[grt-talk]Constructors

[Nikodemus Siivola]

> I noticed today that if you don't pass the right types to constructors
> then bad things happen.  Is there a way to turn on (or create) a
> debug/testing mode so that constructors will throw intelligent error
> messages?
>
> An example of the problem I was having was a line like,
> (grt-vector 0 0 0)
>
> Which bombs, but doesn't say way...Or at least in my code it didn't
> say why.

It wants single floats, not ints is the short answer. The long answer is
the there really should be two constructors:

 * one that wants single floats to be used internally to have better type
   checking and in order to avoid unnecessary type conversions.

 * another that takes just about anything that it can convert into
   single floats

> I was thinking maybe we could define some constants and check for them
> somewhere, and perhaps combine with eval-when-compile, so that we
> could enable a testing mode where you debug your scene.  Then when you
> have  it all tweaked you turn it off for efficiency.

I think that the scene building functions should not need to be optimized
for speed, but for user convenience: you need to get pretty spectacular
before the scene building time is significant -- especially compared to the
scene rendering time.

And yes, the whole scene building API needs to be rethought.

 -- Nikodemus