C / C++ / MFC Discussion Boards

Rob Caldecott13-Jul-03 23:17

13-Jul-03 23:17

Bad programming practise IMHO - you should only use ! on a boolean expression - not on something that returns an int. I would always write code like this as "if (strcmp(psz1, psz2) == 0" or "if (strcmp(psz1, psz2) != 0".

Just my 2c.

When I am king, you will be first against the wall.

Re: !strcmp

Ryan Binns13-Jul-03 23:22

Ryan Binns

13-Jul-03 23:22

Robert Edward Caldecott wrote:
Bad programming practise IMHO

Agreed.

Ryan

"Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

Re: !strcmp

DaveE9th13-Jul-03 23:29

DaveE9th

13-Jul-03 23:29

Thank you all, I get it now. I was thinking that the strcmp function would return a 1 for a match, not a 0. Is there a particular reason for this? Thanks again, Dave

Big Grin | :-D

"The man who reads nothing is better educated than the man who reads nothing but newspapers."- Thomas Jefferson

Re: !strcmp

Ian Darling13-Jul-03 23:33

Ian Darling

13-Jul-03 23:33

strcmp returns a negative or positive number if the first string is less than or greater than the second string (check which way round they actually are in MSDN), which is why it returns 0 for equality.

--
Ian Darling

get mouse coordinate

henli13-Jul-03 18:36

henli

13-Jul-03 18:36

I am trying to get the mouse coodinate on picture box/control while mouse click accour on it in order to draw some circle based on that coordinate. But so far I can get it. I can get the mouse coordinate only on form itseft not on picture box.

Any one can help me?I really appreciate it, thank you.

Re: get mouse coordinate

Nick Parker13-Jul-03 19:13

Nick Parker

13-Jul-03 19:13

Try GetCursorPos() function, you just pass it a pointer to a POINT structure.

-Nick Parker

Re: get mouse coordinate

Ryan Binns13-Jul-03 22:53

Ryan Binns

13-Jul-03 22:53

If you're using MFC, use MapWindowPoints(), if you're not using MFC, using ClientToScreen(), to convert from the form to the screen coordinates, and ScreenToClient() to convert from the screen to the control coordinates.

Hope this helps,

Ryan

"Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

how can i add toolbar to activex control??

logologologo13-Jul-03 16:48

logologologo

13-Jul-03 16:48

how can i use toolbar control in my activex control.
thanks! every one

a vary hard question ---about using OpenDriver()

gdzfy13-Jul-03 16:09

gdzfy

13-Jul-03 16:09

see:
http://www.codeproject.com/script/comments/forums.asp?msg=550923&forumid=1647#xx550923xx

and

http://www.codeproject.com/script/comments/forums.asp?msg=549039&forumid=1647#xx549039xx
now my test result is :
the clean app works, but the clean DLL does not.

a good man in china

what is the different between the the framewrok of the DLL and appliacation in vc++

gdzfy13-Jul-03 14:54

gdzfy

13-Jul-03 14:54

what is the different between the the framewrok of the win32 DLL and that of the win32 appliacation in vc++ 6.0 ??I encountered a problem ,and i have to know that,where can i found the information.??

a good man in china

Re: what is the different between the the framewrok of the DLL and appliacation in vc++

John M. Drescher13-Jul-03 15:10

John M. Drescher

13-Jul-03 15:10

Your question really does not make sense. As I said two days ago when you asked a similar question, a DLL is a part of an application. However this knowledge will in no way help you solve a problem with your DLL or your application.

John

Re: what is the different between the the framewrok of the DLL and appliacation in vc++

John M. Drescher13-Jul-03 15:11

John M. Drescher

13-Jul-03 15:11

gdzfy wrote:
I encountered a problem

Could you explain your problem? Maybe we can help.

