64 bit XP - C / C++ / MFC Discussion Boards

John R. Shaw31-May-07 9:17

31-May-07 9:17

You have to check all the values passed to GetDIBits very carefully. That functions is very touchy and will fail if a single bit is not correct. I do not think the error message has anything to do with the code you are showing, as GeDIBits will often fail without generating any error at all.

See CDibData[^], it might help.

Note: CDibData has a minor bug that I still have not updated, but it has been a while since I played with graphics.

INTP
"Program testing can be used to show the presence of bugs, but never to show their absence."Edsger Dijkstra

Re: GetDIBits() function call fails

Mark Salsbery31-May-07 9:30

Mark Salsbery

31-May-07 9:30

I see a few problems -

TheDelChop wrote:
GetObject(hSavedXYBitmap,sizeof(BITMAP),(LPSTR)(&bmp));

Irrelevent, but cast to a LPSTR?? No cast to a void pointer is necessary Wink | ;)

Problems:
Creating a BITMAPINFO the size of a BITMAPINFOHEADER.
Using the planes value from the DDB when it HAS to be 1 in a DIB.
bmiHeader.biSizeImage is calculated wrong - rows of pixel data in a DIB need to be DWORD aligned.
You've provided no color table (16-colors) for your destination 4-bit DIB
The resulting GetDIBits call should fail based on the above.

Something like this maybe will get you closer:

...
int nNumColors = 1 << cClrBits;
 
LONG lBytesPerRow = (((bmp.bmWidth * (long)cClrBits + 31L) & (~31L)) / 8L);
 
BYTE* pBitmapBits;
 
LONG SizeOfBitmapInfo = sizeof(BITMAPINFO) + ((nNumColors - 1) * sizeof(RGBQUAD));
  
BITMAPINFO *pbmi = (PBITMAPINFO) LocalAlloc(LPTR, SizeOfBitmapInfo);
memset(pbmi, 0, SizeOfBitmapInfo);
pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
pbmi->bmiHeader.biWidth = bmp.bmWidth;
pbmi->bmiHeader.biHeight = bmp.bmHeight;
pbmi->bmiHeader.biPlanes = 1;
pbmi->bmiHeader.biBitCount = cClrBits;
pbmi->bmiHeader.biCompression = BI_RGB;
pbmi->bmiHeader.biSizeImage = lBytesPerRow * bmp.bmHeight;
//pbmi->bmiHeader.biXPelsPerMeter = 0;
//pbmi->bmiHeader.biYPelsPerMeter = 0;
//pbmi->bmiHeader.biClrUsed = 0;
//pbmi->bmiHeader.biClrImportant = 0;
 
// I forget if you need to do this before GetDIBits() :doh:
//// Initialize color table
//for (int i = 0; i < nNumColors; i++)
//{
//   pbmi->bmiColors[i].rgbBlue = ; 
//   pbmi->bmiColors[i].rgbGreen = ; 
//   pbmi->bmiColors[i].rgbRed = ; 
//   pbmi->bmiColors[i].rgbReserved = 0; 
//}
 
pBitmapInfoHeader = (PBITMAPINFOHEADER)pbmi;
 
lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED,pbmi->bmiHeader.biSizeImage);
 
test = ::GetDIBits(hdc, hSavedXYBitmap, 0, (WORD) pbmi->bmiHeader.biHeight, lpBits, pbmi, DIB_RGB_COLORS);
if (test == 0)
   test = GetLastError();

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

Newbie Question

joshp121731-May-07 8:45

joshp1217

31-May-07 8:45

I want to compile a project that I have created. The project has class objects separated in different files i.e. main.cpp, card.h, card.cpp, deck.h, deck.cpp. How am I able to do this so the deck class can create in instance of the card class i.e. vector<card*> x; I know this is really newbie but I got to know.

Re: Newbie Question

David Crow31-May-07 10:31

David Crow

31-May-07 10:31

joshp1217 wrote:
How am I able to do this so the deck class can create in instance of the card class

class deck
{
    deck();
    ~deck();
 
    card c;
}

Or you can do it in one of the deck's members:

void deck::foo( void )
{
    card c;
}

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Re: Newbie Question

Matthew Faithfull31-May-07 11:10

Matthew Faithfull

31-May-07 11:10

Remember to make sure that all the files that use a type ( e.g card class ) have a #include line that references the file that defines the type.
If card is defined in card.h then deck.cpp might look something like this.

