C / C++ / MFC

chandu00427-Jun-09 0:01

chandu004

27-Jun-09 0:01

did you try with memcpy.
hope that should work for you.
but, if you can let us know the purpose, we can give better suggestions.

--------------------------------------------
Suggestion to the members:
Please prefix your main thread subject with [SOLVED] if it is solved.
thanks.
chandu.

jalsa G27-Jun-09 0:06

jalsa G

27-Jun-09 0:06

I need to send the data on tcp socket before that i have MD5 the packet data data.

so i want to convert the structure data to byte.

regards

Jalsa

chandu00427-Jun-09 0:11

chandu004

27-Jun-09 0:11

try with memcpy.

jalsa G wrote:
before that i have MD5 the packet data data

can you explaing this a bit more clearer?

--------------------------------------------
Suggestion to the members:
Please prefix your main thread subject with [SOLVED] if it is solved.
thanks.
chandu.

CPallini27-Jun-09 0:41

CPallini

27-Jun-09 0:41

Well a struct is a just bunch of (adjacent) bytes, hence you can pass the address of the struct (and the proper size) to the sending function.
Of course if endianess is a issue then you have to handle it.

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

«_Superman_»27-Jun-09 2:51

«_Superman_»

27-Jun-09 2:51

Also the byte alignment can sometimes cause problems.

For example with a byte alignment of 4 bytes, the following structure would be of 8 bytes length.

struct test {<br />
char a;<br />
int b;<br />
};<br />

Doing a memcpy will write 8 bytes to a byte array while the needed size is 5 bytes.
In such cases you would need a #pragma pack(1) before declaring the structure.

«_Superman_»
I love work. It gives me something to do between weekends.

kumar sanghvi27-Jun-09 3:01

kumar sanghvi

27-Jun-09 3:01

Hi if possible please try to suggest me any solution for the thread Setting Font.. which
i posted below...

Does it have a part for C++ builder?

CPallini27-Jun-09 4:28

CPallini

27-Jun-09 4:28

Indeed. Anyway you may send only sizeof(char)+sizeof(int) bytes. Of course then you've to make sure sizeof(int) is the same on both the sides. Roll eyes | :rolleyes:

favorxx26-Jun-09 21:20

favorxx

26-Jun-09 21:20

I've found the C/C++/MFC, but not found the C++ builder, does it have one for C++ builder in this website? Confused | :confused:

Re: Does it have a part for C++ builder?

CPallini26-Jun-09 23:37

CPallini

26-Jun-09 23:37

Do you mean a forum for C++ Builder? No we haven't. Anyway you try to ask your question here.
Smile | :)

Re: Does it have a part for C++ builder?

favorxx27-Jun-09 2:19

favorxx

27-Jun-09 2:19

Thank you very much

How to read footer at a sector using C++/VC++

Shiv Murti Pal26-Jun-09 20:51

Shiv Murti Pal

26-Jun-09 20:51

How to read footer at a sector using C++/VC++

Write PE with VC6 [modified]

tuan111126-Jun-09 17:51

tuan1111

26-Jun-09 17:51

Hi!
I want to write to PE run on empty OS.
It help winAPI run on "Empty OS"
Please,full code & guide
Thanks : -D
-D -D -D -D -D -D
Vietnam.
by:tuan1111 Smile | :)

modified on Monday, July 20, 2009 9:24 PM

Re: Write kernel OS

Michael Schubert26-Jun-09 23:52

Michael Schubert

26-Jun-09 23:52

You're not giving up, are you?

tuan1111 wrote:
I'm reading bootloader

Try to read an English course first.

Alternatively, run your post through several, randomly selected languages on translate.google.com, I'm sure it will make more sense then.

tuan1111 wrote:
I say the hard things I want them

What?

tuan1111 wrote:
Please provide code

Let me correct that for you:
Pleeze sendz codez

Re: Write kernel OS

sashoalm27-Jun-09 1:37

sashoalm

27-Jun-09 1:37

The above post wouldn't be out of place in this site[^]

Smile | :)

There is sufficient light for those who desire to see, and there is sufficient darkness for those of a contrary disposition.
Blaise Pascal

Context sensitive help in MFC app

Sternocera26-Jun-09 10:39

Sternocera

26-Jun-09 10:39

Hello,

I'm developing an MFC application that I'd like to provide context sensitive help for. Does MFC provide such a facility? I think that .chm files are deprecated in Windows vista - something called MAML is used instead.

My questions is, what is the modern, preferred way to create context sensitive help within MFC?

Regards,
Sternocera

[SOLVED] Help needed with Alphablend function [modified]

Rozis26-Jun-09 10:01

26-Jun-09 10:01

Is there anbody out there who has a working code snippet that uses WinApi function Alphablend()?
Can Alphablend() be used with a bitmap that has no alphachannel?

