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Re: Intellisense question - function headers

Maxwell Chen6-May-06 16:06

6-May-06 16:06

OK. There are (at least) three kinds:

1) Intellisense:
  This one is --- When you are typing, and you hit the [Complete word], then it pops up a dropdown list control.
  In VC++ 6, you may press [Enter] to select the 1st match.
  In VC++ 2003, it does not select any item by default. Thus [Enter] gives you newline. When you [Keydown], it selects an item. Then press [Enter] completes that word.

2) Parameter information:
  When you type '(' right after a function token, it pops up for the prototype(s) of the function. When there are more than one, you have to click the tiny arrow buttons. There is no hot key for that.

3) Quick type information:
  When mouse hovers on some token, it prompts you the type.

Maxwell Chen

Re: Intellisense question - function headers

Gary R. Wheeler7-May-06 4:22

Gary R. Wheeler

7-May-06 4:22

Unfortunately Intellisense doesn't support this, at least in VS2003. I don't know about VS2005; maybe they fixed it (one can hope).

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Change Gamma Ramp

Robsori6-May-06 4:41

Robsori

6-May-06 4:41

Does anybody have sample code in C++ to change the gamma ramp. I want to set the colours, contrast and brightness of an LCD panel.
Similar with: http://www.majorgeeks.com/Gamma_Panel_d2796.html

Regards.

Re: Change Gamma Ramp

C^hris L^osinger6-May-06 16:10

C^hris L^osinger

6-May-06 16:10

gamma adjustment is a simple mapping:

double fGammaInverse = 1.0 / gamma;
for each pixel
  for each color component
    pixVal = (BYTE) (256 * pow ((double)pixVal / 256.0, fGammaInverse));

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Re: Change Gamma Ramp

Robsori6-May-06 21:33

Robsori

6-May-06 21:33

Thank you for your answer.
I've saw the example on NirSoft web site http://www.nirsoft.net/vc/change_screen_brightness.html
where I can make the screen brighter or darker but how can increase or decrease the intensity of the red/green/blue components?
For example: How can to increase only the blue component in all RGB values to add more blue color to the entire display?

Robert.

GDI/GDI+ In Flight Simulator 2004

seefer6-May-06 3:46

seefer

6-May-06 3:46

Hi all.

I've seen some very helpful GDI/GDI+ arrticles on here which have helped me immensely. However I have what may be an unusual question.

I'm an avid Flight Simulator 2004 fan and have started to dabble in creating my own airfcraft avionics systems and gauges written in C/C++. However, I'm finding that in order to implement some of the more complex avionics systems seen in many 'glass cockpit' aircraft today, I need a fast 2D vector drawing approach.

FS2004 implements user-created avionics displays and gauges as DLLs that expose a number of callback functions in order to draw the graphics. However, it seems that FS2004 is limiting the gauge drawing graphics to a GDI/GDI+ surface, even though FS2004 does actually use Direct3D for the main external display showing the terrain.

I have the following questions:

Is there a way to draw to a GDI/GDI+ suface using hardware accelerated DirectX calls? I have noticed that in the gdiplus.h header file there is a declaration for a IDirectDrawSurface7 structure, hence my theory that I may be able to use DirectX instead of GDI to draw to the surface that FS2004 uses for gauges.

If not, am I better off sticking to GDI rather than GDI+ as GDI allegedly makes more use of hardware acceleration than GDI+?

Finally, can anyone recommend a high performance, open source, realtime vector drawing API that I could turn to in order to provide the actual line and 2D shape drawing routines to represent some of today's avionics displays?

Many thanks

DE

Re: GDI/GDI+ In Flight Simulator 2004

Jim Crafton6-May-06 17:48

Jim Crafton

6-May-06 17:48

seefer wrote:
Is there a way to draw to a GDI/GDI+ suface using hardware accelerated DirectX calls?

I could be wrong but I don't think so. However you may want to check out this:
http://antigrain.com/[^]
It's for C++ and I've used it with quite nice results.

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Re: GDI/GDI+ In Flight Simulator 2004

seefer7-May-06 2:11

seefer

7-May-06 2:11

Much obliged Jim.

I've taken a brief look Antigrain and it's certainly a nice piece of work and I'll be taking a more in depth look at it. However my initial imppression is that it is largely written for portability and not high performance. This is the right choice on the part of the author because Antigrain appears to be a general foundation on which to build that serves to clearly explain the algorithms used to improve vector drawing presentation quality.

Am I wrong in this assumption? In your work with it have you found it provides far greater drawing speed than GDI, which is what I need in an API for my projects. All of the Antigrain examples seem largely geared towards graphics 'document' type applications rather than real-time animation rendering.

Can you recommend any other APIs of a more 'language-specific' nature that are created to provide high performance rendering routines in it's implementation as well as general drawing algorithms?

Thanks.

convert int to string

sunita ramesh6-May-06 2:58

sunita ramesh

6-May-06 2:58

Hi all,
Please any one tell me

How to convert int to string ,string to int in vc++.

thanks

sunita

Re: convert int to string

Stephen Hewitt6-May-06 3:10

Stephen Hewitt

6-May-06 3:10

One way:

ostringstream ss;
ss << "The number is " << 42;
string s = ss.str();

There are many ways. You didn't really explain the context properly so I assumed that by "string" you meant STL strings. Note that the above code assumes that you've included <string> and <sstream> and have put using namespace std; somewhere appropriate.

Steve

Re: convert int to string

sunita ramesh6-May-06 18:37

sunita ramesh

6-May-06 18:37

hi,
Thanks for ur reply.