<br />
//deck.cpp<br />
<br />
#include "card.h"<br />
<br />
<br />
deck::deck()<br />
{<br />
  card the_cards[52];//An array of 52 cards for the deck<br />
}<br />

If the definition of deck itself, in deck.h, depends on the definition of card then it's deck.h that should #include "card.h"

Think of it as, when the compiler sees #include "card.h" it goes and reads the card.h file and after that it knows about the card class otherwise it's as if it never heard of it.
The trick is that every time it moves on to compiling a different .cpp file (compilation unit) it forgets everything it found out before and starts again knowning nothing except C++. Sounds dumb but it really works Wink | ;)

Nothing is exactly what it seems but everything with seems can be unpicked.

Re: Newbie Question

joshp121731-May-07 11:15

joshp1217

31-May-07 11:15

I thought that was how it should work but when I sent it up that way, i was getting errors like the Deck class didnt recognize the Card class because when i said vector<card*> m_Cards;(this is in the deck.h with #include "card.h" at the top) it basically would say that a vector cant have any empty type. The IDE i am using is Dev-C++ I dont know if that has anything to do with it but any further help would greatly be appreciated because I could do this with ease in C# but I need to do it in C++.

Re: Newbie Question

Matthew Faithfull31-May-07 11:37

Matthew Faithfull

31-May-07 11:37

Should that perhaps be vector<card> m_Cards; or did the html formatter just make your vector type parameter disappear? OMG | :OMG:

If not it might explain the empty type error, might even need #include<vector> and std::vector<card>m_Cards;
There's very little of the using AClass::BClass; stuff in C++ although
using namepsace std; works just fine and should let you use a vector as per the first example above. I'm no STL guru but then if you've done loads of C# you're no newbie either Big Grin | :-D

Nothing is exactly what it seems but everything with seems can be unpicked.

64 bit XP

Monty²31-May-07 7:40

Monty²

31-May-07 7:40

This Code fails on XP 64 bit even if the file exists in the target folder

The exe is 32 bit

CString str;
str = "C:\\WINDOWS\\system32\\drivers\\acpi.sys";

if(!PathFileExists(str))
{
     //Fails but the file exists and can be seen in explorer
     //fopen fails to with err=2 (invalid path)
}

i can paste any file in that folder (text file or whatever) and the result will be file not found (errcode=2)

it shows same behaviour in "c:\windows\system32" folder

So is there some security issue i am not seeing cause this thing runs fine in vista with UAC enabled

Thanks

Solution for those interested

Monty²31-May-07 22:41

Monty²

31-May-07 22:41

http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=1673046&SiteID=1[^]

C++ where friends have access to your private members !

Re: Solution for those interested

Mark Salsbery1-Jun-07 6:22

Mark Salsbery

1-Jun-07 6:22

Good to know! Thanks for the update!

Mark

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

Registry vs .Ini files.

Anurag Gandhi31-May-07 7:37

Anurag Gandhi

31-May-07 7:37

Hi all,
I want to know that which is the better and faster way to access, read and write configuration settings: .ini files or windows registry. Speed matters much for me.
Please help me.

Anurag Gandhi.

Re: Registry vs .Ini files.

David Crow31-May-07 7:57

David Crow

31-May-07 7:57

Anurag Gandhi wrote:
Speed matters much for me.

It sounds as though you need some other storage mechanism then. Neither INI files nor the registry are meant for heavy-duty (constant) access where speed is critical.

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Re: Registry vs .Ini files.

Anurag Gandhi31-May-07 8:00

Anurag Gandhi

31-May-07 8:00

Thanks for reply.
But then, tell me the better way of storing the congiuration settings.
Thanking you in advance.

Anurag Gandhi.

Re: Registry vs .Ini files.

David Crow31-May-07 8:15

David Crow

31-May-07 8:15

Anurag Gandhi wrote:
But then, tell me the better way of storing the congiuration settings.

By "congiuration settings," I assume you mean settings that are read once at program startup, and written once at program shutdown or via some Properties dialog?

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Re: Registry vs .Ini files.

Anurag Gandhi31-May-07 8:17

Anurag Gandhi

31-May-07 8:17

Exactly.
Any idea about that? Which method is faster?

Anurag Gandhi.

