfxInternalPumpMessage()  Zeile 183 + 0x18	C++
 	mfc71ud.dll!CWinThread::PumpMessage()  Zeile 916	C++
 	ZpCommonCoreud.dll!Common::Gui::CoreGuiHelper::Pump(const bool throwStopException=true)  Zeile 286 + 0x1e	C++
 	ZpCommonCoreud.dll!Common::Gui::CoreGuiHelper::Pump()  Zeile 340 + 0x9	C++
 	ProducerUD.exe!Gui::Dialogs::BuildDialog::PumpMessages()  Zeile 492 + 0x8	C++
 	ProducerUD.exe!Gui::Dialogs::BuildDialog::Log(const ATL::CStringT<unsigned short,StrTraitMFC_DLL<unsigned short,ATL::ChTraitsCRT<unsigned short> > > & text={...})  Zeile 497 + 0xd	C++
 	ZpRenderingud.dll!Rendering::RenderEngine::Implementation::CheckForTemplateFileChanges()  Zeile 454 + 0x4a	C++
 	ZpRenderingud.dll!Rendering::RenderEngine::BuildProjectFolder(const long projectFolderID=0x0000006c)  Zeile 1097	C++
 	ProducerUD.exe!Gui::Dialogs::BuildDialog::OnStartProcessing(unsigned int p1=0x00000000, long p2=0x00000000)  Zeile 232 + 0x18	C++
 	mfc71ud.dll!CWnd::OnWndMsg(unsigned int message=0x00008003, unsigned int wParam=0x00000000, long lParam=0x00000000, long * pResult=0x0013ea40)  Zeile 2013 + 0x11	C++
 	mfc71ud.dll!CWnd::WindowProc(unsigned int message=0x00008003, unsigned int wParam=0x00000000, long lParam=0x00000000)  Zeile 1745 + 0x1e	C++
 	zlzwfud.dll!Zeta::Windows::Forms::Specialized::DialogBase::WindowProc(unsigned int message=0x00008003, unsigned int wParam=0x00000000, long lParam=0x00000000)  Zeile 221	C++
 	mfc71ud.dll!AfxCallWndProc(CWnd * pWnd=0x0013ee04, HWND__ * hWnd=0x0116057a, unsigned int nMsg=0x00008003, unsigned int wParam=0x00000000, long lParam=0x00000000)  Zeile 241 + 0x1a	C++
 	mfc71ud.dll!AfxWndProc(HWND__ * hWnd=0x0116057a, unsigned int nMsg=0x00008003, unsigned int wParam=0x00000000, long lParam=0x00000000)  Zeile 389	C++
 	mfc71ud.dll!AfxWndProcBase(HWND__ * hWnd=0x0116057a, unsigned int nMsg=0x00008003, unsigned int wParam=0x00000000, long lParam=0x00000000)  Zeile 209 + 0x15	C++
 	user32.dll!_InternalCallWinProc@20()  + 0x28	
 	user32.dll!_UserCallWinProcCheckWow@32()  + 0xb7	
 	user32.dll!_DispatchMessageWorker@8()  + 0xdc	
 	user32.dll!_DispatchMessageW@4()  + 0xf	
 	mfc71ud.dll!AfxInternalPumpMessage()  Zeile 188	C++
 	mfc71ud.dll!CWinThread::PumpMessage()  Zeile 916	C++
 	mfc71ud.dll!AfxPumpMessage()  Zeile 195 + 0xb	C++
 	mfc71ud.dll!CWnd::RunModalLoop(unsigned long dwFlags=0x00000004)  Zeile 4566 + 0x5	C++
 	mfc71ud.dll!CDialog::DoModal()  Zeile 527 + 0xc	C++
 	zlzwfud.dll!Zeta::Windows::Forms::EnhancedDialog::DoModal()  Zeile 113 + 0x8	C++
 	zlzwfud.dll!Zeta::Windows::Forms::Specialized::DialogBase::ShowModal()  Zeile 69 + 0x8	C++
 	ProducerUD.exe!Framework::ProducerMainWindow::ExecuteGuiBuild()  Zeile 1639 + 0x15	C++
 	ProducerUD.exe!Framework::ProducerMainWindow::OnBuild()  Zeile 1745	C++
 	mfc71ud.dll!_AfxDispatchCmdMsg(CCmdTarget * pTarget=0x03f18588, unsigned int nID=0x00008008, int nCode=0x00000000, void (void)* pfn=0x004031d4, ....)  Zeile 89	C++
 	mfc71ud.dll!CCmdTarget::OnCmdMsg(unsigned int nID=0x00008008, int nCode=0x00000000, void * pExtra=0x00000000, AFX_CMDHANDLERINFO * pHandlerInfo=0x00000000)  Zeile 396 + 0x27	C++
 	mfc71ud.dll!CFrameWnd::OnCmdMsg(unsigned int nID=0x00008008, int nCode=0x00000000, void * pExtra=0x00000000, AFX_CMDHANDLERINFO * pHandlerInfo=0x00000000)  Zeile 897 + 0x18	C++
 	mfc71ud.dll!CWnd::OnCommand(unsigned int wParam=0x00018008, long lParam=0x00000000)  Zeile 2550	C++
 	mfc71ud.dll!CFrameWnd::OnCommand(unsigned int wParam=0x00018008, long lParam=0x00000000)  Zeile 320	C++
 	mfc71ud.dll!CWnd::OnWndMsg(unsigned int message=0x00000111, unsigned int wParam=0x00018008, long lParam=0x00000000, long * pResult=0x0013f4dc)  Zeile 1759 + 0x1c	C++
