BMP 24 bit to 1 bit - C / C++ / MFC Discussion Boards

Tomasz Sowinski5-Jun-02 1:16

5-Jun-02 1:16

To export classes from .dll, you need to mark them as __declspec(dllexport). To import, you'll need __declspec(dllimport). Since the specifiers go to .h files, you'll need a way to mark them as exported when compiling .dll, and imported when using .dll in other project. This can be easily done with preprocessor:

#if BUILDING_MY_DLL
#define EXPORTED __declspec(dllexport)
#else
#define EXPORTED __declspec(dllimport)
#endif

class EXPORTED MyClass
{
//...
};

I'm usually inserting #if/#endif stuff in special .h file included before any exported class declaration.

BUILDING_MY_DLL should be defined in Project Settings, C++ category, Preprocessor section. Of course, it cannot be defined when you're just using .dll in other project.

Brendan O`Connor wrote:
Lastly,does mixing STL and MFC cause any exceptions?Is it good to mix them?

You can mix them. Is it good? It depends who you'll ask. If it works for you, go with it.

Tomasz Sowinski -- http://www.shooltz.com

- It's for protection
- Protection from what? Zee Germans?

Re: classes,dlls and class wizard

James R. Twine5-Jun-02 4:53

James R. Twine

5-Jun-02 4:53

Brendan O`Connor wrote:
Lastly,does mixing STL and MFC cause any exceptions?Is it good to mix them?

   Since the other questions have been answered, I will add a little tidbit to your last question.  Since you are talking about exposing/exporting classes from DLLs, you should be aware that exposing/exporting STL collections across DLL boundaries may cause you problems, due to the way that (some) STL classes use static members.

   These STL classes that will have problems (as well as some workarounds) are detailed in the MSDN Knowledge Base.

   Note that under some situations, the collections will seem to work fine for a while, and then may just start to fail for no obvious reason.  Because of that simple fact, never assume that "it works" is a reason to beleve that "it works well", or "it's correct".

   (IOW, never "go with" something just because "it works", unless you can explain why it works.)

   Peace!

-=- James.
"Some People Know How To Drive, Others Just Know How To Operate A Car."
(Try Check Favorites Sometime!)

Re: classes,dlls and class wizard

Tomasz Sowinski5-Jun-02 4:52

Tomasz Sowinski

5-Jun-02 4:52

James R. Twine wrote:
IOW, never "go with" something just because "it works", unless you can explain why it works

How many users of MFC and STL can explain how they work?

Tomasz Sowinski -- http://www.shooltz.com

- It's for protection
- Protection from what? Zee Germans?

Re: classes,dlls and class wizard

James R. Twine5-Jun-02 5:21

James R. Twine

5-Jun-02 5:21

Tomasz Sowinski wrote:
How many users of MFC and STL can explain how they work?

   I believe you should read my comments again; I wrote: "unless you can explain why it works".  Why something works is much different than How something works.  For example, I can briefly explain why a plane is a better choice for getting to Japan than a car is, without having to get into properties of lift or how an piston-based ICE works.

   And, all of the genuinely competent developers that I know can explain how MFC's CWnd-based classes work, how the handle lookups are done, the situations when CWnd::GetDlgItem(...) will return a pointer to a "real" object, and when it will just return a pointer to a temporary CTempWnd object instead, why some care needs to be taken when using these classes across threads, etc, which covers the how quite nicely.

   I would have to guess that most of the people answering questions here could do the same as well, or at least know their limitations, otherwise they risk giving out incorrect information to others...  It would be very depressing to find out that this was not true.

   Peace!

-=- James.
"Some People Know How To Drive, Others Just Know How To Operate A Car."
(Try Check Favorites Sometime!)

Re: classes,dlls and class wizard

James R. Twine6-Jun-02 18:43

James R. Twine

6-Jun-02 18:43

Did you have any further issues?

Peace!

-=- James.
"Some People Know How To Drive, Others Just Know How To Operate A Car."
(Try Check Favorites Sometime!)

Re: classes,dlls and class wizard

Tomasz Sowinski6-Jun-02 23:50

Tomasz Sowinski

6-Jun-02 23:50

No - you've made your point clear.

Tomasz Sowinski -- http://www.shooltz.com

- It's for protection
- Protection from what? Zee Germans?

