POV-Ray : Newsgroups : povray.programming : more oddities, in parse.cpp this time Server Time
1 Jun 2024 22:26:00 EDT (-0400)
  more oddities, in parse.cpp this time (Message 1 to 2 of 2)  
From: Daniel Hulme
Subject: more oddities, in parse.cpp this time
Date: 28 Oct 2004 12:20:16
Message: <20041028172016.5c4f843f@dh286.pem.cam.ac.uk>
Hey peeps, when you write code for POV 4.0, could you try to document it
a little? I suppose the opacity of the code (no pun intended) is one of
the main reasons for a rewrite. Anyway, in my reading of the code, I
have been looking at parse.cpp, and I am worried. The Parse_Object_Mods
function does stuff with the object's bounding box, but (AFAICS) the
bbox is not always created before Parse_Object_Mods is called. In blobs,
hfields, fractals, and maybe meshes and mesh2es (I haven't quite worked
out what's going on with them), the bbox computation function is called
after Parse_Object_Mods. Is this for a reason (like the object modifiers
must be known before a bbox can be computed, or the objects can make use
of the transforms to compute a more efficient bbox), or, OTOH, should
the bbox-modification code in Parse_Object_Mods be moved to
Post_Process? Or is it all hunky-dory and I'm just being unnecessarily
careful? I only ask because I need to add code that modifies the
(existing) bbox after the modifiers have been processed, and would like
to know whether it is safe to add it in Parse_Object_Mods or whether it
has to be in Post_Process.

Also, I'm not sure whether anyone cares about typos in comments, but
line 715ish (probably just above there as I have added some code) there
is a line:
     * Read sperical component (old syntax).
which should probably read "spherical".

Daniel

-- 
A most peculiar man    With the windows closed      And Mrs Reardon says
He died last Saturday  So he'd never wake up  He has a brother somewhere
He turned on the gas   To his silent world   Who should be notified soon
And he went to sleep   And his tiny room    .oO( http://sad.istic.org/ )


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From: Daniel Hulme
Subject: Re: more oddities, in parse.cpp this time
Date: 28 Oct 2004 12:30:44
Message: <20041028173043.31e24cea@dh286.pem.cam.ac.uk>
Erm, update on my understanding.
Looking more closely at the blob stuff I see why Parse_Object_Mods has
to come after Make_Blob (which calls Compute_Blob_BBox), but still think
it looks a bit dangerous calling Parse_Object_Mods without an existing
bbox.

Daniel

-- 
A most peculiar man    With the windows closed      And Mrs Reardon says
He died last Saturday  So he'd never wake up  He has a brother somewhere
He turned on the gas   To his silent world   Who should be notified soon
And he went to sleep   And his tiny room    .oO( http://sad.istic.org/ )


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