RE: [pdf-devel] Type 4 & implementation limits

[Leonard Rosenthol]

Type 4 functions specifically state that they are bound by the implementation 
limits in Annex C.


-----Original Message-----
From: address@hidden [mailto:address@hidden On Behalf Of Johannes Tax
Sent: Sunday, January 24, 2010 10:31 PM
To: address@hidden
Subject: [pdf-devel] Type 4 & implementation limits

Hello,

I have some questions regarding type 4 functions and implementation 
limits. The specifiction says that an error must be raised if an 
operation tries to exceed an implementation limit, so I assume the same
holds true for type 4 functions. I have seen some macros for library 
specific limits (PDF_I32_MAX, no MIN defined yet), should those limits 
also be used for the type 4 floating point return values or should 
floating point specific limits be defined? If so I would also recommend
to add some special value that can be returned by the pdf_fp_* functions
to signal an over-/underflow, something similar to HUGE_VAL in libc.

The specification also explicitely allows that intermediate results of 
type 4 functions do not fall under the implementation limit restrictions.
It would be possible to allow larger values for intermediate results, 
as we are calculating with doubles but returning pdf_real_t (float). Is
this desirable? If so, against which limits should the intermediate 
results be checked then? Against libc's limits?

Johannes

-- 
Johannes Tax
address@hidden