Actually i am storing picture number in
int picno;
I need to convert this picture number to string.

can i able to convert?

sunita

Re: convert int to string

Stephen Hewitt6-May-06 19:36

Stephen Hewitt

6-May-06 19:36

Almost exactly the same as the previous example:

ostringstream ss;
ss << picno;
string s = ss.str();

Steve

Re: convert int to string

_AnsHUMAN_ 6-May-06 3:59

_AnsHUMAN_

6-May-06 3:59

have a look at atoi() and itoa()

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Re: convert int to string

ThatsAlok6-May-06 22:45

ThatsAlok

6-May-06 22:45

sunita ramesh wrote:
How to convert int to string ,string to int in vc++.

CString::Format, wsprintf, _ttoi

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Re: convert int to string

Osama E. Adly7-May-06 4:18

Osama E. Adly

7-May-06 4:18

Using MFC:
Convert int to string

<br />
int x=12345;<br />
CString s;         // s = "" (empty string)<br />
s.Format("%d", x); // s = "12345" as string<br />

Convert string to int

<br />
int x=0;<br />
CString s="12345";<br />
x = atoi(s);       // x= 12345 as integer<br />

Osama E. Adly

Re: convert int to string

Hamid_RT7-May-06 18:16

Hamid_RT

7-May-06 18:16

see
http://msdn2.microsoft.com/en-us/library/yd5xkb5c.aspx[^]

Text exchange VB 16 bit / VC 32

Dihirk6-May-06 2:53

Dihirk

6-May-06 2:53

Hello

I am trying to exchange data between VB4 (16 Bit) and vc 6 using OLE. I have a problem when I try to modify string data in VB which need to be sent to c.
I can get a LPSTR from VB completely but I can not modify that in the c and give that back. AS far as I understand that would be possible with a BSTR *. But I could not get that to work in nether way.
In the following example the VB code calls the c++ code and the messagebox just shows one character 'T'. Thats all.
What am I doing wrong?
And what do I need to do to be able to modify the text in the c code so that the modification can be seen in the VB code after the call

Thanks in advance

Dirk

//////////////////////
// c++
//////////////////////

void TestDlgAutoProxy::test(BSTR FAR* text)
{
TCHAR szFinal[255];
_stprintf(szFinal, _T("%s"), (LPCTSTR) *text);
AfxMessageBox(szFinal);
}

///////////////////////////
// VB code
///////////////////////////
Private Sub Command2_Click()
Dim text As String
Dim x As Variant
t = "Text from VB to C"
x = oAuth.test(t)
MsgBox t
End Sub

Re: Text exchange VB 16 bit / VC 32

Milton Karimbekallil6-May-06 5:16

Milton Karimbekallil

6-May-06 5:16

BSTR is a COM type, you cant simply type cast that to wchar_t. Try the following.

_bstr_t bstr(*text);<br />
AfxMessageBox(bstr);

For details about string conversions, you can have a look at Michael Dunn's articles:

http://www.codeproject.com/string/cppstringguide1.asp[^]
http://www.codeproject.com/string/cppstringguide2.asp[^]

cheers milton.

Re: Text exchange VB 16 bit / VC 32

Dihirk6-May-06 5:34

Dihirk

6-May-06 5:34

Thanks Milton,

that way works fine.

How can I modify -> text, so that the change can be used in the calling function?

It must be very basic but how can I just change that variable text?

Like in the old c it would be

sprintf (text, "Thats what I want");

All other data exchange was no problem .. (yet Wink | ;-)

)

Thank you
Dirk

Re: Text exchange VB 16 bit / VC 32

Milton Karimbekallil6-May-06 5:47

Milton Karimbekallil

6-May-06 5:47

You must be able to modify the value of text as you are receiving it into a BSTR pointer. So you can write the following to modify it.

_bstr_t bstr(*text);<br />
bstr += _bstr_t(" appened string here");<br />
AfxMessageBox(bstr);

No need to change the Vb code. Since by default VB passes function parameters by reference.

cheers...milton.

Re: Text exchange VB 16 bit / VC 32

Dihirk6-May-06 22:55

Dihirk

6-May-06 22:55

Thanks Milton..

that works.

Dirk

Re: Text exchange VB 16 bit / VC 32

Dihirk7-May-06 2:47

Dihirk

7-May-06 2:47

Hi Milton,

there is one question left.

Is there a way to convert that bstr into a character string?
So I need a modification also in the other way round.

cheers
Dirk

Re: Text exchange VB 16 bit / VC 32

Maxwell Chen7-May-06 2:53

Maxwell Chen

7-May-06 2:53

Dihirk wrote:
convert that bstr into a character string?

sprintf(...) ?!

Maxwell Chen

Re: Text exchange VB 16 bit / VC 32

Dihirk7-May-06 3:11

Dihirk

7-May-06 3:11

Hi Maxwell,

yes, your are right it must be that easy...

I used the wrong format

sprintf (str, "%s", *bstr);

which just resulted in the first character of ther bstr..

correct is

sprintf (str, "%S", *bstr);

Your answer made me sure to look further at the point where I was before.

Thanks

Dirk

Class Bascis Question...

HakunaMatada6-May-06 1:55

HakunaMatada

6-May-06 1:55

Hi All,

The blocks of code shown below basically do the same thing...

CTest1 c ;<br />
c.Hello() ;

CTest1 *t ;<br />
t = new CTest1() ;<br />
t->Hello() ;<br />
delete t ;<br />
t = NULL ;

They call the Hello() function in CTest1.
My Question is, when should we use them?
What is the advantage of one over the other?
Are there specific instances where one is preferred over the other?

Thanks...

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