 	ProducerUD.exe!CXTPFrameWndBase<CFrameWnd>::OnWndMsg(unsigned int message=0x00000111, unsigned int wParam=0x00018008, long lParam=0x00000000, long * pResult=0x0013f4dc)  Zeile 177	C++
 	mfc71ud.dll!CWnd::WindowProc(unsigned int message=0x00000111, unsigned int wParam=0x00018008, long lParam=0x00000000)  Zeile 1745 + 0x1e	C++
 	ProducerUD.exe!Framework::ProducerMainWindow::WindowProc(unsigned int message=0x00000111, unsigned int wParam=0x00018008, long lParam=0x00000000)  Zeile 442	C++
 	mfc71ud.dll!AfxCallWndProc(CWnd * pWnd=0x03f18588, HWND__ * hWnd=0x004b09e4, unsigned int nMsg=0x00000111, unsigned int wParam=0x00018008, long lParam=0x00000000)  Zeile 241 + 0x1a	C++
 	mfc71ud.dll!AfxWndProc(HWND__ * hWnd=0x004b09e4, unsigned int nMsg=0x00000111, unsigned int wParam=0x00018008, long lParam=0x00000000)  Zeile 389	C++
 	mfc71ud.dll!AfxWndProcBase(HWND__ * hWnd=0x004b09e4, unsigned int nMsg=0x00000111, unsigned int wParam=0x00018008, long lParam=0x00000000)  Zeile 209 + 0x15	C++
 	user32.dll!_InternalCallWinProc@20()  + 0x28	
 	user32.dll!_UserCallWinProcCheckWow@32()  + 0xb7	
 	user32.dll!_CallWindowProcAorW@24()  + 0x51	
 	user32.dll!_CallWindowProcW@20()  + 0x1b	
 	XTP9510Libud.dll!CXTPHookManager::HookWndProc(HWND__ * hWnd=0x004b09e4, unsigned int message=0x00000111, unsigned int wParam=0x00018008, long lParam=0x00000000)  Zeile 106 + 0x1c	C++
 	user32.dll!_InternalCallWinProc@20()  + 0x28	
 	user32.dll!_UserCallWinProcCheckWow@32()  + 0xb7	
 	user32.dll!_CallWindowProcAorW@24()  + 0x51	
 	user32.dll!_CallWindowProcW@20()  + 0x1b	
 	ZpCommonCoreud.dll!Common::Gui::SubclassWindow::WindowProc(unsigned int msg=0x00000111, unsigned int wp=0x00018008, long lp=0x00000000)  Zeile 147 + 0x5c	C++
 	ZpCommonCoreud.dll!Common::Gui::HookWndProc(HWND__ * hwnd=0x004b09e4, unsigned int msg=0x00000111, unsigned int wp=0x00018008, long lp=0x00000000)  Zeile 219 + 0x19	C++
 	user32.dll!_InternalCallWinProc@20()  + 0x28	
 	user32.dll!_UserCallWinProcCheckWow@32()  + 0xb7	
 	user32.dll!_DispatchClientMessage@20()  + 0x4d	
 	user32.dll!___fnDWORD@4()  + 0x24	
 	ntdll.dll!_KiUserCallbackDispatcher@12()  + 0x13	
 	user32.dll!_NtUserTranslateAccelerator@12()  + 0xc	
 	mfc71ud.dll!CFrameWnd::PreTranslateMessage(tagMSG * pMsg=0x001640e8)  Zeile 203 + 0x1b	C++
 	ProducerUD.exe!CXTPFrameWndBase<CFrameWnd>::PreTranslateMessage(tagMSG * pMsg=0x001640e8)  Zeile 144 + 0xc	C++
 	ProducerUD.exe!Framework::ProducerMainWindow::PreTranslateMessage(tagMSG * pMsg=0x001640e8)  Zeile 1142	C++
 	mfc71ud.dll!CWnd::WalkPreTranslateTree(HWND__ * hWndStop=0x004b09e4, tagMSG * pMsg=0x001640e8)  Zeile 3129 + 0x12	C++
 	mfc71ud.dll!AfxInternalPreTranslateMessage(tagMSG * pMsg=0x001640e8)  Zeile 238 + 0x12	C++
 	mfc71ud.dll!CWinThread::PreTranslateMessage(tagMSG * pMsg=0x001640e8)  Zeile 795 + 0x9	C++
 	mfc71ud.dll!AfxPreTranslateMessage(tagMSG * pMsg=0x001640e8)  Zeile 257 + 0xf	C++
 	mfc71ud.dll!AfxInternalPumpMessage()  Zeile 183 + 0x18	C++
 	mfc71ud.dll!CWinThread::PumpMessage()  Zeile 916	C++
 	mfc71ud.dll!CWinThread::Run()  Zeile 637 + 0xb	C++
 	mfc71ud.dll!CWinApp::Run()  Zeile 701	C++
 	mfc71ud.dll!AfxWinMain(HINSTANCE__ * hInstance=0x00400000, HINSTANCE__ * hPrevInstance=0x00000000, wchar_t * lpCmdLine=0x00020dfc, int nCmdShow=0x00000001)  Zeile 49 + 0xb	C++
 	ProducerUD.exe!wWinMain(HINSTANCE__ * hInstance=0x00400000, HINSTANCE__ * hPrevInstance=0x00000000, wchar_t * lpCmdLine=0x00020dfc, int nCmdShow=0x00000001)  Zeile 25	C++
 	ProducerUD.exe!wWinMainCRTStartup()  Zeile 390 + 0x39	C
 	kernel32.dll!_BaseProcessStart@4()  + 0x23

