Le 23/06/2013 20:00, James Holsenback nous fit lire :
>> it looks like the "if (isCopy == false)" does not test positive when the
>> isosurface is wrapped in an object, but it does when the isosurface is
>> naked.
>>
>> Bill P.
>>
> 
> I'm wondering when it was broken, or if that's the intended behavior ...
> perhaps some kind of note in the documentation /might/ be the way to go.
> Just a thought.

isCopy seems to be intended to avoid displaying the same warning over
and over for the same isosurface (as duplicated isosurface indeed are
not copied but reference the same sub-structure).

#declare Ob = isosurface{...}; // that's not a copy
object {Ob ... } // that's a copy

Previously (3.6.1) the warning was displayed at the destruction of the
isosurface (when the sub-structure was actually referenced by no one else)	

  if((Stage == STAGE_SHUTDOWN) && (mginfo->refcnt == 0))

In 3.7, isCopy was introduced with change 4707, 16th February 2009,
along with the change introducing means for objects to submit message on
shutdown.
It was reported in windows source with change 4714, 21th February 2009.

If the symptom "isosurface embbeded in object (CSG) does not show the
warning" is correct, it might be a "feature/bug". The parser copied the
isosurface object and deleted the original before the render started.
When the render ends, it find only copies and because the refcnt is not
used anymore (for that purpose), it miss the last remaining true data to
display.

Instead of isCopy, what about adding in mginfo a boolean
"printed_warning" (actual name should be more appropriate), set to false
on creation, and turn to true on the first call (instead of last for
3.6.1) of the warning displaying function (test for false, set to true
if false) ? (and dropping isCopy in the process)

For instance, i'm afraid the following sequence would fails with current
code:

#declare Foo = isosurface{ ... };
#declare Bar = object { Foo ... };
#undef Foo;

(or any pop of #local context, such as building the isosurface via macro
or loop, or replacing the value of a previous #declare/#local )

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