Re: Registry vs .Ini files.

Maximilien31-May-07 8:45

Maximilien

31-May-07 8:45

Unless you have a gazillion settings, speed and performance is not really important for that.

Me think you need to spend your effort somewhere else.

Maximilien Lincourt
Your Head A Splode - Strong Bad

Re: Registry vs .Ini files.

David Crow31-May-07 8:45

David Crow

31-May-07 8:45

Anurag Gandhi wrote:
Any idea about that? Which method is faster?

No idea. It's never been important enough to matter. I would guess a difference of a few ms. Ini files are easier moved to other computers, whereas registry items can be secured. Speed would be the short pole in the tent.

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Re: Registry vs .Ini files.

Matthew Faithfull31-May-07 8:25

Matthew Faithfull

31-May-07 8:25

When I faced a similar problem a few years ago I went for a binary file with fixed size records. Essentially you lay out your configuration settings in a struct and then read and write them as a simple binary record to an offset in the file based on size * record_number. I needed multiple records that could be read and written simultaneously. I had multiple copies of the software sharing the file over a network so I also used partial file locking to lock the individual records to prevent corruption. It all depends what sort of configuration data you want to store.
Obviously this method doesn't lead to portable or human readable/editable config information. Frown | :(

If this is important you could use an ini file read once on startup and written once on shutdown with the same data. This way you get configuration backup and crash corruption protection as well Big Grin | :-D

Nothing is exactly what it seems but everything with seems can be unpicked.

Re: Registry vs .Ini files.

Anurag Gandhi31-May-07 8:35

Anurag Gandhi

31-May-07 8:35

Thanks Matthew.
It seems to be a good solution.

Anurag Gandhi.

Re: Registry vs .Ini files.

#realJSOP1-Jun-07 3:21

#realJSOP

1-Jun-07 3:21

Program settings should

0) Be user-specific

1) Should be saved in the registry if at all possible

2) and if #1 isn't possible, saved in a file in the user's appropriate application data sub-folder.

3) "Data" is not the same as "settings". "Settings" are rarely written, and typically only read at startup, eliminating the need for much more performance than we already get by reading/wqriting to the registry. "Data" on the other hand is read/written all the time, hence the need for better performance.

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

Anyone know of a VS2005 add-in to do this?

Stick^31-May-07 6:45

Stick^

31-May-07 6:45

I'm looking for a VS2005 add-in to auto increment the build number each time I compile.

Anyone know of a working VS2005 add-in? What do you use/do to accomplish this task?

Patrick

Re: Anyone know of a VS2005 add-in to do this?

David Crow31-May-07 8:13

David Crow

31-May-07 8:13

Does this meet your needs?

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Re: Anyone know of a VS2005 add-in to do this?

Stick^31-May-07 8:46

Stick^

31-May-07 8:46

Actually, I was able to get that mostly working, but had some problems.

First, it doesn't update the product number. I could probably fix that as he provides the source, but the second problem lead me to continue for more of an "add-in" solution.

The 2nd problem is that this results in a file that has the version set in the properties, but if you mouse over it, the hover text always says, 1.0.0.0. That would just confuse my users.

So, I'm searching for something someone has turned into a drop-in add-in, or something that doesn't have these issues.

Also, I prefer to have the .rc2 VERSIONINFO be the source, vs. another file, although that is really nothing, I can edit either easily.

Patrick

Convert a number in Cstring and then CString in number?

Immunity1831-May-07 6:40

Immunity18

31-May-07 6:40

How can i convert a string ( "1234.5") as a double =1234.5

I know only to convert number to string

str.Format( _T ("%f") ,double );

how i do the reverse? Big Grin | :-D

Re: Convert a number in Cstring and then CString in number? [modified]

Roger Stoltz31-May-07 6:52

Roger Stoltz

31-May-07 6:52

double atof( const char *string );

[edit]

I assume that the one who voted my post '1' is unfamiliar with the basic standard library functions in C/C++. atof() is declared in stdlib.h.
To get a double from a CString would look like this:

CString str = "12345.6";
double value = 0.;
value = atof( str );

Further information can be found here[^].

[/edit]

-- modified at 13:44 Thursday 31st May, 2007

"It's supposed to be hard, otherwise anybody could do it!" - selfquote
"High speed never compensates for wrong direction!" - unknown

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