Now the exception is correctly catched by my application and it continues to work, but when leaving the main message handler at this point:

>	ProducerUD.exe!Framework::ProducerMainWindow::OnBuild()  Zeile 1748	C++
 	mfc71ud.dll!_AfxDispatchCmdMsg(CCmdTarget * pTarget=0x03f18588, unsigned int nID=0x00008008, int nCode=0x00000000, void (void)* pfn=0x004031d4, ....)  Zeile 89	C++
 	mfc71ud.dll!CCmdTarget::OnCmdMsg(unsigned int nID=0x00008008, int nCode=0x00000000, void * pExtra=0x00000000, AFX_CMDHANDLERINFO * pHandlerInfo=0x00000000)  Zeile 396 + 0x27	C++
 	mfc71ud.dll!CFrameWnd::OnCmdMsg(unsigned int nID=0x00008008, int nCode=0x00000000, void * pExtra=0x00000000, AFX_CMDHANDLERINFO * pHandlerInfo=0x00000000)  Zeile 897 + 0x18	C++
 	mfc71ud.dll!CWnd::OnCommand(unsigned int wParam=0x00018008, long lParam=0x00000000)  Zeile 2550	C++
 	mfc71ud.dll!CFrameWnd::OnCommand(unsigned int wParam=0x00018008, long lParam=0x00000000)  Zeile 320	C++
 	mfc71ud.dll!CWnd::OnWndMsg(unsigned int message=0x00000111, unsigned int wParam=0x00018008, long lParam=0x00000000, long * pResult=0x0013f4dc)  Zeile 1759 + 0x1c	C++
 	ProducerUD.exe!CXTPFrameWndBase<CFrameWnd>::OnWndMsg(unsigned int message=0x00000111, unsigned int wParam=0x00018008, long lParam=0x00000000, long * pResult=0x0013f4dc)  Zeile 177	C++
 	mfc71ud.dll!CWnd::WindowProc(unsigned int message=0x00000111, unsigned int wParam=0x00018008, long lParam=0x00000000)  Zeile 1745 + 0x1e	C++
 	ProducerUD.exe!Framework::ProducerMainWindow::WindowProc(unsigned int message=0x00000111, unsigned int wParam=0x00018008, long lParam=0x00000000)  Zeile 442	C++
 	mfc71ud.dll!AfxCallWndProc(CWnd * pWnd=0x03f18588, HWND__ * hWnd=0x004b09e4, unsigned int nMsg=0x00000111, unsigned int wParam=0x00018008, long lParam=0x00000000)  Zeile 241 + 0x1a	C++
 	mfc71ud.dll!AfxWndProc(HWND__ * hWnd=0x004b09e4, unsigned int nMsg=0x00000111, unsigned int wParam=0x00018008, long lParam=0x00000000)  Zeile 389	C++
 	mfc71ud.dll!AfxWndProcBase(HWND__ * hWnd=0x004b09e4, unsigned int nMsg=0x00000111, unsigned int wParam=0x00018008, long lParam=0x00000000)  Zeile 209 + 0x15	C++
 	user32.dll!_InternalCallWinProc@20()  + 0x28	
 	user32.dll!_UserCallWinProcCheckWow@32()  + 0xb7	
 	user32.dll!_CallWindowProcAorW@24()  + 0x51	
 	user32.dll!_CallWindowProcW@20()  + 0x1b	
