C / C++ / MFC

Re: please help : how to draw BSpline by using mouse ???

27-Nov-09 7:14

a04.lqd wrote:
my teacher give an exercise:

And that was to help you learn to do things for yourself, not to get someone else to do it for you. Read your course notes.

a04.lqd27-Nov-09 7:19

a04.lqd

27-Nov-09 7:19

my teacher only introduce what is Bspline and give this exercise to me...
each student in my class is the same.
they have another exercise, different from my exercise , ex: use surface to draw a face, draw a car by benzier curve...

it is realy hard....
all informations i must find out

help me... thank you very much.

Re: please help : how to draw BSpline by using mouse ???

Richard MacCutchan27-Nov-09 7:27

Re: please help : how to draw BSpline by using mouse ???

27-Nov-09 7:27

a04.lqd wrote:
all informations i must find out

Yep, life is hard Sigh | :sigh:

Cedric Moonen27-Nov-09 7:28

Cedric Moonen

27-Nov-09 7:28

Please read the posting guidelines. There's even no clear question in your message. You don't believe that somebody here will just provide you with the code, do you ?
Ask a precise question. Explain what you have tried and where you are stuck exactly.

Cédric Moonen
Software developer

Charting control [v2.0]
OpenGL game tutorial in C++

Re: please help : how to draw BSpline by using mouse ???

CPallini27-Nov-09 7:26

Re: please help : how to draw BSpline by using mouse ???

27-Nov-09 7:26

a04.lqd wrote:
how to draw BSpline by using mouse ???

Just press the left button and move the mouse following a BSpline shape (remember to choose the pen tool). Big Grin | :-D

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]

Richard MacCutchan27-Nov-09 7:28

Re: please help : how to draw BSpline by using mouse ???

27-Nov-09 7:28

CPallini wrote:
Just press the left button and move the mouse

Now why didn't I think of that?

«_Superman_»27-Nov-09 9:15

«_Superman_»

27-Nov-09 9:15

GDI has a function called PolyBezier that can be used to draw b-splines.

«_Superman_»
I love work. It gives me something to do between weekends.

Microsoft MVP (Visual C++)

Question about double #INF and #NAN

Jeff Archer27-Nov-09 5:02

27-Nov-09 5:02

Does anyone understand the bit-wise representations of #INF and #NAN for the type double? Or could you point me to some real information on the internet?

Also, what is the difference between Quiet NAN and Signaling NAN?

I have been trying to find it with google all morning and I have found a lot of claiming to know but no actual knowledge.

I know that for type float the bits are:
0x7FFFFFFF; // #NAN
0x7F800000; // #INF

I believe that for type double the bits would:
0x7FFFFFFFFFFFFFFF; // #NAN
0x7FF0000000000000; // #INF

However, this is just changing the exponent from 8 to 10 bits and assuming that if would be the same. I would feel much better if I could find some supporting documentation.

CPallini27-Nov-09 5:54

27-Nov-09 5:54

Isn't this [^] useful?
Smile | :)

Jeff Archer27-Nov-09 7:08

27-Nov-09 7:08

Yes, and thanks. But I'm still kind of looking for a nice table like they have for the 32 floats. Don't want to make the table myself because I'm not the expert. Just want to be able to refer to the expert.

Richard MacCutchan27-Nov-09 7:17

27-Nov-09 7:17

If you scroll up the page the nice table is there on the screen.
[edit]sorry I note those are not doubles, but I'm sure a bit of simple extrapolation will do it[/edit]

Jeff Archer27-Nov-09 7:51

27-Nov-09 7:51

Thanks.

I was hoping to find such a table for double. Really, just a supporting documentation. I believe the values in my original question were correct.

CPallini27-Nov-09 7:23

27-Nov-09 7:23

If you're looking for NAN it may be either

0xFFFM
or
0x7FFM

i.e. sign bit may be either 0 or 1 and 52 bit-wide mantissa M != 0 is implementation-dependent (may carry additional info).