DAO and Visual Studio .NET

5-Jun-02 1:02

Hi!
I can't build with VC++ 7.0 the project that use DAO. The VC++ 6.0 build correctly the same project. I receive the following error message:
fatal error LNK1120: 1 unresolved externals
"public: class ATL::CStringT > > __thiscall CdbLastOLEError::GetDescription(void)"

Do you now somebody the resolution?
Thanks

Feri

BMP 24 bit to 1 bit

Nish Nishant5-Jun-02 0:46

Nish Nishant

5-Jun-02 0:46

Okay

I finally found some samples on MSDN that show how we can save an bitmap from an HBITMAP

The problem is it's saving it in 24 bits Frown | :-(

(

Is there anyway that I can change the bits/pixel setting of my DC?

Or say once I have the bitmap ready in memory, is there anyway by which I can change it from a 24 bit bitmap to a 1 bit bitmap???

Regards
Nish

p.s. only GDI, no GDI+ Cry | :((

Regards,
Nish
Native CPian.
Born and brought up on CP.
With the CP blood in him.

Re: BMP 24 bit to 1 bit

Tomasz Sowinski5-Jun-02 1:06

Tomasz Sowinski

5-Jun-02 1:06

Well, you can always BitBlt from 24-bit to 1-bit memory DC. But quality will be totally unacceptable. You should perform some dithering (Floyd-Steinberg error diffusion, perhaps).

Tomasz Sowinski -- http://www.shooltz.com

- It's for protection
- Protection from what? Zee Germans?

Re: BMP 24 bit to 1 bit

Nish Nishant5-Jun-02 1:14

Nish Nishant

5-Jun-02 1:14

Tomasz Sowinski wrote:
Well, you can always BitBlt from 24-bit to 1-bit memory DC. But quality will be totally unacceptable. You should perform some dithering (Floyd-Steinberg error diffusion, perhaps).

Quality is not a problem. The bitmap consists of just black and white.
I draw it on my CView using *blush* SetPixel Blush | :O

Here is the code I am using :-

HDC hDC;	
hDC = ::GetDC(m_hWnd); 
	
HDC hMemDC = CreateCompatibleDC(hDC);
RECT r;
::GetClientRect(m_hWnd,&r);
SIZE size;
size.cx = r.right-r.left;
size.cy = r.bottom-r.top;
	
HBITMAP hBitmap = CreateCompatibleBitmap(hDC, size.cx, size.cy);	
	

if (hBitmap)
{
	HBITMAP hOld = (HBITMAP) SelectObject(hMemDC, hBitmap);
	BitBlt(hMemDC, 0, 0, size.cx, size.cy, hDC, 0, 0, SRCCOPY);
	SelectObject(hMemDC, hOld);	
		
	if(m_hBitmap)
		DeleteObject(m_hBitmap);
		
	m_hBitmap = hBitmap;
		
	DeleteDC(hMemDC);
	::ReleaseDC(NULL, hDC);		
}

I guess I should change my CreateCompatibleDC to #CreateDCwith1Bits#!

But how do I do that? Is there any GDI function for that?

Regards,
Nish
Native CPian.
Born and brought up on CP.
With the CP blood in him.

Re: BMP 24 bit to 1 bit

Tomasz Sowinski5-Jun-02 1:18

Tomasz Sowinski

5-Jun-02 1:18

If you replace hDC with hMemDC in a call to CreateCompatibleBitmap, hBitmap will be monochrome. There's some rule which GDI uses when blitting to monochrome DCs - I don't remember exactly, but it may be related to current text color. You'll have to experiment a little bit or browse through MSDN or CP.

Tomasz Sowinski -- http://www.shooltz.com

- It's for protection
- Protection from what? Zee Germans?

Re: BMP 24 bit to 1 bit

Nish Nishant5-Jun-02 1:29

Nish Nishant

5-Jun-02 1:29

Tomasz Sowinski wrote:
If you replace hDC with hMemDC in a call to CreateCompatibleBitmap, hBitmap will be monochrome. There's some rule which GDI uses when blitting to monochrome DCs - I don't remember exactly, but it may be related to current text color. You'll have to experiment a little bit or browse through MSDN or CP.

Well, it created a 1-bit bitmap. But it was all blank Frown | :(

I dunno what kinda stupid logic it used. Basically it was a bitmap with a lot of white and a black signature. I think 99% of the area would have been white. yet I expected it to convert that properly to a 1-bit bitmap Frown | :(

Now what do I do? Confused | :confused:

Nish

Regards,
Nish
Native CPian.
Born and brought up on CP.
With the CP blood in him.

Re: BMP 24 bit to 1 bit

Tomasz Sowinski5-Jun-02 1:34

Tomasz Sowinski

5-Jun-02 1:34

Nish - Native CPian wrote:
Now what do I do?