John

Re: what is the different between the the framewrok of the DLL and appliacation in vc++

gdzfy13-Jul-03 15:21

gdzfy

13-Jul-03 15:21

yes,two days ago i intented to ask this question ,but i wrote the wrong sentence and ask the thing i had know.
well,here is my problem: I am making the SDK programing----writing a dll,and I have to open a driver(impeg32.dll) firstin order to use the API.THAT is I have to use the
Opendriver() In my dll,but it fails.
Maybe you can see the thread i had askde three days ago:
http://www.codeproject.com/script/comments/forums.asp?msg=548929&forumid=1647#xx548929xx
thank you very much!

a good man in china

Re: what is the different between the the framewrok of the DLL and appliacation in vc++

John M. Drescher13-Jul-03 15:52

John M. Drescher

13-Jul-03 15:52

Your question makes sense now. Thanks. You are asking what is different about a win32 dll from a win32 application that could cause the dll not to be able to open a device driver using OpenDriver() while the application can. I'm sorry I too have never used the OpenDriver() command.

John

Re: what is the different between the the framewrok of the DLL and appliacation in vc++

gdzfy13-Jul-03 15:55

gdzfy

13-Jul-03 15:55

well,that is all right.

a good man in china

Clickety Police

John M. Drescher13-Jul-03 15:57

John M. Drescher

13-Jul-03 15:57

Here is the link that you can click on:
http://www.codeproject.com/script/comments/forums.asp?msg=548929&forumid=1647#xx548929xx[^]

John

A simple C solution

eggie513-Jul-03 14:49

eggie5

13-Jul-03 14:49

How do I make a simple C solution in VS.NET??? just a C console application...

/\ |_ E X E GG

Re: A simple C solution

C^hris L^osinger13-Jul-03 16:42

C^hris L^osinger

13-Jul-03 16:42

doesn't look like there is a way.
maybe you could start with a C++ console app then take out the stuff you don't need, and add a .C file.

i needed to start a Win32 DLL in VS.Net last week. there's no way to do that either. so, i started on in VC6, then opened it in VS.Net.

-c

CheeseWeasle

Re: A simple C solution

Nick Parker13-Jul-03 19:15

Nick Parker

13-Jul-03 19:15

Chris Losinger wrote:
i needed to start a Win32 DLL in VS.Net last week. there's no way to do that either. so, i started on in VC6, then opened it in VS.Net.

Sounds like a hassle. Dead | X|

-Nick Parker

Re: A simple C solution

Joe Woodbury14-Jul-03 9:07

Joe Woodbury

14-Jul-03 9:07

First, I assume you mean a simple C++ console app. No reason to use C.

To do this in VC.NET 2003 (2002 will be similar):

Click File|New|Project.

Click on "Visual C++ Projects"

In the right hand list box, scroll down to "Win32 Console Project"

Enter the name and location in the appropriate spots and click "OK".

(You can also select "Win32 Project." When the wizard comes up, click on "Application Settings" on the left and then "Console Application", and any other options on the right.)

Wininet and php scripts

georgiek5013-Jul-03 13:03

georgiek50

13-Jul-03 13:03

I would like to write a short application using Wininet that interacts with search engines of websites that use php scripts and specifically the POST method to search their database. Where can I find some information concerning these topics?

Problem with AnimatePalette

BillA13-Jul-03 11:44

BillA

13-Jul-03 11:44

I'm having a problem using AnimatePalette. My application's main window is a CFrameWnd subclass with a CView subclass. The CView handles WM_PALETTECHANGED and WM_QUERYNEWPALETTE. All of the graphics in the view are done in child windows. These windows are all of a subclass of CWnd. All are transparent, as they are graphics overlaid on to frame-grabbed video displayed by the CView. Some of the overlaid graphics have to blink on and off, so the parent (CView) window calls SetTimer in its WM_CREATE handler and has a WM_TIMER handler which switches the blinking palette entries from the background color (black in this case) to the foreground color (green in this case) and back by using AnimatePalette. The child windows Select and Realize the palette in their WM_PAINT handlers. This all seems to work just fine.

I have blinking graphical entities in two of the child windows. If I hide one of the windows, the entities in the other window STOP blinking! If they were "off" (i.e. background color) when I hid the sibling window, they never come back "on" (i.e. foreground color) or if "on", they never go back "off" until I show the hidden sibling window again. (I've set up an WM_KEYUP handler to hide/show the child windows).

What am I doing wrong? My CPalette is a data member of the parent (CView) window. Each of the child (CWnd) windows has a data member which holds a pointer to the CPalette object in the parent.

