C / C++ / MFC

Display an image from a buffer ???

19-Jul-02 1:34

And this:

int **table;
table = new int*[nb_lines];
for(int i = 0; i < nb_lines; i++) {
   table[i] = new int[nb_columns];
}

I think ...

Hello World!!! Smile | :)

from Raphaël

Raphael Kindt19-Jul-02 1:03

19-Jul-02 1:03

Hi,

I've got a pointer pointing an image (buffer) and I want to display this image in the client area (view)...
How to do this simply ???

Thanks in advance...

Hello World!!! Smile | :)

from Raphaël

C^hris L^osinger19-Jul-02 3:37

C^hris L^osinger

19-Jul-02 3:37

what kind of "buffer" ?

to display anything in Windows, you've got to convert it to a DIB or HBITMAP first.

-c

To explain Donald Knuth's relevance to computing is like explaining Paul's relevance to the Catholic Church. He isn't God, he isn't the Son of God, but he was sent by God to explain God to the masses.
/. #3848917

Fractals!

Raphael Kindt19-Jul-02 3:59

19-Jul-02 3:59

I get an image from a frame grabber...
Thus the image comes from a buffer in the SDRam memory. I think it must exist an Object which encapsulate un pointer which pointe to this buffer...
I think... No?

Hello World!!! Smile | :)

from Raphaël

C^hris L^osinger19-Jul-02 4:00

C^hris L^osinger

19-Jul-02 4:00

do you have any documentation?

most devices will return a DIB (HDIB, LPDIB, LPBITMAPINFO, etc) or an HBITMAP.

-c

Fractals!

Raphael Kindt19-Jul-02 4:46

19-Jul-02 4:46

For the moment I use some code and that works... but I don't find that very clean...

BITMAPINFO* m_pInfo; // is a member of the view

void CArchitectureView::SetBitmapInfoHeader()
{
   unsigned short max_shade = 256;
   m_pInfo = (BITMAPINFO *) malloc (sizeof(BITMAPINFOHEADER) + max_shade * sizeof(RGBQUAD));
   //Initialize the header of the DIB
   m_pInfo->bmiHeader.biBitCount = 8;
   m_pInfo->bmiHeader.biClrUsed = max_shade;		
   m_pInfo->bmiHeader.biSize= 40;
   m_pInfo->bmiHeader.biPlanes = 1;		//always = 1
   m_pInfo->bmiHeader.biCompression = BI_RGB;
   m_pInfo->bmiHeader.biSizeImage = 0;
   m_pInfo->bmiHeader.biXPelsPerMeter = m_pInfo->bmiHeader.biYPelsPerMeter = 0;
   m_pInfo->bmiHeader.biClrImportant = 0;
   m_pInfo->bmiHeader.biWidth = 0;
   m_pInfo->bmiHeader.biHeight = 0;

   //Initialize the color table of the DIB
   for(int i = 0; i < (int)m_pInfo->bmiHeader.biClrUsed; i++) {
      m_pInfo->bmiColors[i].rgbBlue = m_pInfo->bmiColors[i].rgbGreen = m_pInfo->bmiColors[i].rgbRed = i * (BYTE)(256 / m_pInfo->bmiHeader.biClrUsed);
      m_pInfo->bmiColors[i].rgbReserved = 0;
   }
}

I use this method during the Initialize of the view...

void CArchitectureView::OnInitialUpdate() 
{
   CView::OnInitialUpdate();
   if(m_pInfo == NULL)
      SetBitmapInfoHeader();
}

And the OnDraw() methods... pIm is a pointer to the image

void CArchitectureView::OnDraw(CDC* pDC)
{
   CArchitectureDoc* pDoc = GetDocument();
   ASSERT_VALID(pDoc);

   if(pDoc->ImAff == NULL)
      return;
   int H = pDoc->MyImList->GetImage(0).GetHeight();
   m_pInfo->bmiHeader.biWidth = pDoc->MyImList->GetImage(0).GetWidth();
   m_pInfo->bmiHeader.biHeight = -H;

   int mode = pDC->SetStretchBltMode(COLORONCOLOR);
   void* pIm = (void*)(pDoc->ImAff);

   StretchDIBits(pDC->GetSafeHdc(),
      0, 0, m_pInfo->bmiHeader.biWidth, H,
      0, 0, m_pInfo->bmiHeader.biWidth, H,
      pIm, m_pInfo, DIB_RGB_COLORS, SRCCOPY);

   pDC->SetStretchBltMode(mode);
}

yeap... It's clean???

