Prev: How to close Excel workbook from Matlab
Next: mclmcrrt73.dll
From: John Lyle on 14 Nov 2009 01:59
I have a DLL function that returns a char* but I need to cast this to a struct*. Specifically I am trying to use the cvGetSeqElem() function from OpenCV (http://opencv.willowgarage.com/documentation/dynamic_structures.html#cvGetSeqElem) like this:

cvRect = calllib('cxcore', 'cvGetSeqElem', cvSeq, 1);

where cvSeq is of type CvSeqPtr. This returns a string. How do I now cast this to a CvRect* to read the returned values? The MATLAB signature is:

[cstring, CvSeqPtr] = cvGetSeqElem(CvSeqPtr, int32)
From: roger on 14 Nov 2009 05:45
On Nov 14, 7:59 am, "John Lyle" <mathwo...(a)myallit.com> wrote:
> I have a DLL function that returns a char* but I need to cast this to a struct*. Specifically I am trying to use the cvGetSeqElem() function from OpenCV (http://opencv.willowgarage.com/documentation/dynamic_structures.html#....) like this:
>
> cvRect = calllib('cxcore', 'cvGetSeqElem', cvSeq, 1);
>
> where cvSeq is of type CvSeqPtr. This returns a string. How do I now cast this to a CvRect* to read the returned values? The MATLAB signature is:
>
> [cstring, CvSeqPtr] = cvGetSeqElem(CvSeqPtr, int32)

are you trying to typecast in matlab? better do it in c/c++ if you
can.
R
From: John Lyle on 14 Nov 2009 23:34
Yes I am, is that not possible? I'm trying to use the OpenCV DLLs directly in MATLAB without writing any C++ wrapper code.

roger <northsolomonsea(a)gmail.com> wrote in message <5badc0bd-f0dd-44e8-9153-b0975f7ffe2b(a)l2g2000yqd.googlegroups.com>...
> On Nov 14, 7:59?am, "John Lyle" <mathwo...(a)myallit.com> wrote:
> > I have a DLL function that returns a char* but I need to cast this to a struct*. Specifically I am trying to use the cvGetSeqElem() function from OpenCV (http://opencv.willowgarage.com/documentation/dynamic_structures.html#...) like this:
> >
> > cvRect = calllib('cxcore', 'cvGetSeqElem', cvSeq, 1);
> >
> > where cvSeq is of type CvSeqPtr. This returns a string. How do I now cast this to a CvRect* to read the returned values? The MATLAB signature is:
> >
> > [cstring, CvSeqPtr] = cvGetSeqElem(CvSeqPtr, int32)
>
> are you trying to typecast in matlab? better do it in c/c++ if you
> can.
> R
From: roger on 15 Nov 2009 05:52
On Nov 15, 5:34 am, "John Lyle" <mathwo...(a)myallit.com> wrote:
> Yes I am, is that not possible? I'm trying to use the OpenCV DLLs directly in MATLAB without writing any C++ wrapper code.
>
>
>
> roger <northsolomon...(a)gmail.com> wrote in message <5badc0bd-f0dd-44e8-9153-b0975f7ff...(a)l2g2000yqd.googlegroups.com>...
> > On Nov 14, 7:59?am, "John Lyle" <mathwo...(a)myallit.com> wrote:
> > > I have a DLL function that returns a char* but I need to cast this to a struct*. Specifically I am trying to use the cvGetSeqElem() function from OpenCV (http://opencv.willowgarage.com/documentation/dynamic_structures.html#...) like this:
>
> > > cvRect = calllib('cxcore', 'cvGetSeqElem', cvSeq, 1);
>
> > > where cvSeq is of type CvSeqPtr. This returns a string. How do I now cast this to a CvRect* to read the returned values? The MATLAB signature is:
>
> > > [cstring, CvSeqPtr] = cvGetSeqElem(CvSeqPtr, int32)
>
> > are you trying to typecast in matlab? better do it in c/c++ if you
> > can.
> > R

Typecasting in matlab is very basic and afaik you can't cast non
(matlab) base types, apart from that it's inefficiently implemented.
Better write a small wrapper, if typecasting is all it does it will be
easy enough.
From: John Lyle on 16 Nov 2009 00:35
OK thanks for your help

roger <northsolomonsea(a)gmail.com> wrote in message <5601f08d-e6c6-4fa1-8b24-f8f83c6c0c91(a)g23g2000yqh.googlegroups.com>...
> On Nov 15, 5:34?am, "John Lyle" <mathwo...(a)myallit.com> wrote:
> > Yes I am, is that not possible? I'm trying to use the OpenCV DLLs directly in MATLAB without writing any C++ wrapper code.
> >
> >
> >
> > roger <northsolomon...(a)gmail.com> wrote in message <5badc0bd-f0dd-44e8-9153-b0975f7ff...(a)l2g2000yqd.googlegroups.com>...
> > > On Nov 14, 7:59?am, "John Lyle" <mathwo...(a)myallit.com> wrote:
> > > > I have a DLL function that returns a char* but I need to cast this to a struct*. Specifically I am trying to use the cvGetSeqElem() function from OpenCV (http://opencv.willowgarage.com/documentation/dynamic_structures.html#...) like this:
> >
> > > > cvRect = calllib('cxcore', 'cvGetSeqElem', cvSeq, 1);
> >
> > > > where cvSeq is of type CvSeqPtr. This returns a string. How do I now cast this to a CvRect* to read the returned values? The MATLAB signature is:
> >
> > > > [cstring, CvSeqPtr] = cvGetSeqElem(CvSeqPtr, int32)
> >
> > > are you trying to typecast in matlab? better do it in c/c++ if you
> > > can.
> > > R
>
> Typecasting in matlab is very basic and afaik you can't cast non
> (matlab) base types, apart from that it's inefficiently implemented.
> Better write a small wrapper, if typecasting is all it does it will be
> easy enough.
 |  Next  |  Last
Pages: 1 2
Prev: How to close Excel workbook from Matlab
Next: mclmcrrt73.dll