Thanks, Andreas.

The spec in that area is certainly not easy to follow, but I _think_ I have
types 2 & 3 implemented.  And perhaps I can/should revisit the tintTransform
functionality ...

Daniel

On Sat, Feb 27, 2010 at 6:31 AM, Andreas Lehmkuehler <[email protected]>wrote:

> Hi,
>
> Daniel Wilson schrieb:
>
>  The gradients I'm trying to implement for PDFBOX-615 are defined in part
>> by
>> functions.
>>
>> We are parsing the functions and instantiating derivatives of PDFunction
>> ...
>> but I can't find anything that evaluates the function.  e.g. if I pass the
>> function 2, what does it return?
>>
>> A quick grep didn't find any such examples ... in fact the only classes
>> that
>> contain an instance of PDFunction are PDDeviceN and PDSeparation, both of
>> which return an empty function rather than returning the one that the
>> class
>> was loaded with.
>>
>> Is this a known gap in our support of functions?  Does someone know where,
>> in fact, we do use them?  Or is this one of those things, no one's really
>> sure about?
>>
> That is a known gap. Have a look at [1]. I thought that I understood how
> these
> functions work, but when I tried to implement e.g FunctionType2 I'd
> realized
> that I didn't. Obviously it is a little bit more tricky than I expected or
> probably it is just my limited ability to understand complex english texts.
>
>  Thanks!
>>
>> Daniel
>>
>>
> BR
> Andreas Lehmkühler
>
> [1] https://issues.apache.org/jira/browse/PDFBOX-519
>

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