kicad-developers team mailing list archive

[Tomasz Wlostowski <tomasz.wlostowski@xxxxxxx>]

On 08/10/2013 04:28 PM, Lorenzo Marcantonio wrote:
> On Sat, Aug 10, 2013 at 08:27:26AM -0500, Dick Hollenbeck wrote:
> > a) If tools are extended from a base class, the persistent behaviours could be inherited.
> >
> > b) If tools are pushed on a stack when they become active, and if you have a mechanism(...)
>
> Both of those are good for me, the second one is a little more complex
> and in fact emulates at runtime the VTBL (for example in
> lua virtual calls work *exactly* like that: when a method is not found
> it get searched in the ancestor class).
> (...)
> Another simpler idea is to install fallback handlers, i.e.  everything
> that's not handled by the current tool is subject to 'default
> processing'.

Hi Lorenzo,

IMHO It's a bit similar, but not exactly the same: events come to a tool 
- it can then react and sometimes consume some of them so that other 
tools (lower on the stack) don't receive these events anymore. Event 
handlers are delegates (somewhat similar to signals/slots in Qt) and are 
dispatched dynamically by the TOOL_MANAGER. This could be probably seen 
as an enhanced virtual method mechanism... As for the default handlers - 
there can be a tool permanently residing on the bottom of the stack and 
dedicated for catching such events.

 Do we need dynamic method
> composition? I.e. will tool A be *always* below tool B or there may be
> a tool C below tool B?
I wouldn't preclude such scenario. Having a 2-level stack is as complex 
as having an N-level one.
> I agree. The current 'left button' and 'right button' handlers are
> awfully huge switch statements. Something a little more modular would be
> helpful for the future :D
Fully agree :)
> > Exciting stuff,
>
> That's independently of the GAL, I think some/most of this stuff would
> be useful even for 'stock' kicad, however the GAL *requires* them... too
> bad you can't have the xor blend in opengl:((( I really prefer the xor
> contrast compared to Porter/Duff composition (maybe there is some shader
> trick but good luck having it work fast on the Intel GPUs...).
Shaders aren't that bad under intel drivers (the GAL works just fine on 
a core i7 integrated graphics on my latptop, although Half-life 2 - a 
10-year old game doesn't because some texture formats are not 
supported). Under Linux, if you want performance and truly 
standard-compliant OpenGL, I'm afraid you have to use the evil Nvidia 
binary driver...

Regard,
Tom