 	XTP9510Libud.dll!CXTPHookManager::HookWndProc(HWND__ * hWnd=0x004b09e4, unsigned int message=0x00000111, unsigned int wParam=0x00018008, long lParam=0x00000000)  Zeile 106 + 0x1c	C++
 	user32.dll!_InternalCallWinProc@20()  + 0x28	
 	user32.dll!_UserCallWinProcCheckWow@32()  + 0xb7	
 	user32.dll!_CallWindowProcAorW@24()  + 0x51	
 	user32.dll!_CallWindowProcW@20()  + 0x1b	
 	ZpCommonCoreud.dll!Common::Gui::SubclassWindow::WindowProc(unsigned int msg=0x00000111, unsigned int wp=0x00018008, long lp=0x00000000)  Zeile 147 + 0x5c	C++
 	ZpCommonCoreud.dll!Common::Gui::HookWndProc(HWND__ * hwnd=0x004b09e4, unsigned int msg=0x00000111, unsigned int wp=0x00018008, long lp=0x00000000)  Zeile 219 + 0x19	C++
 	user32.dll!_InternalCallWinProc@20()  + 0x28	
 	user32.dll!_UserCallWinProcCheckWow@32()  + 0xb7	
 	user32.dll!_DispatchClientMessage@20()  + 0x4d	
 	user32.dll!___fnDWORD@4()  + 0x24	
 	ntdll.dll!_KiUserCallbackDispatcher@12()  + 0x13	
 	user32.dll!_NtUserTranslateAccelerator@12()  + 0xc	
 	mfc71ud.dll!CFrameWnd::PreTranslateMessage(tagMSG * pMsg=0x001640e8)  Zeile 203 + 0x1b	C++
 	ProducerUD.exe!CXTPFrameWndBase<CFrameWnd>::PreTranslateMessage(tagMSG * pMsg=0x001640e8)  Zeile 144 + 0xc	C++
 	ProducerUD.exe!Framework::ProducerMainWindow::PreTranslateMessage(tagMSG * pMsg=0x001640e8)  Zeile 1142	C++
 	mfc71ud.dll!CWnd::WalkPreTranslateTree(HWND__ * hWndStop=0x004b09e4, tagMSG * pMsg=0x001640e8)  Zeile 3129 + 0x12	C++
 	mfc71ud.dll!AfxInternalPreTranslateMessage(tagMSG * pMsg=0x001640e8)  Zeile 238 + 0x12	C++
 	mfc71ud.dll!CWinThread::PreTranslateMessage(tagMSG * pMsg=0x001640e8)  Zeile 795 + 0x9	C++
 	mfc71ud.dll!AfxPreTranslateMessage(tagMSG * pMsg=0x001640e8)  Zeile 257 + 0xf	C++
 	mfc71ud.dll!AfxInternalPumpMessage()  Zeile 183 + 0x18	C++
 	mfc71ud.dll!CWinThread::PumpMessage()  Zeile 916	C++
 	mfc71ud.dll!CWinThread::Run()  Zeile 637 + 0xb	C++
 	mfc71ud.dll!CWinApp::Run()  Zeile 701	C++
 	mfc71ud.dll!AfxWinMain(HINSTANCE__ * hInstance=0x00400000, HINSTANCE__ * hPrevInstance=0x00000000, wchar_t * lpCmdLine=0x00020dfc, int nCmdShow=0x00000001)  Zeile 49 + 0xb	C++
 	ProducerUD.exe!wWinMain(HINSTANCE__ * hInstance=0x00400000, HINSTANCE__ * hPrevInstance=0x00000000, wchar_t * lpCmdLine=0x00020dfc, int nCmdShow=0x00000001)  Zeile 25	C++
 	ProducerUD.exe!wWinMainCRTStartup()  Zeile 390 + 0x39	C
 	kernel32.dll!_BaseProcessStart@4()  + 0x23