Thanx

modified on Sunday, June 28, 2009 5:00 AM

PJ Arends26-Jun-09 11:05

26-Jun-09 11:05

I use it on a splash screen.

header file:

typedef BOOL (WINAPI ALPHABLEND)(HDC, int, int, int, int, HDC, int, int, int, int, BLENDFUNCTION);
typedef ALPHABLEND* LPALPHABLEND;

class ...
{
...
   HINSTANCE m_hLib;
   LPALPHABLEND m_lpfnAlphaBlend;
...
};

source file:

// in class c'tor
        m_hLib = LoadLibrary(_T("msimg32.dll"));
        if (m_hLib != NULL)
        {
            m_lpfnAlphaBlend = (LPALPHABLEND)GetProcAddress(m_hLib, "AlphaBlend");
        }

// in class d'tor
    if (m_hLib != NULL)
    {
        FreeLibrary(m_hLib);
        m_hLib = NULL;
    }


BOOL C*********::OnEraseBkgnd(CDC* pDC) 
{
    CDialog::OnEraseBkgnd(pDC);

    if (m_lpfnAlphaBlend != NULL)
    {
        CRect rc;
        GetClientRect(rc);

        BITMAP b;
        if (GetObject(m_hBitmap,
                      sizeof(BITMAP),
                      &b))
        {
            CDC DC;
            DC.CreateCompatibleDC(pDC);
            int s = DC.SaveDC();

            DC.SelectObject(m_hBitmap);
            
            BLENDFUNCTION bf = {0};
            bf.BlendOp = AC_SRC_OVER;
            bf.SourceConstantAlpha = 0x20;

            m_lpfnAlphaBlend(*pDC,
                             (rc.Width() - b.bmWidth) / 2,
                             (rc.Height() - b.bmHeight) / 2,
                             b.bmWidth,
                             b.bmHeight,
                             DC,
                             0,
                             0,
                             b.bmWidth,
                             b.bmHeight,
                             bf);
            DC.RestoreDC(s);
        }
    }
	
    return TRUE;
}

You may be right
I may be crazy
-- Billy Joel --

Within you lies the power for good - Use it!

Rozis27-Jun-09 1:22

27-Jun-09 1:22

Tnx for an answer..

I spelled your code character by character and it seems that i do essentially the same. So this leaves me to ask you some stupid questions:

1. Is bf.BlendOp = AC_SRC_OVER; the same as: bf.BlendOp = 0; ??
2. To my opinion you do nothing to add an alpha channel to your bitmap. Thus your bitmap has no alpha channel - do you agree on that?
3. Because i use another language then you: what does int s = DC.SaveDC() ; do? Is this one essential to Alphablend?

Thanks
Rozis

PJ Arends27-Jun-09 6:08

27-Jun-09 6:08

Rozis wrote:
1. Is bf.BlendOp = AC_SRC_OVER; the same as: bf.BlendOp = 0; ??

from wingdi.h:

#define AC_SRC_OVER                 0x00

Rozis wrote:
2. To my opinion you do nothing to add an alpha channel to your bitmap. Thus your bitmap has no alpha channel - do you agree on that?

From MSDN[^]:

When the AlphaFormat member is AC_SRC_ALPHA, the source bitmap must be 32 bpp. If it is not, the AlphaBlend function will fail.

So you are correct, I did not worry about the alpha channel. I just set the AlphaFormat value to zero.

Rozis wrote:
3. Because i use another language then you: what does int s = DC.SaveDC() ; do? Is this one essential to Alphablend?

See http://msdn.microsoft.com/en-ca/library/dd162945(VS.85).aspx[^] and http://www.flounder.com/savedc.htm[^]

You may be right
I may be crazy
-- Billy Joel --

Within you lies the power for good - Use it!

Rozis27-Jun-09 8:25

27-Jun-09 8:25

hmmm... im out of questions but it still doesn't run. This my code: (warning: this is not C-code, but i'll explain when needed)

hMemDC:=CreateCompatibleDC(hdc) // ':=' is used as '=' in C
if hMemDC!=NULL_PTR
  hbitmap:=CreatecompatibleBitmap(hdc,w,h)
  hold:=SelectObject(hMemDC,hBitmap)
  Rectangle(hmemDC,0,0,w,h)
  blendfunc.BlendOp:=0       // blendfunc is a structure BlendOp a member of this structure
  blendfunc.BlendFlags:=0
  blendfunc.SourceConstantAlpha:=128 //half transparent
  blendfunc.AlphaFormat:=0
  AlphaBlend(hdc,x,y,w,h,hMemDC,0,0,w,h,@blendfunc) // Here's the troublemaker
//StretchBlt(hdc,x,x,w,h,hMemDC,0,0,w,h,SRCCOPY)
//BitBlt(hdc,x,x,w,h,hMemDC,0,0,SRCCOPY)
  SelectObject(hMemDC,hold)
  DeleteObject(hBitmap)
  DeleteDC(hMemDC)
endif

When i use StretchBlt() or BitBlt() instead it works (altough not transparent). I checked if x,y,w and h are possitive - they are. Think you may ask whats '@blendfunc'. It means 'pointer to structure'. Use this construct for years so must be correct (for example in GetClientRect()). Tried a demo-exe from the code project to find out if problem is system related - it worked ok. Checked the prototype and the structure. I must do something really stupid...

Rozis

PJ Arends27-Jun-09 12:14

27-Jun-09 12:14

Rozis wrote:
Think you may ask whats '@blendfunc'. It means 'pointer to structure'.

That is the problem right there. AlphaBlend takes the structure, not a pointer to a structure, as the final parameter.

You may be right
I may be crazy
-- Billy Joel --

Within you lies the power for good - Use it!

Rozis27-Jun-09 23:00

27-Jun-09 23:00

Guess what, you're right!! That was the thing i was overlooking. You're a genius!!!
Did a quick try, made 0x00800000 as the last parameter to Alphablend() and it does the job. And it is lightyears faster then the workaround i made with getpixel(). Problem solved!

The reason i never questioned it, is because a struct is a chunk of memory so i expected this would always be a pointer when used as a parameter. I mean: when a have a struct of let's say 200 bytes and use it as a parameter to a function would this mean these 200 bytes are allocated on the stack?

Saw you're living in Canada, although you have a dutch name. So whenever you are in holland, call me, i have a present for you. Thanks for taking your time.

Rozis

PJ Arends28-Jun-09 19:48