Thread: Storing resources into a single file

I think one typically uses DIB_RGB_COLORS for a 24, 16 or 32bpp image. Have you tried it?

Does your file mapping meet this requirement?

Originally Posted by MSDN

If hSection is not NULL, it must be a handle to a file-mapping object created by calling the CreateFileMapping function with the PAGE_READWRITE or PAGE_WRITECOPY flag. Read-only DIB sections are not supported. Handles created by other means will cause CreateDIBSection to fail.

[edit]Who says that you can pass NULL for ppvBits?[/edit]
[edit2]Got to take into account BITMAPFILEHEADER which is before BITMAPINFO in file.[/edit]

I read that on MSDN as well and did that. I'm calling CreateFile() with GENERIC_READ | GENERIC_WRITE, CreateFileMapping() with PAGE_READWRITE, and MapViewOfFile() with FILE_MAP_READ | FILE_MAP_WRITE.

>>[edit]Who says that you can pass NULL for ppvBits?[/edit]
I just realized that MSDN said nothing about it, so I passed an arg to it.

>>[edit2]Got to take into account BITMAPFILEHEADER which is before BITMAPINFO in file.[/edit]
I'm doing this now:

Code:

    LPBITMAPFILEHEADER pBFH = (LPBITMAPFILEHEADER)m_pMappedFile;
    LPBITMAPINFOHEADER lpBMIH = LPBITMAPINFOHEADER(LPBYTE(m_pMappedFile) + sizeof(BITMAPFILEHEADER));
    DWORD dwOffset = pBFH->bfOffBits;
    LPVOID pBits;

    HDC dc = CreateCompatibleDC(NULL);
    m_hBmp = CreateDIBSection(dc, (LPBITMAPINFO)lpBMIH, DIB_RGB_COLORS, &pBits, m_hFileMapping, dwOffset);

But it is still returning NULL but with GetLastError() returning success... What am I doing wrong?

I do appreciate all the help. This one thorn in my eye is a killer. I can't continue with my project until I resolve this issue.

[edit]
>> You want DIB_PAL_COLORS ? I'll assume yes.
I've been going back and forth just trying to see if anything would change. It hasn't. It seems to me that I'm doing things properly, but apparently I'm not. What can cause GetLastError() to return success upon failure?
[/edit]

Do you check with a debugger that the values pointed to by pBFH and lpBMIH are correct? You should really do that.

Also make sure dc is valid.

Holy cow. You are awesome anontymouse. I just started thinking about the DWORD alignment after rereading MSDN for the nth time. That is a beautiful thing. Now that it's actually loading...

I changed the assignment of dwOffset to:

Code:

DWORD dwOffset = pBFH->bfOffBits - (pBFH->bfOffBits % sizeof(DWORD));

Son of a gun, who'da thunk it would be that simple? Thanks a lot anontymouse and MrWizard. Finally the aspirin for my headache...

[edit]
As for the approach I think I'll be taking, I think padding the bitmap header info is what I'll go with since (as you mentioned) the resources in my file will be made for a specific purpose. Again, thanks.
[/edit]

[edit2]
By the way, I love that first solution "the user might just think that their monitor is shoddy!" Heheh.
[/edit2]