Bill A.

Alignment

gregs13-Jul-03 9:18

gregs

13-Jul-03 9:18

I have been aligning(16 byte) certain data types to allow me to use SSE commands on them, and have no problems apart from when I create instances of them on the stack, where I get a runtime exception in debug mode, complaining about the stack being corrupted when I leave the function that uses it, ie

void SomeProc()<br />
{<br />
  Vector vec;  // the aligned type<br />
<br />
  // ..  do stuff with vector ..<br />
<br />
} // <- stack corrupted

so I'm having to do

void SomeProc()<br />
{<br />
  Vector *vec=new Vector;  // the aligned type<br />
<br />
  // ..  do stuff with vector ..<br />
<br />
  delete vec;<br />
<br />
} // okay

which is time consuming. I have implemented ways to speed it up, but I would like to know if there's a simpler way.

Thanks,
G

Re: Alignment

Joaquín M López Muñoz13-Jul-03 11:47

Joaquín M López Muñoz

13-Jul-03 11:47

AFAIK changing the default alignment for a structure mustn't cause stack corruption issues. Maybe if you post the code for SomeProc we can spot the root of the problem.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: Alignment

gregs13-Jul-03 12:31

gregs

13-Jul-03 12:31

Right: the class vector is defined thus:

// alignment for SIMD instructions<br />
#define jALIGN	__declspec(align(16))<br />
<br />
// The m_vector data structure for optimisation<br />
typedef jALIGN struct VecData {<br />
				float x;<br />
				float y;<br />
				float z;<br />
				float w;<br />
			}VecData;<br />
<br />
class Vector {<br />
public:<br />
// stuff<br />
protected:<br />
	VecData m_vec;		// vector data<br />
};

and the test procedure is

Vector vec(1.0f,1.0f,1.0f,1.0f);<br />
Vector vans=mat1*vec;<br />
PVec(vans);

Where PVec just prints out the value of the vector.

mat1 is a matrix defined thus:

// the actual matrix type<br />
typedef float jALIGN jMat[16];<br />
<br />
class Matrix {<br />
public:<br />
// stuff<br />
protected:<br />
	jMat m_mat;<br />
};

and the transformation function for the non-SIMD version (it happens on all versions) is

Vector Matrix :: operator * (Vector &v)<br />
{<br />
	float x,y,z,w;		// temporary vector<br />
	float vx,vy,vz,vw;	// the parts of v<br />
<br />
	// get the parts of v<br />
	v.Get(vx,vy,vz,vw);<br />
<br />
	// transform vector<br />
	x=( vx*m_mat[jMatIdx(0,0)] ) +<br />
					( vy*m_mat[jMatIdx(1,0)] ) +<br />
					( vz*m_mat[jMatIdx(2,0)] ) +<br />
					( vw*m_mat[jMatIdx(3,0)] );<br />
	y=( vx*m_mat[jMatIdx(0,1)] ) +<br />
					( vy*m_mat[jMatIdx(1,1)] ) +<br />
					( vz*m_mat[jMatIdx(2,1)] ) +<br />
					( vw*m_mat[jMatIdx(3,1)] );<br />
	z=( vx*m_mat[jMatIdx(0,2)] ) +<br />
					( vy*m_mat[jMatIdx(1,2)] ) +<br />
					( vz*m_mat[jMatIdx(2,2)] ) +<br />
					( vw*m_mat[jMatIdx(3,2)] );<br />
	w=( vx*m_mat[jMatIdx(0,3)] ) +<br />
					( vy*m_mat[jMatIdx(1,3)] ) +<br />
					( vz*m_mat[jMatIdx(2,3)] ) +<br />
					( vw*m_mat[jMatIdx(3,3)] );<br />
<br />
	// tidy<br />
	x/=w;<br />
	y/=w;<br />
	z/=w;<br />
	w=1.0f;<br />
<br />
	// and return<br />
	return Vector(x,y,z);<br />
}

where jMatIdx is

// to get [x][y] capability without a multiplication<br />
#define jMatIdx(x,y)	( ((y)<<2) + (x) )

Hope this helps.

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