Something gets wrong and I end up with the following call stack:

>	cccccccc()	
	ntdll.dll!ExecuteHandler2@20()  + 0x26	
	ntdll.dll!ExecuteHandler@20()  + 0x24	
	ntdll.dll!_KiUserExceptionDispatcher@8()  + 0xe

Alternatively, when not installing a customer error handler with _se_set_translator, I end up with the following call stack:

>	cccccccc()

Which, of course leads to those ugly access violations and terminates my application.

Question:

Is anyone of you aware of some circumstances where it could be unsafe to throw exception during processing windows messages? Maybe I throw away some window handle where the associated WindowProc still tries to send messages to that window? Or something similar? Or something completely different?

I'm really really clueless Confused | :confused:

--
Affordable Windows-based CMS for only 99 €: try www.zeta-producer.com for free!

Re: Throwing Exceptions during Message handling

Uwe Keim27-May-05 13:13

Uwe Keim

27-May-05 13:13

Replying to myself Smile | :)

Just found the following quote:

When programming for Windows, it is important to remember that exceptions cannot cross the boundary of a "callback." In other words, if an exception occurs within the scope of a message or command handler, it must be caught there, before the next message is processed.

Source: http://www.microsoft.com/msj/archive/S204D.aspx [^]

--
Affordable Windows-based CMS for only 99 €: try www.zeta-producer.com for free!

casting char to wchar?

bobhou27-May-05 11:03

bobhou

27-May-05 11:03

Hi,
I need some simple text to speech code and
installed MS speech SDK5.1.
I can hardcode like: hr = pVoice->Speak(L"I am glad to speak", 0, NULL);
How can I replace "I am glad to speak" with a char* text?
What does L stand for here? probably XML staff?
Thanks for your help.
Bob

Re: casting char to wchar?

