C / C++ / MFC Discussion Boards

mostafa_pasha19-May-04 10:26

19-May-04 10:26

i use OpenGL to draw 24-Bitmap Image to screen. in OpenGL image data is BGR not RGB!
so after read image data i must swap Red with Blue.
so i must access image data . i see that if my bitmap compressed and i try to read file
with iostream class and read image data , i can not convert it to raw data.
so i try use BITMAP.bmBits and copy image data to new array and then swap that.

Thanks a lot for your attention.

Re: Accessing Image Data(BITMAP)

John R. Shaw19-May-04 11:38

John R. Shaw

19-May-04 11:38

Bitmap image data is stored in (memory and file) BGR order.

INTP

Re: Accessing Image Data(BITMAP)

John R. Shaw19-May-04 11:55

John R. Shaw

19-May-04 11:55

If you wish to access the data directly, this is probably not the best method. If you apply a typecast to bmBits the error will go away but the code will still be wrong.

// accessing data directly, provide bmBits actualy is
// pointing to the image data and not NULL.
unsigned char* pData = (unsigned char*)bmBits;
// manimpulate bits
....

// Making a copy of the image data
// The following is overkill
if( bm.bmBits )
{
    DWORD dwImageSize = bm.bmHeight * bmByteWidth; // not bmWidth
    unsigned char* pData = new unsigned char[dwImageSize];
    if( pData )
    {
        memcpy(pData,bm.bmBits,dwImageSize);
        // manipulate pData contents
        .....
        memcpy(bm.bmBits,pData,dwImageSize);
        delete [] pData;
    }
}

There are articles at CP on manipulating bitmaps directly as well at totorials. The book "Programming Windows" by Charles Petzold covers bitmaps and DIB Sections extensively.

Good Luck!

INTP

Re: Accessing Image Data(BITMAP)

Christian Graus19-May-04 12:16

Christian Graus

19-May-04 12:16

In addition to all of this, it's much easier to use a DIBSection wrapper, or use GDI+.

Christian

I have drunk the cool-aid and found it wan and bitter. - Chris Maunder

Re: Accessing Image Data(BITMAP)

mostafa_pasha19-May-04 16:25

mostafa_pasha

19-May-04 16:25

thanks a lot John with best wishes for your answering..
about format of BITMAP i know if i wanna use in OpenGL i must swap R with B.
Is that right?

Christian thanks for your attention , but GDI+ is not for 3D.i use OpenGL for this
purpose so i can not use GDI+ when i Use dubbleBuffering in OpenGL.
Thanks a lot.

Re: Accessing Image Data(BITMAP)

Christian Graus19-May-04 16:45

Christian Graus

19-May-04 16:45

mostafa_pasha wrote:
i know if i wanna use in OpenGL i must swap R with B.

Only if OpenGL stores the bits in RGB. Windows always used BGR.

Christian

I have drunk the cool-aid and found it wan and bitter. - Chris Maunder

Accessing Image Data(BITMAP)

mostafa_pasha19-May-04 9:29

mostafa_pasha

19-May-04 9:29

Hello,

Setting Background Color

lostris19-May-04 9:02

lostris

19-May-04 9:02

HI everybody!

I need to know how to set the background color of a view.

I have tried using the 'SetBkColor(COLORREF color)' function but I can't get it to work.

I called the following line in the Draw function in class CView.

pDC->SetBkColor(COLORREF color);

And the background color remains white.

Can anybody tell me what to do?

_Lostris. . .

Re: Setting Background Color

Maximilien19-May-04 9:24

Maximilien

19-May-04 9:24

you need to "paint" it.

CDC::FillRect or something similir.

Maximilien Lincourt
Your Head A Splode - Strong Bad

Re: Setting Background Color

lostris19-May-04 19:25

lostris

19-May-04 19:25

FillRect has seemed to work just fine at first, but when I have to scroll the image, the part of the view that was not visible at the start is still white.

Do you have any other suggestions?

Thanx
_Lostris.

Re: Setting Background Color

Edwin Brunner19-May-04 9:24

Edwin Brunner

19-May-04 9:24

MSDN says:
"Sets the current background color to the specified color. If the background mode is OPAQUE, the system uses the background color to fill the gaps in styled lines, the gaps between hatched lines in brushes, and the background in character cells. The system also uses the background color when converting bitmaps between color and monochrome device contexts."

So, if you don't write or draw anything, you won't see the desired color.

My suggestion for the 'OnDraw(..)' function:
CRect rect;
GetClientRect(rect);
pDC->FillSolidRect(rect, RGB(255,0,0));

There might be other solutions.

Re: Setting Background Color

Mahendra_78619-May-04 19:05

Mahendra_786

19-May-04 19:05

In a Win32 application you can set the hbrBackground member of the window class structure
typically in "MyRegisterClass".

wcex.hbrBackground = CreateSolidBrush(RGB(255, 0, 0)); // This makes the window red

In MFC you can do something similar in PreCreateWindow.

