C / C++ / MFC

Re: CPU usage going to 100% full from running a DDE using VC++

9-Aug-04 4:00

swerajan wrote:
...and the CPU usage reaches 100%.

Of which process?

"When I was born I was so surprised that I didn't talk for a year and a half." - Gracie Allen

swerajan9-Aug-04 4:03

swerajan

9-Aug-04 4:03

when i run my application(ddemlsrv.exe) the csrss.exe process gradually uses upto 80% of the CPU along with the ddemlsrv.exe it reaches 100%. I don't understand what is wrong with the program.

How do I read .cda file from a CD? /w Win 32 API

Link26009-Aug-04 3:34

Link2600

9-Aug-04 3:34

I've been trying to write a MP3 ripper myself, because
I can't find any good one online. I have been searching
for this similar project for a while, all I can find is
encoder.

While I do need an encoder, the first step I need is to
know how do I read a .cda file from a CD? I've been wondering
if fread() would work in this case, because I don't even
know if .cda is a binary file or not? Is it a binary file?

Please help me, or if you know similar project elsewhere,
would you please share it?

-----------------------------
C++ without virtual functions is not OO. Programming with classes but without dynamic binding is called "object based", but not "object oriented".

selection problem ---

nainakhawaja9-Aug-04 2:35

nainakhawaja

9-Aug-04 2:35

I m facing a problem in my project. Actually i have drawn a line in VC++ using moveTo and lineTO function. now if user double clicks the line a dialog box should be open. What the problem is to check wheather the user clicks on the line or not. for this i have created the boundry rectangle of the line i.e if the statement is like
pDC->MoveTo(x1,y1);
pDc->LineTo(x2,y2);
then the boundry rect will be Rectangle(x1,y1x2,y2). in this case the tolerance level(clickedpoint+-value) is very high. if user click say 5-10 Points far from the line still the dialog box will be opened. i want to reduce the size of the boundary rect. keep in mind there should not be any effect on the orentation of line
Let me know plzzz if any one have solution to this problem Cry | :((

David Crow9-Aug-04 2:44

9-Aug-04 2:44

Once the rectangle has been defined, and you know the point at which the mouse was clicked, just use PtInRect().

"When I was born I was so surprised that I didn't talk for a year and a half." - Gracie Allen

nainakhawaja9-Aug-04 2:52

nainakhawaja

9-Aug-04 2:52

this will work very well in the case if line is at the angle of 90 or 180 but if the line is at the angle of 60 or 45 etc in such cases the rectangle size will be quite big... i want to reduce that size Frown | :(

Stlan9-Aug-04 3:07

Stlan

9-Aug-04 3:07

I believe you simply should calculate the distance between your line and the point where the user has clicked. If the result is lower than a few pixels, then consider the user has clicked on the line.

As a reminder, the distance between a point M(x0,y0) and a line L with equation Ax+By+C=0 is given by the formula:
d = fabs(Ax0+By0+C) / sqrt(A^2 + B^2)

David Crow9-Aug-04 3:16

9-Aug-04 3:16

My bad. I don't work with graphics (e.g., line drawing) so I forget that lines can be more than just horizontal!

"When I was born I was so surprised that I didn't talk for a year and a half." - Gracie Allen

Dream project for D R M receivers

John R. Shaw9-Aug-04 4:08

John R. Shaw

9-Aug-04 4:08

Normaly I would try something simular to Bresenham's line-drawing algorithm to test if a given point falls on or close to the line.

You can try looking at the DRAWCLI sample program in MSDN or at any victor drawing program you can find (with source), since they all needed to do this.

* Another option you could try, would be to use Regions (regions [Win32]) instead of Rectangles to specify the bounding area. A Region can be any shape you want it to be; therefor, you could use the PtInRegion() function to check if line is selected.

Good Luck!

INTP

samandmag9-Aug-04 1:59

samandmag

9-Aug-04 1:59

Hi all ,
I have just discovered this forum.Looks great !!
I am trying to use downloaded files for compiling a program to decode DRM short wave HI FI .Article from ELEKTOR april 2004.
After getting everythig ready including the visual studio service pack 5 and corresponding processor pack (all installed)
The C++ refuses to acknowledge the existance of the declarations in the header files
xmmintrin.h and mmintrin.h and display 4 errors per line of prototype function
(syntax errors)going to over 5000 errors .
I suspect that the processor pack is not enabled by the program or the processor is not selected ??? My system uses an AMD 2600 with DDR(500 K).
Am I doing anything wrong ??
I just downloaded the article on SSE Confused | :confused:

G Brennet

Non-uniform width button in toolbar

gokings9-Aug-04 1:53

gokings

9-Aug-04 1:53

Does anyone know how to have a button on a toolbar which is of a different width than the other buttons?

