C / C++ / MFC

Re: VC++ Error in Visual Studio 2017 After migration of application from VS2010 to VS2017 Professional

17-Mar-20 2:15

See his post in QA.

leon de boer17-Mar-20 5:04

leon de boer

17-Mar-20 5:04

All the PDB file stuff isn't errors it's just the debugger telling you it can't debug inside the windows dll. You need the non community version for that aka the paid version Smile | :)

The actual error is you don't have the comctl32.dll loaded. I could give you the long explanation of where you add it in the program options but lets give you the new hack way

Simply place this near the top of your main file

#pragma comment( lib, "comctl32.lib" )

In vino veritas

modified 17-Mar-20 21:33pm.

parsing bitmap files (2)

Calin Negru14-Mar-20 21:53

14-Mar-20 21:53

I think I almost got it right. I have a question about the two file reads

if( cf.Read( &BFH, sizeof( BITMAPFILEHEADER ) )
			!= sizeof( BITMAPFILEHEADER ) ||

			// Is the type 'MB'?
			BFH.bfType != 'MB' ||

			// Did we read in the remaining data?
			cf.Read( pDib, dwDibSize ) != dwDibSize )

first it will read the first 14 bytes which is the header and store it in BFH, at the second read it will read a chunk of data but from the looks of it that chunk will include the (first) header again along with whatever else is included

modified 15-Mar-20 4:13am.

Richard MacCutchan14-Mar-20 22:13

14-Mar-20 22:13

No, the second read will start from the byte following the position where the previous read stopped. That is normal file IO operations. It will only re-read the header if you rewind the file after the first operation.

Calin Negru15-Mar-20 3:09

15-Mar-20 3:09

This is my write attempt.

BITMAPFILEHEADER BFH;
	BITMAPINFOHEADER BIH;
	RGBQUAD Palette;
	RGBQUAD  * Pixels = new RGBQUAD[10];

	cf.Read( &BFH, sizeof( BITMAPFILEHEADER ));
	cf.Read( &BIH, sizeof( BITMAPINFOHEADER ));

	for(int i =0; i<10; i++)
	{
		cf.Read(&Pixels[i],sizeof(RGBQUAD));
	
	}
	
	StringCchPrintfA(message,1024,"b0 is %d", Pixels[0].rgbBlue);
	MessageBox(NULL, message, "Textures.exe", MB_OK);
	StringCchPrintfA(message,1024,"g0 is %d", Pixels[0].rgbGreen);
	MessageBox(NULL, message, "Textures.exe", MB_OK);
	StringCchPrintfA(message,1024,"r0 is %d", Pixels[0].rgbRed);
	MessageBox(NULL, message, "Textures.exe", MB_OK);
	
	StringCchPrintfA(message,1024,"r1 is %d", Pixels[1].rgbRed);
	MessageBox(NULL, message, "Textures.exe", MB_OK);
	StringCchPrintfA(message,1024,"g1 is %d", Pixels[1].rgbGreen);
	MessageBox(NULL, message, "Textures.exe", MB_OK);
	StringCchPrintfA(message,1024,"b1 is %d", Pixels[1].rgbBlue);
	MessageBox(NULL, message, "Textures.exe", MB_OK);


	CFile fileWrite;

	Pixels[0].rgbBlue = 100;
	Pixels[0].rgbGreen = 100;
	Pixels[0].rgbRed = 50;
	// Attempt to create the file.
	if( !fileWrite.Open( pszFilename,
		CFile::modeCreate | CFile::modeWrite ) )
		return( FALSE );

	fileWrite.Write( &BFH, sizeof( BITMAPFILEHEADER ) );
	fileWrite.Write( &BIH, sizeof( BITMAPINFOHEADER ) );
	for(int i =0;i<10; i++)
	{
		fileWrite.Write( &Pixels[i], sizeof( RGBQUAD ) );
	}

when I start my program again I expect the values of the first pixel to be updated but they aren`t

Richard MacCutchan15-Mar-20 3:34

15-Mar-20 3:34

The code looks valid enough, are you sure the file is getting created correctly?

Calin Negru15-Mar-20 4:05

15-Mar-20 4:05

you`re right, if I try to create the file under a new name it works.

Richard MacCutchan15-Mar-20 4:24

15-Mar-20 4:24

I have just tried a similar exercise and the changes are correctly made to the output file.

Calin Negru15-Mar-20 7:02

15-Mar-20 7:02

I will run into other C related issues, you`re not getting rid of me.

