C / C++ / MFC

30-May-07 14:36

This[^] article may help.

Mark

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

Re: Run Once Only

Bram van Kampen30-May-07 14:49

Bram van Kampen

30-May-07 14:49

Thanks Mark,

Very Helpfull, Much Appreciated, Will email you a Bottle of Wine Smile | :)

LateNightsInNewry

Re: Run Once Only

Mark Salsbery30-May-07 14:52

VC++ 6.0 Dialog Form with Picture Box

30-May-07 14:52

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

rjrodrig30-May-07 13:51

rjrodrig

30-May-07 13:51

Guys,

Please excuse this dumb question, but I am new to programming in Visual C++ 6.0 and I would like to know how to do the following. I have an array of bytes that it is provided by a Library (myLib.lib). This has a collection of functions that fetch an image from a camera, and provide me the pointer for the 1D array of RGB bytes of an image.

I am writing the application in Visual Basic 6.0 SP6. I want send a command via DLL to a VC++ generated DLL where:

1. when the function receives a command, the function displays a Dialog box
2. The dialog box has a picturebox and paints the array.
3. I saw visual C++ has all the gdi32.lib where Setbitmapbits() is included. However, I thought it was just as simple as using the function but apparently VC has quite a bit things to do in order to use the gdi32.dll or gdi32.lib

I have some experience writing C++ DLL libraries for Visual Basic using _stdcall type of functions. I figure I have to use an RC resource and I know simple Dialogs are available. The questions is how do I make that dialog show up when I call it from VB?

Does anyone know? Any help will be greatly appreciated by those of you who know C++ well. I know VB6 well, so if I can help send me your questions.

Regards,

rjrodrig@yahoo.com

VB on Steroids by VC++

Re: VC++ 6.0 Dialog Form with Picture Box

Hans Dietrich30-May-07 15:09

Hans Dietrich

30-May-07 15:09

rjrodrig wrote:
how do I make that dialog show up when I call it from VB?

You will probably get a better answer if you ask this in the VB Forum.

Best wishes,
Hans

[CodeProject Forum Guidelines] [How To Ask A Question] [My Articles]

directsound,how to compress and decompress sound data

kcynic30-May-07 13:17

kcynic

30-May-07 13:17

I am using directsound.I used to compress ,translate and decompress sound using capXXX.But it is limited in some aspects,so I am changing to Directsound. But Directsound seems a little difficulty and complicated.So,I want want do something to encourage myself with some example.
If there has some example about this?I only want to capture,compress,and decompress sound data,but most of examples on the websource always about how to playback file streams.

Re: directsound,how to compress and decompress sound data

Mark Salsbery30-May-07 15:06

Re: directsound,how to compress and decompress sound data

30-May-07 15:06

kcynic wrote:
But Directsound seems a little difficulty and complicated.So,I want want do something to encourage myself with some example.

In that case, maybe encourage yourself by getting it running well uncompressed.

Then when you're comfotable with that process (streaming audio samples out of and in to
DirectSound buffers) you can add compression.

For compression, a couple methods I know of are:

If you have a codec, you can feed the samples through that.

Included with Windows, there's the Audio Compression Manager[^]

Also, I believe DirectSound capture buffers will capture in a compressed format by using the
DSCBCAPS_WAVEMAPPED when creating the buffer and spcifying a format that maps to an Audio
Compression Manager codec. I'm not sure if playback buffers will map the other direction -
I've never tried it.

Mark

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

kcynic30-May-07 22:31

kcynic

30-May-07 22:31

Thanks,But would you like to tell me if the SDK have codec or not?

Re: directsound,how to compress and decompress sound data

Mark Salsbery31-May-07 5:27

31-May-07 5:27

This link shows available codecs: http://support.microsoft.com/default.aspx?scid=kb;en-us;899113[^]

Depending on what compression manager you end up using, there should be APIs to list/choose
codecs. For example, acmFormatChoose() shows a dialog for selecting audio formats in the audio
compression manager.