I have tried using multiple toolbars, and that works, but does not give the result I want when the window is made resized small and then back large again.

Thanks

Re: Non-uniform width button in toolbar

John R. Shaw9-Aug-04 4:35

John R. Shaw

9-Aug-04 4:35

You will need to derive your own class from CToolBar and override some of the functionality.

Here are the notes from my code to fix the drop down arrow problem:

// From: MFC Knowlege base
// BUG: Resizing CToolbar with Dropdown Arrow Buttons Freezes Apps
// ID: Q190501 

// From: Microsoft Systems Journal (Aug98CQA.zip)
// Problem: When using TBSTYLE_EX_DRAWDDARROWS and TBSTYLE_DROPDOWN
//          the right end of the toolbar gets cut off or if it is a
//          vertical toolbar the bottom gets cut off.
// Fix: CalcSize()
//
// From: John R. Shaw (Me)
// Problem: If you only fix CalcSize() the sizing calculations are
//          still wrong because WrapToolBar() uses the same invalid
//          width value used in CalcSize().
// Fix: WrapToolBar()

If you want I could zip up the code and send it to you. There is no garantee that it will solve your problem, but it would give you a good start.

INTP

Re: Non-uniform width button in toolbar

gokings9-Aug-04 7:39

gokings

9-Aug-04 7:39

Thanks for the information and your offer to zip and send me the code.

I will look into the Q article, as well as another possibility.

If I think the zipped code would be useful, I'll send you an email.

Thanks again for the offer.

sizeof(class) question

kfaday9-Aug-04 1:43

Re: sizeof(class) question

9-Aug-04 1:43

Hi, i've got this class

template<class t=""> class pointer
{
private:
T *p;
};

and i get 4 if i do sizeof(pointer).
if i add a static member data, it doesn;t count. why is it that? is it because there's only one copy of that atribute for all the instances of the class?

then, if i add a virtual function (or 2, or 3), i get 8 if i do sizeof(pointer). why is that?

thanks for your help!

gokings9-Aug-04 1:50

gokings

9-Aug-04 1:50

Adding a static member does not affect the size because a static member does not exist in an object (instantiation) of the class. The memory for the static member is allocated in ONE place, not for each object.

The reason that the size increases when you add a virtual method, is that the object needs a pointer to the VTable. This is a table of pointers, one for each virtual method. This table is specific to your class. Each object of the class will contain a pointer to this VTable. The size of this pointer is 4 bytes.

Re: sizeof(class) question

kfaday9-Aug-04 13:15

Operator for casting a class to void*

9-Aug-04 13:15

thanks~!

kfaday9-Aug-04 1:40

Re: Operator for casting a class to void*

9-Aug-04 1:40

Hi, i would like to know hot to implement an operator to cast a class to void*.
I thought of overloading operator (), but i don't know how to proceed (as i didn't find anything on the web). Any ideas?
thanks!!

Re: Overloading

4apai9-Aug-04 1:47

4apai

9-Aug-04 1:47

The following example overloads the + operator to add two complex numbers and returns the result.
// operator_overloading.cpp
// compile with: /EHsc
#include <iostream>

using namespace std;
class Complex
{
public:
Complex( double r, double i ) : re(r), im(i) {}
Complex operator+( Complex &other );
void Display( ) { cout << re << ", " << im << endl; }
private:
double re, im;
};

// Operator overloaded using a member function
Complex Complex::operator+( Complex &other )
{
return Complex( re + other.re, im + other.im );
}

int main()
{
Complex a = Complex( 1.2, 3.4 );
Complex b = Complex( 5.6, 7.8 );
Complex c = Complex( 0.0, 0.0 );

c = a + b;
c.Display();
}

David Crow9-Aug-04 2:35

Re: Operator for casting a class to void*

9-Aug-04 2:35

Something like:

class MyClass
{
public:
    operator LPVOID() const
    {
        return ???;
    }
};

"When I was born I was so surprised that I didn't talk for a year and a half." - Gracie Allen

kfaday9-Aug-04 13:14