Re: Pixel - C / C++ / MFC Discussion Boards

Krishnakumartg31-Dec-08 1:02

31-Dec-08 1:02

Hi all,

I have a doubt regarding window graphics painting.
As we already know we can draw a rectangle in window.
Ok...
Suppose I am drawing a rectangle with values ( 0, 0, 100, 100 ).

Now my question is,
can I draw a rectangle with values (0.5, 0.75, 100.1, 100.4) or something like that.

Why I am asking because, according to my understanding pixel is the smallest possible drawing resolution.

If it is possible, could you please help to implement that?

Regards,
Krishnakumar

Re: Pixel

CPallini31-Dec-08 2:45

CPallini

31-Dec-08 2:45

GDI primitives accept only integers. You may use GDI+ (see for instance [^]).

Krishnakumartg wrote:
Why I am asking because, according to my understanding pixel is the smallest possible drawing resolution.

The above is obviously true. GDI+ just gives a level of abstraction.
Smile | :)

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]

Re: Pixel

Krishnakumartg31-Dec-08 4:23

Krishnakumartg

31-Dec-08 4:23

Tried the following code.

CDC* pDC = m_Window.GetDC();
Graphics graphic( pDC->GetSafeHdc());

CRect wRect;
m_Window.GetClientRect( &wRect );
wRect.DeflateRect( 0, 0, 1, 1 );
RectF rect( wRect.left, wRect.top, wRect.Width(), wRect.Height());
Color color;
color.SetFromCOLORREF( RGB( 100, 0, 0 ));
Pen pen( color );
graphic.DrawRectangle( &pen, rect );

rect.Inflate( -0.5, -0.5 );
Color color2;
color2.SetFromCOLORREF( RGB( 0, 100, 0 ));
Pen pen2( color2 );
graphic.DrawRectangle( &pen2, rect );

But the graphic.DrawRectangle( &pen2, rect ); draws the rectangle in the next pixel.
Is there anything additional to do to work the floating points?

regards,
Krishnakumar

Re: Pixel

CPallini31-Dec-08 5:22

CPallini

31-Dec-08 5:22

Do you want to break the pixel?
Confused | :confused:

Re: Pixel

Mark Salsbery31-Dec-08 6:18

Mark Salsbery

31-Dec-08 6:18

CPallini wrote:
Do you want to break the pixel?

You can do it, but the stuff that oozes out will make the image blurry...

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: Pixel

Krishnakumartg31-Dec-08 17:07

Krishnakumartg

31-Dec-08 17:07

Mark Salsbery wrote:
You can do it, but the stuff that oozes out will make the image blurry..

If so, what is the change I should make in my code?

Regards,
Krishnakumar

Re: Pixel

Jeremy Falcon1-Jan-09 8:57

Jeremy Falcon

1-Jan-09 8:57

Krishnakumartg wrote:
If so, what is the change I should make in my code?

You'll need to include schematics in your comments on how to build a tiny hammer. Then you'll be able to break just one pixel.

Jeremy Falcon
jeremyfalcon.com[^]

Re: Pixel

CPallini1-Jan-09 6:19

CPallini

1-Jan-09 6:19

Nah: the pixel is the atomic graphic unit and, you known, the atom is indivisible...oops Roll eyes | :rolleyes:

Re: Pixel

Mark Salsbery1-Jan-09 6:22

Mark Salsbery

1-Jan-09 6:22

Don't believe the physicists... You crack open a pixel it oozes GUI goodness! Smile | :)

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: Pixel

Shog⁹1-Jan-09 6:27

Shog⁹

1-Jan-09 6:27

Mark Salsbery wrote:
You crack open a pixel it oozes GUI goodness!

Yeah - GUI Goodness and dangerous radiation. Want all your users growing a third arm, grabbing torches and pitchforks, then storming your office looking for blood? Then go right ahead, crack them pixels, address their internals like it's 1950 and Buck Rogers is gonna save the day in time for supper... 'Cause he ain't, and when your head is on a (pixelated) pike and the guys in bunny suits are cleaning up your mess, don't try using your undead lips to say i didn't warn you...

----

You're right.
These facts that you've laid out totally contradict the wild ramblings that I pulled off the back of cornflakes packets.

Re: Pixel

CPallini1-Jan-09 6:29

CPallini

1-Jan-09 6:29

Mark Salsbery wrote:
Don't believe the physicists...

