Re: a matter of style
On Tuesday 08 December 2009 02:55:56 Alan Grimes wrote:
> Julian Bäume wrote:
> > That's why I think, the Qt API helps to write better code. I saw a
> > construct in the code, reading: "Cell **m_cell;" or something like that.
> > WTF? ;) This is not C, it's C++. Such expressions should really be
> > avoided and I can't think of any example, where there is no other way of
> > expressing this.
> I'm a C programmer. =\
I didn't mean to offend you, here :)
> Sure, C++ is great for organizing stuff but it's HORRIBLE for
> algorithms. For algorithms, I require a language that executes directly
> instead of vertically (try debugging a STL call). I need to be able to
> think in terms of register moves, pushes and pops, and of the memory be
> it stack, heap, or data, and understand exactly what the hell is slowing
> shit down. =\
I disagree, here. You can write nearly as fast code with C++ and Qt, as you do
with plain C++ or plain C. If an algorithm is slow, it can be because of many
things. One thing is bad implementation. If you copy around stuff a lot,
especially when it is not needed, you waste a lot of time (memory operations
are damn slow). Bad implementation can be avoided. Another thing is
algorithmic complexity. You won't be able to implement (perfect) routing in a
fast way. So you need to implement heuristics, that solve the problem fast,
but not with optimal results. These problems can't be avoided. (Not yet ;))
All these problems have a real impact on the speed of programs like KTechLab.
The overhead Qt or any other library might bring here shouldn't count much.
> The connector routing code is inherently a slow problem,
> and therefore to get acceptable performance I reverted to the style