CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

On 01/20/2014 11:25 PM, Alessandro Attanasi wrote:
> Hi all,
>
> I'm going to learn how to plug user defined class into existing CGAL
> kernels.
>
> I read all the documentation
>
> http://doc.cgal.org/latest/Kernel_23/index.html#sectionextensiblekernel
>
> and I copy all the example codes concerning the MyPointC2 class into the
> manual to run them. At the beginning I was not able to compile because
> it needs the MySegmentC2.h file that I didn't find into the manual, so I
> comment out everything about it.
>
> I'm writing to better understand this procedure, for example how to
> change the code in order to have coordinates of MyPoint to be generic
> (using template??), to have more info about MyKernel.h that into the
> documentation is explicitly said to not explain details, how predefined
> Kernels as EPIC could be used?
>
> As last point I don't understand the sentence
>
> "As we enforce type equality between |MyKernel::Point_2| and |Point_2
> <http://doc.cgal.org/latest/Kernel_23/classCGAL_1_1Point__2.html><MyKernel>|,
> the constructor with the color as third argument is not available."
>
> because I tried to create with the example code a point having into the
> consructor the color too, an it works.

It means that the constructor will not be available if you use 
Point_2<Kernel>(x,y,color) of Kernel::Point_2 directly. Of course
if you use your point type directly it will work.
Be careful that if  you color is an integer for example,
Kernel::Point_2(x,y,color) will call the constructor using homogeneous
coordinates and not the one you expect.

Sebastien.

> Thanks
> Alessandro