Of course this is going on my arrogant assumptions...
Smile | :)

Jeff Archer27-Nov-09 7:50

27-Nov-09 7:50

The values in my original question are correct. (I believe) Just looking for supporting documentation.

Thanks again for the time and thought you have put into this.

CPallini27-Nov-09 8:03

Re: Question about double #INF and #NAN [modified]

27-Nov-09 8:03

Well, while your values represent correctly NAN values, they (according to that Wikipedia page) don't cover all the possibilities.
Smile | :)

Jeff Archer27-Nov-09 8:39

Using COM Object Invalid Pointer Error

27-Nov-09 8:39

Sorry, I guess I didn't present that very well.

NAN is an exponent of 0x7FF with a non-zero mantissa.
INF is an exponent of 0x7FF with a zero mantissa.

Here are the actual fuctions I am using...

bool IsInf (double d)
{
      const INT64 iInf = 0x7FF0000000000000;

      if ((*(INT64*)&d & 0x7FFFFFFFFFFFFFFF) == iInf)
            return true;
      return false;
}

bool IsNan (double d)
{
      INT64 exp = *(INT64*)&d & 0x7FF0000000000000;
      INT64 mantissa = *(INT64*)&d & 0x000FFFFFFFFFFFFF;
      if (exp == 0x7FF0000000000000 && mantissa != 0)
            return true;
      return false;
}

modified on Friday, November 27, 2009 3:04 PM

Ash_VCPP27-Nov-09 1:18

Ash_VCPP

27-Nov-09 1:18

Hi All,

I have created COM component(dll) and created one client to use it, Please finnd the code of client:-

HRESULT hr = CoInitialize(0);
		//CoCreateInstance(
		SCRIPTOBJLib::IScriptObjPtr sobj;
		//sobj->QueryInterface(IId_,void* &vp);
		//HRESULT hRes = CComObject<CScriptObj>::CreateInstance(&sobj);
		//CreateInstance(NULL,IID_IUnknown,(void*)&vp);
		//HRESULT hres = sobj.CreateInstance  ( __uuidof(SCRIPTOBJLib::IScriptObj) );

		//HRESULT hres = sobj.CreateInstance("ScriptObj 1.0 Type Library");
		//at this point i am getting the error
		sobj->SetLanguage((unsigned short *)"VBScript");
		CoUninitialize();

Please give me some solutions coz i tried every possible way.

Thanks A Ton
Ash_VCPP
walking over water is just knowing where the stones are.....

Richard MacCutchan27-Nov-09 2:11

27-Nov-09 2:11

Ash_VCPP wrote:
SCRIPTOBJLib::IScriptObjPtr sobj;
//sobj->QueryInterface(IId_,void* &vp);

You have not initialized sobj to an instance of anything.

Ash_VCPP27-Nov-09 2:18

Ash_VCPP

27-Nov-09 2:18

Yes but i tried many ways as you can see it in commented code to initialize it, but getting error HRESULT value= -2147221164.

can you please suggest me how can i initialize com object with example regards of my code.

Thanks A Ton
Ash_VCPP
walking over water is just knowing where the stones are.....

Richard MacCutchan27-Nov-09 2:22

27-Nov-09 2:22

Ash_VCPP wrote:
can you please suggest me how can i initialize com object with example regards of my code.

You have the following declaration in your code

SCRIPTOBJLib::IScriptObjPtr sobj;

So you need to initialize sobj to an instance of SCRIPTOBJLib::IScriptObjPtr. The documentation should explain how to do this. If you do not understand instances of classes I suggest you refer back to he C++ documentation for guidance.

Ash_VCPP27-Nov-09 2:33

Ash_VCPP

27-Nov-09 2:33

But i think initializing COM object is different from normal class, and if not then can you please show me few lines of code to initialize COM object, Because i am wondering with google since last two dyas.

Thanks A Ton
Ash_VCPP
walking over water is just knowing where the stones are.....

Richard MacCutchan27-Nov-09 2:59