I know: I'm physicist... Wink | ;)

Re: Pixel

Krishnakumartg31-Dec-08 17:04

Krishnakumartg

31-Dec-08 17:04

Actually I just wanted to know whether it is possible or not? Smile | :)

And if possible how can it do that?

Regards,
Krishnakumar

Re: Pixel

CPallini1-Jan-09 6:24

CPallini

1-Jan-09 6:24

Krishnakumartg wrote:
Actually I just wanted to know whether it is possible or not?

Yes, it is.

Krishnakumartg wrote:
And if possible how can it do that?

For instance, with a hammer.
Big Grin | :-D

Re: Pixel

Krishnakumartg1-Jan-09 17:21

Krishnakumartg

1-Jan-09 17:21

Re: Pixel

C^hris L^osinger31-Dec-08 2:50

C^hris L^osinger

31-Dec-08 2:50

Krishnakumartg wrote:
can I draw a rectangle with values (0.5, 0.75, 100.1, 100.4) or something like that

not without changing your mapping mode and viewport[^].

Krishnakumartg wrote:
according to my understanding pixel is the smallest possible drawing resolution

that is correct; you can not turn on 1/2 of a pixel. the best you can do is let Windows change the coordinate system you use to refer to the physical pixels. so, you can draw that rectangle, and have 100.1 appear at a different location than 100.0. but all you've really done is changed the way Windows interprets your drawing coordinates.

image processing toolkits | batch image processing

External Hard Disk

rdop31-Dec-08 0:58

rdop

31-Dec-08 0:58

Hi All
I have connected external (USB ) Hard Disk of 250 GB,which have been detected as local drive by system.How can i recognize it as external (Logical) drive?

Re: External Hard Disk

Theo Buys7-Jan-09 2:11

Theo Buys

7-Jan-09 2:11

Use GetLogicalDrives(), GetLogicalDriveStrings() and GetDriveType().

Getting the thread count of a process

Green Fuze31-Dec-08 0:06

Green Fuze

31-Dec-08 0:06

Hey everybody!

How can I get the thread count of a process - like in task manager?
I have a handle to that process, but I can't find a way to get the count of the running threads.

Does anyone know how to do that?

Thanks!!!!

Re: Getting the thread count of a process

Jijo.Raj31-Dec-08 0:39

Jijo.Raj

31-Dec-08 0:39

First get the process id from your handle by calling GetProcessId(). Then Iterate the process in system[^] and locate your process by matching the process id. Then you'll get the total count of threads from PROCESSENTRY32.cntThreads.

Regards,
Jijo.

_____________________________________________________

http://weseetips.com[^] Visual C++ tips and tricks. Updated daily.

Re: Getting the thread count of a process

Green Fuze31-Dec-08 1:32

Green Fuze

31-Dec-08 1:32

Thanks!

<h3>get the .exe current path</h3>

Mustapha Rédouane30-Dec-08 23:15

Mustapha Rédouane

30-Dec-08 23:15

need a code returning the current path of my exe
thx

Re: get the .exe current path

enhzflep30-Dec-08 23:27

enhzflep

30-Dec-08 23:27

GetModuleFileName

Re: get the .exe current path

Krishnakumartg31-Dec-08 3:23

Krishnakumartg

31-Dec-08 3:23

You can use _pgmptr.

Regards,
Krishnakumar

Doubt in CTreeCtrl

KASR130-Dec-08 23:12

KASR1

30-Dec-08 23:12

I have created a tree control and added few items in it.
And i have used TVN_SELCHANGED notify message as below.
But i am not able to get item names using LPNMTREEVIEW structure instead its showing junk chars.

void CMyDlg1::OnTvnSelchangingTreectrl(NMHDR *pNMHDR, LRESULT *pResult)
{
   LPNMTREEVIEW pNMTreeView = reinterpret_cast<lpnmtreeview>(pNMHDR);

   CString str = pNMTreeView->itemNew.pszText; //junk values?
   
   CString str1 = m_TreeCtrl.GetItemText(m_TreeCtrl.GetSelectedItem()); // OK

   .....
}</lpnmtreeview>

Re: Doubt in CTreeCtrl

enhzflep30-Dec-08 23:24

enhzflep

30-Dec-08 23:24

According to MSDN, that is to be expected.

"The itemOld and itemNew members of the NMTREEVIEW structure are TVITEM structures that contain information about the previously selected item and the newly selected item. Only the mask, hItem, state, and lParam members of these structures are valid. The stateMask members of the TVITEM structures specified by itemOld and itemNew are undefined on input."

TVN_SELCHANGED Notification[^]

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