Hi,

I'm converting my pet project from C++ to D. It is an aimbot game cheat.
One of my C++ struct is Vector3. It is a wrapper from D3DXVECTOR3.
I would like to use expression template to calculate where to point the gun. In C++, it is provided by boost::proto or boost::ublas.

My naive implementation (in fact, "copy&paste" from c++ book "thinking in c++") refused to compile.
I've searched dsource.org; the nearest match is Don's BLADE library.

Is there any tutorial, or simpler way to do expression in D; without building AST as in BLADE?

Thanks.

The Anh Tran schrieb:
> One of my C++ struct is Vector3. It is a wrapper from D3DXVECTOR3.
> I would like to use expression template to calculate where to point the gun. In C++, it is provided by boost::proto or boost::ublas.
> 

You calculate where to point the gun at compile-time?

Trass3r wrote:
> The Anh Tran schrieb:
>> One of my C++ struct is Vector3. It is a wrapper from D3DXVECTOR3.
>> I would like to use expression template to calculate where to point the gun. In C++, it is provided by boost::proto or boost::ublas.
>>
> 
> You calculate where to point the gun at compile-time?

No :)

I would like to learn D template programming; all i need is just a compile-time expression.

vPredicted = vEnd
+ (((ProjectileSpeed^2 * |vStart-vEnd|^2 - |(vStart-vEnd) X Velocity | ^2) ^ 0.5
+ (vStart-vEnd) * vVelocity) / (ProjectileSpeed^2 - |vVelocity|^2)) * vVelocity

vXYZ is a struct, re-present 3D coordinate / velocity vector.

On Thu, 07 May 2009 03:31:46 +0200, The Anh Tran <trtheanh@gmail.com> wrote:

> Trass3r wrote:
>> The Anh Tran schrieb:
>>> One of my C++ struct is Vector3. It is a wrapper from D3DXVECTOR3.
>>> I would like to use expression template to calculate where to point the gun. In C++, it is provided by boost::proto or boost::ublas.
>>>
>>  You calculate where to point the gun at compile-time?
>
> No :)
>
> I would like to learn D template programming; all i need is just a compile-time expression.
>
> vPredicted = vEnd
> + (((ProjectileSpeed^2 * |vStart-vEnd|^2 - |(vStart-vEnd) X Velocity | ^2) ^ 0.5
> + (vStart-vEnd) * vVelocity) / (ProjectileSpeed^2 - |vVelocity|^2)) * vVelocity
>
> vXYZ is a struct, re-present 3D coordinate / velocity vector.

If you want something capable of processing the above, it will
probably have to work along the lines of BLADE: use a CTFE function
to parse the string and turn it into whatever code you prefer it to
be.

I do not believe there is such a library in existence, though I may
of course be wrong.

As for which functions are CTFE-able:
http://digitalmars.com/d/2.0/function.html#interpretation

--
 Simen