Mark

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

Monochrome Bitmap Issue

CoffeeAddict1930-May-07 12:23

30-May-07 12:23

I'm having a problem with memory device contexts and bitmaps in MFC. I've gotten to the point to where I can create and use them, but natrually they are all in black in white. See here:

http://img.photobucket.com/albums/v50/blackdwarf/piegraphcontrol.jpg[^]

With a CreateCompatibleDC(NULL) call, a monochrome bitmap gets created for and selected into the CDC. When I actually create my bitmap based off of that CDC, I'm stuck with the monochrome. So my question is, how do I initialize the bitmaps with color outside of OnPaint when I can't just use CPaintDC?

Here is some of the code...

Creating the two bitmaps without a CPaintDC (where I think the problem is):

BOOL CPieGraph::Create(CWnd* pParentWnd, const RECT& rect, UINT nID, DWORD dwStyle /*=WS_VISIBLE*/)
{
	BOOL OverallSuccess = FALSE;
	BOOL CreateResult = FALSE,
		TextDCResult = FALSE,
		PieDCResult = FALSE;
	int SelectText = 0, SelectPie = 0;

	CreateResult = CWnd::Create(CPIEGRAPH_CLASSNAME, _T(""), dwStyle, rect, pParentWnd, nID);

	TextDCResult = TextMemDC.CreateCompatibleDC(NULL);
	PieDCResult = PieMemDC.CreateCompatibleDC(NULL);
	SelectText = m_textBitmap.CreateCompatibleBitmap(&TextMemDC, 250, 20);
	SelectPie = m_pieBitmap.CreateCompatibleBitmap(&PieMemDC, 300, 300);
	OldtextBitmap = TextMemDC.SelectObject(&m_textBitmap);
	OldpieBitmap = PieMemDC.SelectObject(&m_pieBitmap);
	TextMemDC.SetBkColor(RGB(255,255,255));
	PieMemDC.SetBkColor(RGB(255,255,255));
	if((CreateResult == TRUE) && (TextDCResult == TRUE) && (PieDCResult == TRUE) && (SelectText != 0) && (SelectPie != 0))
	{
		OverallSuccess = TRUE;
		ControlRect = rect;
	}
	else
		OverallSuccess = FALSE;

	return OverallSuccess;
}

And OnPaintDC:

afx_msg void CPieGraph::OnPaint()
{
	CPaintDC dc(this);

	CDC ControlMemDC;
	CBitmap ControlBitmap;
	CBitmap* OldBitmap = NULL;

	ControlMemDC.CreateCompatibleDC(&dc);
	ControlBitmap.CreateCompatibleBitmap(&ControlMemDC, 300, 360);
	OldBitmap = ControlMemDC.SelectObject(&ControlBitmap);
	ControlMemDC.SetBkColor(RGB(255,255,255));

	if(UpdateNeeded == true)
	{
		RedrawPieText(TextMemDC);
		RedrawPieChart(PieMemDC);
		ControlMemDC.BitBlt(0, 0, 250, 20, &TextMemDC, 0, 0, SRCCOPY);
		ControlMemDC.BitBlt(0, 25, MainPieGraph.radius * 2, 
			MainPieGraph.radius * 2, &PieMemDC, 0, 0, SRCCOPY);
		//UpdateNeeded = false;
		UpdateNeeded = true;
	}

	dc.BitBlt(ControlRect.left, ControlRect.top, 250, 320, &ControlMemDC, 0, 0, SRCCOPY);
	ControlMemDC.SelectObject(OldBitmap);
}

Bram van Kampen30-May-07 14:28

Bram van Kampen

30-May-07 14:28

Don't know an awfull lot about the issues, but it appears to be at first sight to be a problem about loss of information.It would appear to me that you first create a monochrome bitmap from a source, which you select into the CDC. At that stage the Die is cast as far as the CDC is concerned. The Monochrome bitmap is all it knows about. The CDC has built a Monochrome picture which it knows your Device can display. All Colour Info has been discarded. If at a later stage you want the Bitmap in colour, you have to start again from scratch in the same or another CDC, This time indicating yont to keep the colour. Mind you,to do so you could recycle most of the code. Just leave an indication somewhere about what way you want it, Monocrome or Colour. A Device Context is a Uniform Construct that Converts things like bitmaps etc into something your Hardware can display. (That's the way device-independence is Implemented).