Richard MacCutchan15-Mar-20 7:04

15-Mar-20 7:04

Don't worry, I have the freedom to ignore any messages that don't interest me.

leon de boer15-Mar-20 0:25

leon de boer

15-Mar-20 0:25

You are confused there are two headers one after another you need to read them both before deciding whether to do step 3 and I have put a few hints what you need to do

1.) Read BITMAPFILEHEADER check for "BM", hold offset to bitmap data
2.) Read BITMAPINFOHEADER calc DWORD line stride width from bitmap width and bitdepth, see if you have a palette if so do step 3 else step 4
3.) Read the index palette if the BMP has one
4.) Jump to file offset from step 1 that is your bitmap data. Now you need to remember each line is DWORD (4 byte aligned) that means if you multiply the bytes per each line pixel * bitmap width it has to equal 4. So lets give you an example if you bitmap is 24Bit so each pixel is 3 bytes. So if your image was one pixel in width the first line is the first 3 bytes then there is a pad of one dummy byte and the second line starts at the 4th byte. So there can be 0 to 3 extra bytes per line because each new line must start on a DWORD boundary. So the amount of data you need to read for a line can be a couple bytes more than the just multiplying the bitmpap width * bytes per pixel.

The dummy bytes are usually zero but some smart people worked out long ago if you make all your images odd so you have the extra bytes you can put a hidden watermark, or play spy and put secret messsages in the dummy bytes Smile | :)

In vino veritas

Calin Negru15-Mar-20 1:59

c libraries needed to deal with bitmaps

15-Mar-20 1:59

Richard I have it working. Now on to saving.
phil, leon thanks guys.

Calin Negru11-Mar-20 6:59

11-Mar-20 6:59

I fount a class to read and write bitmaps, it`s old source code that uses MFC. it uses CFile to read and write, when I try to compile I get a

Quote:
WINDOWS.H already included

message. Is there a way to work around the problem?

modified 11-Mar-20 13:07pm.

Richard MacCutchan11-Mar-20 7:44

11-Mar-20 7:44

fearless_ wrote:
Is there a way to work around the problem?

Yes, remove the duplicate include statement.

Calin Negru11-Mar-20 9:49

11-Mar-20 9:49

thanks, with a simple tweak at headers it worked

Calin Negru11-Mar-20 21:51

11-Mar-20 21:51

Would you mind helping me further? I loaded the bitmap, however when I check the values from the array into which the bitmap is loaded they show up as 0 (null).

modified 12-Mar-20 4:05am.

Richard MacCutchan11-Mar-20 22:35

11-Mar-20 22:35

Really. And we are supposed to guess what code and where the error occurs?

Calin Negru11-Mar-20 23:27

11-Mar-20 23:27

here is my code

StringCchPrintfA(pszFilename,1024,"hello.bmp");
	// Attempt to open the Dib file for reading.
	if( !cf.Open( pszFilename, CFile::modeRead ) )
	{
		StringCchPrintfA(message,1024,"error reading file");
		MessageBox(NULL, message, "Textures.exe", MB_OK);
		return( FALSE );
	}
		

	// Get the size of the file and store
	// in a local variable. Subtract the
	// size of the BITMAPFILEHEADER structure
	// since we won't keep that in memory.
	DWORD dwDibSize= cf.GetLength() - sizeof( BITMAPFILEHEADER );
	int bsize =0;
	//dwDibSize =
	bsize=	cf.GetLength() - sizeof( BITMAPFILEHEADER );
	StringCchPrintfA(message,1024,"bitmap size  %d",bsize);
	MessageBox(NULL, message, "Textures.exe", MB_OK);

	// Attempt to allocate the Dib memory.
	unsigned char *pDib;
	pDib = new unsigned char [dwDibSize];
	if( pDib == NULL )
	{
			StringCchPrintfA(message,1024,"error allocating array ");
				MessageBox(NULL, message, "Textures.exe", MB_OK);
				return( FALSE );
	}
		

	BITMAPFILEHEADER BFH;

	// Read in the Dib header and data.
	try{

		// Did we read in the entire BITMAPFILEHEADER?
		if( cf.Read( &BFH, sizeof( BITMAPFILEHEADER ) )
			!= sizeof( BITMAPFILEHEADER ) ||

			// Is the type 'MB'?
			BFH.bfType != 'MB' ||

			// Did we read in the remaining data?
			cf.Read( pDib, dwDibSize ) != dwDibSize )
			{
				StringCchPrintfA(message,1024,"error processing the file ");
				MessageBox(NULL, message, "Textures.exe", MB_OK);
			// Delete the memory if we had any
			// errors and return FALSE.
			delete [] pDib;
			return( FALSE );
			}
		}

modified 12-Mar-20 8:41am.

Richard MacCutchan11-Mar-20 23:36