Due Regards
Mahendra

Setting an edit controls style

monrobot1319-May-04 8:14

monrobot13

19-May-04 8:14

How do you set the style for an edit control? I see that I can use the GetStyle function to retreive it's current style, but how do I change the style during run-time? I tried using SetStyle but apparently that isn't a valid approach.

- Aaron

Re: Setting an edit controls style

David Crow19-May-04 8:17

David Crow

19-May-04 8:17

Use SetWindowLong(hWnd, GWL_STYLE, ...).

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Setting an edit controls style

monrobot1319-May-04 8:48

monrobot13

19-May-04 8:48

Thanks for response. Question: I'm trying to set the ES_PASSWORD style of an edit control..would this be the right way to go about it:

DWORD style = m_wndPassword.GetStyle ();
style |= ES_PASSWORD;
::SetWindowLong (m_wndPassword.GetSafeHwnd (), GWL_STYLE, style);

When I run this the password style doesn't appear to be set at all. Any ideas? Thanks again.

- Aaron

Re: Setting an edit controls style

Andrew Quinn AUS19-May-04 9:03

Andrew Quinn AUS

19-May-04 9:03

Aaron,

If your using MFC then it's easier to use the ModifyStyle method:

m_wndPassword.ModifyStyle(0, 1, ES_PASSWORD);

Hope this helps,
Andy

Re: Setting an edit controls style

David Crow19-May-04 9:17

David Crow

19-May-04 9:17

Perhaps you meant this link?

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Setting an edit controls style

Andrew Quinn AUS19-May-04 9:33

Andrew Quinn AUS

19-May-04 9:33

Thanks David

must have had a mad cut'n'paste moment.

Cheers,
Andy

Re: Setting an edit controls style

monrobot1319-May-04 9:33

monrobot13

19-May-04 9:33

Just tried that Andy, but it wouldn't work either. From the other replies it's looking like I'll need to recreate the control to do this. Thanks for the help though.

- Aaron

Re: Setting an edit controls style

grigsoft19-May-04 9:04

grigsoft

19-May-04 9:04

AFAIK some styles could not be changed at runtime: password/left/right/center.
You have to recreate control.

Igor Green
http://www.grigsoft.com/ - files and folders comparison tools

Re: Setting an edit controls style

David Crow19-May-04 9:19

David Crow

19-May-04 9:19

grigsoft wrote:
AFAIK some styles could not be changed at runtime...

ES_READONLY is another of those styles. But you can use EM_SETREADONLY instead!

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Setting an edit controls style

David Crow19-May-04 9:24

David Crow

19-May-04 9:24

monrobot13 wrote:
Any ideas?

Is the control single or multi-line?

It might not even be possible. Read here.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Setting an edit controls style

monrobot1319-May-04 9:30

monrobot13

19-May-04 9:30

It's single line.

Looking at the replies above am I going to have to recreate the control since it's looking like some styles can't be changed at runtime? I tried ModifyStyle and it didn't work either. Thanks for the help.

- Aaron

Re: Got It Working

monrobot1319-May-04 9:40

monrobot13

19-May-04 9:40

I got it working, but not by modifying the sytle. I used SetPasswordChar and that seems to have changed the style for me. Not sure if that the best way to do it, but it's working. Thanks to everyone who replied for the help.

- Aaron

WaitCommEvent and GetCommMask (and overlapping)

AnotherProgrammer19-May-04 7:51

AnotherProgrammer

19-May-04 7:51

Thanks for the help on my earlier problem.. I have now undertaken rewriting the serial portion of my code to use CreateFile and the like. It's all a bit complicated though, and being new to this, I have a few questions. It starts with overlapping, and also involves WaitCommEvent and GetCommMask. I did a search on the topics and read a few articles that were found, but while they cleared a few things up, they still left me with a few questions unanswered.

First, I understand that SetCommMask allows you to screen for only a few of the events. But after calling SetCommMask to look for only what you want, how does one screen for these events and process them appropriately? I know you can use WaitCommEvent, but in that case, why would you even need GetCommMask? I also need to use overlapping for this program, but I'm not sure how to implement it or even what it actually is (do I need to use the overlapped structure at all?).

I was able to find this piece of example code on MSDN: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/devio/base/monitoring_communications_events.asp

I do not fully understand how it operates, though.

Also, this article was very helpful, to a point: http://www.codeproject.com/system/serial_com.asp

Where I got lost was the huge block of code where he uses the OVERLAPPED structure and the Threadfn function, after which he writes "If you understood the above code , you will understand the whole of this article and the source code provided." Gulp.

As always, the help is very much appreciated.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.