Jack Puppy27-May-05 13:47

Jack Puppy

27-May-05 13:47

L"text" -> The L implies Unicode text. (wchar)

Just remove the L and you should be fine.

Pssst. You see that little light on your monitor? That's actually a government installed spy camera. Smile and wave to big brother!

Re: casting char to wchar?

ThatsAlok27-May-05 19:10

ThatsAlok

27-May-05 19:10

USE these MACRO T2BSTR -- Converting Char * to Wide String!
W2T --- Converting WideString to char*

bobhou wrote:
I can hardcode like: hr = pVoice->Speak(L"I am glad to speak", 0, NULL);
How can I replace "I am glad to speak" with a char* text?

Above code will written like this using String conversion macro!

char szSpeak[]="I am glad to speak";
USES_CONVERSION; //Activate Macros :)

 hr = pVoice->Speak(T2BSTR(szSpeak), 0, NULL);

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta

Re: casting char to wchar?

Tim Smith28-May-05 6:29

Tim Smith

28-May-05 6:29

NO!!!!!!

Don't use T2BSTR. First off, it will leak a BSTR as you used it. MS strongly suggests that you use CComBSTR for conversions to and from BSTR.

Also, I think the API routine uses a const WCHAR *. Thus creating a BSTR not only means you are using the wrong data type, but you are also wasting computer resources creating the BSTR.

Tim Smith

I'm going to patent thought. I have yet to see any prior art.

Re: casting char to wchar?

Jörgen Sigvardsson28-May-05 6:39

Jörgen Sigvardsson

28-May-05 6:39

Another thing worth mentioning with these string conversion macros, is that they are potentially dangerous in loops, as they allocate memory on the stack, and not on the heap.

--
An eye for an eye will only make the world blind.

Re: casting char to wchar?

Tim Smith30-May-05 7:33

Tim Smith

30-May-05 7:33

That isn't true for 7.0 and greater. The conversion macros became first class objects and avoid the whole loop issue.

I think... Smile | :)

Tim Smith

I'm going to patent thought. I have yet to see any prior art.

Re: casting char to wchar?

Jörgen Sigvardsson30-May-05 7:36

Jörgen Sigvardsson

30-May-05 7:36

From my atlconv.h (atl7/vs.net 2k3):

#define W2A(lpw) (\
	((_lpw = lpw) == NULL) ? NULL : (\
		_convert = (lstrlenW(_lpw)+1)*2,\
		ATLW2AHELPER((LPSTR) alloca(_convert), _lpw, _convert, _acp)))

They added the Cx2y-classes, and deprecated the macros, so that existing code wouldn't break.

--
An eye for an eye will only make the world blind.

Re: casting char to wchar?

bobhou28-May-05 12:55

bobhou

28-May-05 12:55

How do I use this MACRO?
Thank you very much for your kind help
Bob

Re: casting char to wchar?

Michael Dunn28-May-05 10:14

Michael Dunn

28-May-05 10:14

Quick answer: Use the string conversion macros in atlconv.h:

char* txt = "Hello Bob";
hr = pVoice->Speak ( A2W(txt), 0, NULL );

--Mike--
Visual C++ MVP Cool | :cool:

LINKS~! Ericahist | 1ClickPicGrabber | CP SearchBar v2.0.2 | C++ Forum FAQ
Strange things are afoot at the U+004B U+20DD

Re: casting char to wchar?

bobhou28-May-05 12:53

bobhou

28-May-05 12:53

Thank you so much for your help.

However, there are some errors occur:
1. using the following order
#include <atlconv.h>
#include <stdafx.h>
#include <sapi.h>

it gives error C2065: 'A2W' : undeclared identifier

2. if #include <stdafx.h>
#include <sapi.h>
#include <atlconv.h>

It gives 14 errors with first one as:
d:\program files\microsoft visual studio\vc98\atl\include\atlconv.h(48) : error C2065: '_ASSERTE' : undeclared identifier.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.