OpenMesh 1.9.5 ported to D

[Bill Baxter]

Jascha Wetzel wrote:
> Bill Baxter wrote:
>>> i'm curious about where it can be taken with D. circulators should 
>>> simplify to delegates. maybe some of the traits business can be 
>>> simplified as well.
>>
>> Well you can't really get rid of the circulators entirely.  Sometimes 
>> you want to go around the edges of a vertex more than once.  But "one 
>> time around" is certainly the common case.  A second set of functions 
>> that provide an opApply for circulators (and iterators) to handle that 
>> common case would be nice.
> 
> ah, right, and they need some state like the start vertex.
> actually, the way they look right now is pretty good.

I went ahead and added those opApplys to the iterators after your 
suggestion.

> foreach ( vh; VertexVertexIterT(mesh, start_vh) ) { ... }

>>  Or maybe the easiest is to endow the iterators and circulators with 
>> an opApply so that this works:
>>    foreach(vhandle; mesh.vertices_begin()) {
>>       ...
>>    }
> 
> yep, for those that don't have a state.

They all have a state.  You mean for those that don't need a particular 
starting state?

> There wouldn't be any advantage at runtime, but FinalMeshItems and 
> AttribKernel would pretty much collapse, simplfying the whole Traits 
> stuff a lot. Unless i'm mistaken, the only benefit from having those two 
> is to check for availability of standard properties at compile-time.
> In D we can have compile-time checks for any property. Here is a prototype:
> http://mainia.de/ctprops.d

That is pretty slick.

> That way, having standard properties merely means having a convention 
> for their names and types. We could therefore easily add a large number 
> of standard properties without bloating the lib and loose a lot of 
> Traits complexity at the same time - D rules :)

I think would still be useful to have the most common types -- Point, 
Normal, etc, defined as part of the mesh type since most practical 
algorithms require those.  I hacked up your ctprops to do something 
along those lines.

I also think that it's good to be able to define your mesh at some point as
   class Mesh(traits = DEFAULT_TRAITS)
so that if you just want a "standard mesh" you don't have to think too much.

In other words there needs to be a way to define a set of Prop!s.

So I whipped something up along those lines and put it here.

http://www.dsource.org/forums/viewtopic.php?p=16708#16708


Apart from the properties I think it might be nice if you could supply a 
template mixin to the Mesh, and it would mix that for you.  In that way 
you can inject whatever you want into your MyMesh type.  In C++ I'd make 
it a base class alongside the PropertyContainer thing.  But no MI in 
D...  Maybe PropertyContainer could be a member of the mesh instead of a 
base.


--bb