Hello World!!! Smile | :)

from Raphaël

C^hris L^osinger19-Jul-02 6:09

C^hris L^osinger

19-Jul-02 6:09

that's really about as clean as you are going to get. image drawing is not simple. Frown | :(

-c

Fractals!

IPicture image output

jalldridge18-Jul-02 23:52

jalldridge

18-Jul-02 23:52

In my app I have an IPicture and would like to save this as a gif file (I'm aware of licensing restrictions). However I'm unsure of the best way to go around this? I've found lots of info on other image formats but not this one.

Can anybody shed any light on the best way of doing this please.

Thanks

Jas

Virtual List Box

Anonymous18-Jul-02 23:43

Anonymous

18-Jul-02 23:43

I added a ListControl, which is working fine (no Owner data though)
i can put text into it, but weird thing is that i get the text backward.
I.e:

original text:

aaaaaaaaaaaaa
bbbbbbbbbbbbb
ccccccccccccccccc

ListControl text:
cccccccccccccccc
bbbbbbbbbbbb
aaaaaaaaaaaa

this is weird, now the code i put text into the listControl is this (a function i did):

static int VList(char Temp[])
{
if (hList3==NULL) return 1;
LVITEM LvItem;
memset(&LvItem,0,sizeof(LvItem));
//============================
LvItem.mask=LVIF_TEXT;
LvItem.iItem=0;
LvItem.iSubItem=0;
LvItem.pszText=Temp;
SendMessage(hList3,LVM_INSERTITEM,0,(LPARAM)&LvItem);
return 0;
}

it get the text and put it into the ListControl, but backwarded..
now, i saw in a MFC example that in order to make it Virtual ListControl, i need to use the "Owner data" property, but if i check it i get no text in the ListControl,can anyone tell me why and how to fix it ??

thank u all,
Ben

Re: Virtual List Box

Roger Allen18-Jul-02 23:58

Roger Allen

18-Jul-02 23:58

You get the text backwards because you insert every new peice of text at position 0 (top of the list). So if you add aaaa at 0 and then add bbbbb at 0, it pushes aaaaaaaa to 1 etc..

Add the item to the end by getting the count of items in the list:

LvItem.iItem = control.GetItemCount() ;

Roger Allen
Sonork 100.10016

If I had a quote, it would be a very good one.

CArray trouble

silverspoon18-Jul-02 23:36

silverspoon

18-Jul-02 23:36

Hallo! I have a problem concerning adding new elements to a CArray with an CArray inside (which is a pointer)
class cl
{
int i;
CArray<int,int> *ptrint;
CString str;
}
CArray <cl,cl> tst;
when I try to Add a new element to tst, first of all I did the following:
cl toinsert;
toinsert.i = 3;
toinsert.str = _T("asdf");
toinsert.ptrint = new CArray<int,int>
toinsert.ptrint.Add(3);
toinsert.ptrint.Add(4); //2 elements insertet in my int-array
tst.Add(toinsert);
well, this works, but actually the memory of the int-array can not be released by
tst.ptrint->SetSize(0);
and with delete it doesn't work too.
Next thougth was that I get memory just for my "toinsert"-thing and .Add will copy the Data - so I deleted the "toinsert"-thing after inserting but then the int-Array vanishes.
after all I tried to do this:
tst.ptrint = new CArray<int,int>;
which has to work normally but it doesn't !!!

Has anybody a good idea how to solve this problem - I'm getting crazy
thanks a lot out there

Martin Ziacek19-Jul-02 0:03

Martin Ziacek

19-Jul-02 0:03

CArray is a template, you cannot use it that way.

You have to declare it in a way, when compiler will know type to insert into it, e.g:

CArray <cl, cl&> tst;

Alexandru Savescu19-Jul-02 0:09

Alexandru Savescu

19-Jul-02 0:09

I think you are better off if you use a std::vector of std::vector. I have used them successfully.

Best regards,
Alexandru Savescu

silverspoon19-Jul-02 0:22

silverspoon

19-Jul-02 0:22

thanks a lot you guys, i'll try the std:vector asap, for now i have solved my problem by using a struct cl instead of class cl where i have direct access to my pointer and where i can get mem whereever i want.
i know i have made an error above, its a CArray <t,t> a.s.o.

thank you !