Hope this is Usefull. Smile | :)

LateNightsInNewry

Mark Salsbery30-May-07 15:16

30-May-07 15:16

To add to LateNightsInNewry's reply...

To fix it...

When you call CreateCompatibleBitmap(), you should use the screen or paint DC, not the memory
DC. The memory DC you created with CreateCompatibleDC() is the one with a monochrome bitmap
selected into it. If you create a bitmap compatible with that, it will also be monochrome.

Outside of OnPaint, you can get a screen DC with

::GetDC(0)

or something like

CDC ScreenDC;
ScreenDC.CreateCompatibleDC(0);

Mark

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

CoffeeAddict1930-May-07 17:08

30-May-07 17:08

Thanks, both of you. I think it'll work. I'll try it tommorow when I wake up.

Mark Salsbery31-May-07 5:36

31-May-07 5:36

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

CoffeeAddict1931-May-07 8:19

31-May-07 8:19

Actually I just got a cup about 30 minutes ago. Smile | :)

Unfortunatly, the problem still remains. Frown | :(

I tried using GetDC:

CDC* ScreenDC = NULL;
CreateResult = CWnd::Create(CPIEGRAPH_CLASSNAME, _T(""), dwStyle, rect, pParentWnd, nID);

TextDCResult = TextMemDC.CreateCompatibleDC(NULL);
PieDCResult = PieMemDC.CreateCompatibleDC(NULL);

ScreenDC = GetDC();
ASSERT(ScreenDC == NULL);
SelectText = m_textBitmap.CreateCompatibleBitmap(ScreenDC, 250, 20);
SelectPie = m_pieBitmap.CreateCompatibleBitmap(ScreenDC, 300, 300);
ReleaseDC(ScreenDC);

At first the assert statement wasn't in there and I just got black and white, then I put it in and I got a debug assertation on the same line, indicating that ScreenDC was null, and that GetDC didn't do the job. Any idea why?

CoffeeAddict1931-May-07 8:38

31-May-07 8:38

Well the assert statement was wrong...it should have been ASSERT(ScreenDC != NULL), but it is still not rendering color for some reason. Fonts, brushes, and pens work fine, just not color.

Mark Salsbery31-May-07 8:53

Re: Monochrome Bitmap Issue [modified]

31-May-07 8:53

CoffeeAddict19 wrote:
but it is still not rendering color for some reason.

Hopefully my modified post below will help Smile | :)

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

Mark Salsbery31-May-07 8:43

31-May-07 8:43

CoffeeAddict19 wrote:
indicating that ScreenDC was null

~~Is Create() failing?~~ Never mind, I see you fixed the ASSERT

I steered you wrong with the CreateCompatibleDC, sorry D'Oh! | :doh:

*EDIT* I DID show you a way to do what you were already doing though :)

This should work from anywhere:

CWindowDC ScreenDC(0);
 
CBitmap bitmap;
bitmap.CreateCompatibleBitmap(&ScreenDC, 20, 20);
 
//**Test - Check the resulting bitmap's format...
BITMAP bitmapstruct;
bitmap.GetObject(sizeof(BITMAP), &bitmapstruct);

You'll see in the BITMAP struct, the format matches the screen format.

Try this:

CreateResult = CWnd::Create(CPIEGRAPH_CLASSNAME, _T(""), dwStyle, rect, pParentWnd, nID);
CWindowDC ScreenDC(0);
TextDCResult = TextMemDC.CreateCompatibleDC(&ScreenDC);
PieDCResult = PieMemDC.CreateCompatibleDC(&ScreenDC);
SelectText = m_textBitmap.CreateCompatibleBitmap(&ScreenDC, 250, 20);
SelectPie = m_pieBitmap.CreateCompatibleBitmap(&ScreenDC, 300, 300);

Mark

-- modified at 14:54 Thursday 31st May, 2007

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

CoffeeAddict1931-May-07 9:58

31-May-07 9:58

Thanks mark! I HAVE MADE COLOR! Check it out:

http://img.photobucket.com/albums/v50/blackdwarf/piechart_color.jpg[^]

Shouldn't take me long to get long of the pesky black area around the edges. Maybe I'll write a simple tutorial on making controls someday. There already is one, but another viewpoint couldn't hurt.

Mark Salsbery31-May-07 10:05