Can't you use this SetPixel stuff directly on hMemDC? It would create the same thing. Getting client DC and blitting from it isn't the best way - there may be some topmost window (WinAmp, for example) floating above, etc.

Tomasz Sowinski -- http://www.shooltz.com

- It's for protection
- Protection from what? Zee Germans?

Re: BMP 24 bit to 1 bit

Tim Smith5-Jun-02 1:37

Tim Smith

5-Jun-02 1:37

Set the background color of the source DC (the 24 bit bitmap) to the color of the color you want to be black in your monochrome bitmap.

::SetBkColor (hdcSrc, RGB (0, 0, 0));

Tim Smith

I know what you're thinking punk, you're thinking did he spell check this document? Well, to tell you the truth I kinda forgot myself in all this excitement. But being this here's CodeProject, the most powerful forums in the world and would blow your head clean off, you've got to ask yourself one question, Do I feel lucky? Well do ya punk?

Problem with MicrosoftAccessDriver

4-Jun-02 23:53

Hi!
I try to put MicrosoftAccessDriver version 4.00.6019.00 on Windows98 and recieve a message
The setup routines for Microsoft Access Driver ODBC driver could not be loaded due to system error code 1157.
Tell me,please,what is it means.
May be that i can not put driver with last version on Windows98 and Windows95?
Help me,please!!!

Re: Problem with MicrosoftAccessDriver

Ed Gadziemski5-Jun-02 14:13

Ed Gadziemski

5-Jun-02 14:13

Check article Q260558 on support.microsoft.com.

VisC++ and installShield

Tali4-Jun-02 23:20

Tali

4-Jun-02 23:20

Hey,
So this is what I want to do: I work for a video game company, and I am working on the installer for the game. What they want is a graphically attracting version of the installer made with installShield (you know, weapons, fires, movies, etc.). I own installShield professional 5.5, and it allows you to display movies in the background, but I want to actually customize my own dialog boxes, while still keeping the functionality of installShield. I tried to use the tutorial about adding DLL's to installShield, but I do not know how to make an MSI file in installShield, or much less what an MSI file is.

Any help would be GREATLY appreciated.

Thanks,
Tali

Re: VisC++ and installShield

Ed Gadziemski5-Jun-02 14:17

Ed Gadziemski

5-Jun-02 14:17

MSI stands for MicroSoft Installer. An .msi file is one of the files that go with the new Windows Installer. Check out msdn.microsoft.com for more info.

HBITMAP to Jpg anyone

Nish Nishant4-Jun-02 22:57

Nish Nishant

4-Jun-02 22:57

As in subject!

Nish

Regards,
Nish
Native CPian.
Born and brought up on CP.
With the CP blood in him.

Re: HBITMAP to Jpg anyone

-Dy4-Jun-02 23:07

-Dy

4-Jun-02 23:07

Check out the very good Free Image Project [^]

Dylan Kenneally
London, UK

Re: HBITMAP to Jpg anyone

Nish Nishant4-Jun-02 23:28

Nish Nishant

4-Jun-02 23:28

Thanks. If nothing else works out, I'll have to use something like that

Nish

Regards,
Nish
Native CPian.
Born and brought up on CP.
With the CP blood in him.

Re: HBITMAP to Jpg anyone

Rama Krishna Vavilala4-Jun-02 23:52

Rama Krishna Vavilala

4-Jun-02 23:52

It should be possible using GDI+ if you can use it. Attach the HBITMAP to an Bitmap object and call Save method. There is a way to select the format in which you want to save.

Re: HBITMAP to Jpg anyone

Nish Nishant5-Jun-02 0:51

Nish Nishant

5-Jun-02 0:51

Sadly I am using VC++ 6 and I don't have the new PSDK either Frown | :-(

Sucks to be me Cry | :((

Nish

Regards,
Nish
Native CPian.
Born and brought up on CP.
With the CP blood in him.

Re: HBITMAP to Jpg anyone

C^hris L^osinger5-Jun-02 1:51

C^hris L^osinger

5-Jun-02 1:51

i know where you can get a nice, cheap, commercial solution Smile | :)

-c

Cheap oil. It's worth it!

ISEffects - effects for images

Re: HBITMAP to Jpg anyone

Tomasz Sowinski5-Jun-02 2:26

Tomasz Sowinski

5-Jun-02 2:26

AFAIK, Nish's bosses aren't going to buy any non-Java tools...

Tomasz Sowinski -- http://www.shooltz.com

- It's for protection
- Protection from what? Zee Germans?

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